Green Building Guidelines (new buildings)
Transcription
Green Building Guidelines (new buildings)
Green Building Guidelines, UAE New Buildings These guidelines are applicable for the Ministry of Public Works new projects (new buildings) in the Emirates; adaptations to existing buildings are not part of this document. 1|P a g e 2|P a g e 3|P a g e 4|P a g e Prepared by TEC Project Team Najeeb M. Al-Ali, MSc, BEng; Mohsen M. Aboulnaga, PhD, MSc, BSc; Fahad Al Qassim, MBA; Eisa Al Hammadi, BSc; Mohamed Sami, BSc $ / ادى – ا$% /" – اس# ! ا/ أـ اـ – اس/ ا – اذ اآر/اس MoPW Project Team Zahra Al Aboodi; Fraeed Al Kathiri; Ibrahim Al Khamiri; Mahmood mustafa Abu Al Shawareb; Afifa bin Hamad; Kusai R. Kulaib; Ahmed Alwa’ael أ ا/ اس- آ5: / اس- د8 )33% /)ارب – ا7 أا$345 د/*ى – اس2 إ*اه" ا/*ى – اس/0 ا.*! /دى – اس- زه*ة ا/)دة ا This document is prepared by the project joint team between The Executive Council (TEC), Government of Dubai and Ministry of Public Works (MoPWs) UAE. DOCUMENT VERSIONS First issued on DOCUMENT NUMBER: MoPWs – 01-290109-01 th 29 January 2009 ©TEC and MoPW 2009 The contents of the documents is belong TEC and MoPWs. No part or section will be copied or circulated outside the two organisations without written approval from the Ministry of Public Works. 5|P a g e Contents Glossary ................................................................................................................................................................................ 8 Executive Summary ............................................................................................................................................................ 13 Introduction ....................................................................................................................................................................... 14 Background ........................................................................................................................................................................ 17 Project Outlines and Framework ....................................................................................................................................... 19 Design development ...................................................................................................................................................... 19 Building Types .................................................................................................................................................................... 21 Green Building Guidelines .................................................................................................................................................. 22 Group I: Envelop Efficiency ................................................................................................................................................ 23 Criterion: Glazing .................................................................................................................................................. 24 Criterion: Façade‘s Wall Insulations (non-glazed) ................................................................................................ 25 Criterion: Shading ................................................................................................................................................. 26 Criterion: Glazing and Building Orientations ........................................................................................................ 28 Criterion: Daylighting ........................................................................................................................................... 30 Criterion: Clearstory Windows ............................................................................................................................. 33 Criterion: Skylights: Sun-optic .............................................................................................................................. 34 Criterion: Glare Control ........................................................................................................................................ 35 Criterion: Photosensors ........................................................................................................................................ 35 Criterion: Light Colour Materials .......................................................................................................................... 37 Group II: Cooling Systems .................................................................................................................................................. 38 Criterion: Under-floor Cooling/Heating................................................................................................................ 39 Criterion: Radiant Cooling .................................................................................................................................... 40 Criterion: Solar Absorption Cooling (SAC) ............................................................................................................ 42 Criterion: District Cooling (DC) ............................................................................................................................. 44 Group III: Energy Efficiency ................................................................................................................................................ 46 Criterion: Site Selection ........................................................................................................................................ 47 Criterion: Air Conditioning Efficiency ................................................................................................................... 49 Criterion: CFC-free Refrigerants ........................................................................................................................... 51 Criterion: Lighting Fixtures and Lighting Bulbs ..................................................................................................... 52 Criterion: Motion and Control Sensors ................................................................................................................ 55 Criterion: Swimming Pools ................................................................................................................................... 56 Criterion: Solar Water Heating (SWH) ................................................................................................................... 57 Criterion: CO2 Sensors (Thermal Comfort) ........................................................................................................... 59 Criterion: Renewable Energy ................................................................................................................................ 60 Criterion: Building Management Systems (BMS) and Smart Devices .................................................................. 61 Group IV: Water Use and Efficiency ................................................................................................................................... 62 Criterion: Water Fixtures ...................................................................................................................................... 63 6|P a g e Criterion: Water-efficient Landscaping ................................................................................................................ 64 Criterion: Water Collection – Condensation and Rain ......................................................................................... 67 Criterion: Recycled Water (Grey Water) .............................................................................................................. 59 Group V: Indoor Environmental Quality (IEQ) ................................................................................................................... 61 Criterion: Operable Windows ............................................................................................................................... 62 Criterion: Ventilation Systems and Ceiling Fans ................................................................................................... 63 Criterion: Indoor Air Quality (IAQ)........................................................................................................................ 64 Criterion: Low-emitting (VOCs) Materials ............................................................................................................ 66 Criterion: Clean Materials and Chemical Pollutions ............................................................................................. 67 Criterion: Smoking and Non-smoking Zones ........................................................................................................ 68 Criterion: Noise and Acoustics Controls ............................................................................................................... 69 Criterion: Water Tanks (shading and insulations) ................................................................................................ 72 Group VI: Site Heat Island .................................................................................................................................................. 74 Criterion: High Reflective Roofs (Cool Roofs) ....................................................................................................... 75 Criterion: Site’s Material Configuration ............................................................................................................... 77 Criterion: Bright (Light) Colour Material for Pavements ...................................................................................... 78 Criterion: Sloped/Cascaded (Staggered) Roofs .................................................................................................... 79 Criterion: Green Roofs .......................................................................................................................................... 80 Appendices I-IVX (1-14) ...................................................................................................................................................... 84 Appendix I: Grouping of Green Building Criteria: short listing Analysis ............................................................................. 85 Appendix II: Glazing — SHGC, SC and LSG ......................................................................................................................... 86 Appendix III: Insulation Materials ...................................................................................................................................... 91 Appendix IV: Photosensors ................................................................................................................................................ 93 Appendix V: Emergency Exits Lighting and Efficient Bulbs ................................................................................................ 94 Appendix VI: Lighting Fixtures and Motion Sensors.......................................................................................................... 95 Appendix VI: Swimming Pools – Covering Materials ....................................................................................................... 100 Appendix VIII: Solar Water Heating Systems ................................................................................................................... 102 Appendix IX: Water Fixtures ............................................................................................................................................ 107 Appendix X: Operable Windows and Ventilation Systems .............................................................................................. 110 Appendix XI: Indoor Air Quality (IAQ) .............................................................................................................................. 112 Appendix XII: Cool Roof Materials and Solar Reflectance Index ...................................................................................... 117 Appendix XIII: Bright (Light) Colour Materials for Pavements ......................................................................................... 119 Appendix IVX: Sloped/Cascaded (Staggered) Roof .......................................................................................................... 120 7|P a g e Glossary Air Change/Hour (ACH) The term “Air Change per Hour” is defined as the part of the total volume of air inside the building that is replaced by a volume of outside air per hour. Normally, 1 ACH is adequate for minimum ventilation requirements. Air Gap or Cavity Air gap is an insulation media. It is a cavity wall insulation that is injected into the cavity between the inner and outer leaves of brickwork that make up the external wall of the building. There are a variety of different insulating materials with different air gap widths. By combining with the still captive air, the insulation acts as a barrier to heat gain or loss. Air Leakage The air leakage rating (AL) is a measure of how much air leaks through the crack between the window’s sash and frame*. Heat loss and gain occur by infiltration through cracks in the window assembly. The lower the AL, the less air will pass through cracks in the window assembly. An air leakage rating (AL) of 0.30 cfm/sq.ft or less is recommended. Ballast Electrical ballast is a device intended to limit the amount of current flowing in an electric circuit. Fluorescent lamps require a ballast to stabilize the lamp and to provide the initial striking voltage required to start the arc discharge. This increases the cost of fluorescent luminaries, though often ballast is shared between two or more lamps. Electromagnetic ballasts with a minor fault can produce an audible humming or buzzing noise. Brightness differences Attributes to a visual sensation according to which an area appears to emit more or less light. Cool Roof The term “cool roof” refers to a roof surface that reflects much of the sun's energy. A cool roof replaces or coats existing roofs to reflect the infrared or “hot” spectrum that is produced by the sun, in order to improve a roof’s reflectivity to more energy-efficient levels. Most roofing types have cool options available including metal, tile, roofing membranes, reflective coatings and shingles. While a cool roof reflects a high percentage of the sun’s heat, conventional dark coloured roofs generally absorb more of the sun’s heat. Much of the heat absorbed is re-emitted into the conditioned space within the building, hence increasing the need for air-conditioning. Cool Daylighting It is known as cooling load avoidance daylighting and not a new term. It is a descriptive term to differentiate daylighting design the takes into consideration whole building energy impacts of integrated daylighting design from designs that do not do this. Cool daylighting is truly a whole building approach to daylighting that looks to not only reducing electric lighting needs but to reduce (or at minimum not increase) cooling loads within the daylight building. Daylighting The amount of visible light transmitted into building spaces. Daylight Distribution It is the amount of light scattered on the floor area as a ratio of the total daylight entering the space. Daylight Factor (DF) It is the ration of the illumination at a point on a given plane due to the light received directly or indirectly from the sky of assumed or known luminance distribution, to the illuminance on a horizontal plane due to an unobstructed hemisphere of this sky. The contribution of direct sunlight to both illuminances is excluded. Daylight Illumination Level (DIL) It is a series of spectral power distribution curves based on measurements of natural daylight and recommended by the CIE. Values are defined for the wavelength region 300 to 830nm. Daylight Technologies A set of systems used in building to provide effective lighting inside buildings such as light well, light Shelves, etc… Disability glare It took place when a light source reflects from or otherwise covers the visual task, like a veil, obscuring the visual target, reducing its contrast and making the viewer less able to see and discriminate what is being viewed. Discomfort glare It arises when light from the side of the task is much brighter than the light coming from the task. The eyes attempt to focus on the light from the task, but so much extra light is entering the eye from the side that the visual processes are confused and it is difficult to concentrate for long periods. Direct Radiation The amount of short-wave radiation received on horizontal or vertical surfaces. 8|P a g e Displacement Ventilation (DV) It is an air distribution system in which incoming air originates at floor level and rises to exhaust outlets at the ceiling. dB (db) It is abbreviation for decibel, the logarithmic acoustical unit scale for sound levels. Efficacy The ratio of light produced to energy consumed. It's measured as the number of lumens produced divided by the rate of electricity consumption (lumens per watt). Emissivity Emissivity is a measure of how much heat is emitted from an object by radiation. Heat is transferred to and from objects through three processes: conduction, convection, and radiation. For instance, on a hot day, heat will be conducted through a window from the outside, causing the inside pane to become warm. Low-emissivity, or low-e, coatings are put on window panes to reduce the amount of heat they give off through radiation. In hot climates, where the outside of the window will typically be hotter than the inside, low-e coatings work best on the interior of the outside window pane. In cold climates, where the inside of the window is typically hotter than the outside, the low-e coatings work best on the inside window pane, on the side that faces toward the outside. Fenestration It is the arrangement and design of windows in a building. Fin It is an extended control element placed on the exterior facades of the building and fixed vertically on the sides of an opening (a window). It reflects and redirects natural light which falls laterally upon the fin to the inside; used to create shad cast shadow on the facades and block solar radiation. Foot Candle (FC): It is a measurement of the intensity of illumination. A foot candle is the illumination produced by one lumen distributed over a 1-square-foot area. For most home and office work, a 30–50 foot candle of illumination is sufficient. For detailed work, 200 foot candles of illumination or more allows more accuracy and less eyestrain. For simply finding one's way around at night, 5–20 foot candles may be sufficient. Glare The excessive brightness from a direct light source that makes it difficult to see what one wishes to view. A bright object in front of a dark background usually will cause glare. Bright lights reflecting off a television or computer screen or even a printed page produces glare. Intense light sources, such as bright incandescent lamps, are likely to produce more direct glare than large fluorescent lamps. However, glare is primarily the result of relative placement of light sources and the objects being viewed. Glazing It is a sheet of glass or plastic panes in a window, door, or skylight. Glazing Factor It is the ratio of glazing areas to room area. Grey water: It is the waste water generated from showers and baths wash including soaps contents, laundry water and other drainage water but excluding toilet water. It may or may not include kitchen water and kitchens are often equipped with garbage grinders. It is also known as waste water discharged from lavatories, bathtubs, showers, clothes washers, and laundry trays. Fenestration The word “Fenestration” comes from the Latin root word fenestra, which means an opening such as a window. Heat Gain It is the transfer of heat from outside to inside by means of conduction, convection, and radiation through all surfaces of the building’s envelope. Heat Island Heat island refers to urban air and surface temperatures that are higher than nearby rural areas. Many cities and suburbs have air temperatures up to 5.6°C (10°F) warmer than the surrounding natural land cover. Heat Island contributes to high energy use, mainly for cooling in hot climates Illumination The distribution of light on a horizontal surface. The purpose of all lighting is to produce illumination. Insulating Glass (IG) It is a two or more pieces of glass spaced apart and hermetically sealed to form a single glazed unit with one or more air spaces in between (known also as double glazing). Insulation Construction materials used for protection from noise, heat, cold or fire. 9|P a g e Lighting The electrical light received at work station. Artificial or industrial lighting consumes 15% of the household’s electrical energy use. Lighting & Daylighting The quantity and quality of light around us determine how well we see, work, and play. Light affects our health, safety, morale, comfort, and productivity. Lighting Fixture A lighting fixture or luminaire is an electrical device used to create artificial light or illumination. A complete lighting fixture unit consists of the light source or lamp, the reflector for directing the light, an aperture (with or without a lens), the outer shell or housing for lamp alignment and protection, an electrical ballast, if required, and connection to a power source. Light-to-Solar-Gain Ratio Light-to-Solar-Gain Ratio (LSG) is a measure of the ability of a glazing to provide light without excessive solar heat gain. It is the ratio between the visible transmittance of a glazing and its solar heat gain coefficient. Light Shelves (LS) LS are light control elements usually positioned horizontally above eye level in a vertical pass through (glazed) component to mainly protect the interior spaces to the openings against direct solar radiation, obstructing and redirecting light to the interior ceiling. Skylight An opening located in a horizontal or tilted roof. It permits the zenithal entry of daylight increasing the luminic level of the lower space under the skylight. It can also assist in providing ventilation. Light Tracking Skylights It is a special type of skylight that follow the direction and movement of the sun throughout the day to get the daylight into the interior space. With most skylights, the downward sunlight beaming can be obtained down into your house when the sun is overhead. Light-well It is also known as light duct. It is an interior light space which conducts natural light to interior spaces of the building. Its surfaces are finished with high reflective materials. Low-E Glass Low-E glass gives a year-round energy savings and comfort by helping manage the sun's energy and the cooling system energy in your building. A Low-E glass is coated with microscopically-thin, optically transparent layers of silver sandwiched between layers of antireflective metal oxide coatings. In the summer, Low-E glass let in visible sunlight while blocking infrared and ultraviolet solar energy that drives up cooling costs and damages curtains, window treatments, carpeting and furnishings. And in the winter, Low-E glass products offer greater comfort and reduced heating costs by reflecting roomside heat back into the room. Lumen Lumen is a measurement of light emitted by a lamp. As reference, a 100-watt incandescent lamp emits about 1750 lumens. Motion Sensors Motion Sensors and its control unit automatically turn indoor or outdoor lights on when they are needed (when motion is detected) and turn them off a short while later. They are very useful for indoor lighting to save energy and for outdoor security and utility lighting provided by incandescent lamps. Because utility lights and some security lights are needed only when it is dark and people are present, the best way to control might be a combination of motion sensor and Photosensors. Operable Window It is the window that can be opened for ventilation. Overhang It is a control element which is part of the building itself protruding horizontal from the façade above a Photosensors Photosensors are electronic control units that automatically adjust the output level of electric lights based on the amount of light detected. Lighting control devices enable occupants to control their lighting environment by either dimming the lights or switching them on and off. Some control devices, such as light switches, manual dimmers, and window blinds, can be directly accessed and controlled by occupants. Others, such as occupancy sensors, timers, and Photosensors, often are designed to take the place of occupant actions. Prismatic Glazing It is a control element placed in a pass through component (glazed) which share two environments redirecting light by its optical-geometrical characteristic. Reflectance (Ceiling) It is a surface that enable light returns the incidence visible radiation used to alter the special distribution of light. 10 | P a g e Reflective Glass Window glass coated to reflect radiation striking the surface of the glass. Seasonal Affective Disorder Seasonal Affective Disorder, also known as SAD, winter depression or the winter blues is an affective, or mood, disorder. Most SAD sufferers experience normal mental health throughout most of the year, but experience depressive symptoms in the winter or summer. The condition in the summer is often referred to as Reverse Seasonal Affective Disorder. This phenomena result from poor indoor lighting and insufficient Daylighting in building spaces or a combination of both. Shading Coefficient Shading Coefficient (SC) is a measure of the ability of a window or skylight to transmit solar heat, relative to that ability for 1/8-inch clear, double- strength, and single glass. It is being phased out in favour of the Solar Heat Gain Coefficient (SHGC), and is approximately equal to the SHGC multiplied by 1.15. It is expressed as a number without units between 0.00 and 1.00. The lower a window's SHGC or SC, the less solar heat it transmits, and the greater are its shading ability. Shading device It is a device that designed and mounted on the building’s facades to obstruct, reduce or diffuse solar radiation fall in on this facades and partially protect it against heat gain. SHGC Solar Heat Gain Coefficient (SHGC) is the fraction of incident solar radiation admitted through a window, both directly transmitted and absorbed and subsequently released inward. SHGC is expressed as a number between 0 and 1. The lower a window's solar heat gain coefficient, the less solar heat it transmits. A SHGC of 0.40 or less is recommended in warm climates. Solar Reflectance Index SRI is a value that incorporates both solar reflectance and emittance in a single value to represent a material's temperature in the sun. SRI quantifies how hot a surface would get relative to standard black and standard white surfaces. It is calculated using equations based on previously measured values of solar reflectance and emittance as laid out in the American Society for Testing and Materials Standard (ASTM) E 1980. It is expressed as a fraction (0.0 to 1.0) or percentage (0% to 100%). Solar Reflectance “Albedo” Solar reflectance, occasionally called “Albedo”, is to measure of the ability of a surface material to reflect sunlight – including the visible, infrared, and ultraviolet wavelengths – on a scale of 0.0 - 1.0. Spandrel The term spandrel is used to indicate the space between the top of the window in one story and the sill of the window in the story above in a building with more than one floor. It is typically employed in cladding facades with curtain walls. In insulating units, or as laminated glass, spandrel glass is typically specified for buildings' non-vision areas to mask construction materials. Even refurbished buildings covered in a combination of vision and spandrel glass can appear to be constructed entirely of glass. Sunlight It is the direct portion of the daylight coming directly from the sun at a specific location which is not diffused on arrival. Sun-optics skylight system it is a type of a skylight that track the solar movement to capture daylight and it is equipped with optic devices Sustainable development means improving people’s quality of life in a way that maintains the capacity of the planet over the long term. Human security, prosperity and wellbeing depend on a healthy and abundant environment. The sustainable use of natural resources, pollution prevention, and conservation of natural habitats are central to alleviating poverty and improving the quality of life. Top lighting Light that enters through the top part of the interior space such as clearstories, light duct or light well, and skylights, etc… Task Lighting Facilitates particular tasks that require more light than is needed for general illumination, such as under-counter kitchen lights, table lamps, or bathroom mirror lights. Thermal Bridge Thermal Bridge is known as heat leak, or short-circuiting. It is common that heat flows through a path of least resistance than through insulated paths. Insulation around a bridge is of little help in preventing heat gain or loss due to thermal bridging; the bridging has to be rebuilt with smaller or more insulative materials. For example, an insulated wall which has a layer of rigid insulating material between the studs and the finish layer. When a thermal bridge is desired, it can be a heat source, heat sink or a heat pipe. 11 | P a g e Thermal Emittance Thermal Emittance of a material refers to its ability to release absorbed heat. Scientists use a number between 0 and 1, or 0% and 100%, to express Emittance. With the exception of metals, most construction materials have emittance above 0.80. Thermal Resistance (R) R- value measures insulating power and the higher the R-value, the better the insulating power. The Rvalue is the inverse of the U-value (1/U = R). Translucent Glass It is a glass that allows only a portion of light to pass through, making objects seen through it appears unclear; opaline is in this category. It is used in buildings facades and skylights to offset the excessive Daylighting or sunlight in summer and reduce glare. U-Value (U-factor) is a measure of how well heat flows through an object (thermal conductivity). It is also referred to as the heat transfer coefficient or the coefficient of heat transmission. The U-value is measured by how 2 much heat in W (Btu) flows through a certain area (ft ) each hour for a certain temperature difference 2 2 K (°F), so it is measured in W/m K (Btu/ft hr°F). The U-value is the reciprocal of the R-value (1/R = U). The lower the U-value, the better the insulation value of the material. Many building and insulation products have their U-value indicated on their label. A U-value of 0.35 or less is recommended in cold climates. Nonetheless, in warm climates a low U-value is helpful during hot days or whenever heating is needed, but it is less important than Solar Heat Gain Coefficient (SHGC). Vegetated Roof (VR) A VR or green roof is “a building that its roof is either partially or completely covered in plants”. It also defined as they must be a stable living ecosystem that makes the urban environment more liveable, efficient and sustainable. A green roof consists of vegetation and soil, or a growing medium, planted over a waterproofing membrane. Additional layers, such as a root barrier and drainage and irrigation systems may also be included. Green roofs can be used in many applications, including industrial facilities, residences, offices, and other commercial property. It is widely used in Europe and the USA to save energy consumption and reduce the impact of urban heat island. Visual Acuity Visual acuity (VA) is acuteness or clearness of vision, especially form vision, which is dependent on the sharpness of the retinal focus within the eye, the sensitivity of the nervous elements, and the interpretative faculty of the brain. Visual acuity depends upon how accurately light is focused on the retina (mostly the macular region); it is largely affected by the insufficient or poor level of indoor lighting or Daylighting, and surrounding environment. Visible Light Transmission The visible light transmittance (VLT) is an optical property that indicates the amount of visible light transmitted through the glass. VLT is expressed as a number between 0.0 and 1.0. The higher the VLT, the more daylight is transmitted. A high VLT is desirable to maximize daylight. In hot climate it should not be below 0.30 and not above 0.60. VOCs Volatile Organic Compounds (VOCs) are molecules containing carbon and varying proportions of other elements such as hydrogen, oxygen, fluorine, and chlorine. They are the "precursors" that react in sunlight and heat to form ground-level ozone. Watt A watt is the absolute unit of power equal to the work done at the rate of one joule per second. Window azimuth It is the angle which the window is tilted normal to the sun; it measured from the North as 180 deg. Window’s sill a control element placed horizontally on the bottom of a window opening. It reflects and redirects natural light that falls upon the sill increasing the luminic level in the interior spaces. 180 to * The rating reflects the leakage from a window exposed to a 25-mile-per-hour wind, and is measured in cubic feet per minute per linear foot of sash crack. 12 | P a g e Executive Summary The Green Building Guidelines is a scheme set off by The Executive Council (TEC), Government of Dubai and the Ministry of Public Works (MoPW), based on the request of the Ministry of Public Works, to develop the guidelines for Sustainable/Green Building for the new projects under the jurisdiction of MoPW; intended to be carried out in all Emirates of the U.A.E. In addition, these guidelines represent a bundle of green building elements that will be largely adopted by the League of Arab States (LAS). It is understood that each Arab country will appropriately exploit and implement these guidelines accordingly to properly suite its’ socio-economic structure, urban settings and regulations, and technological advancement, and above all priorities. As per the directives of his Highness Sheikh Khalifa Bin Zayed Al Nahyan President of The UAE for the need to achieve Sustainability as part of the UAE’s Strategic plan and the emergence of the idea of the project after the courageous announcement and eminent directive of His Highness Sheikh Mohammed Bin Rashid Al Maktoum, UAE Vice President, Prime Minister and Ruler of Dubai to make new buildings being constructed in Dubai by January 2008 eco-friendly and meet the highest international standards suitable for Dubai and UAE. This announcement, that reflects the bold vision and stride of His Highness, is directed to withstand the current environmental challenges and preserve the environment of the UAE in general and Dubai in particular. It also bound for rigorous implementation of the highest international safety and eco-friendly standards in all avenues of life to profoundly ensure a safe and secure living style for all citizens and residents in the UAE. The intents of such project are mainly to save energy, conserve water, improve health conditions and lower CO2 emission generated by the cooling and water demands required for new buildings. The project is structured to include the guidelines for new buildings; according to its nature, type and location. This project is considered as part of a well thought plan to make new buildings being constructed in these emirates livable and healthier, and to a larger extent, contributes towards creating and maintaining sustainable built environments and eco-friendly cities. Also, it reflects the joint efforts of Dubai Government and Ministry of Public Works in spreading the awareness on sustainable/green buildings and participating in the international endeavor to combat global environmental challenges such as Climate Change, making the UAE the first country in the Middle East and North Africa (MENA) region to acknowledge and adopt such approach. This report represents the green building guidelines for new projects to be carried out by the Ministry of Public Works (MoPW). It highlights the shortlisted Green Building elements in the six focal categories groups: Envelope Efficiency, Cooling Systems, Energy Efficiency, Water use and Efficiency, Indoor Environmental Quality (IEQ), and Site Heat Island. In this project, we portray the developed guidelines for new buildings. Each template highlights the intent, specifications, technical data, and the building types covered by such guidelines. In principles, these guidelines will fundamentally lead to huge saving in both energy and water use, enhance indoor environmental quality, improve health conditions, increase the productivity of buildings’ occupants, lower the emissions of the green house gases (GHG) mainly, carbon dioxide (CO2) and contribute towards the reduction of Global Warming and counterbalance Climate Change, above all contribute to boost the economy of all emirates. This project is a joint effort between The Executive Council (TEC), Government of Dubai and the Ministry of Public Works (MoPW), and this report is an outcome of such joint effort. Two teams representing each party participated in developing these guidelines. Note: These guidelines are applicable for the Ministry of Public Works new projects (new buildings) in all Emirates; adaptations to existing buildings are not part of this document. These guidelines are intended for buildings that only fall under the jurisdiction of UAE Ministry of Public Works. 13 | P a g e Objectives The objective of this project is to establish the Green Building Guidelines that will be applied to the new projects under the jurisdiction of the Ministry of Public Works (MoPW). The nature of the MoPW projects was reviewed in order to relate each criterion of these guidelines to the relevant building type. The buildings’ types were reviewed and endorsed by the MoPW team for the analysis. The current building regulations that are concerned with the overall building performance, water and energy consumption rates, and indoor environmental quality as well as their environmental impact were reviewed, with the intention to develop Green Building Guidelines for the Ministry of Public Works. These guidelines will be fully utilized and implemented on the new project that are commissioned and supervised by the MoPWs across the UAE. Anticipated savings due to the implementation of the green building guidelines, in some of the elements with emphases on Dubai, are listed in Figure 1. Anticipated Saving from implementing Dubai Green Building Policy 80% 70% 75% 60% 40% 30% 30% 20% 12% 9% 10% 6% 0% Heating & Cooling Lighting water Heating Total Consumption Domestic Water Anticipated Savings Fig.1 Anticipated percentage of savings resulting from implementing the Green Building Guidelines Introduction A review on the Green House Gases (GHG) emission in various emirates has been conducted. GHG emissions in Dubai as an example, resulting from electricity and water desalinization at all power stations, were presented in Figure 2. The data shown are gathered from DEWA for total emission in 2003-2007. Figure 3 illustrates Dubai total energy generated in 2006. DEWA Emission of Green House Gases 2006 (g/hw/ hr) CO2 - Equivalents (10 4 ) 23% NMVOC 4% Particulates 3% Dubai Total Energy Generated 2006 Systems Energy Requirments 22274.272 (GWh) SO2 0% NOx 24% CO2 (10 4 ) 23% N2O 1% CO 20% CH4 2% Fig.2 Dubai GHG emissions resulting from electricity generation and water desalinization (all power stations) Energy improted from ADWEA (GWh) 2010.924 8.52% Exported Energy to Dubai (GWh) 106.298 0.48% DEWA Energy Requirements (GWh) 20370.101 91% Fig.3 DEWA annual power energy requirements against demands Source: DEWA 2006, Dubai 14 | P a g e Federal Water Use and Energy Consumption Rates The federal water consumption and electricity use rates in the Northern Emirates including Sharjah, Ajman, Ras Al Khaima and Fujairah (excluding Umm Al Qwain) representing the 5 main zones (Middle, Eastern B, Eastern A, Western A and Northern) are illustrated in Figure 4. Also, the ADDC water and energy consumptions are highlighted in Figure 5 and 6. Finally, the ADDC total water and energy use are shown in Figure 7 and 8. It is clear from Figure 5 that water use is higher in both domestic and government buildings whereas for energy consumption it was higher in domestic, commercial, and government buildings. 10000 9008 9000 7879 8000 7000 6375 6804 6339 6496 5595 6000 4921 4854 4609 5000 4000 3000 2000 1000 1748 1679 1490 1212 1188 822 1004 683 957 674 867 615 2356 2129 1934 0 2003 Middle 2004 Eastern B 2005 Eastern A 2006 Western A 2007 Northern Fig.4 Water consumption in northern emirates in million gallons (not including Umm Al Qwain) Data Source: MoPWs 7,000,000,000 45,000,000,000 40,000,000,000 6,000,000,000 35,000,000,000 5,000,000,000 30,000,000,000 25,000,000,000 4,000,000,000 20,000,000,000 3,000,000,000 15,000,000,000 2,000,000,000 10,000,000,000 5,000,000,000 1,000,000,000 0 Domistic Commercial Government Agriculture Industrial Other 0 Domistic 2003 2004 2005 2006 2007 Commercial 2003 Fig.5 ADDC Water Use in Million Gallons Data Source: MoPWs Government 2004 2005 Agriculture 2006 Industrial Other 2007 Fig.6 ADDC Energy Consumption in kWh Data Source: MoPWs 14,972,207,843 85,984,656,793.00 79,557,774,786.00 14,216,698,317 82,811,570,766.00 13,106,569,494 13,150,421,335 2004 2005 11,309,736,802 67,619,968,132.00 36,031,372,097.00 2003 2004 2005 2006 Fig.7 ADDC Total Water Use in Gallons Data Source: MoPWs 2007 2003 2006 2007 Fig.8 ADDC Total Energy Consumption in kWh Data Source: MoPWs 15 | P a g e The annual water and electricity use per sector in Dubai, for example, are portrayed in Figure 9 and 10. However, the water consumption as a result of using inefficient fixtures is shown in Figure 11 whereas the savings due to the use of efficient fixtures is depicted in Figure 12. Water consumption in an office building in the USA and that saved by using efficient flushing apparatus are illustrated in Figure 13 and Figure 14. The heat losses due evaporation and ventilation are also presented in Figure 15 and Figure 16. Also, the numbers of swimming pools are shown in Figure 17 and Figure 18. Finally, Figure 19 portrays the water use in different countries including Dubai. Dubai Electricity Consumption per Sectors Dubai Water Consumption 2006 Total = 64,926 MIG Total = 21475 GWh Source: DEWA 2006 Source: DEWA 3,311 5% 1,999 9% 1,475 7% 7,092 11% 6, 580 31% 2,356 11% 16,009 25% 9,065 42% 38,514 59% Residential Commercial Industrial Governement Fig.9 Dubai annual water consumption per sector Residential Commercial Industrial Others (Governement) Station Aux and Disalinations Fig.10 Dubai annual electricity consumption per sector Data Source: DEWA ADEWA, SEWA, FEWA Typical Water Consumption in a Residentail Bldg. (California) Typical Inefficient Indoor Water Use in the USA (80 gallon per person per day (300 Liter /Day/Person) Dishwashers 3% Dishwashers 1.4% Toilet Leaks 5% Leak 13.7% Toilets 26.7% Toilets 28% Clothes washer 22% Clothes washer 21.7% Bath 9% Toilets Other Domestic 2.2% Showers Faucets 12% Faucets Bath Showers 16.8% Showers 21% Clothes washer Faucets 15.7% Bath 1.7% Dishwashers Toilet Leaks Fig.11 USA water consumption in an inefficient building Toilets Showers Faucets Bath Clothes washer Dishwashers Other Domestic Leak Fig.12 Typical water consumption using efficient fixtures Source: Rock Mountain Institute (RMI), USA Watrer Use distribution in a typical office building Water Use in Homes in USA with Standard, 1.6 Gallon, & Dual Flush Toilets Domestic (toilets, urinals, faucets, etc.), cooling/heating, and landscaping uses 18.8 9% 41% 20% 9.1 6.9 3.61 1.54 1.25 2% Non-conserving Home 1% 27% Domestic Kitchen cooling /heating once through cooling lanscaping Misc./UAF Fig.13 Water use in a typical office building, in the USA Conserving home (1.6 gpf toilet) Avg. Gallons / Person / Day Conserving home (dual flush toilet) Avg. Gallons / Flush Fig.14 Water saving by adopting efficient flushing apparatus Source: Rock Mountain Institute (RMI), USA Outdoor Energy Heat losses Indoor Energy Heat losses Losses gto ground and others 10% Others 3% ventilation 27% Radiation to sky 20% Evaporation 70% Evaporation 70% Fig.15 Heat losses due to evaporation, radiation and ground Fig.16 Heat losses due to evaporation, ventilation and other Source: eere.energy.org 16 | P a g e Dubai Swimming Pools Capacity Dubai Current & Projected Swimming Pools 2003 - 2007 Number of Swimming Pools 583 2003 232 6339 351 184% Increase 627 2004 231 396 695 2005 306 389 2233 587 2006 272 315 324 2007 Total = 2816 583 Individual villas 2003 283 % Increase 130 194 Total swimming pools Residential Commercial and Hotels Fig.17 Number of swimming pools by building types 2007 2011 Fig.18 Licensed & projected swimming pools Source: Building Department, Dubai Municipality 2007 International Water Consumption 2007 Belgium Nertherland/Austria Germany Denmark UK/Finland Jordan France sweden Norway Japan Spain Canada USA Dubai 107 125 127 131 150 150 164 190 200 254 265 310 360 515 0 100 200 300 400 500 600 Liters per Person per Day (Lpd) Fig.19 Water consumption in different countries Source: DEFRA 2006 (www.edie.ne) and DEWA 2006 Background The projected sectors in the USA that have Green Building activities by sector are shown in Figure 20. Green Buildings are more beneficial in terms of return on investments, building values, staff productivity, health and wellbeing as well as economy. It is clear from Figure 21 that an increase of about 15 percent for 3 indicators; return on investments, building value, and staff productivity can be achieved and at least 10 percent for health and well-being of occupants. By-in-large, the 3 major sectors that have most of the green building activities are public facilities, educational and commercial forming about 75 percent followed by health care facilities at 11 percent. Based on the st nd th analysis most of the MoPW projects are falling in the 1 , 2 and 4 sector (public services, educational and health care). Green Building Activity by Sector R&D 5% Hotel/ Residential 5% Industrial 4% Transportation 1% Public Facilities 30% Health Care 11% Commercial 20% Educational 24% Fig.20 Sectors expected to have the most Green Building activities Source: Green Building Market Barometer www.greenbuildingnews.com 17 | P a g e Return on Investments Building Value green buildings Staff Productivity conventional buildings Health & Well-being being of Occupants %0 % 10 % 20 % 30 % 40 % 50 % 60 % 70 % 80 % 90 % 100 Fig.21 Benefits from Green buildings compared to conventional buildings The MoPW’s scope of work and projects projects’ profile The scope of work and project’s profile of the Ministry of Public Works are highlighted in Figure 22 and Figure 23. Design and Construct Government Buildings Design and Construct Roads and Bridges Maintenance of Government Buildings Maintenance of Roads and Bridges Fig.22 22 The scope of work of the Ministry of Public Works’ Projects Source: www.mopw.gov.ae Educational (Schools and KG's) Government Buildings (Officies) Roads and Bridges Hosptials MoPW' s Government Projects Fishing and Sea Ports UAE National Residential Villas Polices HQs Massjids Fig.23 Projects profile of the Ministry of Public Works Source: www.mopw.gov.ae About Hundred (100) Green Building uilding criteria were identified. Analyses were carried out to record the impact of o these criteria on building types. The building uilding types includ included ed in analysis are: a) public services; airports and ports, hospitals and clinics, and police facilities; b) recreation: leisure; c) religious: mosques; d) educational: universities, colleges and schools; e) residential: low-rise offices and villas; and f) industrial: factories and warehouses. warehouses To study and group these elements stakeholders’ barriers were proposed, assessed and evaluated ev (Appendix 1). The results of the analysis led to the selection of 53 criteria in total. It was then shortlisted to 43 elements. 18 | P a g e Project Outlines and Framework The following figure illustrates the framework and approach and phases of the project. Fig.24 Project’s outlines and scope of work The final shortlist The impact of the 43 shortlisted Green Building criteria on stakeholders and building types was carried out to identify the features and develop the guidelines as shown in Figure 25. Features 100 Criteria 6 Groups Features final Shortlist 53 Criteria 43 Criteria Guidelines Fig.25 Methodology and procedures of the project analysis to prioritising Green Building criteria Design development The course of action in the design process is the first crucial component in producing a sustainable building. For the design phase to be effective, it is vital to define the owner’s objectives (i.e., MoPW) and the set of criteria including sustainable and green goals, and baselines (benchmarks) before commencing the design process. process This is mainly to minimize the potential of elevating ing project costs. A sustainable “green” building can be delivered much easier in the early phases of the project, and it can be decreased as the process develops as shown in Figure 26. It could be achieved but the costs will definitely be increase increased. Fig.26 Impact of the early design input on potential for sustainability and other building’s life-cycle life Source: ASHRAE Green Guide 2006, ASHRAE Inc. 19 | P a g e Green Building Criteria and Related Groups The following chart (Fig.27) depicts the six groups identified with the selected green building criteria including alternative cooling systems; envelop (fabric) efficiency; energy efficiency; water efficiency; indoor environmental quality; and site and heat island. Nonetheless, the eliminated elements in these guidelines are shown in Figure 28. District Cooling, Solar Absorption Cooling Shading Devices, Floor Cooling, External Wall Insulation, Chilled Water Walls, Glazing, Radiant Cooling, Daylighting, Glazing Orientation, Glazing Area and Type, Glazing Characteristics, Skylights. Water Fixtures , Rain Water, Water Efficient Landscaping, Condensation, Recycled Water, Non-desalinated Water for AC. Cooling Systems Building Fabric Efficiency Energy Efficiency Water Efficiency Indoor Air Quality Low-emitting Materials (VOCs), High-emitting Materials (VOC’s), Operable Windows, Ventilation Systems, Chemical & Pollution, CO2 Sensors, Non-smoking & Smoke Control, Noise and Acoustic Control. Site & Heat Island Site Selection Building’s Orientation, AC Equipment Efficiency, CFC-free Refrigerants, Electrical Lighting, Control Sensors, Smart Control Devices, Thermal comfort, Water Heating , Swimming Pools, Electrical Cables, Renewable Energy, Ventilation. Roof Shapes, High Reflective Roofs, High Emissivity Materials, Green Roofs, Site Configuration. Fig.27 Green Building criteria and its related groups District Cooling , Floor Cooling, Shading Devices, Chilled Water Walls, External Wall Insulation, Radiant Cooling, Glazing, Solar Absorption Cooling, Daylighting, Photo-sensors devices (schools), Clear Storey Windows, Glazing Orientation, Building Orientation, Glazing Area and Type, Glazing Characteristics , Skylights, Light Color External Paints, Glare Control. Water Fixtures , Rain Water (irrigation), Water Efficient Landscaping, Condensation, Recycled Water (Grey Water) , Non-desalinated Water for AC, Collecting AC surplus water, Waste Treatment Plants . Low-emitting Materials (VOCs), High-emitting Materials (VOC’s), Operable Windows, Ceiling Fans, Ventilation Systems, Chemical & Pollution, CO2 Sensors, Non-smoking & Smoke Control (safety), Noise and Acoustic Control, Water Tanks (shading and insulation). Cooling Systems Building Fabric Efficiency Energy Efficiency Site Selection, AC Equipment Efficiency, CFC-free Refrigerants, Lighting Fixtures, Lighting bulbs and systems Motion Control Sensors, BMS - Smart Control Devices, Thermal comfort, Solar Water Heating , Swimming Pools, Electrical Cables, Renewable Energy, Efficient & Passive Ventilation, Clear Storey Windows, Landscape lighting. Water Efficiency Indoor Air Quality (IAQ) Site & Heat Island Roof Shapes (schools), High Reflective Roofs, High Emissivity Materials, Green Roofs (Rsdl), Site Configuration. Fig.28 Eliminated Green Building criteria and its related groups Note: The elements highlighted in Blue are optional and that in Red are added elements whereas the crossed ones are these eliminated in the analysis to match the MPWs projects’ requirements. 20 | P a g e Proposed Mandatory and Optional Elements The following chart portrays the elements that are proposed to be mandatory and those to be optional (the latter are highlighted in blue). It is clear from the chart that Group I has no optional element whereas Group II, III, IV, V, VI have 2, 2, 3, 1 and 2 respectively (Figure 29). I. Envelope Efficiency II. Cooling Systems III. Energy Efficiency • Glazing • Wall Insulations (nonglazed Façades), • Shading, • Daylighting, • Clear Storey Windows, • Glazing Orientation, • Building Orientation, • Glazing Area & Type, • Glazing Characteristics, • Skylights, • Light Color External Paints, • Glare Control, •Photo-sensors Devices (Schools). • Floor Cooling (Schools) • Radiant Cooling, • District Cooling, • Solar Absorption Cooling. • Site Selection, • AC Equipment Efficiency, • CFC-free Refrigerants, • Lighting Fixtures, • Lighting Bulbs and Systems, • Motion Control Sensors, • Thermal comfort, • Solar Water Heating , • Swimming Pools • Efficient & Passive Ventilation, • Clear Storey Windows (schools & others) , • Landscape Lighting • Renewable Energy • BMS- Smart Control Devices IV. Water Efficiency V. Indoor Air Quality VI. Site & Heat Island • Water Fixtures, • Rain Water Collection for Irrigation, • Water Efficient Landscaping, • Recycled Water (Grey Water), • Non-desalinated Water for AC, • Collecting AC Surplus Water, • Waste Treatment Plants. • Low-emitting Materials (VOCs), • Operable Windows, • Ceiling Fans, • Chemical & Pollution, • CO2 Sensors, • Non-smoking & Smoke Control (safety), • Noise and Acoustic Control, • Water Tanks (Shading & Insulation), • Ventilation Systems, (Supply air through Floor or Walls) . • High Reflective Roofs, • High Emissivity Materials, • Site Configuration, • Green Roofs (Res.), • Roof Shapes (schools). Fig.29 Mandatory and optional Green Building criteria and its related groups Building Types The following 11 building types represent 6 folds that were included in the analysis and applied to the MoPW projects: I. Public Services Airports and Ports Hospitals and Clinics Police facilities Sea ports and its service facilities (as presidential grants only) Buildings that are used for medical purposes and treatments including medical clinics institutions Police headquarters, facilities, centre and stations II. Recreation Leisure Sports and recreation facilities including theaters III. Religious Religious Buildings in which people gather for religious activities such as mosques (masjids) IV. Educational Schools Universities & Colleges Training Centres V. Residential Low-rise offices/ residences: Villas VI. Industrial Warehouses Buildings that are used for academic or technical classroom instruction, such as elementary, middle, or high schools Buildings used for academic or vocational classroom instruction, such as lecture room with the vicinities of college or university campuses as well as related facilities on campus Buildings that are used for technical classroom instruction, such as training centre’s, driving and aviation, and hospitality instructions and training Buildings that are less than 10 floors and used for residential and office purposes Detached or attached residential buildings (privately owned and used) Buildings used to store goods, manufactured products, merchandise, raw materials, or personal belongings (self-storage). 21 | P a g e Green Building Guidelines (new buildings) The guidelines presented hereafter are concerned with new buildings that to be handled, designed, supervised, and commissioned by The Ministry of Public Works (MoPW). These guidelines encompass more than 40 criteria in total representing 6 main groups. These elements are listed as follows: Group I: Envelop Efficiency 1. Glazing 2. Wall Insulations (non-glazed Façades) 3. Shading 4. Glazing and Building Orientations 5. Daylighting 6. Clearstory Windows 7. Skylights: Sun-optic 8. Glare Control 9. Photo-sensors Devices 10. Light Colour External Paints Group II: Cooling Systems 1. Under-floor Cooling/Heating 2. Radiant Cooling 3. Solar Absorption Cooling 4. District Cooling Group III: Energy Efficiency 1. Site Selection 2. Air-conditioning Efficiency 3. CFC-free Refrigerants 4. Lighting Fixtures and Lighting Bulbs 5. Motion Control Sensors 6. Solar Water Heating 7. Swimming Pools 8. Thermal Comfort (CO2 Sensors) 9. Renewable Energy 10. BMS-Smart Control Devices and Systems Group IV: Water Use and Efficiency 1. Water Efficient Fixtures 2. Water Efficient Landscaping 3. Recycled Water (Grey Water) 4. Condensation and Rain Water Collections 5. Non-desalinated Water for AC Group V: Indoor Environmental Quality – IEQ 1. Operable Windows 2. Ventilation Systems and Ceiling Fans 3. Indoor Air Quality 4. Low-emitting (VOCs) Materials 5. Clean Materials and Chemical Pollutions 6. Smoking and Non-smoking Zones 7. Noise and Acoustics Controls 8. Water Tanks (shading and insulations) Group VI: Site Heat Island 1. High Reflective Roofs (Cool roofs) 2. Site’s Materials Configuration 3. High Emissivity and Reflective Materials for Pavements 4. Roof Shapes 5. Green Roofs Note: The following elements of the guidelines are depicted for the application to new buildings not the existing buildings. 22 | P a g e Group I: Envelop Efficiency 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Glazing Wall Insulations (non-glazed Façades) Shading Glazing and Building Orientation Daylighting Clearstory Windows Skylights: Sun-Optic Glare Control Photo-sensors Devices Bright Colour External Materials and Paints To ensure sustainability of the external envelop of a building, many issues should be considered and judged, for example, the glazing that is used for the building’s fabric must take into account the following factors: a. b. c. d. e. f. g. h. i. j. k. Energy performance (requirements) Heat gains and losses Shading and sun control Thermal comfort Water vapour and condensation control Ultraviolet control Color effects Daylighting Visual requirements (privacy, glare, and view) Acoustic control Safety As glazing is the larger portion of the building’s facades and is the part that mainly gain and lose heat quickly, the optimum choice of windows and glazing systems will predominantly depend on certain criteria, including: the building use, the local climate, utility rates, and building orientation. When considering the selection of the glazing for each façade of the building many factors and characteristics must be taken into account such as: • • • • • Window/ glazing Solar Heat Gain Coefficient/Factor (SHGC or SHGF), Glazing shading coefficient (SC), Glass Visible Transmittance or Light transmission (Tv- glass or Lt-glass), Window U-value, and Others. Another major element to ensure a holistic high building performance is achieved and efficiency requirements are met is daylighting. Daylighting is a system approach that should be fully addressed but natural light isn't simply a feature to be added to the design process, it is rather a central design principle that drives the entire design of buildings hence, the following should be considered: Orientation and footprint, Climate, region and general availability of natural light, How Buildings use energy , When the window opens, Urban vs. suburban, Floor to floor and floor to ceiling heights, Window to wall ratios, Placement of glazing toplighting, sidelighting or both, Glazing performances: SHGF, SC, U-value, and visible light transmittance, Exterior and interior shading and solar control, Integration with electric lighting systems: lighting power densities, controls and electric lighting design, Reduced cooling loads via cool daylighting and energy efficient envelope and equipment, Interior design: colour, reflectance, furniture selection, and Floor plan; how far will daylight penetrate into deeper spaces? The next part will highlight the green building guidelines for Group 1, Building Envelop, which is part of the short listed elements. These are 10 elements for group 1. 23 | P a g e Criterion: Glazing Group: Guideline no.: Envelop Efficiency 1 Statement: All glazing areas on external façades or any exposed internal glazing of new Buildings shall meet the standards drawn in accordance to Solar Heat Gain Coefficient (SHGC). SHGC shall be 0.30 and max 0.37. Consequently, the Shading Coefficient (SC) shall be 0.25 – 0.30 maximum provided a Visible Light (VL) not exceeding 0.60 is achieved and LSG over 1.40 and maximum 1.80 is maintained. Intent: Reducing heat gain through the building’s façades to minimize cooling load and decreasing growth in peak electric generating capacity consequently, saving energy and lowering carbon emissions. Building Types: All types of air-conditioned spaces in buildings: public services, health, recreation (leisure), educational, religious, and residential as well as Industrial (factories) except warehouses. Specifications: Solar Heat Gain coefficient (SHGC) or often called Solar Heat Gain Factor (SHGF), the percentage of solar heat gain transmitted through the fenestration product as a whole. SHGC is function of the Shading Coefficient (SC) multiply by a constant factor (1.19). The SHGC values can range from around 0.2 to 0.8 or less depending on coatings, tinting, frame area relative to glass areas, and other factors. The lowest SHGF values are typically found in windows with Low-E coatings formulated to reduce solar gains (Refer to Appendix II). a. Ensure that glazing shall be always double-glazing with Low-E coatings on the interior of outside pane (Fig.30). b. Allow thermal break to eliminate thermal bridges in glazing above 40% aluminium sections. c. Make sure that Northern facades of buildings shall be designed for passive solar cooling and have glazing with medium SHGC of 0.37 to allow for maximum VL of 0.80 and beneficial for solar heat gain in winter months (Dec. – Feb.). d. Apply SHGC of 0.30 in case the glazed facades of the building are tilted 15° to 45° from the north direction (north-east, north-west). e. Ensure that East and West facades receiving plenty of undesirable sun have SHGC of 0.30. f. Guarantee that the Shading Coefficient (SC) for glazing areas on facades oriented towards the North shall be as low as 0.25 and maximum 0.35. For facades facing East, South, and West it should be 0.25 and not to exceed 0.30. g. Allow for the glazed shaded lobbies of parking areas in buildings to have SHGC of 0.37 - 0.45 with SC = 0.42 and 0.48 to ensure VL of 0.6 and 0.8 respectively. h. Apply SHGC of 0.37 - 0.45 with SC = 0.42 and 0.48 to ensure VL of 0.6 and 0.8, and LSG of 1.60 and 1.80 respectively for glazed areas for showrooms should have. i. Use double glazing in open outdoors at offices building and building’s entrances or revolving ones. j. Ensure that the roof glazing in shopping malls, exhibitions, universities, schools and hospitals etc.., shall have partially or totally translucent to minimize solar heat gain building up during solar time in summer days. Technical Data: SHGC SC U-value VL LSG 0.30 - 0.37 (SHGC = SC x 1.19) 0.25 and not above 0.30 2 below 1.5 W/m °K above 0.30 but not to exceed 0.60 above 1.25 and maximum of 1.80 Fig.30 Different types of Low-E and solar control glazing Image sources: www.filmcote.co.uk / www.pentagonprotection.com/ www.yourglass.com Refer to Appendix II. 24 | P a g e Criterion: Façade‘s Wall Insulations (non-glazed) Group: Guideline No.: Envelop efficiency 2 Statement: All façades and external claddings of new buildings shall be probably insulated to meet the standards drawn in accordance to thermal insulation for energy savings. The thermal resistance 2 (R) of the external walls and roofs shall be equal to 2.86—5.00 m °K/W and the corresponding 2 Heat Transmission Coefficient (U-value) not to exceed 0.25—0.35W/m °K. Radiant barrier insulation shall be used to block 95 percent radiant heat impinging on walls. Intent: Reducing heat gain through the building fabric to minimize the cooling load and peak demands consequently, conserving energy, lowering carbon emissions and combat global warming. Building Types: All types of air-conditioned spaces in buildings: public services, recreation (leisure), educational, religious, and residential as well as industrial (factories) except warehouses. Specifications: a. Ensure that all insulation materials are complying with ASHRAE Standards and ASTM tests. b. Introduce the air gap cavity as an insulation medium. The air gap should be 50mm (2 inches) to make the total external wall 30cm, i.e., 12 inches (refer to Appendix III). c. Make sure that spandrels or windows frame combining many aluminium sections to have thermal break to eliminate thermal bridges. d. Use reflective insulations “Radiant Barrier” or “radiant chips” with a low emittance below 10 percent and high reflectance above 90 percent to block solar radiant heat flow into the buildings’ envelop. e. Make sure the thermal insulation value of such material meet the above U-value for roof in case part of the roof is open (skylight) and Teflon is used instead of glazing. Technical Data: 2 • Thermal resistance (R) External Walls Roof 2.86 – 5.00 m °K/W 2 Equal or below 2.86 m °K/W 2 Equal or below 5.00 m °K/W • Heat Transmission Coefficient (U-value) External Walls Roof 0.25 – 0.35 W/m °K 2 not to exceed 0.35 W/m °K 2 not to exceed 0.25 W/m °K • Fire resistance (fire rated wall) 1-2 hrs 2 • Types of Thermal insulation Mineral wool Packing (fire stopping) Installing building insulation Building insulation materials Super insulation R-value (insulation) Passive house Zero energy building Wool insulation Fig.31 Different wall insulation materials Image sources: www.fiberglass--insulation.com / www.yixinky.com Refer to Appendix III. 25 | P a g e Criterion: Shading Group: Guideline no.: Envelop Efficiency 3 Statement: Shading devices on external façades or any exposed glazed areas of new buildings shall meet the standards drawn in accordance to reducing Solar Heat Gain on glazed facades. Shading devices shall be incorporated to provide shade and shadow to control the excessive sunlight impinging on these surfaces and minimize heat transmission during solar hours. Intent: Reducing heat gain through the building’s façades to minimiz minimize e cooling load and ensure a comfortable workplace, decreasing growth in peak electric generating capacity consequently, saving energy and lowering carbon emissions. Building Types: All types of air air-conditioned spaces in buildings: public services, recreation (leisure), and health, educational, religious, residential and industrial. Specifications: a. Ensure that gglazing areas are always shaded with shading devices (Fig.32). b. For glazing on the northern facades there is no need for shading devices unless the building shape is elliptical (Fig.33) (Fig.33). c. Incorporate appropriate shading devises on Eastern and Western ern facades that receive plenty of undesirable direct solar radiation from the sun to minimise solar heat gain, especially on the peak hours in hot summer months, i.e., morning from 8.00 to 12.00am and afternoon from 2.00pm to 6.00pm. d. Add shading elements underneath the skylight or atrium if these skylights are covering the opened roof or atrium to control the direct sun beams and reduce glare. glare e. Design the building to shad itself and benefit from the surroundings. f. Use exterior shading shadings to minimize heat gain during hot summer months (Fig.34, 35 & 36). g. Give west and south windows and glazed area shading priorities. h. Make glazed lazed areas on the external facades that receive solar radiation recessed inwards to minimise direct heat gain in hot summer months. i. Install fixed shading devices in all applications but if the budget allows then use movable devices to synchronize with the solar movement j. Break up overhangs can be used for less projection. k. Use landscapes andscapes to rationally provide shad/shadow on the building facades. Technical Data: South facades Horizontal shading devices and elements (Fig.32) Eastern and western facades vertical/horizontal (sloped) shading devices (Fig.32) (Fig • Type Light shelves, overhangs, horizontal louvers, vertical Louvers, and dynamic tracking or reflecting systems a) Recessed glazing on South facade f) Shading near glazed areas b) b), c), d) horizontal shading devices on western facades g) vertical devices h) shading entrances e) landscape to provide shadow i) shading devices: skyl skylight ight j) internal louvers for shading Fig.32 Different ifferent types of shading devices for shading glazed areas and building facades facade Images source: Authors 26 | P a g e Fig.33 Shading devices on an elliptical shape to control heat gain from east and west directions Images source: Authors Fig.34 Types of external light shelves for shading Images source: Authors www.chicagogreenworks.com www.ksarchitects.com/ www.yourenergyoptions.com Fig.35 Shading devises and light shelves to ensure maximize shading and ensure adequate daylighting Centre for Disease Control (CDC) Arlen Spectre Headquarters and Emergency Operations Centre in Atlanta Image source: www.aia.org Fig.36 Shading and light shelves to provide shading enhance natural daylighting and save energy Images Source: www.hku.hk 27 | P a g e Criterion: Glazing and Building Orientations Group: Guideline no.: Envelop Efficiency 4 Statement: All new buildings shall be properly oriented to benefit from the correct site directions to minimise heat gain into the building fabric, maximize the benefit for natural light, and allow for good crossventilation plus solar capturing in case PV panels to be installed on the building facades. Large glazed facades shall first benefit from the Northern direction and be minimized on Eastern and Western facades. Intent: Reducing heat gain through the building’s façades to minimize cooling load and decreasing growth in peak electric generating capacity consequently, saving energy and lowering carbon emissions. Building Types: All types of air-conditioned spaces in buildings: public services, recreation (leisure), health, educational, religious, and residential as well as industrial. Specifications: a. Maximize the site's potentiality to achieve the best possible climate orientation for new buildings in hot dry and hot humid climates such as of the UAE. b. Give orientation the priority to exclude the sun year-round and maximize the exposure to cooling breezes when possible in hot humid and hot dry climates with few heating requirements. c. Align new buildings towards the East-West axis where windows face either north or south directly so that glazed areas and facades, receive maximum hot morning and afternoon sun radiation. d. Design new buildings with large Northern windows to take in cool, diffuse North light. e. Minimize the height of the window on the South side (strip windows work well), and shade the window from direct sunlight. When the sun is high in the South sky, a canopy or a tree makes an excellent sunshade. f. Minimize windows on East-West, especially west-facing windows; due to the sun is low in the morning and evening and perpendicular on theses facades, creating a lot of glare and excessive solar heat gain. g. Ensure that the optimum directional orientation is given. This depends on the site specific factors and local landscape features such as trees, hills, or other buildings that may shade the space during certain times of the day. h. Align new buildings North side of the new buildings to capture direct sunlight in winter months (Dec. – Feb.) when the sun is in the Northern sky, permitting windows to create passive indoor heating when needed. i. Give orientation of buildings with rectangular shapes (long axis) towards East-West, so the walls facing these directions receive less direct sun radiation in the summer months. Nonetheless, passive solar heat gain occurs on the south side of the building in winter months (Dec. – Feb.). j. Incorporate PV panels on the main and lager building facades of new buildings. This should be o oriented on South-facing facades within 30 to the East or West of true South to provide around 90 percent of the maximum static solar collection potential. k. Locate larger glazing areas on the Northern facades to reduce heat gain hence, cooling loads. l. Give proper orientation to large glazing areas to reduce the solar heat gain during solar time and maximize cooling during comfortable months (November – April). m. In case the site, urban sittings or municipal plot direction, is not correctly placed towards North or South then the direction of the building shall take advantage from the best direction. Technical Data: • For North-South sites on the South axis of the street it should be wide enough to allow for an entry at the front as well as private North-facing spaces. Set new buildings back to accommodate a North-facing garden or trees (Fig. 37). • Sites along the North-South direction are the best solution due to good access to Northern sun yet have minimum potential for overshadowing by adjacent buildings. In summer, nearby buildings provide protection from low East and West sun. 28 | P a g e • Sites running East-West should be wide enough to accommodate North-facing outdoor space. Overshadowing by nearby buildings is more likely to occur on these sites. • North is the best direction to locate windows, living areas, and large office spaces. If the view is to the south avoid large areas of glass so that heat gain is minimized. West-facing or Eastfacing glazed facades will create overheating in summer months if not properly shaded. Fig.37 Site subdivision with predominantly North and South facing orientation Image source: www1.eere.energy.gov • In case the site is having a poor orientation or limited solar access due to constraints; urban settings and regulations, an energy efficient building is still achievable through careful design. • In hot dry climates Surface to Volume ratio (S: V) should be kept low to minimize heat gain (Fig.38). • Trees orientation on sites: Shade to the South-West and West is very important for blocking peak solar gain in late afternoon summer. Ensure that trees are located less than 30ft from the building to maximize shading on building surfaces (Fig.39). a) Example of minimum and maximum shape V/S Ratio b) Relationship between Volume to Surface Ratio Fig.38 Impact of Volume to Surface Ratio (V/S) on heat gain Image source: www.learn.londonmet.ac.uk) Fig.39 Site running East-West with a building facing North-South and landscape orientation Image source: www1.eere.energy.gov/ www.fsec.ucf.edu 29 | P a g e Criterion: Daylighting Group: Guideline no.: Envelop Efficiency 5 Statement: All spaces in new buildings shall meet the standards drawn in accordance to Daylighting provision. Glazing areas on external façades shall be selected to ensure good provision and distribution of Daylighting. Internal spaces in new buildings should be exposed to sunlight; enough to make these spaces healthier and meet sunlight and daylight requirements for health standards. At least 70 percent of the floor areas should have daylight well distributed across to allow occupants to effectively perform their activity inside buildings. Intent: Reducing the building’s electrical energy consumption and decreasing growth in peak electric generating capacity consequently, saving energy and lowering carbon emissions. In addition, maximizing occupant productivity and reducing possible cases of building-related illnesses, thus, significantly improve life-cycle cost and reducing operating costs. Building Types: All types of air-conditioned spaces in buildings: public services, recreation (leisure), health, educational, religious, and residential as well as industrial including factories and warehouses. Specifications: General a. Sunlight transmitted through building facades for health requirements • Ensure building’s spaces to receive sunlight beam for at minimum of an hour in 90 percent of all residential spaces and 80 percent of other building types; • Use Sun-optics skylight system on building's roof to control the direct Solar Heat Gain (SHG) from the sun. b. Daylight Factor (DF) • Achieve the minimum Daylight Illumination Level (DIL) of 275 Lux (27 Fc), an equivalent to 3 on work stations. c. Daylight distribution: • Distribute light to illuminate a minimum of 70 percent on each regular occupied floor area; • Achieve a minimum Glazing Factor of at least 3 percent in 70 percent of all occupied areas. Specific d. Ensure that at least 70 percent or more of the floor area shall be designed to receive natural daylight and ensure good distribution especially, deeper spaces. This is to reduce the human eye adjustments to high levels of luminance due to even distribution (by and large, better lighting quality can be provided if light is reaching a task indirectly such as that bounced from a white walls, i.e., directly from a natural or artificial source). e. Increase perimeter daylight zones — extend the perimeter footprint to maximize the usable Daylighting area. f. Maximize the use of toplighting and reduce sidelighting to ensure good distribution. g. Allow daylight penetration high in the building’s spaces. Windows located high in a wall or in roof monitors and clerestories will result in deeper light penetration and reduce the likelihood of excessive brightness. h. Make sure that daylight is reflected within a space to increase room brightness. Light shelves, if properly designed, should have the potential to increase room brightness and decrease window brightness. i. Use different building orientations to benefit from different Daylighting strategies; for example, light shelves which are effective on south façades shall be used though are ineffective on the eastern or western facades. j. Incorporate slope ceilings to direct more light into spaces. Sloping the ceiling away from the fenestration area will help in further increasing the surface brightness of the ceiling. k. Avoid direct beam daylight on critical visual tasks. Poor visibility and discomfort will result if excessive brightness differences occur in the vicinity of critical visual tasks. l. Filter daylight before entering. The harshness of direct light can be filtered by vegetation, curtains, louvers, or the like, and will also help distribute light. m. Incorporate daylight technologies such as light tracking skylights, translucent light wells and prismatic glazing, etc.., to daylight provision for spaces that by-product, aren’t receiving sunlight or daylight. 30 | P a g e n. Isolated spaces, with smaller windows and internal corridors shall have daylighting technologies incorporated to capture natural light during the day, such as light wells (ducts) and light shelves to boost and increase the daylight environments. o. Incorporate light shelves, light wells, and roof light trackers to capture daylight. p. Use the building’s north and south facades for daylight strategy to achieve best daylight direction and application and avoid the use of eastern and western direction (Fig.40). Technical Data: • Daylight deeper penetration into the building spaces. The depth of the room is not less than about two and one-half times (2 ½) the distance between the top of a window and the sill. • Keep reflectance of the building spaces at the following values to significantly impact daylight performance: Ceiling Wall Floors over 80 percent above 50 percent around 20 percent Fig.40 Direction where Daylighting should be best utilized a) 6x6 skylight to illuminate a1000 Sq.ft a 50FC+ fc for an 8 hr Daylighting b) section through the skylight b) 4x8 fixture to illuminate a 1200 Sq.ft a 50FC+ fc for an 8 hr Daylighting Fig.41 Types of skylights used in building a) Shilton school, WN- USA e) High windows b) Light shelves c) cool daylighting d) internal light shelves Images source: www.daylighting.org f) Atrium with top light shelves g) high window h) landscape to filter daylight i) side light shelves Fig.42 Daylighting techniques in buildings to create natural and cool daylighting Images source: www.metaefficient.com www.nrel.gov 31 | P a g e Fig.43 Daylighting techniques (light wells) in buildings to create natural and cool daylighting www.i.treehugger.com www.lotuslive.org www.archrecord.construction.com www.hcgsinc.com a) External light shelves b) lights helves covering a facade c) Vertical light shelves and light wells at Stittsville Public School www.wyomingbuildingscience.com www.timgriffithphotographer.com www.designshare.com d) Light shelves, the Univ. of Washington Images Source: www.ga.wa.gov e) External light shelves with long windows www.leebey.com f) EPA facades: External Light shelves www.epa.gov g) Phoenix City Hall Fig.44 Daylighting techniques (light shelves) in buildings to create natural and cool daylighting www.sanvanahtrims.com • Ensure typical daylight factors for various spaces are kept according to DF shown in Table 1. Table 1: Typical Daylight Factor (DF) in relation to buildings’ spaces and functions Space Type and function Daylight Factor (DF) Discussion Groups 14 Residential Living Room 1 Residential Kitchen 2 Office - detail work 4 Office – drafting 6 Office – corridors 1 Schools - classrooms 2 Schools - art rooms 4 Hospitals - wards 1 Hospitals - waiting rooms 2 Sports facilities 2 Warehouse - bulk storage 0.5-1 Warehouse - medium size storage 1 Warehouse - small item storage 2 Source: Daylight in Architecture, a European Reference Book, James & James, UK, 1998. 32 | P a g e Criterion: Clearstory Windows Group: Guideline no.: Envelop Efficiency 6 Statement: New buildings shall incorporate clearstory windows to maximize the use of natural daylight into internal spaces and minimise the dependency on electrical lighting during the day. Clearstory windows shall be properly placed and oriented to reduce the solar heat gain during solar time, maximize daylight and sunlight – in the early morning hours – and perhaps, provide ventilation when needed to circulate the air inside buildings during comfortable months (November to April). Fig.45 A clearstory window Image source:blog.seattlepi.nwsource.com Intent: Increasing the penetration of Daylighting into building spaces and lessening the incoming glare. In addition, reducing the heat gain through the buildings’ fabric that minimize the cooling loads and growth in peak electric generating capacity, resulting in improving IAQ, saving energy, and lowering carbon emissions. Building Types: All types of air-conditioned spaces in buildings: public services, recreation (leisure), health, educational, religious, and residential as well as industrial (factories and warehouses). Specifications: a. Encourage side or inclined clearstory windows on areas that receive less direct solar beams or reflected radiation, i.e., on Western facades. b. Locate clearstory windows mainly on the Northern facades to reduce heat gain hence, cooling loads. c. Ensure clearstory windows are installed with glazing at the same specifications according to the facades orientation as per the specifications listed for Criterion 1: Glazing. d. Make sure the glazed areas and roofs of the public buildings, schools, health care centres and hospitals, as well as factories and residential buildings have clearstory windows installed to attract daylight and direct daylight inward. e. Guarantee that deeper spaces in buildings are provided with clearstory windows as much as possible to attract daylighting and distribute it evenly well across the floor space. f. Allow for natural ventilation through clearstory windows to encourage cross ventilation in winter months and cool days specially when air temperature outside is below 25 deg C. g. Provide vertically elongated (height to width is larger) clearstory windows especially, in deeper rooms and spaces to grantee proviso nod daylighting thus, better performance. h. Permit for the sunlight to penetrate into the buildings’ spaces through installing clearstory windows, especially in residential units and villas when the sun is at low angle and at least for an hour daily to ensure health requirements are met. Technical Data: • Clearstory windows to face the Northern or South directions only; and • Low-emissivity (Low-E) glazing must be used in clearstory windows. Fig.46 Different vertical and horizontal types and styles of clearstory windows Image source: www.betterbuilding blog.oregonlive.com eccdom.blogspot.com www.architectureweek.com 33 | P a g e Criterion: Skylights: Sun Sun-optic Group: Guideline no.: Envelop Efficiency 7 Statement: New building shall be equipped with sun sun-optics optics skylights to control the direct radiation impinging on the buildings’ spaces and the use of electrical light inside buildings that result in minimising the dependency on the use of electrical energy during solar time. Intent: Reducing heat gain through the building’s façades and roofs to minimize minimiz cooling load and decreasing growth in peak electric generating capacity consequently, reducing operation costs, saving energy and lowering carbon emissions. In addition, help in providing adequate a Daylighting when needed especially, in schools and hospit hospitals. Building Types: All types of air air-conditioned spaces in buildings: public services, recreation (leisure), health, educational, religious and residential as well as industrial (factories and warehouses). Specifications: optic skylights so that the distribution a. Design buildings’ roofs to cater for the installation of sun-optic of daylight is increased and the demand on electrical power is reduced. b. Incorporate the sun sun-optic skylights to catch up to 30 percent more light transmission at low sun angles according to appropriate hours of buildings’ operation hours. c. Install Sun-o optic's Skylight prisms to refract the sunlight into micro light beams, spreading the natural light throughout the building spaces without allowing direct sunlight (UV) to damage interiors/furniture, /furniture, i.e., free from "hot spots”. d. Choose Sun Sun-optics system that lead to lights off 70 - 80 percent of the time, with less AC. e. Design and install sskylights kylights to carry a minimum 30psf tributary roof load or greater per site as specified in the current International Building Code (IBC). Technical Data: optic skylight gglazing materials must have a max. Light distribution characteristic that • Sun-optic maximizes the shading factor and diffusing qualities of glazing;; and minimum haze factor of 90 percent orr greater according to ASHRAE 90.1-2007 Per-addendum ddendum D. • The combined inner/outer lens target values shall be be: Light Transmittance: minimum 68 - 100 percent Class 1 & Class 3* 3 Acrylic outer dome. Light ight Transmittance: minimum 60 percent; clear Polycarbonate ycarbonate (LEXAN SLX). SLX) Diffusion / Haze Factor: minimum 100 percent. U-value: value: 0.82 or lower (glazing and framing) in accordance with NFRC 100 or "unlabeled skylight" default requirements of ASHRAE 90.1 – 2004. • For roof-light light glazing the U-values for a 12mm air space shall be as follows: Double glazed 12mm glass 1.9 or Double glazed 12mm Argon filled glass 1.6 U-values values are rounded to the nearest 0.1W/m²K. Lower U-values mean better the heat retention. (Refer to Pilkington K glass thickness, 4mm). a) Sun-optics optics Skylights with louvers at a school, USA b) Sun-optic skylight of an auditorium at Univ. of Oregon Fig.47 Use of skylights to Control the sunlight and provide daylight in schools to save energy e a) A classroom at 8.00am b) At 10.00am c) At 3.00pm d) at 4.00pm Fig.48 Control the operation costs by using sun sun-optic optic skylights to minimize heat gain and save energy Image sources: St Francis High School 34 | P a g e Criterion: Glare Control Group: Guideline no.: Envelop Efficiency 8 Statement: All spaces of new buildings shall be provided with a sensible brightness and meet glare index to avoid both disability and discomfort glare. All external façades, windows, and the reflectance of interior materials shall meet the standards drawn in accordan accordance ce to free glare environments. Intent: Reducing unwanted brightness, visual discomfort and heat gain through the building’s façades. Also, minimizing cooling load and decreasing growth in peak electric generating capacity consequently, achieving comfort, saving energy and lowering Carbon emissions. Building Types: All types of air air-conditioned spaces in buildings: public services, recreation (Leisure), health, educational, religious, residential and industrial including ffactories. actories. Specifications: a. b. c. d. e. f. g. h. i. j. k. l. ut down the size and brightness of the visible patch of sky and by increasing the interior Cut brightness by the judicious use of surface areas of high reflectance. reflectance Control entry of direct sun beams and combine natural light ht with artificial light. Make sure the light coming from the source inside the building is equal or higher than that coming from outside (windows) to provide less exposure to such conditions; conditions and reduce possibility of having headaches and eye fatigue. Ensure reflection reflections from objects within the room are controlled to minimise glare. Select window windows with less bright factor in comparison with the room surfaces. surfaces Make sure that building’s spaces are brighter; to better match the windows’ brightness. Ensure elements of landscape (trees) are placed in front of large windows or glazed facades to reduce discomfort glare. Ensure postures especially, computer screens on working plane inside buildings are designed design to avoid strains in relation to the VDU to avoid gglare. Integrate iindirect natural lighting systems that prevent overheating and glare. Consider integrating Photovoltaics into large south glazing areas to reduce glare. glare Apply light shelves on windows facing South att about head height, highly reflective ceilings, and light-colo coloured interior surfaces. Ensure that rroof glazing or clearstory windows in commercial buildings, buildings exhibitions, universities, schools and hospitals, etc., shall be partially or totally translucent to minimize solar heat gain and glare building up during solar time in summer days. Technical Data: • • 2 Lighting ighting levels in building should be are between 200 and 400 cd/m (cd=candela) in conjunction with Lux levels (ambient light) of 500 and 600 are created to avoid glare. A shading system that delivers a light transmission (T65) should be of 3 percent or less. Images source: www.lbwcarpentryandupvc.co.uk www.lbwcarpentryandupvc.co.ukwww.treehugger.com/ www.buildingdesign.co.uk/www.metaefficient.com/ www.buildingdesign.co.uk www.dca.state.ga.us/www.agsinc.org Fig. Fig.49 Different types of solutions to reduce or avoid glare Images source: www.agsinc.org/ greenlineblog.com// Authors 35 | P a g e Criterion: Photosensors Group: Guideline no.: Envelop Efficiency 9 Statement: New building shall be equipped with Photosensors devices to control the use of electrical light inside buildings, when these spaces are not in use so that energy could be conserved by switching off or dimming the electric lights. This would be also done wh when en the building spaces are naturally illuminated and lighting output is not required. Photosensors shall be properly installed to contribute towards reducing energy consumption, especially after working hours. Intent: Reducing cooling load, providing ccomfort and decreasing growth in peak electric generating capacity consequently, and saving energy and lowering carbon arbon emissions. Building Types: All types of air air-conditioned spaces in buildings: public services, recreation (Leisure), health, educational,, religious, residential except villas and industrial including factories but not warehouses. Specifications: a. Place and arrange for the Photosensors to be on the ceiling of rooms and receive light from the work plane (desk) below, as well as other room surfaces. b. Ensure that Photosensors are not installed in front of areas Fire exit and in spaces of frequent use such as elevators lobby on ground floor and building entr’acte to avoid visual disturbances c. Position osition Photosensors above the operating desks (known known as work plane) to ensure no interference of activities with its function. d. Avoid locating the Photosensors in part of the deeper space or room with smaller windows that cannot sense Daylighting. e. Make sure that photosensors are position at the right places, adjacent adjace place near the door of the space and can tract the light from the window to effectively operate. Technical Data: • Inside the building, use a closed-loop system where a photosensor is mounted on the ceiling of the room where the electric lighting is bei being controlled. • Outside the building, exploit open open-loop system where a photosensor is mounted on the outside of a building that controls the electric light level inside the building. building • At 20 percent dim level, the energy savings is approximately 60 percent compared to operating the lamp at full power. • Ballasts that dim lamps down to less than 5 percent light output have a maximum energy savings of about 80 percent compared to full light output operation. Fig.50 Types of Photosensors to control the use of electrical light in buildings Image source: lighting research centre - www.lrc.rpi.edu Fig.51 Examples of Photosensors inside buildings Photos Credit: Authors Refer to Appendix IV. 36 | P a g e Criterion: Light Colour Materials Group: Guideline no.: Envelop Efficiency 10 Statement: All external materials on new building facades shall be highly reflective with high emissivity index to reduce heat gain and transmission through the building envelop. All materials used for cladding and painting the external fabric of buildings and facades shall comply with heat reduction requirements and standards to reduce the heat gain during solar months. Intent: Reducing heat gain through the building’s façades to minimizing cooling load and decreasing growth in peak electric generating capacity consequently, saving energy and lowering carbon emissions. Building Types: All types of air-conditioned spaces in buildings: public services, recreation (leisure), health, educational, religious, and residential, as well as industrials and warehouses (industrial). Specifications: a. Apply reflective material on building facades to reduce heat gain in hot summer months. b. Ensure that only light or white or bright colour are applied on the building finish materials c. Eliminate dark colours from being used in external buildings facades to minimise rate of absorbed heat. d. Use water-based paints, finishes and sealants and perhaps, some milk-based paints for external envelop applications. e. Install cladding on building facades with light colours. f. Avoid using dark colour cladding material s on the external fabric to reflect offset heat gain. g. Use paint on the external facades with thermal shield characteristics to reduce heat absorption and reduce the transmission of heat conducted into the inter layers of the building fabric. h. Use external paints that are made of an eco-friendly base to avoid harming the environment. Technical Data: • Reflectance index should be 0.90 -0.95. • Absorption index should be 0.1 or less. Fig.52 Examples of light and white colour external finishes materials Image source: Author Fig.53 Examples of dark colour external claddings and roof finishes Image source: Author 37 | P a g e Group II: Cooling Systems Mandatory: 1. 2. Under-floor Cooling/Heating Radiant Cooling Optional: 3. 4. Solar Absorption Cooling District Cooling To ensure sustainability of the cooling systems for resources management, energy use, water, sub-systems and their applied techniques in buildings, many issues ought to be considered and judged. For example, Under-floor Cooling (UFC) or Radiant Cooling (RC), and its’ operation management in buildings should take into account the following factors: a. b. c. d. e. f. g. h. Size and space cooling Type of spaces Cooling time and peak loads Peak demands requirements Off-peak and peak demands rates Installation and operation Cost effectiveness Total loads As cooling in hot and humid climates is a prime element required to make the indoor spaces liveable and comfortable, energy demands and peak load demands in buildings are the larger portion of the electricity supply. It is estimated that in such harsh climate up to 70 percent of the electrical energy is consumed for cooling. Thus, it must be conserved. To lower the Air Conditioning, Heating and Ventilation loads, cooling system such as Under-floor Cooling, Radiant Cooling, and their appropriate selection shall be adopted and utilized. Also, the use of District Cooling (DC) should be encouraged and provided as the main source of cooling buildings in areas where DC generation stations are available. Hence, the choice of efficient system and type of cooling will mainly depend on many factors including building type, local climate, utility rates, building size and occupants’ activities as well as hours of building’s use. When considering the selection of the above factors, four key indicators must be taken into account: • Energy consumption per sq. ft., • Peak-demands, • Saving targets, and • Carbon emission. The next part will highlight the Green Building Guidelines for Group 2, Cooling Systems, which is part of the short listed elements. These include 4 elements: 2 are mandatory; and 2 optional. 38 | P a g e Criterion: Under-floor Cooling/Heating Group: Criterion No.: Cooling Systems 1 Statement: All space cooling and systems in new buildings shall meet the standards drawn in accordance to cooling systems and meet the cooling demands and effectively supply cool air into buildings’ spaces. Intent: Distribute the cool air evenly, lowering energy use in buildings. In addition, reduce cooling peakdemands consequently, reducing electricity use and energy consumption needed in the desalination process hence, lowering Carbon emissions. Building Types: All types of buildings: public services, health, educational, religious and industrial except recreation (leisure) and small residential. Specifications: The Under-floor cooling and heating system is a unique combination of highly efficient inverter driven compressor and variable set point temperature capability that allows the system to match its output precisely to the actual cooling/heating demands of the building. To make it a complete system, the following should be considered: System A a. Use Under-floor cooling system to manage cold air and ensure it effective distribution. b. Ensure heat pump technology is incorporated into the cooling system to represent a flexible and cost effective substitute to a fossil fuel boiler, with a cooling and sanitary warm water option. The inherent energy efficiency characteristics make it an ideal solution to reduce energy consumption, cost, and CO2 emissions. c. Apply barriers under the floor to direct the cold air to dense racks and in the ceiling to return it from the hot aisle. d. Utilize a raised floor to allow installing the system. e. Ensure the raised floors are initially built to assist in handling chiller lines, power feeds and the updraft required by mainframe equipment. System B f. Exploit outdoor unit extracts free low temperature heat from surrounding air and increases its temperature. Upgraded heat is transmitted via refrigerant circuit to indoor hydro-box. g. Use a fan coil range and connected to Altherma Under-floor system for cooling. h. Grantee the system has an ability to optimally control heat emitter temperature level. i. Install a conventional room controller if the over individual room temperatures and comfort levels is needed to be regulated. Image sources: www.enr.construction.com www.plenaform.com www.metaefficient.com Fig.54 Under-floor cooling/heating systems Image sources: www.effectivecooling.com www.greencampus.harvard.edu Technical Data: • The under floor cooling or heating system would include: The header manifolds, control valves, room thermostats, and the Altherma system*. • Water Temperature setting: Reduce the water temperature to 4°C and circulate it via the fan coil units. • Energy use KPI lead to: For every kilowatt of energy used up to 4kws or more can be absorbed by the system. *This system is compatible with modern conventional under floor heating/cooling systems and can substitute existing fossil fuel powered boilers. 39 | P a g e Criterion: Radiant Cooling Group: Criterion No.: Cooling Systems 2 Statement: All space cooling and systems in new buildings shall meet the standards drawn in accordance to Radiant Cooling Systems and meet the cooling demands and effectively supply and distribute cool air into buildings’ spaces. Intent: Distributing the cooled air evenly, lowering energy use in buildings. In addition, reducing cooling peak-demands consequently, reducing energy consumption needed in the desalination process hence, lowering Carbon emissions. Building Types: All types of air-conditioned spaces in buildings: public services, health, educational, religious, and residential and industrial except leisure (recreation). Specifications: Radiant Floor Cooling: Radiant floor tubing can be used to cool buildings. It is recommended for dry-hot climates and hothumid with a dehumidification means. In arid climates, the cool floor can be used to supplement or replace standard ducted air systems. a. Ensure the floor temperature is kept at (20°C) 68°F by using either a small cooling chiller connected to the floor tubing or make it steady at 13°C (55°F) temperature of the ground by a mean of an earth loop. b. Make sure the system works in winter with a water temperature between 25°C and 45°C. a. Grantee that water operating temperatures in summer are between 13°C and 15°C. b. Apply a thickness of 30 cm is left along the internal walls where the systems will run or laying the systems on the slab and then doing a metallic electro-welding net. 2 c. Grantee the joint areas shall not exceed 40 m with maximum length of 8 m for screeds intended for the application of stone or ceramic coverings. d. Ensure joint areas of rectangular rooms can exceed these dimensions but maximum to the length relation of 2 inches to 1 inch. e. Guarantee that the pipes are covered by a protective sleeve at least 20 cm long in connection with the crossing of the joints. f. Apply a tightening test prior to place of the support layer, in order to verify that pipes have not been receiving any damage during the laying operations. g. Proceed with the filling up of the circuits, one by one, and vent eventual air pockets. h. Ensure water test is done at least twice expected working pressure; no less than 6 bar. i. Make sure over-cooling the floor is effectively controlled to avoid wet slippery surfaces. j. Apply humidification media and good ventilation, i.e., ceiling fan to offset the wet-bulb temperature effect, if exist. Dry Floor Cooling/heating: k. Ensure Reflective insulation is installed under the tubes to direct the heat upward. l. Install tubing from above the floor, between two layers of subfloor. m. Guarantee that tubes are made from aluminium diffusers to spread the water's heat across the floor so that the floor is evenly heated. n. Make sure that the tubing and heat diffusers are secured between furring strips (sleepers) which carry the weight of the new subfloor and finished floor surface. Fig.55 Different types and images of radiant cooling systems Image source: www.effectivecooling.com 40 | P a g e Technical Data: • The radiant cooling or heating system includes: Perimeter wall insulation, Insulating panel, Pipes, Dilatation joints, Load of the system, and System’s tightening and then layer of the concrete. Types of radiant cooling Super flat system, and Water system. • Types of Radiant Floor Heating, Radiant air floors (air is the heat carrying medium)*, Electric radiant floors**, and Hot water (hydronic) radiant floors***. • Types of Tubing Use cross-linked polyethylene or rubber tubing with an oxygen diffusion barrier, Make sure radiant floor systems are not made from copper or steel tubing embedded in the concrete floors unless it is protected, i.e., no room for eventual corrosion, Fluid additives also help protect the system from corrosion, and Copper tubing is considerably good for its superiority in heat transfer abilities more than that of plastic-based tubing. • Controlling the System Avoid waiting time for radiant floor that uses a concrete slab takes many hours to heat up when it is if it is d permitted to become cold, Install floor thermostat instead of wall thermostat to control**** floor systems, and Ensure that the system is often designed to keep the circulation pump (s) running while the thermostat only controls the boiler's burner. • Cooling/heating If a geothermal can be effective in Emirates, radiant floor systems can be headed using a heat pump instead heated by a boiler. It would be a great way to save energy in buildings where the heating and cooling loads are similar in size such as in villas and low- rise residential buildings. *Air can’t carry large quantities of heat so radiant air floor is not cost-effective in residential applications. **Electric radiant floors are usually only cost-effective if your electric utilities authorities offer time-of-use rates and it is at low charges. It allows the "charge" the concrete floor with heat during off-peak hours. When the thermal mass of the floor is large enough, the building’s spaces will be kept comfortable as a result of the heat stored in it for a good number of hours at no additional electrical input. Thus, saving energy dirham but it is not yet considered in the Emirates. *** Hydronic (liquid) systems are the most commonly used and applied in buildings and cost-effective. ****sophisticated types of controls sense the floor temperature, outdoor temperature, and room temperature so the building spaces are kept comfortable; an energy saving system. 41 | P a g e Criterion: Solar Absorption Cooling (SAC) Group: Criterion No.: Cooling Systems 3 Statement: All space cooling and systems in new buildings shall meet the standards drawn in accordance to Solar Absorption Cooling powered by steam, hot water, or natural gas to be used to offset high electrical demand or consumption charges. This would mainly utilize solar energy. Intent: Counterbalancing high electrical demand and lowering energy use in buildings. In addition, reduce cooling peak-demands consequently; reducing energy consumption needed in the desalination process and ease the load on grid, and even feed in to the grid hence, lowering air pollution and Carbon emissions. Building Types: All types of air-conditioned spaces in buildings: public services, health, educational, religious, and residential and industrial except leisure (recreation). Specifications: Solar Absorption Chillers*: a. Use Absorption chillers when natural gas prices (used to give off steam) are significantly lesser than electrical cost. b. Apply absorption chillers for cooling in larger space cooling tonnages (above 500 tons) as it have a more favourable first cost when compared to electric technologies. c. Install and operate absorption chillers in areas where district steam is available. d. Install absorption chillers for cooling at sites with limited access to electricity power. e. Non-use of CFC or HCFC refrigerants in cooling to maintain a clean environment. f. Ensure that Absorbers must have a cooling tower; air cooled units are not an option - even for the smaller units. g. Guarantee that chilled water temperature is at its lowest temperature 4°C (39°F). h. Make sure that absorbers are not utilized in a low-temperature refrigeration application. i. Ensure that at a very low temperature water is vaporized at 100°C (212°F) at normal atmosphere pressure; in an absorber, water vaporizes cold enough to produce 4°C chilled water. j. Use absorption chillers where steam is available from an on-site process, i.e., steam from a turbine. k. Utilize absorption in large complex like hospital where large steam plants are available. l. Ensure that the absorbers with a COP of 1.0 burn 12,000 BTUs of gas for each ton-hour of cooling. There is an electric load on the absorbers for pumps (in addition to cooling towers and chilled water loops) that must be considered as well. m. Make sure that the steam-fired units require 50-125 psi steam and about 10 lbs/ton-hour steam usage to minimise cost, i.e., lower the required pounds/ton usage due to higher steam pressure). *It is a cooling system to cool air using chilled water. It is generated steam (evaporation) from heated water by the sun. There are two drivers in the cooling process: one is the water (utilized as the refrigerant that is the working medium that experiences a phase change that causes the cooling affect); and second is salt (lithium bromide) where heat is used to separate the two fluids. Fig.56 Solar Absorption Chillers with its solar PV panels for heating water for AC Image sources: Authors Image sources: www.ecsaustralia.com 42 | P a g e Fig.57 Solar Absorption Chillers with its system using flat plate collectors for heating water Image sources: www.soleuae.com Sun-Chiller Solar Absorption Cooling a. Use Sun evacuated-tube solar thermal technology with absorption chilling to economize the environmental and financial conditioning energy costs for facilities with exceptional cooling loads (Fig.58). b. Exploit Sun-chiller as a primary chiller during peak-demand hours with electric as backup. c. Make use of the Sun system to provide space heating in cold seasons (Nov. – Feb.) like that of the Northern Emirates. d. Capitalize on the use of Sun evacuated-tube to heat domestic water in buildings by solar power year-round. Fig.58 Sun-chillers system used for space cooling/heating (sun evacuated tubes with absorption chillers) Image sources: www.cogeneration.net / www.sunchiller.com Technical Data: • To make the absorption chillers cost effective the gas cost should be is below US$4.50/MCF and the electric cost is above US$0.08/KWH or equivalent. • Types of absorption chillers for cooling: Air cooled, single effect Water cooled, single effect Double effect - direct fired Double effect - indirect fired Table 2: Type of Equipment and Required Efficiencies of Absorption Chillers Equipment Type Required Efficiency Full Load COP (IPLV) 1. Air cooled, single effect 0.60, but only allowed in heat recovery applications 2. Water cooled, single effect 0.70, but only allowed in heat recovery applications 3. Double effect - direct fired 1.0 (1.05) 4. Double effect - indirect fired 1.20 Source: ASHRAE Green Guide: The Design, Construction, and Operation of Sustainable Buildings, American Society of Heating, Refrigerating and Air Conditioning Engineers, Inc., BN- Elsevier, Boston, USA, 2006 43 | P a g e Criterion: District Cooling (DC) Group: Criterion No.: Cooling Systems 4 Statement: Space cooling in new buildings shall meet the standards drawn in accordance to District Cooling (DC) when DC distribution plant is available; meet the uniform supply and effective distribution requirements of cool air in buildings. DC should involve the provision of thermal energy from more than one or more central energy plants to multiple buildings and large campus such as hospitals, universities and public buildings, via network of interconnecting pipes where chilled water (cooling) or hot water (heating) are supplies. Intent: Distributing cooled air evenly, reducing structural loads by eliminating big cooling equipment (cooling towers and chillers). In addition, decreasing more than 50 percent of chillers electricity consumption in large buildings and smoothing cooling peak-demands consequently; decreasing energy and water consumption needed in cooling hence, lowering Carbon emissions and air pollution. Building Types: All types of air-conditioned spaces in buildings: public services, recreation (leisure), educational, religious, and residential (high-rise towers) and industrial except small residential buildings and villas. Specifications: a. Ensure District Cooling is used in large buildings and facilities to save electricity. b. Use DC to avoid boilers and chillers in buildings and give roof and floor more flexibility. c. Supply chilled water in buildings to ensure uniform air distribution and improve comfort. d. Ensure high efficiency boilers and chillers are used in DC plant to grantee saving. e. Use due-fuel boilers and alternative-fuel boilers including renewable-fuel. f. Utilize alternative energy-efficient refrigerant, e.g., ammonia; and non-electrical chillers. g. Exploit hybrid chillers plants (various combinations of electrical & non-electrical chillers); energyefficient series or series-parallel chiller configurations for high Delta-T systems. h. Use thermal storage to enhance performance in DC and save electrical energy, especially at offpeak rates and reuse the energy to cut the peak-demands. i. Apply cogenerations of combined heat and power (CHP) and ensure higher level of operation efficiency and reliability. j. Minimise the use of desalinated water in all District Cooling Plants or in new DC plants. k. Ensure that chilled water is pumped in pipes for Air-conditioning in buildings at 4°C. l. Use of chilled water not an ice-based technique for thermal storage. District Cooling Plant Fig.59 District Cooling plant and sketch of supply of chilled water and return of warm water Cooling Towers Chillers Chilled Water pumped in pipes at 4°C for AC Fig 60 District Cooling with Thermal Storage technology support Image source: www.energytechpro.com 44 | P a g e Technical Data: • Use the following as non-desalinated water alternatives in DC: Sea Water, Treated Sewage Water (Phosphorus less than 0.3 mg/l and total nitrogen of 3 mg/l or less), Grey water. Recommendations: o Grey water: suggested due to less residual and Hazard, o Treated Sewage Water: Not strongly recommended due to hazardous and comfort resulting from high level of Nitrates and phosphorus unless it is reduced to acceptable level, o Sea Water: Not recommended due to high cost, but could be applied for projects such as manmade islands or similar. • Other technical data as per the following references: 1. ASHRAE 2006 GreenGuide. 2. ASHARE 2004. 2004 ASHRAE Handbook-Systems and Equipment, Chapter 11, District Cooling and Heating, Atlanta, USA www.ashare.org. Note: Storage Tanks: it operates during off-peak overnight hours, chilled water or ice storage tanks on the project produce chilled water or ice for the mechanical system’s cooling needs during off-peak hours (overnight), reducing overall power consumption and the load on the utility grid. The cost of this system could offset within five years due to annual energy savings. 45 | P a g e Group III: Energy Efficiency Mandatory: 1. 2. 3. 4. 5. 6. 7. 8. Site Selection Air-conditioning Efficiency CFC-free Refrigerants Lighting Fixtures and Lighting Bulbs Motion Control Sensors Solar Water Heating Swimming Pools Thermal Comfort (CO2 Sensors) Optional: 9. Renewable Energy 10. BMS- Smart Control devices and systems To ensure sustainability of the energy consumption resources, energy water concept, systems and applied techniques in buildings and on their site, many issues ought to be considered and judged. For example, efficiency of Air Conditioning systems and its operation management in buildings should take into account the following factors: • • • • • • • Demands requirements Hours of use Peak and off peak demands Type of chillers Type of cooling towers System output percentage Total efficiency and savings In hot dry and hot humid climates, cooling is an essential element required to make indoor spaces liveable and comfortable. Energy and peak load demands for cooling in buildings are the larger portion of the electricity supply. It is estimated that in such harsh climates up to 75 percent of the electrical energy is consumed for cooling thus, it must be conserved. Increasing the efficiency of the Air Conditioning, Heating and Ventilation systems (HVAC), cooling towers and chillers, and their appropriate selection shall contribute to such saving and better performance. Hence, the choice of efficient cooling equipment and type of AC systems will mainly depend on many factors including the type of building, local climate and types of water and availability, building size and occupants’ activities as well as hours of building’s use. When considering the selection of the above factors, four key indicators must be taken into account: • Energy consumption per Square foot, • Equipment efficiencies, • Saving targets, and • Carbon emissions. The next part will highlight the Green Building Guidelines for Group 3, Energy Efficiency, which is part of the short listed elements. These include 10 elements: 8 are Mandatory; and 2 optional. 46 | P a g e Criterion: Site Selection Group: Criterion No.: Energy Efficiency 1 Statement: All sites of new buildings shall meet the standards drawn in accordance to site selection and be properly chosen to ensure long term biodiversity and sustainability. Intent: Minimizing the negative environmental impact that may accompany the project and reducing the effect of the site on building’s overall performance. In addition, protect biodiversity and reducing the exposure to high noise level and air pollution hence, lowering carbon emissions. Consequently, improving the environmental quality and increasing productivity. Building Types: All types of buildings: public services, recreation (leisure), educational, religious, and residential and industrial. Specifications: a. Select the site to reduce the impact on the building in terms of first cost, construction and operation, maintenance of the facility. b. Prudent the site that lower the impact on prime land. c. Choose the site sensibly to lower the environmental impact. d. Select the site location to reduce transportation of materials and embodied energy during construction and operation. e. Minimise site selection that trespass on public parks and farmland. f. Avoid building on or near sites that considered as wetland. It must be 1.00km away from its boarder to ensure sustainability and biodiversity (Fig 61). g. Decide on new sites that are near public roads network, bridges and highways to reduce loss of land, provide access to the new facility, and avoid extra cost of new roads. h. Opt for sites supporting long-term biodiversity (species*present within its’ proximity). i. Choose new site to minimise infrastructures required to support the facility operation. j. Select sites in urban and developed areas to ensure good building orientation. k. Decide on the site to be nearby or within the immediacy of water supply sources. l. Pick the sites that are nearby or within the immediacy of power distribution network to reduce demand on supply and resources but within the allowable limits to avoid risk. m. Opt for sites that would have access to various energy sources including renewable n. Ensure that selected sites shall be within an acceptable good range to residential areas and other services to enable building users to reduce daily transportation and time. o. Make sure that all parties are involved in the site selection process to avoid post-occupancy defects and minimise additional cost for the project. p. Grantee that sites selection are made to avoid incoming pollution, i.e., prohibit building near an obvious pollution source. q. Ensure that the selection of sites has good link to good drainage systems and would not affect groundwater level. r. Avoid selecting sites that are nearby electrical transport medium or high voltage towers. s. Ensure new sites are selected as none of 3 Brownfield‡ categories to minimise risk. t. Maintain new sites to be within an acceptable distance from major airport to avoid environmental pollutions, i.e., air and noise. *It can be measured by the numbers and types of different species, or the genetic variations within and between species. Fig.61 Hazardous, industrial areas, and noisy sites to be avoided when selecting a new site for buildings Images source: www.gulfnews.com/ www.skyscrapercity.com 47 | P a g e Technical Data: • Brownfield‡ are classified as: Industrial: containing chlorinated solvents and other contaminants, Per-occupied defence sites: mainly exotic chemicals, toxins, and explosive residue, Petroleum site: contained leakage of underground petroleum storage tanks that have contaminated the soil and groundwater. • Safe distances from electrical power transport high-voltages towers: 500 meters. Tables 3 and 4 illustrate these safe distances and limitations, Homes, schools, etc. away from high voltage power lines consistently have less than this level, usually 0.02 or 0.03 micro Tesla. A 110 KV AC line would usually reach this level at 100 meters, a 400 KV line at 200 meters. The distance could vary with current loadings, Home and school buildings should not be close to 11000 Volt overhead AC lines which may not reach this level until 15 - 20 meters. • The undesirable health effect risks due to the Electro Magnetic Force (EMF) field levels surrounding HVAC can be reduced if EMF field levels of buildings and outdoor areas used for human activities are limited to the following: Table 3: Limits of Electro Magnetic Force (EMF) field of buildings Type of Use Sensitive areas: a. Workplace used by adult women, pregnant women and women of childbearing age b. Residences that occupied by children c. Schools, childcare or health facilities Maximum alternating current (AC) EMF levels permitted indoors or outdoors (Microtesla*) 0.1mt Less sensitive areas: a. workplace used by male adults only 0.3 mt * 1 Microtesla is equivalent to 10 Milligauss • New Buildings should maintain a safe distance from current or new High Voltage Alternating Current (HVAC) transmission lines according to the following Table. Table 4: Safety of HVAC overhead transmission lines Voltage of Transmission Lines Distance in Meters * 10kV-25kV 25m 25kV-100kV 75m 100kV-250kV 150m 250kV-400kV 300m *distance refers to the horizontal distance from the perpendicular of the nearest set of conductors to the nearest edge of the building. Source: Smart, Robin F. (2005) Health Effect of High Voltage Transmission Lines: A Survey of the Medical Literature. www.notowers.co.nz 48 | P a g e Criterion: Air Conditioning Efficiency Group: Criterion No.: Energy Efficiency 2 Statement: All air-conditioning equipment and systems such as, cooling towers, chillers, compressors, and heat pumps, and air-handling units (AHU) in new buildings shall meet the standards drawn in accordance to air-conditioning efficiency and install efficient and high performance equipment to save energy, improve operation and reduce energy waste. Intent: Enhancing performance and lowering energy use and cost in buildings. In addition, decreasing cooling peak-demands consequently, reducing electricity use and energy consumption needed in the desalination process hence, lowering Carbon emissions. Building Types: All types of air-conditioned spaces in buildings: public services, health, recreation (leisure), educational, religious, and residential and industrial. Specifications: a. Apply efficient Ac equipment including Air handling units (AHU), cooling towers, chillers heat pumps, and boilers. b. Ensure the system and equipment efficiencies are meeting the approved standards. c. Install cooling and heating equipment that have the correct size to save energy. 2 d. Ensure that 600-1000 Gross ft /ton cooling load is to achieve high performance. e. Optimized energy efficiency through a 20% energy reduction compared to ASHRAE 90.1-99 Chillers: a. Use high-efficiency chillers to save energy and improve performance (Fig. 62). b. Eliminate the use and storage of R-500 refrigerant at the plant (a type of refrigerant no longer being produced due to its ozone-depleting properties) c. Reduce the plant’s annual energy usage by 10 percent (approximately 2,500,000 kWh HVAC: a. Install Variable Frequency Drives (VFD) to greatly increase the energy efficiency of motors circulating chilled water. b. Set cooling equipment and system performance targets in terms of kW/ton (kW/kWR) as per the below techinical data. c. Select energy star system with installed programmed thermostats. Control: a. Use Heat Recovery. b. Provide up to 5100 cfm of 100% outside air for ventilation. c. Make sure the Enthalpy energy recovery system is 80 percent effective, ASHRAE requires 50 percent efficiency for AHU over 5000 cfm. d. Ensure Optimal chiller operation delivers more hours at peak efficiency, particularly in variableprimary flow applications. e. Install multiple Tracer controllers to enhance ing operation efficiency in buildings. f. Opt for Unit level open protocol flexibility including BACnet,… etc. g. Ensure that high energy recovery wheels (30 percent more efficient than code) is used on the 100 percent outside air ventilation systems for the apartments. h. Install variable speed drives (VSD) for variable flow pumping provides only the amount of heating or cooling water to provide thermal comfort for the complex. i. Ensure that ventilation air treated and dehumidified is independent of other HVAC systems to eliminate overcooling and reheat required on the main HVAC systems. j. Allow all HVAC equipment located within mechanical penthouses to have an ample room of proper maintenance to greatly increases the equipments average service life. Fig.62 Different types of efficient chillers with control tracer panel Images’ sources: Harvard University - www.greencampus.harvard.edu / www.trane.com 49 | P a g e Distribution: a. Install low flow fume hoods in building spaces such as teaching labs, 60 cfm instead of the standard 100 cfm, to reduce heating, cooling, and fan energy consumption. Thermal Storage: a. Use thermal storage medium (chilled water or ice) that is produced during the off-peak period of electricity demand and store it in tanks possible to reduce electricity consumption and also reduce the capacity of generators and transformers. b. Release the chilled water or melted ice melts during peak period of electricity demand, and absorbs thermal heat. Technical Data: • Design Process System responsive to partial loads, and 80% of the year, system operates at < 50 percent of peak capacity. • Efficiency Index as per ASHRAE 90.1. Chillers Cooling tower Chiller-water pump Condenser water pump Air-handling unit 0.51 kW/ton 0.011 kW/ton 0.026 kW/ton 0.021 kW/ton 0.05 kW/ton (0.145 kW/kWR) (0.003 kW/kWR) (0.007 kW/kWR) (0.006 kW/kWR) (0.014 kW/kWR) • Mechanical equipment Efficiency Requirements are listed in Table 5 as per ASHRAE Benchmark 6.5: Mechanical Equipment Efficiency Requirements (www.ashrae.org). Table 5: Chillers Efficiency Equipment Type Size Category Required Efficiency-chillers with or without ASDs Required Efficiency - Chillers with ASDs Operational Compliance Path Full Load (kW/ton) IPLV (kW/ton) Full Load (kW/ton) IPLV (kW/ton) All 1.2 1.0 N/A N/A All 1.08 1.08 N/A N/A All 0.840 0.630 N/A N/A <100 tons 0.780 0.600 N/A N/A ≥100 tons and < 150 tons 0.730 0.550 N/A N/A ≥150 tons and ≤ 300 tons 0.610 0.510 N/A N/A >300 tons 0.600 0.490 N/A N/A <150 tons 0.610 0.620 0.630 0.400 ≥150 tons and ≤ 300 tons 0.590 0.560 0.600 0.400 >300 tons and ≤ 600 tons 0.570 0.510 0.580 0.400 600 tons 0.550 0.510 0.550 0.400 Air cooled w/condenser Air cooled w/o condenser Water cooled, reciprocating Water cooled, rotary screw and scroll Water cooled, centrifugal a. Compliance with full load efficiency numbers and IPLV numbers are both required. b. Systems with single chillers that operate on 460/480V require ASDs (ASDs are optional in multiple chiller systems). c. Water-cooled centrifugal water-chilling packages that are not designed for operation at ARI Standard 550/590 test conditions (and thus cannot be tested to meet the requirements of Table 2.5.5) of 44* F leaving chilled water temperature and 85*F entering condenser water temperature shall meet the applicable full load and IPLV/NPLV requirements in Appendix B., Tables 1-6. 50 | P a g e Criterion: CFC-free Refrigerants Group: Criterion No.: Energy Efficiency 3 Statement: All air-conditioning and cooling equipment in new buildings shall meet the standards drawn in accordance to eco-friendly refrigerants, i.e., chlorofluorocarbon (CFC) based refrigerants. All refrigerants used in the cooling process and system must be CFC free. Intent: Minimizing the negative environmental impact that resulting from the use of conventional refrigerants and non-use of CFC. In addition, less ozone depletion of the earth's atmosphere due to using CFC free refrigerant. Reducing the impact on the environment and ensure long term sustainability and consequently Building Types: All types of air-conditioned spaces in buildings: public services, health, recreation (leisure), educational, religious, and residential and industrial. Specifications: a. Use industrial Refrigerant that are a non-ozone depleting product and completely safe for the environment. b. Ensure that cooling equipments and Air conditioning chiller system are totally free from CFC gases and refrigerant. c. Do not use CFCs, ozone-depleting refrigerant chemicals to cool most of the large commercial, industrial and institutional buildings. d. Replace CFCs, ozone-depleting refrigerant chemicals by eco-friendly substances. e. Avoid using refrigerants such as R-22 (HCFC-22). f. Use Industrial 12a Refrigerant for cooling process. g. Ensure that HFC R-410a and R-134a are used for chillers and the use of R-123 is phase out. h. Exploit fan-coil units equipped for direct-expansion cooling that is free from CFC. i. Consider specifying CFC-free refrigerants such as R-407C, (trade name Suva 9000 or Klea 66); or R-410A (trade name AZ-20, Suva 9100, or Puron). j. Utilize Ammonia* as a refrigerant to reduce the damage to the ozone layer significantly. k. Use common refrigerants 1,250, but the GWP for ammonia is zero to lower the impact on global warming potential (GWP). *The coefficient of performance for cooling of “Ammonia” is higher than that of common refrigerants; therefore ammonia chillers provide both environmentally friendly and high energy efficient benefits. Fig.63 Water-cooled Ammonia Chillers Image source: www.emsd.gov.hk Technical Data: • Refrigerants: the quantity of refrigerant shall not exceed the density limit in ASHRAE 15: Safety Standard for Refrigeration Systems, when using comfort AC packages. The limit for R-22 is 9.4 lb (4.26 Kg) per 1000 sq. ft. (92.9 Sq. m). • If CFC or HCFC equipment are used: Give enough space around equipment, into and out of the building for future replacement. Provide isolation valves at all inlets, outlets, gauges, etc. to reduce fugitive emissions. Install high-efficiency purges on chillers. Ensure that operations and maintenance manuals include equipment documentation complete with start-up and shut-down procedures, and logs that record refrigerant charge types, amounts and dates. 51 | P a g e Criterion: Lighting Fixtures and Lighting Bulbs Group: Criterion No.: Energy Efficiency 4 Statement: All indoor and outdoor lighting shall meet the standards drawn in accordance to energy saving. All lighting fixtures inside and outside buildings shall incorporate high efficiency bulbs (lamps) including active electronic drivers (ballasts) and Lighting control Systems. Intent: Minimizing the heat gain through indoor lighting fixtures, saving 30 to 75 percent of electrical energy in professional and consumers lighting by lessening cooling load and consequently, contributing to the partial reduction of electrical lighting consumption (about 15 percent) and lowering Carbon emission. In addition, providing higher quality lighting on work stations to eliminate Visual Acuity and increasing occupants’ productivity. Building Types: All types of air-conditioned spaces in buildings: public services, recreation (leisure), educational, religious, and residential and industrial. Specifications: I. Low voltage lighting bulbs and fixtures For all offices, educational, health care and Industrial buildings: a. Use Master TL-D super 80 fluorescent lamps with electronic ballasts and rating capacity of 14 32 Watts. b. Apply Low Voltage Halogen lamps with reflectors. c. Install lighting fixtures with good quality translucent covers. d. Use fixtures with efficient reflectors to maximize the distribution of light on task levels. e. Install efficient lighting bulbs from 5 Watts - 32 Watts inside buildings. f. Guarantee bulbs with magnetic ballast are not be used in all the above building types. g. Ensure service and emergency staircases are fitted with timers at a 10-mintute interval. In case of emergency/fire alarms are active all means of egress mainly exits/staircases shall be automatically illuminated as per NFPA* and Civil Defence the requirements (Appendix V). h. Use efficient lighting bulbs and fixtures outside buildings including sidewalks, alleys, local roads and its shoulders, parking area inside the plot. II. Low voltage lighting bulbs For residential buildings including villas:a. Use efficient bulbs with capacity of 5 – 32 Watts. b. Install typical fluorescent bulbs of sizes 0.60m and 1.20m at a capacity 14 - 32 Watts with electronic ballasts. c. Do not use Bulbs with magnetic ballast in all buildings. d. Ensure service and emergency staircases are fitted with timers at a 10-mintute interval. In case of emergency/fire alarms are active all means of egress mainly exits/staircases shall be automatically illuminated as per NFPA* and Civil Defence the requirements (Appendix V). e. Use efficient lighting bulbs and fixtures outside buildings. III. Use Fibre Optic lights instead of ordinary lights in swimming pools. Lighting power density is the maximum allowable measurement of Watts/Sq.ft for a given type of space. Technical Data: • Long life compact size bulbs, light weight and with high lumen (Table 6): 80% energy saving Wide voltage range Instated and flicker free start Cool Daylight (CDL) • Optimal performance criteria for lighting: 5.9 Lighting Controls, 6.7 Lighting Power Density, and 8.7 Task/Ambient. • Maximum lighting equipment power density Table 7. 52 | P a g e Fig.64 Efficient fixtures and bulbs (Photo Credit: Authors) Fig.65 Efficient lighting bulbs including LED Bulbs for efficient Lighting Images sources: www.google.com and www.metaefficient.com Table 6: Bulbs wattage capacity for retail, office, industrial and home lighting Bulb type Rating Capacity (Watts) CFL Compact Fluorescent Lamps CFL-I 5 – 18 11 – 23 TL 8 – 23 ESH Energy Saving Halogen 11 – 32 SSL Solid State Lighting (Light Emitting Diode - LED) 20 – 35 Source: Proceedings of MENAREC-4 Renewable Energy Conference 2007. Table 7: Maximum Lighting Equipment Power Density Space type Office Conference Room Toilet Room Corridors Stairways Lighting Power Density (W/Sq.ft) 1.1 1.3 0.9 0.5 0.6 Sources: ASHRAE 90.1-2004 Lighting Power Density Requirements. Table 8: Recommended lighting levels at working station in workplaces Activity/Space Building Type Artificial Lighting Glare Index Illuminance (Lux) 300 to 500 (300 on desks, in hospital) 16 19 Schools Colleges 300 to 500 19 Lecture theatres and Examination halls Schools Colleges Hospitals 500 (300 on desks, in hospitals 16 Music rooms and Music practice rooms Educational and Recreational buildings 300 16 Art Craft Needlework (Studios) Schools Colleges Factories Offices Recreational buildings 300- 500 16 Formal teaching & seminar spaces Schools Colleges Hospitals, etc Deep (open) plan teaching spaces To be continued 53 | P a g e Table 8: Cont’d Activity/Space Building Type Artificial Lighting Glare Index Illuminance (Lux) 500 Woodwork Metalwork Engineering (Teaching) Schools Colleges Training Centres Recreational buildings 16 Laboratories Educational buildings Hospitals Offices Research establishments Factories 500 to 750 (300 to 500 on bench in hospitals) 16 Staff rooms Common rooms Educational buildings Hospitals Offices Factories 150 to 300 (100 average in hospitals) 19 Offices (enclosed) Offices Educational buildings 500 (300 on desks, in Libraries) 19 Factories Hospitals Banks Insurance buildings Post Offices Deep (open) plan offices Landscaped offices Offices Colleges Banks Insurance buildings, etc 500 to 750 19 Typing Business machine Punch card Offices Colleges Banks Post offices, Etc 500 to 750 19 Computers Offices Banks Educational buildings Hospitals 500 to 750 Limit luminance where VDUs are used 19 Drawing and Design offices Educational buildings Offices Factories 500 to 750 plus local lighting to 1000 on boards 16 Workshops Machine shops Processing Production plane Factories Offices Hospitals, Etc Rough work 300 Medium 500 Fine 750 to 1000 very fine 1000 to 1500 (300 to 500 on bench, in hospitals). 19 Source: Basic Data for the Design of Buildings: Daylight. Draft for Development, DD 73: 1982, British Standards Inst. * NFPA National Fire Protection Association (USA). Refer to Appendix VI. 54 | P a g e Criterion: Motion and Control Sensors Group: Criterion No.: Energy Efficiency 5 Statement: All lighting fixtures inside and outside buildings shall meet the standards of energy efficiency and shall incorporate smart and control sensors. All space zonings shall have motion lighting sensors combined with photosensors to control lighting inside buildings. Intent: Minimizing the heat gain generated from indoor lighting fixtures, saving 30-75 percent of electrical energy in professional and consumers lighting by lessening cooling load and consequently, lowering Carbon emissions. In addition, providing higher quality lighting (Illumination) on work stations to eliminate Visual Acuity, increasing occupants productivity. Building Types: All types of buildings including public, industrial and commercial buildings: airports, ports, religious and hospitals, and educational (schools and universities), as well as residential. For lighting sensors, all types of buildings except residential (private) and warehouses. Specifications: Motion lighting sensors For all building types except residential buildings excluding villas: a. Use motion lighting sensors to control electrical energy use in all type of buildings except those of residential nature (villas) and warehouses. b. Apply motion lighting sensors only in the corridors in each floor of residential buildings for commercial use except villas to control electrical energy consumption. c. Install motion sensors in service areas such as staircases, corridors and lobby of lifts. d. Ensure that operation time is fully considered according to space type and activities, and age of building users. e. Make sure motion sensors are installed around the building spaces will automatically be switched when the space is unoccupied. f. Guarantee that motion and daylight sensors are installed at the peripheral areas, of the building spaces when the office is unoccupied or when there is ample daylight, the sensors will automatically turn off or dim down to minimize energy consumption. Fig.66 Different types of motion sensors and photosensors Image sources: www.drivewayalarmproducts.com/www.northstaralarm.com Fig.67 Different spaces with installed motion control sensors Photos: Author Refer to Appendix IV. 55 | P a g e Criterion: Swimming Pools Group: Criterion No.: Energy Efficiency 6 Statement: All indoor swimming pools shall meet the standards drawn in accordance to energy saving. Swimming pools shall be covered with insulation sheets and outdoor swimming pools shall be also covered if heated and when are not in use. Intent: Reducing the indoor heat losses resulting from evaporation and ventilation and controlling the water heating or cooling peak load demands and consequently, saving energy by 30-50 percent and lowering Carbon emissions. Building Types: All types of air-conditioned buildings including hospitals and spas, educational buildings, residential (commercial), Leisure and sport facilities and industrial except warehouses Specifications: a. Cover swimming pools when it is not in use to save water and energy b. Ensure that swimming pool covers are made of insulated materials to save energy. c. Make sure that all covering swimming pools shall meet the following standards: Fire retardant Mildew and Chlorine Resistant UV Stabilized for 1000 Hours on Weatherometer Bottom Vinyl is Chlorine and Bromine Resistant 50°C heat crack Thickness : 0.040 cm Abrasion Resistance : 200 Cycles Heat Seals Between Halves to Prevent Heat Loss d. Guarantee that the cover is superior grade 400 and 500 micron polyethylene which includes a UV inhibitor. Technical Data: • For indoor swimming pools, if are not in sue: transparent plastic (bubble/solar cover, vinyl cover, Insulated vinyl cover) • For outdoor swimming pools (optional): Bubble solar cover Vinyl cover Insulated vinyl cover 2 Pre-stressed 550g/m green reinforced PVC and fitted with a central filter panel. Fig.68 Outdoor and indoor swimming pool covers Image source: www.covers4pools.co.uk / www.poolandspa.com / www.forgeleisure.co.uk/ www.pinelog.co.uk a. Solar cover b. winter cover c. above ground cover d. indoor cover e. automatic cover Fig.69 Different types of swimming pool covers Image source: www.1st-direct.com Refer to Appendix VII. 56 | P a g e Criterion: Solar Water Heating (SWH) Group: Criterion No.: Energy Efficiency 7 Statement: Water heating shall meet the standards drawn in accordance to energy saving. Water heating in new buildings shall be provided by Solar Water Heating Systems (SWHS), mainly for public, hospital, residential, and leisure, schools and religious. For non-shallow roof install SWHS if the building roof area permits. Intent: Reducing energy consumption for water heating by renewable source and using solar energy to minimize the peak load demands. Also, minimising the water losses due to evaporation, consequently, saving in water and electrical energy, and lowering carbon emissions. Building Types: All types of air-conditioned spaces in buildings: public services, recreation (leisure), educational, religious, industrial and residential except high-rise buildings that have insufficient roofs surface areas (built on 80% - 100% of the site or roof area is fully utilized by MEP services and equipment) for the installations of large numbers of SWH panels. Specifications: a. Ensure that water distribution for washing and hygiene proposes except cooking, into toilets and bathroom and hot water in Kitchens are heated by means of solar energy. b. Use appropriate numbers of solar PV panels on the building’s roof to ensure sufficient storage and supply of hot water for the building users. For public buildings, the number of panels should be calculated according to number of users. For households: Two (2) panels for a family below 3-4 persons Three (3) panels for villas above 4 persons c. Utilize the right type of solar water heating system in new building including: I. For heating water 2 collectors: Skylight appearance, attractive looks Solid and built to last Certified high performance All-copper black-chrome absorber plate Durable tube-to-fin absorber bond Double strength tempered solar glass Anti-glare finish Modular hardware for any tilt Wind and impact resistant Structural certification High output even on marginal days. II. For water heating of swimming pools: 2 collectors: Specs: 2-Gobi 410 w/unions, 2-F1, 2-BU, 1-LX 220/B control, sensors, 1-Cupronickelexgr. HEX32 CNTB, 1- Col. Loop pumps and fit.15-42F, 1-Expantion tank-EX2, 1-air vent -bushingpressure relief-gauge, 4 Gal. Dyno-flo. III. For water heating in other building types (public and commercial buildings): above 3 collectors based on sizing and capacity. d. Use water tank incorporated with electric heating elements in case of cloudy skies and no sunshine for long hours in winter months. e. Ensure thermostat on hot water heaters to be kept at 120° F (49°C) to save energy. f. Make sure that hot water use is efficiency importantly adopting the following: Reduce hot water consumption, Lower the water heating temperature, Insulate water tank and hot water pipes, Install heat traps and a timer on water heaters, and Install a drain –water heat recovery system. g. Install electronic (smart) meters to measure electrical, hot and cold water consumption in new buildings that have solar water heating systems. 57 | P a g e a.Non-pressure solar water heater type used in buildings d. Balcony style SWH collector b. Integrated SWH c. Vacuum tube with heat pipe e. Non-pressured SWH collector f. Pressure SWH collector Fig.70Types of Solar water heating systems used in buildings a. Three target tube b. Electrical heater c. controller for pressure SWH Fig.71 Accessories of Solar water heating collectors Images source: www.xiankesolar.com Technical Data: • Type - Solar collectors’ applications used in buildings fall under 2 types: a. Flat-plate collector, and b. Evacuated-tube solar collectors. • Operation a. Passive b. Active, which have circulating pumps and controls For active systems, there are two types of active solar water heating systems: Direct Circulation Systems, and Indirect Circulation Systems. • Sizing The storage cylinder — allow for 40 - 60 liters/person/day. 2 Allow a minimum of 80 and preferably 100 liters storage/m of collector. A typical size for a family of four will be between 200 and 300 liters. All collectors should be independently tested for their thermal performance to BS EN 12975 or BS EN 12976 or DCL standards tests: - 2 Solar Heating Water System, 410 flat plate collector(s) - 20w PV panel and pump station - HP SS SW CL heat exchange assembly Fing.72 Sizes of solar water heating collectors Fig.73 Commercial water heating system Image source: www.google.com Refer to Appendix VIII. 58 | P a g e Criterion: CO2 Sensors (Thermal Comfort) Group: Criterion No.: Energy Efficiency 8 Statement: All spaces of new buildings shall meet the standards drawn in accordance to thermal comfort and health requirements. All spaces occupied by building users shall be equipped with Carbon Dioxide (CO2) sensors to ensure comfort and maintain good indoor air. Intent: Improving indoor air quality and occupant satisfaction in workspaces. Ensuring ventilation rates are kept at the required effective rates and lessening indoor pollution and improving thermal comfort. In addition, reducing energy use consequently, conserving energy and lowering carbon emissions besides enhancing indoor health thus, increasing productivity. Building Types: All types of air-conditioned spaces in buildings: public services, recreation (leisure), educational, religious, and residential and industrial except warehouses. Specifications: a. Install Carbon Dioxide (CO2) sensors to reduce the energy required for cooling/heating outdoor air when occupancy is less than peak design and save energy. b. Use the ASHRAE 62 calculation procedure to establish a minimum outdoor-air quantity. c. Mount CO2 gas sensors to ensure Demand Controlled Ventilation (DCV) is effectively measured and monitored. d. Monitor DCV by good distribution of CO2 sensors to satisfy the conflicting requirements for minimum energy consumption while simultaneously maintaining Indoor Air Quality. e. Introduce and ensure as much outside "fresh" air into building spaces to maintain a balance of both CO2 gas monitoring and energy demands. f. Install CO2 sensors to reduce signs of poor building ventilation and provide conform. g. Ensure that proper demand control ventilation strategies along with CO2 sensors measurement are kept to grantee indoor air is clean for occupants’ health and comfort. h. Make sure that environmental carbon dioxide levels in ventilation systems and indoor living spaces are in compliance with ASHRAE and other ventilation efficiency standards. i. Ensure that 1,000ppm of CO2* is not exceeded to grantee Comfort (odour) criteria are satisfied (ASHRAE Standard 62–1989, Section 6.1.3). j. Make sure that CO2 sensors are fixed in the space or at return-air duct to measure the indoor concentration. k. Use the variation between the indoor and outdoor CO2 concentrations to adapt the outdoor-air damper location hence, provide the proper amount of ventilation. *The absolute 1,000 ppm value is interpreted as the ceiling CO2 concentration for acceptable indoor air quality. This was based on Specific ventilation rate of 15 cfm/person, Activity level at 1.2 MET, and Outdoor CO2 concentration of 300 ppm. Technical Data: • CO2 sensors operation: Operating temp 0.0° to 50°C) Operating humidity 15% to 90% non-condensing • CO2 measuring range: Measuring range 0.00 to 2000ppm Output 0.00 to 10.0V Fig.74 Different Types of Carbon Dioxide (CO2) Sensors and Detectors Image source: www.futurelc.com/ www.controlsupply.com/ www.thermokon.de 59 | P a g e Criterion: Renewable Energy Group: Criterion No.: Energy Efficiency 9 Statement: All new buildings shall meet the standards drawn in accordance to thermal comfort and energy conservation requirements. At least one source of Renewable energy should be used to generate electricity for the buiding annual energy use. Intent: Lowering energy and water use in buildings by decreasing cooling peak-demands from conventional power generation plants. In addition, minimising heat gain through the buildings’ roofs from shading provided by the PV arrays hence, minimizing the cooling load, consequently lowering carbon emissions. Building Types: All types of air-conditioned spaces in buildings: public services, recreation (leisure), educational, religious, and residential and industrial. Specifications: a. Make sure that 15 percent of the building total annual energy use are generated from renewable energy sources. Wind energy a. Make sure that windmills are installed in areas where wind speed is above 8m/s to usher cost effectiveness. b. Install wind turbines on the building roof known as Wind building-integrated energy generation System to generate portion of electrical load demands the required for building operation such as for lighting, appliances and water heating (Fig.75). Solar thermal a. Use solar thermal technology to heat the swimming pools and in turns, save energy. Solar energy b. Install onsite-PV to generate at least 10 kW power, 60 panel photovoltaic array at the. This PV array would be enough to supply energy to run the garage and is connected to the rest of the buildings so that surplus energy can be utilized and a battery is not needed. The system is expected to produce approximately 12,450 kWh of electricity per year (Fig.76.a) c. Install single a PV shoe box lighting system in front of buildings to generate power for exterior light. It produces 2kWh of electricity per day in summer while a 0.7 kWh could be generated in winter (Fig 76.b). d. Integrate thin film technology of buildings’ facades to generate electricity from the sun in areas with no power or transportation of electricity is expensive. Technical data • To maximize electricity generation low-profile turbines should be used and mounted on buildings’ roof and to take advantage of the high pressure ward wind flowing over buildings Placement should be in the prevailing wind direction, and With no obstruction. Fig.75 Types of wind turbines used in building or wind farms Images Source: www.gizmag.com/wind-turbines-harness-building-power a. Small PV array on a site b. Science Centre PV shoe box c. solar water collectors d. 435 panel, 75.6 kW solar array sits Fig.76 Examples of renewable energy sources used in building or sites to generate electricity, lighting and heating water Image sources: www.gizmag.com/north-carolina-campus-goes-solar 60 | P a g e Criterion: Building Management Systems (BMS) and Smart Devices Group: Criterion No.: Energy Efficiency 10 Statement: All new buildings shall meet the standards according to Energy control and incorporate smart and control systems to monitor building performances. All space zonings zoning shall have BMS installed to monitor the operation of the building and detect fire and variation in temperature and indoor relative humidity and to record comfort conditions. Intent: Controlling ng the thermal comfort and safety inside buildings spaces, improving i indoor air quality and occupant ccupant satisfaction with work space and providing sufficient natural ventilation rate when required. Also, lessening indoor pollution and heat gain through the building bu fabric and minimizing the cooling load consequently, conserv conserving energy and lowering carbon emissions. Building Types: All types of air air-conditioned spaces in buildings: public services, health, recreation (leisure), health, educational and religious as well as residential and industrial. Specifications: a. Ensure that buildings are operated, managed and monitored by building management systems (BMS) to conserve energy, water and minimise indoor air pollution and reduce waste in resources and provide security and safety. b. Make sure buildings are operated, managed and mon monitored itored by building management systems (BMS) to lower carbon emission resulting from energy and water use consequently reduce the building footprint per user. c. Install energy meters in the building to assist in the auditing process (Fig.77). d. Ensure in centralized vertical ducts energy meters are installed and are easy to be accessed. e. Ensure that hot water has a control temperature meter. f. Make sure that the heat meters and electricity meters are connected through the M-Bus M network to 26 M M-Bus masters. g. Ensure nsure all fire fighting systems are connected to the BMS. h. Connect all large rooms are monitored to ensure safety and comfort is secured. i. Control air temperature, humidity and lighting systems by BMS. j. Provide an energy and water to reduce waste. k. Ensure thermal comfort in terms of air and hum and air speed are audited. l. Allow lighting system be monitored by BMS to reduce electrical consumption. m. Ensure all AC equipment are monitored and controlled BMS. Technical Data: • M-Bus Bus masters should be coupled to a digital substations communicating through RS232. • Smart Intelligent Systems SIS based on advanced technology should be used. Fig. 77 Building Management Systems (BMS) Image sources www.automatedbuildings.com a. An electrical car char charging socket b. a BMS device c. Lighting operation controlled by BMS Fig.78.. Smart devices and BMS used in buildings’ spaces to manage and control operation. Image source: Authors 61 | P a g e Group IV: Water Use and Efficiency Mandatory: 1. 2. 3. 4. Water Efficient Fixtures Water Efficient Landscaping Recycled Water (Grey Water) Condensation and Rain Water Collections Optional: 5. 6. Non-desalinated Water for AC Collection of Surplus AC Water To ensure sustainability of the water resources, water efficient systems and applied techniques in buildings and on their site, many issues ought to be considered and judged. For example, water fixtures installed in and water management applied to buildings should take into account the following factors: a. b. c. d. e. f. g. h. Fixtures’ type and efficiency Water requirements Landscaping requirements Types of vegetation Irrigation systems Water treatments Removal percentage Hygiene and Safety As water is a major element used alongside energy in buildings the larger portion of the supply must be conserved, mainly the potable water; consumed water should be treated or recycled. Part of the potable water that are currently used for flushing and irrigation should be replaced by recycled water (treated grey water) for flushing toilets. Thus, saving a large portion of clean and potable water plus, maintaining our natural recourses. Therefore, the choice of efficient fixtures, type of landscaping and appropriate irrigation systems mean the treatment of grey water will depend on many factors including building type, local climate, utility rates, and building size and occupants activities as well as hours of building’s use. When considering the selection of the above factors, four key indicators must be taken into account: • Water consumption per person, • Type of landscape and areas • Saving targets, and • Carbon emissions. The next part will highlight the Green Building Guidelines for Group 3, Water Use and Efficiency, which is part of the short listed elements. These are 4 mandatory elements and 2 optional ones. 62 | P a g e Criterion: Water Fixtures Group: Criterion No.: Water Use and Efficiency 1 Statement: All service areas (public toilets, lavatories and kitchens) in new buildings shall meet the standards drawn in accordance to Water Efficiency and install water efficient fixtures and apparatus including water closets, showers, urinals, and Lavatories’ faucets to reduce water use by 40 percent (bath and showers), 28 percent (flushing), 9 percent (kitchens) and 20 percent (laundry). Intent: Reducing potable water use in buildings by at least 30 percent – 40 percent and for building’s sewage conveyance (grey water) up to 75 percent and 100 percent for air-conditioning water. In addition, conserving water use and consequently, reducing energy consumption needed in the desalination process hence, lowering Carbon emissions. Building Types: All types of buildings: public services, recreation (leisure), educational, religious, and residential and industrial. Specifications: a. Use high efficient fixtures (Low-flow fixtures) and sanitary apparatus to reduce water demands (potable and non-potable water), and to minimize water supply and drainage. b. Ensure Low-flow fixtures achieve water savings of 20 percent – 50 Percent. c. Install Dry fixtures such as composting toilets and occupant sensors in commercial and industrial buildings to reduce the potable water demand. d. Opt for storm water and greywater for non-potable applications including toilet and urinal flushing, mechanical systems and custodial uses. e. Ensure that new faucet flow rates shall not exceed 2.5 gpm at 80 psi or 2.2 gpm at 60 psi. f. Make sure new showerhead flow rates shall not exceed more than 2.5 gallons per minute (gpm) at a water pressure of 80 pounds per square inch (psi). g. Built in flow limiter in all water fixtures and devices installed on apparatus in public and commercial buildings including residential type for commercial use, including: Faucets a. Use aerators with low flow rates to ensure maximum water efficiency. b. Install aerators that come with shut-off valves that allow you to stop the flow of water without affecting the temperature. c. Use aerator (screw-on tip of faucet) that ultimately determines the max. Flow rates. Showerheads a. Select a showerhead with a flow rate less than 2.5 gpm for maximum water efficiency. b. Use Energy-efficient dishwashers and clothes washers (Energy Stars). Technical Data: • Water Closets (W.C.)—periodical flushing capacity with toilets no more than 1.6 gpf/0.8 gpf. • Showers — low flow showers’ heads There are two basic types of low-flow showerheads: Aerating showerheads mix air with water, forming a misty spray; and Laminar-flow showerheads* form individual streams of water. • Use similar aerator technology and multiple flow settings to save water: Low-flow shower heads use about 2½ gallons of water per minute compared to between 4 and 5 gallons per minute used by conventional heads; Low-flow faucet aerators can cut water usage by 40 percent from 4 gallons/min to 2½; Ultra-low-flush toilets with maxi. 1.6 gpf compared with 3.5 gpf of standard ones. • Faucets — low flow devices with built in flow limiter or sensors: Kitchen faucets shall be equipped with aerators that restrict flow rates to 2.2 gpm; Bathroom faucets shall be fitted with ones that restrict flow rates by 66 percent from 1.5 to 0.5 gpm. • Urinals — install efficient urinals. * In a humid climate, use a laminar-flow showerhead as it won't create as much steam and moisture as an aerating one. Refer to Appendix IX. 63 | P a g e Criterion: Water-efficient Landscaping Group: Criterion No.: Water Use and Efficiency 2 Statement: All soft landscape (greenery and planted areas) on the site of new buildings shall meet the standards drawn in accordance to Water Use and install water efficient landscaping and irrigation systems including the selection of indigence and desert landscaping, trees, and srubs that consume less water and retain much of it. Intent: Reducing water use for irrigating the site of new buildings by at least 30 – 40 Percent. In addition, maintaining our natural resources by conserving water use; consequently, reducing energy consumption needed in desalination process hence, lowering carbon emissions. Building Types: All types of new buildings: public services, recreation (leisure), health, educational and religious as well as residential and industrial. Specifications: a. Apply water-efficient landscape including trees and shrubs that retain less water to reduce demands on potable and non-potable water, and minimize water supply. b. Exploit materials and systems that consume less water. c. Use water-wise plants. Native and adaptive plants that consume less water species and varieties that are resistant to local plant diseases and pests. d. Use only low-water-use plant material in nonturf areas. e. Limit the use of turf in areas where it is necessary and select low water-using grass. f. Avoid irrigation on windy days. g. Design dual watering systems with sprinklers for turf and low-volume irrigation for flowers, trees, and shrubs. h. Mulch around shrubs and trees to conserve water. i. Apply high technologies to eliminate the use of potable water by 50 percent through one or any combination of: Plant species factor; Irrigation efficiency systems; Plant landscaping that does not require permanent irrigation or no irrigation; and Desert landscaping. Water Management: a. Group plants with similar water needs such as deciduous trees and plants, coniferous trees and plants, earth berms, walls, fences, sheds, and garages (Fig.79). b. Apply drought resistant landscaping with efficient sprinkling and irrigation technology. c. Select the plants in courtyard and around the building that are hot, dry, shady, or damp. d. Check watering requirements of the site’s plants so that it is located in the right place. e. Cover soil to minimize wild plant growth, slow erosion and evaporation, and enhance it. f. Irrigate greenery areas of landscaping on site in the morning and after the dew has dried to reduce losses due to evaporation. g. Make sure that watering-off peak to reduce load on municipal water and help utility management and ensure adequate reservoir levels. h. Apply shading to reduce water losses in summer and keep deep soil periodically moist. i. Notice yard areas that suffer from poor drainage and standing water. j. Distribution system with pressure reduction and Install metering. k. Inspect irrigation system regularly for leakage, broken pipes, stuck, clogged or broken heads, and needed adjustments (every week in traffic areas); once a month in non-traffic. Fig.79 Different types of landscaping Image source: www.archiverde.it/uk To ensure water savings on new building’s site, a landscape plan shall be fully prepared to meet the following requirements: a. Design of water use shall not exceed 80 percent of the Reference Evaporationspiration (ETo) for the total landscape area. 64 | P a g e b. The irrigation system shall average 65 percent or greater in efficiency. c. Proper scheduling of the irrigation and management practices must be addressed. d. Ensure a soil’s test shall be carried out to propose the appropriate landscape plan. e. The irrigation scheduling shall take into account the soil permeability including soils lab to provide recommendations for compaction relief. f. In heavy soils, overhead sprays shall not be used on slopes steeper than 25 percent. All areas including slopes shall utilize multiple start times to pulse the irrigation and allowing for maximum infiltration of the applied water. Accordingly, use drip or subsurface irrigation on all non-paved areas shall have a minimum of 2 percent slope and shall not allow standing water in any landscape area. g. A separate irrigation meter and backflow device shall be installed in all projects. h. Controllers shall be reprogrammed seasonally and all projects other than residential shall include an automatic rain shutoff device or be linked to a local weather station. i. All valves shall be operated under proper operating pressure. Pressure reduction shall be provided as necessary for drip and underground systems (a valve specified for drip use shall be used for such systems). j. Check valves to be incorporated at all points where elevation differences cause low head drainage. Flush valves shall be installed at the end of all drip lines. k. Spray heads shall be fitted at maximum head to head spacing and shall use flat spray patterns in most situations. l. Overhead spray shall be scheduled to run between 9.00pm and 9.00am. m. Ensure a maintenance procedure manual with irrigation schedules are provided by the Landscape Architect for each site of the projects commissioned by the MoPW including: Mowing (trim) heights for the turf areas, Aeration and de-thatching, Irrigation system maintenance including daytime visual inspection, cleaning of filters, flushing of lines, adjusting and/or repairing heads and calibration of rain gauges, Replacement of mulch, Type of fertilization and pest control, Pruning regularly as needed, and Scheduling of irrigation. Post-installation procedures: A landscape irrigation audit will be required and it should clearly state the landscape plans. The following tips are essential: a. Ensure lawn (grass) areas shall not exceed 25% of the total landscape area in commercial or residential projects except in recreational needs or practical turf areas to save water. b. Check that the bulk area of the landscape is encompassed with low water use plants. c. Avoid using overhead spray in narrow, irregular or odd shaped areas where uniformity of application cannot be achieved. d. Make sure that overhead spray shall not be used in areas less than 8' wide unless it is shown that a uniform application of water can be achieved without overspray into adjacent areas under site wind conditions. e. Guarantee irrigation is designed for summer winds averaging 4.5 - 5.0 m/s. f. Ensure that the majority of the plants are adapted to local climatic conditions, after an establishment period, and placed on a reduced or non-irrigation schedule. g. Confirm any plant to be used has similar water needs and is grouped together in hydrozones. h. Make sure the total water use of all hydrozones does not exceed the annual water budget. i. Utilize Multiple start times (pulsing) to reduce runoff and allow infiltration. j. Apply Drip irrigation with disc filters for non-potable water or self cleaning screen filters for projects over one acre in size. The drip or underground system shall provide for uniform wetting of a minimum of 75 percent of the root zone and supply water to opposite sides of the plant. All emitters on any particular circuit shall have the same flow rate with larger trees and shrubs provided with more emitters. All emitters used on slopes shall be pressure compensating devices. k. Water features may be used if they use re-circulating water and are included in the estimated total water use. l. Cover soil with Mulch of 7.5cm (3 inches) thick in all planting areas except low groundcovers and turf. In the low groundcover areas, the mulch shall be applied around but not touching the crown of the plant stem (trunk). 65 | P a g e m. Install the non-potable water irrigation systems where non-potable water will be available in the foreseeable future. n. Design and operate the recycled water irrigation system in accordance with all local municipal codes and the concerned Emirate regulations. Technical Data: Landscape areas • It must include, in the plan, the following requirements to ensure water savings: Hydro zones, Plant materials, details and specifications, Container size and quantities, spacing, and other landscape materials including paved areas including ponds and water features, Total landscape area, total irrigated area, and total turf area, and Designation of recreational turf (Grass/lawn) areas and specifying needed amount of additional water above the Maximum Applied Water Allowance. Irrigation systems • The system shall ensure the inclusion of the following items to opt for water savings: Minimize or avoid runoff, low head drainage, overspray or similar conditions, Use repeat cycles (pulsing) so that precipitation rate does not exceed infiltration rates Have hydro-zones valved separately, Show precipitation rate of each head or emitter used, Overhead spray in areas < 8' wide and on slopes steeper than 4-1 should not be used, Separate irrigation meter and backflow, Install automatic control valves wired to automatic controller, Proper operating pressure for valves, Master valve for systems larger than 12 stations, Low angle nozzles for gear driven/impact rotors, Minimum head to head coverage, Pop-up fixed spray head to be flat spray except on slopes where low angle nozzles might, be necessary to avoid undercutting the slope, Disc filter for non-potable systems or self-cleaning filters for drip systems shall be > 1 acre, Matched emitter rates on each circuit, Irrigation details and specifications, Monthly irrigation schedule chart, and Automatic rain shut off device. Landscape efficiency • Ensure the Landscape Coefficient (KL) is calculated using the following equation: Landscape Coefficient (KL) = Water Use x Density factor x Microclimate (1) Where - Water Use: is a number represented as 0.9 (highest), 0.5 (average) and 0.2 (lowest), - Density Factor (DF): is an indication of how closely the plant material is spaced in relationship to the material’s mature root/branch spread. DF is as high as 1.3, average as 1.0 and low as 0.5, and - Microclimate: is represented whether it is hot or windy. It is ranging from a min of 1.2 to a max of 1.4 with the average cool and shade factor of 1.0 and 0.5 respectively. The Five vegetation types in relation to Water Use, Density Factor and Microclimate are listed in Table 9. Table 9: Landscape Coefficient (KL) in relation to the vegetation types Water Use Density Factor Vegetation High Avg. Low High Avg. Low Hot/ Windy Trees 0.9 0.5 0.2 1.3 1.0 0.5 1.4 Shrubs 0.7 0.5 0.2 1.1 1.0 0.5 1.3 Groundcover 0.7 0.5 0.2 1.1 1.0 0.5 1.2 Mix Group 0.9 0.5 0.2 1.3 1.1 0.6 1.4 Turf grass 0.8 0.7 0.6 1.0 1.0 0.6 1.2 Microclimate Avg. Cool/ Shade 1.0 0.5 1.0 0.5 1.0 0.5 1.0 0.5 1.0 0.8 Source: www.ci.fairfield.ca.us 66 | P a g e Criterion: Water Collection – Condensation and Rain Group: Criterion No.: Water Use and Efficiency 3 Statement: All new buildings shall meet the standards drawn in accordance to Water efficiency and install pipes and gutters on buildings roofs to capture rain water and store it in special tanks for future use. Also, water films created as a result of condensation in hot humid summer months especially, on the outer pane of the external leaf of large areas of glazing on buildings’ facades shall be collected and stored in separate tanks; used after treatment when needed for irrigation. Intent: Reducing potable water use in buildings and its site, and conserving water. Consequently, decreasing energy consumption needed for the desalination process hence, lowering Carbon emissions. Building Types: All types of air-conditioned spaces in buildings: public services, recreation (leisure), educational, religious, and residential and industrial. Specifications: Condensation Water a. Collect condensation water from the external leaf of the outer pane of glazed surface on building’s facades in summer (Fig.80) b. Incorporate gutters (slightly slopped) on the facades to collect condensed water c. Install a ground water tank to stockpile the gathered water on the building’s site. d. Use this water, after treatments for landscape irrigation. Rain Water a. Collect rain water from the building’s roof using gutters and vertical pipes. b. Install a ground water tank (sensible size) to stockpile rain water on the building’s site for landscape purpose (Fig.81 and Fig.82.b). c. Determine the sizes of water tanks according to the average precipitation rates in each location (Emirate) and the roof size (roof area plus height until the gutter). d. Connect vertical pipes with horizontally-sloped pipes to reach the water tank’s inlet. e. Filter rain water before entering the water tank (Fig.81 and Fig.82.a). f. Ensure access for and excavation depth for the water tank. g. Guarantee that pipes used for supplying rain is separate from that of potable water. h. If rain water is collected from parking lots a special filter and treatments are needed. i. Segregation of oil through filters is needed before water enters into the water thank. j. Separation of oudour is required in water tanks. Fig.80 Condensation collection using gutters Image: www.metaefficient.com Fig.81 Rain water storage tanks for industrial and commercial buildings www.spec-net.com.au www.ainsmag.co.uk a) Rain water collection b, c, d) Different sizes of galvanized steel water tanks to store rain water Fig.82 Water tanks used for providing irrigation water from the rain water collection Image source: www.buildingdesign.co.uk Image source: www.flickr.com 67 | P a g e Technical Data: Aboveground (External) Water Tank • The rain water collection system (aboveground level) shall include the following elements: Tank (storage capacity of 600 gallons or above) Inlet strainer with cover Outlet with threaded inserts and plugs Over flow elbow kit Leaf catcher kit Water diverter kit Inlet pipe connector Float valve assembly External pressure pump Pump cover Flex hose kit with ball valve Rate of gallons/min required from the pump Rain water tanks in a School Fig.83 Types of external water tanks used for providing water for irrigation from rain water collection (outside building) Image source: www.metaefficient.com www.bluescopesteel.com.au www.rainharvest.com Underground Water Tank • The rain water collection system (underground level) shall include the following elements: Tank (storage capacity of 600 gallons or above) Oil and odour separations underground filter Inflow smoothing filter Water inlet Floating filter Suction hose Multigo pressure pump Pressure hose Automatic switch Over flow trap Installation controls Solenoid valve Mains backup with air gap Anti surcharge Rate of gallons/min required from the pump Fig.84 Underground water tank for rain water collection Image source: www.starkenvironmental.com Note: Sizes of water tanks shall be designed according to each Emirate’s precipitation records (a10-year period) 68 | P a g e Criterion: Recycled Water (Grey Water) Group: Criterion No.: Water Use and Efficiency 4 Statement: New buildings shall meet the standards drawn in accordance to Water Use and utilize Recycled Water (Treated Grey Water) only that used up in showers, baths and faucets, and specifically reused for flushing toilets, landscape irrigation, and air-conditioning cooling towers. Intent: Reducing potable water use in buildings by at least 20 percent and water resources plus decreasing the potable water used in air-conditioning systems by up to 70 percent. In addition, conserving water use and consequently, reducing energy consumption needed in the desalination process hence, lowering Carbon emissions. Building Types: All types of air-conditioned spaces in buildings: public services, recreation (leisure), educational, religious, and residential and industrial. Specifications: a. Avoid the discharge of water used up by showers, bathtubs and lavatories in buildings into the drainage system but collect this Grey Water and reuse it for flushing toilets. This process shall be in line with that of the International Plumbing Code (IPC). b. Carry out the collected Grey Water from the building service areas to a separate drainage system from that of the black water (solid drainage). c. Transport the Grey Water to a Grey Water Treatment Plant for recycling. This could be on the building site level or the neighbourhood and district level (Fig.85). d. Install sensible water tank (at least 50 gallons) to store this grey water. e. Make sure that Grey Water doesn’t include visible tints and it should be hygienically sound and odour free. It may be necessary to correct pH and hardness but it is unlikely. f. Guarantee that water is disinfected before supplying it into pipes (Fig.85.a). g. Analyze the water that includes solids both settleable and suspended, a moderate level of BOD and FOG (fats, oils and greases) both in a free form and emulsified from kitchen* and shower/bath water (Fig.85). h. Recycle the treated grey water and it must have very low levels of Biological Organic Deposition (BOD), FOG and suspended solids (Fig.86.b). i. Ensure that stored Grey Water, in the storage tanks, should not exceed 72 hours and it’s dyed either blue or green with a vegetable dye. Grey Water can be used as sub-surface landscape irrigation but a proper procedure for treatment is required. *Kitchen waste water adds significantly to the organic load hence demands additional treatment equipment. a.FLO EC Electro coagulation treatment b. Sodium Hypochlorite Dosing for Residual Disinfection c. Pre-Treatment Screening Fig.85 Process of Grey water recycling and treatment for buildings water use Images source: www.eflo.com a. 250 Litres per hour EFLO EC b) Grey Water in the 3-phase treatment i.Raw ii.After EFLO EC iii.Clean Water Fig.86 EFLO EC system and samples of grey water before and after treatment Images source: www.eflo.com 59 | P a g e Technical Data: • To provide environmentally sound Grey Water Recycling system in Commercially used buildings (hotels and offices) and industrial buildings the following treatment must be followed: Commercial buildings Pre-treatment, Aerobic treatment, Membrane filtration, and Clear water storage. Domestic buildings Use ultra-filtration membrane ISB technology. General • Clarification Tank: Ensure the removal of sinking and floating sludge. • Media Filtration: Guarantee the removal of suspended flocked particles. • Disinfection: Provide Sodium hypochlorite dosing to disinfect and provide residual disinfection in the delivery side of recycled grey water back to the residents. • For the distribution, piping materials should meet one of the standards listed in IPC 2006 Table 605.4. • The Grey Water entering the water tank shall pass first through an approved filter such as a media, sand, or diatomaceous earth. • Guarantee that the Grey Water collection tank is fitted with a vent sized in accordance with IPC 2006, Chapter 9, and based on the diameter of the reservoir influent pipe. • The overflow pipe to Grey Water tank should have an equal or larger diameter as the Gray Water influent pipe collection. • The overflow pipe and drain shall have direct connection to the sanitary drainage system. Table 10: Limits of removal of containments in grey water Containment 1. Suspended Solids % Removal not less than 90 2. Oil & Grease 95 3. Total Organic Carbon 97 4. BOD 70 5. Metal Ions in Concentrations < 100mg/l 97 6. Bacteria (Fecal Coli forms) 98 - 99+ 60 | P a g e 7. Textile Dye 98 8. Pesticides 96 Source: www.ipc.org Group V: Indoor Environmental Quality (IEQ) Mandatory: 1. 2. 3. 4. 5. 6. 7. Operable Windows Ventilation Systems and Ceiling Fans Indoor Air Quality Low-emitting (VOCs) Materials Clean Materials and Chemical Pollutions Smoking and Non-smoking Zones Noise and Acoustics Controls Optional: 8. Water Tanks (shading and insulations) To ensure sustainability of buildings in terms of the environmental quality and health, many issues ought to be considered and judged. For example, the quality of air, acoustics satisfaction and acceptable noise levels inside the spaces of new buildings and its readiness to be healthy and comfortable, it is important that many factors should be taken into account to usher such quality: a. b. c. d. e. f. g. h. i. j. k. Size and area of indoor spaces, Number of users, Hours of use, Time of the year, IAQ limits, Exposure time, Low and high frequency sound, Vibration levels and dB allowable levels, Type and quality of AC equipment, Limits of materials emittance, and Total quality of indoor air, light, thermal and acoustical environments. In hot dry and hot humid climates IEQ is a vital criterion to make indoor spaces liveable and comfortable. Lighting pollution, air pollution and the level of CO2 and CO concentration, ventilation rates, and VOCs, as well as noise and vibration levels in buildings are also important elements to assess the indoor environment quality (IEQ). It is estimated that productivity could be increased by 15 percent due to the improvement of such environments, thus, well-being. Reducing the level of pollution and material emittance rates (low VOCs) besides the appropriate material selection and AC equipment shall contribute to such improvement of IEQ. Hence, the choice of efficient cooling equipment and type of AC systems that produce less noise and vibration rates, proper design and fittings of internal spaces to reduce noise level, will mainly depend on many factors including: the type of the building, local climate condition and its microclimate zone, the building size and occupants’ activities as well as hours of building’s use. When considering the selection of the above factors, five key indicators must be taken into account: • Lighting quality, 61 | P a g e • Air Pollution level, • Overall air quality, • NCR, and • Productivity rate per hour, The next part will highlight the Green Building Guidelines for Group 5, Indoor Environmental Quality (IEQ), which is part of the short listed elements. These include 8 elements: 7 are Mandatory; and 1 optional. Criterion: Operable Windows Group: Criterion No.: Indoor Environmental Quality (IEQ) 1 Statement: All glazing areas of new buildings shall meet the standards drawn in accordance to Indoor Air Quality and shall provide an operable window for each space, at least one per each occupied room and more than one for zones occupied by group users. Intent: Improving indoor air quality and occupants’ satisfaction with work spaces and providing sufficient natural ventilation rates during comfortable months. Also, lessening indoor pollution and heat gain through the building fabric to improve thermal comfort and minimizing the cooling load consequently, conserving energy and lowering carbon emissions. Building Types: All types of buildings: public services, recreation (leisure), health, educational, religious, and residential and industrial. Specifications: a. Make sure that buildings’ spaces have operable windows in each occupied room and more than one for zones occupied by larger group users. b. Increase the number of operable windows in large spaces to minimise the development of symptoms of Sick Building Syndrome (SBS) due to poor indoor air. c. Use operable windows to encourage cross-ventilation when outside air temperature is almost 5 deg C above the set indoor temperature of 20 deg C, i.e., 25 deg C, to eliminate health problems resulting from poor indoor air quality. d. Ensure adequate fresh air is provided into the indoor to eliminate the experience of symptoms such as eye, nose and throat irritations, coughing, headache, skin allergy/rash. e. Avoid making buildings fully airtight especially, schools and children care centres and with no operable windows as such buildings will eventually become unhealthy and identified ill-buildings. f. Ensure operable windows are preferably opened outwards but in certain cases inward. g. Make sure that the area of operable windows is meeting ASHRAE Standards, 62.1-2004– Paragraph. 5.1. NV. h. Guarantee that naturally ventilated buildings shall comply with ASHRAE 62.1-2004, paragraph 5.1. Technical Data: • Maximum opening angle of 30° to ensure safety especially, in high rise buildings. • Size of operable window is at least 1.00 Sq.m. • Opening could be done in comfort months (November to March) Fig.87 Different building facades with Operable windows Photos: Author 62 | P a g e Fig.88 Different opening directions of the Operable windows Image source: invisiblethreads.com invisiblethreads.com/ www.bedwellhomes.com/www.cbe.berkeley.edu www.cbe.berkeley.edu Refer to Appendix X. Criterion: Ventilation Systems and Ceiling Fans Group: Criterion No.: Indoor Environmental Quality (IEQ) 2 Statement: All spaces of new buildings shall meet the standards drawn in accordance to Indoor Air Quality and shall provide effective ffective delivery and mixing of fresh air to provide safety and comfort for, and wellbeing of buildings’ occupants occupants. In most new buildings, allll ventilation systems shall be effective and preferably include lower floor cooled air inlet instead of ceilings iinlets, and incorporate incorporat ceiling fans wherever ver appropriate. Intent: Improving indoor air quality and occupants’ satisfaction and providing sufficient natural ventilation rates during comfortable months months. In addition, decreasing indoor air pollutions and improving thermal comfort inside buildings. The floor ventilation systems will help in increasing effectiveness of air flow and its mixing and distribution. Consequently, reducing cooling load and conserving energy thus, lowering carbon emissions. Building Types: All types of buildings: public services, recreation (leisure), health, educational, and religious, as well as residential and industrial. In addition, the spaces of large areas such as ballrooms and open office spaces with low partitions. Specifications: Ventilation Systems: a. Make sure that HVAC systems and building envelop shall optimize air change effectiveness. b. Optimize Air change effectiveness using a variety of ventilation strategies including displacement ventilation, low-velocity velocity ventilation, and plug plug-flow ventilation such as under-floor under or near floor delivery. c. Check and test Air change effectiveness of the building after construction. d. Follow the recommended design approaches in ASHRAE 2001 FFundamentals undamentals Chapter 32, Space Air Diffusion. e. Ensure effective ventilation in at least 90 percent of each room or zone area in the direction of airflow for at least 95 percent of hours of occupancy in naturally ventilated spaces. f. Ensure that naturally aturally ven ventilated buildings comply with ASHRAE 62.1-2004, 2004, Para. Para 5.1. g. Apply under-floor floor air delivery system as it increases ventilation effectiveness in compliance with ASHRAE 129-1997 1997. Ceiling fans: a. Install ceiling fans in areas of large numbers of users to effect effectively ively distribute the air. b. Increase the speed when relative humidity level increased in the indoor air. c. Save up to 40 percent on electricity bill in the summer months and 10 percent in the winter ones. Technical Data: • Ceiling fans with an indoor air speed below 0.3m/s. 63 | P a g e Fig.89 Different types of ventilation systems Image source: www.applegate.co.uk/ www.ferret.com.au/ www.alliedhvac.com Fig.90 Side and under-floor ventilation systems Image source: www.construction www.construction-innovation.info/ www.buildinggreen.com/ www.gsa.gov/ www.achatrading.com Refer to Appendix X. Criterion: Indoor Air Quality (IAQ) Group: Criterion No.: Indoor Environmental Quality (IEQ) 3 Statement: All occupied spaces of new buildings uildings shall meet the standards drawn in accordance to Indoor Air Quality (IAQ) and comply with the acceptable threshold and be free from Volatile Organic Compounds (VOCs). Occupied spaces not complying with the threshold prior to building occupancy measures shall be adopted to ensure the IAQ conditions are complying with the allowable allowabl limits to remove hazardous and air pollutants substances. Intent: Reducing ing the impact of indoor finishing materials’ contaminations after construction and their VOC on air quality. Improving the air quality inside buildings consequently, minimizing m such impact on occupants’ health and enhancing their productivity and well being. Building Types: All types of buildings: public services, recreation (leisure), health, educational, and religious, as well as residential and industrial except warehouses that are not used as offices and storing goods for human consumption and medical use. Specifications: a. Ensure the IAQ for comfort and health are meeting the minimum imum requirements of ASHRAE* 62.2.2004/ Section tion 4-7, Ventilation for Acceptable IAQ or the latest edition. b. Make sure ventilation per person (Air change change/hour/person) is meeting the standard of 1-2 ACH. c. Install power vent equipment that emits VOCs and Ozone. d. Utilize effective moisture control to curb humidity and prevent mold problems. e. Avoid using hard--to-seal seal building cavity such as dropped mold plenums for air movement unless these areas are totally otally well constructed and sealed, and has non non-toxic toxic substances. f. Eliminate using artificial rtificial carpet carpets (wall-to-wall carpet) in bedrooms to reduce air contamination. g. Utilize moisture control to curb humidity and prevent mold problems. h. Install power vent eq equipment uipment to emit building up VOCs and ozone level inside building i. Provide IAQ monitoring to sustain long term occupants’ health and comfort. j. Install combustion appliances that are sealed by eco eco-friendly labels. k. Ensure permanent minimum IQA performance moni monitoring for CO2, CO, O3, NOx, and VOCs. l. Apply building control via the 3 areas of minimum airflow rates such as VAV Systems control, mixed-mode mode ventilation system, and dynamic reset of outdoor air intake flows. m. Measure the supply airflow rate and CO2 concentrations ntrations in the return air ducts, mixed air plenum, and outdoor air ducts on a continuous basis. n. Reset the minimum outdoor airflow based on the changes in occupancy or changes in zone air distribution effectiveness. o. Measure the CO2 concentration in occupy occupying zones and small spaces. p. Make sure the design minimum outdoor airflow rates are provided for a set period in advance of occupancy to compensate for the lag between increased occupancy and increased CO2 levels. q. Ensure naturally aturally ventilated buildings comply with ASHRAE 62.2, paragraph 5.1 or latest edition: edition Conduct a baseline IAQ testing prior to occupancy according to the USEPA**and UAE, if exists. Demonstrate that contaminant maximum concentrations are not exceeding the allowable limits (refer efer to technical data below). Ensure commercial ommercial building buildings (offices) that have shell and core comply with the threshold of IAQ as stated in the below technical data. 64 | P a g e Technical Data: If the results of the Indoor Air quality (IAQ) tests exceed the above threshold perform flush out to lower the contaminant levels in the building and to comply with the IAQ threshold: A. Ventilate building spaces before occupancy by supplying a total fresh air volume of 14,000cu. ft/ Sq.ft of floor area with RH 60 percent and air temperature at least 18 °C - 20°C, • A minimum two-week building flush-out with new Minimum Efficiency Reporting Value (MERV) 13 filtration media at 100 percent outside air; and • After the flush out, replace the filtration media with new MERV 13 filtration media, except the filters solely processing outside air. B. If occupancy is required prior completion, flush it out with a min. air volume of 3,500cu.ft./Sq.ft, C. Once the space is occupied ventilate the space at a minimum rate of 0.30cfm/Sq.ft. Table 11: Types of indoor contaminate and the levels of allowable air quality to offset it No. Indoor Contaminants Allowable Air Concentration Levels (EPA) 1. Carbon monoxide (CO) < 9 ppm 2. Carbon dioxide (CO2) < 800 ppm 3. Airborne mold and mildew Simultaneous indoor and outdoor readings 4. Formaldehyde < 20 µg/m3 * 5. Total VOC < 200 µg/m3 * 6. 4 phenyl cyclohexene (4-PC) < 3 µg/m3 7. Total particulates (PM) < 20 µg/m3 8. Regulated pollutants < NAAQS 9. Other pollutants < 5% of TLV-TWA VOC: Volatile Organic Compounds *Above outside air concentrations. 4-PC is an odorous contaminant constituent in carpets with styrene-butadiene-latex rubber (SBR). TLV-TWA: Threshold Limit Value - Time Weighted Average. P.S. The above levels do not account for contributions from office furniture, occupants, and occupant activity. Source: Facilities Operation Manual for EPA campus in Research Triangle Park, NC. Table 12: AQI categories that correspond to different levels of health concern (the 6 levels) Air Quality Index Values When the AQI is in this range Levels of Health concerns Air quality conditions are Colours as indicated by colours 0 to 50 Good Light 51 to 100 Moderate Light orange 101 to 150 Unhealthy for Sensitive Groups Orange 151 to 200 Unhealthy Red 201 to 300 Very Unhealthy Dark Red 301 to 500 Hazardous Maroon Source: US Environmental Protection Agency -USEPA (www.usepa.org) Each category corresponds to a different level of health concern. The six levels of health concern and what they mean are: a) Good: The AQI value for any community is between 0 and 50. Air quality is considered satisfactory, and air pollution poses little or no risk. b) Moderate: The AQI for any community is between 51 and 100. Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people. For example, people who are unusually sensitive to ozone may experience respiratory symptoms. c) Unhealthy for Sensitive Groups: When AQI values are between 101 and 150, members of sensitive groups may experience health effects. This means they are likely to be affected at lower levels than the general public. For example, people with lung disease are at greater risk from 65 | P a g e exposure to ozone, while people with either lung disease or heart disease are at greater risk from exposure to particle pollution. d) Unhealthy: everyone may begin to experience health effects when AQI values are between 151 and 200. Members of sensitive groups may experience more serious health effects. e) Very Unhealthy: AQI values between 201 and 300 trigger a health alert, meaning everyone may experience more serious health effects. f) Hazardous: AQI values over 300 trigger health warnings of emergency conditions. * ASHRAE ** USEPA American Society of Heating Refrigerant, Air-conditioning Engineers. US Environmental Protection Agency. Refer to Appendix XI. Criterion: Low-emitting (VOCs) Materials Group: Criterion No.: Indoor Environmental Quality (IEQ) 4 Statement: All finishing materials used in the interior inside new buildings shall meet the standards drawn in accordance to Low-emitting materials with less Volatile Organic Compounds (VOCs). External and internal materials should meet the allowable limits. Intent: Lowering emitting gases from finishing materials and contaminations thus, lessening indoor pollutions. Also, improving the indoor air quality and lowering the need for extra ventilation rates to offset such impact. Consequently, reducing energy consumption and minimizing the impact of VOCs on occupants’ health thus, enhancing their productivity and well-being. Building Types: All types of buildings: public services, recreation (leisure), health, educational, and religious as well as residential and industrial. Specifications: Exterior cladding and finishes a. Ensure that Low Volatile Organic Compounds (VOCs) such as adhesives, sealants, paints, tiles, glazing are applied all finishes of the exterior. Interior finishes b. Apply Low VOCs such as adhesives, sealants, paints, composite wall, carpet systems, ceramics, dry wall partitions that comply with the limits (g/L) listed in Table 13. c. Make sure that all architectural paints, coatings and primers applied to the interiors do not exceed the VOCs contents limits (Table 13). d. Make sure that anti-corrosive and anti-rusting paints applied to the interior ferrous metal do not exceed VOC contents limits listed in Table 13. e. Ensure that clear wood finishes and floors coatings do not exceed the allowable limits (Table 13). f. Guarantee all applied stains and shellacs do not exceed VOC critical Limits portrayed in Table 13. g. Utilize aerosol adhesives that has eco friendly seal standard. Removable Low-emitting materials g. Ensure installed carpets meet testing and product requirements of eco-friendly/municipal limits. h. Make sure carpet cushion installed meet testing and product requirements of GLPPl. i. Guarantee all adhesive used to glue floor carpets meet the requirements of environmental quality VOC contents limits of 50 g/L. j. Ensure composite wood and agrifibers* have non-added urea-formaldehyde resins k. Avoid products containing formaldehyde, e.g., carpet, wall panels, and cabinetry. l. Use added urea-formaldehyde resins for laminated adhesives used in fabricated on-site composite wood assemblies. Technical Data: Materials are limited to office buildings Materials applied to interiors should ensure that VOCs are meeting the allowable below limits. Table 13: Interior materials and its allowable VOCs contents limits No. Materials applied to interiors 1. Architectural paints, coatings and primers Allowable VOCs contents’ limits Gram per Litre (g/L) Flats 50 66 | P a g e Non-flat 2. 3. Anti-corrosive & anti-rusting paints applied to ferrous metal Clear wood finishes 4. 5. Floor coatings Sealers 6. Shellacs 7. Stains Varnish Lacquer Waterproofing sealers Sanding sealers All other sealers Clear Pigmented 150 250 350 550 100 250 275 200 730 550 250 Source: US Environmental Protection Agency -USEPA (www.usepa.org) *Agrifibers is a fabric that made of natural Agri-fabrics such cotton and wool used in building panels. Refer to Appendix XI Criterion: Clean Materials and Chemical Pollutions Group: Criterion No.: Indoor Environmental Quality (IEQ) 5 Statement: All spaces of new buildings shall meet the standards drawn in accordance to Indoor Air Quality and shall provide effective delivery of clean and recycled materials to reduce hazardous and pollution effect and ensure safety and well-being of building occupants. All new buildings should ensure indoor air quality prior occupancy to grantee healthy spaces. Intent: Improving Indoor air quality and occupant satisfaction in buildings spaces, and providing sufficient natural ventilation during comfortable months to lessen indoor pollutions resulting from buildings’ fabrics, consequently, improving health, conserving energy and lowering carbon emissions. Building Types: All types of buildings: public services, recreation (leisure), health, educational, and religious as well as residential and industrial. Specifications: a. Integrate products fabricated from (plants) that are harvested within 10 years cycles or shorter. b. Use materials of lesser environmental impact such as: • Supplement Cementing Materials (SCM), and • Apply Fly ashes and Silica fume as recycled materials. c. Use recycled carpet whenever possible. d. Try to use drywalls with at least 75 percent recycled content, including 10 percent or greater postconsumer content. e. Install use drywalls produced from synthetic gypsum or fly ashes instead of natural gypsum. f. Install 100 percent recycled glass tiles instead of ceramics tiles. g. Select bamboo as hard flooring finishes due to its attractiveness and sustainable alternative to conventionally harvested hardwood flooring. h. Utilize recycled paints for ceiling and walls and others finishes surfaces or use latex paint over oil based as it releases fewer toxins, and contain less petrochemicals and is easy to be disposed of. i. Avoid using Vinyl flooring due to its content of petroleum-derived plastic. j. Choose linoleum floors to eliminate indoor pollution due to its characterisation as renewable materials made of all-natural resources. k. Use absorbent materials in patios, paths, walkways, and consider laying gravel, wood ships, nutshells or salvaged materials. l. Use water or vegetable based adhesive in all materials used in interiors. m. Apply recycled material for roofs and elastomeric roof coatings. n. Minimize and control pollution entry into the building. o. Choose materials and products that ensure high levels of renewability, reusability and Select green materials that are assessed in terms of its environmental impact over its life cycle. p. Ensure all materials used in buildings are at low levels of embodied energy, i.e., energy required to extract, process, and transport; and negative effects on outdoor and indoor environments. Technical Data: • Fixed entryway systems should be at least 6.00ft long in prime direction to capture dirt/ particulates, 67 | P a g e • Exhaust each space with (-) pressure and closed doors if hazardous gases/chemicals occur, and • In mechanically ventilated buildings provide regularly occupied areas with air filtration media with a minimum efficiency reporting value (MERV) of 13 or better for both return and outside air. a. Glass tiles b. Mature coconut flooring c. Recycled aluminium tiles d. managed wood source Fig.91 Clean and renewable flooring materials to reduce waste and indoor chemical pollutions Image source: www.ecofriendlyflooring.com Criterion: Smoking and Non-smoking Zones Group: Criterion No.: Indoor Environmental Quality (IEQ) 6 Statement: All spaces in new buildings shall meet the standards drawn in accordance to non-smoking regulations and IAQ. Smoking shall be not allowed inside buildings. All smoking areas shall be separately designated with the appropriate level of ventilation. Intent: Improving indoor air quality and occupant satisfaction with work space and providing sufficient natural ventilation rate during comfortable months, lessening indoor pollution and heat gain through the building fabric to improve thermal comfort and minimizing the cooling load consequently, conserving energy and lowering Carbon emissions. Building Types: All types of buildings: public services, recreation (leisure), educational, religious, and residential and industrial. Specifications: a. b. c. d. e. f. g. h. i. j. k. l. m. Prohibit smoking inside buildings. Guarantee that all spaces in the buildings are free from smoking. Design entrances to assist in preventing smoke and dirt from entering the building. Create a buffer zone before the entrance to limit the flow of smoke inwards resulting from smokers entering the building. Ensure that designated smoking zones are not located near the entrance or near a fresh air intake (Fig.92). Locate designated room to effectively contain, capture and remove Environmental Tobacco Smoke (ETS) from the building. Minimize uncontrolled pathways for ETS transfer between buildings by sealing penetration in walls. Ensure doors leading to common hallways are weather-stripped to minimize air leakage. Develop a non-smoking policy for the building throughout the year based on its type and users. Install Tobacco smoke detectors in buildings’ spaces to eliminate smoking in all non-smoking environments and reduce hazard. Install non-smoking sign to guide the building users. Use ozone directly into ducts of ventilation systems to reduce the impact of smoke in smoking areas, if exist and to purify air supplied indoor (Fig.93.b). Install air zones and air filters to remove the solids from contaminated indoor air. Technical Data: • Exterior designated smoking area should be located 30 ft or more from entrance. • Exterior designated smoking areas should be located 30 ft from entries, air intakes and operable windows. 3 • Typical levels in public buildings where smoking is allowed should not exceed 120µg/m . • Exposure to CO concentrations from smoking should be according to WHO approved limits. 68 | P a g e Fig.92 Zones of the building that smoking areas should not be allowed: entrances, corridors, courtyards, and operable windows Image sources: google.com/casestudies.cascadiagbc.org a. Large spaces Photos 4-7: Author b. Air duct c. Rooms d. Sport halls Fig.93 Different devices to control smoking and remove odours from small, large and sport buildings’ spaces Image sources: www.air-zone.com Criterion: Noise and Acoustics Controls Group: Criterion No.: Indoor Environmental Quality (IEQ) 7 Statement: All spaces of new buildings shall meet the standards drawn in accordance to noise and acoustics controls. Air-conditioning equipment shall be selected to ensure low noise level for the outdoor and indoor sources. Indoor spaces shall be fitted with sound barriers and surfaces that contribute to less noise and better acoustical quality. Equipment shall be chosen with low vibration rates. Intent: Improving acoustical quality inside building and reduce noise level from outdoor cooling equipment such as cooling towers. Improve the indoor environment quality to ensure indoor sound quality and occupant satisfaction within the work place space and providing acceptable noise level. Consequently, improve productivity and health condition. Building Types: All types of buildings: public services, recreation (leisure), educational, religious, and residential and industrial. All types of spaces in buildings with large spaces such ballrooms, exhibition halls and office space with low partitions. Specifications: Acoustics: Indoor Sound Sources: Fan and mechanical equipment noise and vibration a. Oppress noise always at the source. b. Control the path of airborne and structural born noise. c. Ensure that boilers and chillers in buildings have very low vibration and local building environments are free from noise and vibrations associated with such equipment. d. Ensure that noise level inside building spaces are kept below 50 dB. e. Make sure that distraction is not increased in buildings by eliminating the presence of too much high-frequency sound relative to low-frequency sound. f. Allow for high-frequency sound in spaces as it helps well in masking speeches. g. Make sure there is a balance between low-frequency and high-frequency to guarantee satisfaction. h. Ensure that sound travel through and noise creates from equipment: fans, pumps, chillers, compressors, vacuum pumps; and duct system airflow; and pipes system noise flow are kept at the minimum level. i. Apply sound barrier (landscaping) and street absorbers. j. Eliminate noise and vibration sound generated from cooling equipment k. Use sound insulation (noise barrier) inside building and between spaces l. Efficient Insulation for rooms with high noise levels. m. Apply wall liners in sport facilities to reduce the reflection of sound through surfaces (Fig.94). n. Specify acoustical ceilings with noise reduction coefficient (NRC) of 0.75 in open office spaces. o. Choose systems furniture with sound absorbing surfaces on both sides. p. Avoid placing lighting fixtures directly over partitions as sound reflects to adjacent cubicle. 69 | P a g e q. Locate copy machines in separate rooms away from offices and provide separate ventilation to minimize ozone in the workspace. r. Ensure that Sound masking is utilized to reduce the interference from distracting office sounds and render speech from co-workers virtually unintelligible by introducing unobtrusive background sounds into the office environment. s. Ensure that doors are not located adjacent to each other or have doors directly across from each other to reduce noise from adjoining classrooms, conference rooms and private offices. Fig.94 Acoustical control of air conditioning equipment and ventilation systems Image source: www.acoustical.co.uk/ www.applegate.co.uk Fig.95 Ceiling acoustical control panels and building roofs Image source: www.itopwww.epfl.ch/ www.power-master.co.uk/ www.igra-world.com Outdoor Sound Sources: Cooling towers, Direct expansion and Condensing units, Dry coolers, and Exhaust fans. a. HVAC systems should be specified to have an ambient sound level compatible with the occupancy. b. Avoid through-the-wall air return louvers that draw air from one room through another in private offices, conference rooms, and other rooms where confidential discussions are expected to occur. All air returns should be ducted. c. Do not locate air supply or return registers close to each other on opposite sides of a partition wall. Doing so will cause sound to pass directly from one room to another, negating the acoustical value of the partition. d. Specify quiet HVAC equipment. Though the price may be somewhat higher, the alternative of using standard equipment may lead to costly and disruptive remediation. e. Ensure fan noise (cooling towers) is controlled by using larger units with slower fan speeds. f. Install more efficient and quit motors with variable speed controls. g. Control water noise via interrupting the path of noise from the tower by using barriers and silencers. Alternatively, reduce the height of which the water falls or travels and make it fall on smooth surfaces. h. Select low-noise fans and use duct silencers to effectively reduce the noise level. i. Use larger slower moving fans in dry coolers to reduce noise level. j. Ensure that compressors are enclosed in sound sealed compartment or wrapped in a sound sealed barrier of composite materials to reduce the source of noises. k. Install green roofs near noisy source can reduce sound reflection by up to 3 dB and improve sound insulation by up to 8 dB. Safety & Fire protection a. Spray fire protection such as ENVIROSPRAY 300 on absorber for the acoustic treatment. It is excellent reverberation control, high thermal ratings, condensation and vapour barriers and high transmission loss walls. 70 | P a g e b. Refrain using fire suppression systems containing ozone-depleting substances: CFCs, HCFCs and Halon c. Ensure fire exits are not obstructed d. Apply indoor materials with less toxic fumes Technical Data: • Compressors should be kept at lower frequency bands of 31.5, 63 and 125 Hz. • Lower fan tip speeds to reduce noise level. • Use variable speed drives in fans instead of inlet guide vanes or volume dampers to reduce noise by 10 dB. • The Use of VFD on cooling towers can reduce the noise level by 6 dB. • Locating a sound source near reflective surfaces result in adverse increase in the effective sound level of the equipment. • Keep sound sources a minimum of 10ft from walls • Using thermal storage systems can lead to reduction in noise level due to shut down of cooling towers and associated condensers pumps from peak time 9.00am - 5.00pm. • Follow recommended background noise reduction design criteria for typical occupancies in Architectural Graphic Standards. For example, in office buildings: Small conference rooms NC 30-35 Small private offices, libraries NC 30-35 General offices NC 35-40 Computer rooms NC 40-50 • Specify low reverberation times (0.6-0.8 seconds) for office areas with exposed ceiling structure, to minimize echoing and unwanted sound reinforcement. • Ensure a cork layer is installed underneath the carpet to absorb overhead sound resulting from footfall noise. • Follow the ANSI S12.60-2002, Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools. • Ensure that noise level inside religious facilities, classrooms/lecture halls, office spaces and conference rooms, theatres and public buildings such as in court rooms, libraries; broadcast studios and Sports arenas are meeting the requirement of sound level. 71 | P a g e Criterion: Water Tanks (shading and insulations) Group: Criterion No.: Indoor Environmental Quality (IEQ) 8 Statement: All water tanks located on the building’s roof shall meet the standards drawn in accordance in to IAQ, water safety and health. Water tanks shall be shaded and insulated to protect the inside water temperature from increasing above 35ºC and avoiding the growth of legionary disease transmitted through water vapour in bathroom and showers. Intent: Preventing the development of water born legionalla in water tanks and lessening the spread of legionary diseases inside bathrooms and hygiene areas. Also, improving indoor air quality and occupant satisfaction with work space, and lessening indoor pollution hence, providing health buildings. Consequently, lowering reported medical cases and enhance well-being. Building Types: All types of buildings: public services, recreation (leisure), health, educational, religious, and residential as well as industrial. Specifications: a. Make sure that water tanks installed above the building’s roof is properly insulated. b. Install water tanks with high thermal capacity to protect water from excessive solar radiation and heating in summer. c. Ensure these water tanks are located in areas where it receives less sun to avoid the increase in water temperature above 50ºC. d. Provide shading to all sides of the water tanks installed on the building’s roof to minimise heating of water. e. Reduce the danger of Legionellosis that thrives at the lower heated water ranges of 37ºC. f. Ensure that the water temperatures are revised to cater for ASHRAE prudent recommendations for the hot-water supply temperature to be 40ºC – 49ºC. g. Protect against possible Legionellosis can be achieved by generating hot-water centrally (in a wellinsulated heater/storage tank) at 60ºC then mixing to lower temperature through mixing valve. h. Prevent building up of legionellosis in the water by regular monitoring. i. Ensure that water tanks used to supply water for air-conditioning systems are properly checked and maintained. j. Conduct tests and take samples of water in Ac systems to ensure that the water is safe and clean. k. Conduct random measurements inside bathrooms and shower to ensure these areas are free from legionella*. l. Avoid the use of natural rubbers, wood, and some plastics as these materials support the amplification of Legionella, while other materials, such as copper, inhibit their growth. 72 | P a g e * Legionella is water borne and can be aerosolized. They may survive as long as 139 days at room temperature in distilled water and for more than a year in tap water. Fig.96 Legionellosis that infects water in storage tanks and through shower heads by the bacterium Legionella Pneumophila Images’ Sources: www.lenntech.com/ www.imclive.com/ www.plumbingengineer.com/ www.flow-clean.co.uk/ www.tomher.com.my Technical Data: • Sources that amplifiers and disseminator legionella are Cooling Towers Evaporative Condensers Domestic Hot Water Systems Spas & Whirlpools Humidifiers Decorative Fountains Reservoir Misters in supermarkets Portable Cooling Units with stagnant water Faucets and showerheads • The water temperature should approaches 131 deg F so that it starts to kill the organism. • The bacteria should be prevented from growing in cooling tower water or in domestic hot water systems, specifically those systems set at a tepid water temperature range. High temperatures, greater than 131 F, can be used to control the bacteria. • Follow ASHRAE Guideline 12 - Minimizing the Risk of Legionellosis Associated with Building Water Systems including: Hot water should be stored at temperatures of 67 deg C (120 deg F), or above. Elevated holding tanks for hot and cold water should be inspected and cleaned annually. Copper silver ionization should be used for high-risk applications such as hospitals. In high-risk applications, showerheads and faucet aerators should be removed monthly to clean out sediment and scale and to clean them in chlorine bleach. Emergency shower and eyewash stations should be flushed at least monthly. During the release of fire water during a fire emergency it is assumed that fire department personnel will be wearing protective respiratory equipment and that non-fire fighting personnel will exit the burning area. Appropriate precautions should be taken when testing the fire protection system. High temperature flushing or chlorination is recommended. • Avoid environmental conditions which promote the growth of Legionella are: Water temperatures between 20 to 50 deg C (68 to 122 deg F). Optimal growth occurs at temperatures between 35 to 46 deg C (95 to 115 deg F). Stagnant water. A pH range of 2.0 to 8.5. Sediment in water which supports the growth of supporting microbiota. Microbiota including algae, protozoa and others. The presence of L-cysteine-HCL and iron salts. 73 | P a g e Fig.97 Range of water temperatures that enable the legionella to grow or die Image source: www.engr.psu.edu Links: www.bbc.co.uk/dna/hub/A882371 and www.stl-inc.com Group VI: Site Heat Island Mandatory: 1. 2. 3. High Reflective Roofs (Cool Roofs) Site’s Materials Configuration High Emissivity Materials for Pavements Optional: 4. Roof Shapes (Schools) 5. Green Roofs To ensure sustainability of the site Heat Island applied techniques on the site fabric and in and around buildings, many issues ought to be considered and judged. For example, cool roof of the building should take into account the following factors: a. b. c. d. e. f. Coating material Color and brightness of covering Reflecting index High emissivity of applied materials Shape and slope direction of roof Type of roof plantation As the Heat Island Impact is a phenomenon that contributes to the rise in air temperature above urban areas, major element mainly, the materials covering the roof shall be replaced by reflective to ensure surface temperature is kept cooler, thus air temperature. The choice of roof coating, greening the building roof and site pavements mean the energy consumption will be less due to the selection of roof upper coating and colour of the materials covering ground will depend on many factors including building type, local climate, utility rates, and building size. Also, less air pollution, reducing AC cooling loads; saving energy, improving air and water quality, decreasing storm water runoff; and minimize noise. In the selection of the above factors, four key indicators must be taken into account: 74 | P a g e • Surface temperature reduction, • Urban air temperature reduction, • Saving targets, and • Carbon emissions. The next part will highlight the Green Building Guidelines for Group 6, Site Heat Island, which is part of the short listed elements. These include 5 elements: 3 are mandatory; and 2 optional. Criterion: High Reflective Roofs (Cool Roofs) Group: Guideline No.: Site Heat Island 1 Statement: All roofs of new buildings shall meet the standards drawn in accordance to Heat Island Effect. All covering and finishes’ materials shall have High Albedo Reflectance characteristics, i.e., bright and white colour with Solar Reflectance Index (SRI) of at least 0.80 preferably, 0.90 with high emittance value from 0.85 - 0.90. Intent: Controlling the overall heat gain through the building roof surface area, and in-turn, lowering temperature of the air passing over these surfaces resulting in a decrease in the overall temperature of the area, known as "Heat Island Effect." Also, reducing peak cooling demands and consequently, saving energy and lowering Carbon emissions. Building Types: All types of air-conditioned spaces in buildings: public services, recreation (leisure), educational, religious, and residential as well as industrial (factories and warehouses). Specifications: a. Cool roofs are typically white and have a smooth texture (minimum surface emissivity of 0.90). b. Asphalt roofs with a cap sheet and modified bitumen roofs should be coated with a material having an initial reflectance greater than ≥ 0.7 and an emittance ≥ 0.8. c. Use high Albedo that constitutes at least 75 percent of the total roof area. b. Use ENERGY STAR® compliant of highly reflective and high emissivity roofing (emissivity at least 0.90 when tested in accordance with ASTM 408 for a minimum of 75 percent of roof surface. c. Apply cool roof with concrete, specifically white cement tiles, with an SRI of 90 percent (0.90). d. Use new concrete made with White Portland Cement (WPC) has an SRI of 86 percent (0.86). e. Install white reflective roof membrane such as white acrylic paint to reduce solar heat gain. f. Black non-metallic surface i.e., black acrylic paint that has an Emittance ≥ 0.9 shall not be used. g. Black and dark colour asphalt shingles should not be used on roofs due its’ low SRI. h. Eliminate opaque non-metallic materials on roofs that have an emittance 0.75 - 0.95. i. Use roof materials that emit the majority of received heat and have an emissivity of 0.96. j. In case the roof is fully or most of its areas covered with PV cells that provide shades the cool roof coating may not be required. k. Ensure that largest exposed roof areas of villas are coated with cool membrane and preferably all, if possible. l. Apply White Acrylic paint at SR 0.8, emittance 0.9 and SRI 100. Refer to tables and Appendix XII. 75 | P a g e Fig.97 Images of Heat Island Effect in dense urban areas Image source: www.lbnl.org Fig.98 Cool roof membrane applied to building’s roof for reducing surface temperatures & offsetting Heat Island Effect Photos: Authors Technical Data: • For roofing products that qualify as cool roofs, it fall in the following categories: Single-ply and liquid-applied includes: 1) White PVC (polyvinyl chloride), 2) White CPE (chlorinated polyethylene), 3) White CPSE (chlorosulfonated polyethylene, e.g. Hypalon), and 4) White TPO (thermoplastic polyolefin). Liquid-applied products may be used to coat asphalt cap sheets, modified bitumen, and other substrates. Products include: 1) White elastomeric coatings; 2) White polyurethane coatings; 3) White acrylic coatings; and 4) White paint (on metal or concrete). Combinations of high Albedo and vegetated roof can be used providing they collectively cover 75% of the roof area. Table 14: Solar Reflectance and Emittance of Different Roofing Materials Coatings Material Total Solar Reflectance 0.71 0.73 0.65 0.30 - 0.55 0.54 Emittance Reflective Coatings Elastomeric coating over asphalt shingle Aged elastomeric on plywood Elastomeric coating on shingle Aluminium pigmented roof coating Lo-mit on asphalt shingle White Metal Roofing Siliconized white 0.59 0.85 Single-Ply Membrane Black EPDM Grey EPDM White EPDM White T-EPDM 0.86 0.23 0.69 0.81 0.86 0.87 0.87 0.92 Paint White Aluminium paint 0.85 0.80 0.96 0.40 Asphalt Shingles Black Dark brown Medium brown Light brown Green Grey Light grey 0.03 - 0.05 0.08 - 0.10 0.12 0.19 - 0.20 0.16 - 0.19 0.08 - 0.12 0.18 - 0.22 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.86 0.89 0.42 - 0.67 0.42 76 | P a g e White 0.21 - 0.31 0.91 Note: Shaded products all have a reflectivity greater than 0.70 and an emittance greater than 0.80. Source: Berdahl and Bretz 1995, Akbari 1990, Parker et al. 1993, LBNL Cool Roofing Materials Database Refer to Table 1 and Appendix XII. Criterion: Site’s Material Configuration Group: Criterion No.: Site Heat Island 2 Statement: All site materials shall be selected and arranged to meet the standards drawn in accordance to Heat Island Effect. All covering and finishes materials applied to the site of new buildings shall have High Albedo Reflectance characteristics i.e., bright colour with Solar Reflectance Index (SRI) at least 0.80 preferably, 0.90 with high emittance value from 0.85- 0.90. Intent: Controlling overall heat gain through pavements and hard landscape of the site of new buildings. In-turn, lowering temperature of the air passing over these surfaces resulting in a decrease in the overall temperature of the air and surfaces of these areas, known as "Heat Island Effect." Also, reducing peak demands and consequently, saving energy and lowering Carbon emissions. Building Types: All types of buildings: public services, leisure, educational, religious, residential and industrial. Specifications: a. Ensure that site’s Urban Fabric (SUF) including roofs (light and dark), site pavements configuration (parking, roads and sidewalks, and vegetations and water landscape, is organised to lower their surface temperature. b. Grantee that driveways, access lanes, parking areas, and streets are made of concrete pavers to reduce the impact of surface temperature and air temperature on forming the Heat Island. c. Warrant that site surrounding the building are typically made of light/bright colours and have smooth and semi-smooth textures (minimum surface emissivity of 0.90). d. Use materials that have high Albedo and constitute at least 75 percent of the total site area. e. Eliminate standing water on the site pavement and for proper drainage, by applying a slope on the driveway towards the street at a minimum of 1percent or 1/8 in. per foot. f. Ensure concrete’s higher (brighter) reflectance is used for pavements of the site to lower infrastructure and ongoing lighting costs, while boosting safety for vehicles and pedestrians. Concrete parking areas require fewer lighting fixtures than other surfaces hence, less energy. g. Guarantee Asphalt applied to parking areas on sit is made from bright concrete materials or modified bitumen that is coated with a material of initial reflectance ≥ 0.7 and emittance ≥ 0.8. h. Make sure black/dark colour asphalt materials are not used on site’s pavements due low SRI. i. Use concrete tiles on site, specifically white cement tiles, with an SRI of 90 percent (0.90). j. Apply new concrete made with White Portland Cement and has an SRI of 86 percent (0.86). k. Ensure pavement materials emit the majority of received heat and have an emissivity of 0.96. 77 | P a g e l. Specify concrete mixes for pavement pavements using Fly Ash or Slag as a percent of the cement reduction and exploiting recycled aggregates from crushed concrete to change the properties of the mix design compared to a conventi conventional mix. Technical Data: • Apply light concrete including recycled aggregates with the following reference: Specify concrete with an emissivity of 0.90 when tested for ASTM 408 and an initial reflectance of at least 0.25 when tested for ASTM E903. Fig.99 Elements of the urban fabric fabrics to assist in reducing the Heat Island Effect Fig.100 Bright coloured surfaces to help in lowering the Heat Island Effect in urban areas Images source: www.concretethinker.com Criterion: Bright (Light) Colour Material for Pavements Group: Site Heat Island Criterion No.: 3 Statement: All pavements on the new building’s site including plazas, sidewalks, courtyards, alleys, and shoulders, etc, within the plot as well as hard landscape areas shall be bright (light) colour with high Albedo i.e., Solar Reflectance from 0.75 to 0.95. Intent: Controlling the overall heat gain through the pavement and hard landscape of the site of new buildings. In-turn, lowering temperature of the air passing over these surfaces resulting in a decrease in the overall temperature of the air and surfaces of these areas, area known as "Heat Island Effect." Also, reducing ing peak cooling demands and consequently, saving energy and lowering Carbon emissions. Building Types: All types of air-conditioned conditioned spaces in buildings: public services, recreation recreati (leisure), health, educational, religious, and residential as well as industrial (factories and warehouses). Specifications: a. Apply light-coloured/high coloured/high-Albedo Albedo materials (reflectance of at least 0.3) and/or open grid pavement for at least 75 percent of the site’s non-roof roof impervious surfaces including parking lots, walkways, Plazas, etc. b. Ensure half or more of parking spaces is underground or covered by structured parking; c. Use an open-grid grid pavement system (less than 50 percent impervious) for f a minimum of 50 percent of the parking lot area. d. Apply bright concrete oncrete masonry units units, i.e., pavers, concrete pavers, paving stones, paving block, and brick pavers to pave driveways, access lanes, parking areas, streets, plazas, walks, patios, swimming pool decks, floors floors-on-grade, and other flat surfaces. e. Select bright/light ight colo coloured or porous concrete pavers to fully reflect the radiation of solar heat helping in reducing ing the urban Heat Island Effect. f. Choose interlocking pavers and paving materials that can have a great effect on ambient air temperature in urban areas compared to suburban or rural areas hence, reduce the impact on Heat Island Effect.. 78 | P a g e g. Use light coloured concrete paving to effectively lower the ambient air temperature thus, decrease the energy required for cooling buildings. Technical Data: • Apply light coloured material for pavements using the following reference: White colour Materials of SRI of 90. Paige colour materials of SRI of 80. Light yellow or gray materials of SRI of 75. Consider specifying 70 percent to 90percent of recycled coarse aggregate and 5 to 15 percent for fine aggregate for cement pavement. The largest paver size shall be 6-1/2 inch wide, 9-1/2 inch long and 5-1/2 inch thick. Nonetheless, it can be much smaller. The compressive strength of pavers shall be at least 8000 psi. Fig.101 Light colour paving materials to reduce surrounding air temperature and offset Heat Island Effect Image sources: www.concretethinker.com Refer to Appendix XIII. Criterion: Sloped/Cascaded (Staggered) Roofs Group: Guideline No.: Site Heat Island 4 Statement: All building roofs shall meet the standards drawn in accordance to lowering the impact of Heat Island phenomenon on rising air temperature in urban areas and shall be at a slope angle of 45° or above with the lowest point of the roof plane facing North; highest roof plane facing the south. Intent: Lessening the direct heat gain caused by the direct (short) wave solar radiation through the roof surfaces and reducing cooling load peak demands to eliminate the rise in air temperature, known as “Heat Island Effect”; consequently, saving energy and lowering Carbon emissions. Building Types: All types of air-conditioned spaces in buildings: public services, recreation (leisure), educational, religious, and residential as well as industrial (factories and warehouses). Specifications: a. Ensure that building roofs are inclined or cascaded enough in the right direction (North) to reduce the direct solar radiation impinging on the building’s roof. b. Grantee that the roof would receive the lowest solar radiation rate and heat compared to the roof being horizontal. c. In case chillers, cooling towers, AHUs and piping’s, and other MEP services to be installed on the building’s roof, guarantee the sloped roof should be on surface area that free from services, i.e., Total Roof Area – Total Services Areas = Net sloped Areas. d. In case building services are provided by district cooling plants make sure the building roof is complying with sloped or cascaded regulations. e. In case the building roof is totally shaded (e.g., by pergola or screening shading) apply no slope for the roof. f. If the roof is composed of multiple layers (roof slab is at different heights), make sure the largest area of the roof should be sloped facing North-South, and the rest could be if possible. Technical Data: 79 | P a g e • To ensure receiving less short-wave radiation, i.e., direst heat on the roof, the slope should be in accordance to the following inclinations: The slope of the roof shall be above 45° and up to 60° or more for high-rise multi-storey buildings such as public offices, hospitals, and residential. The slope shall be 25° and up to 45° for low-rise buildings such as exhibitions, universities and schools, sport facilities, and villas. For deeper low-rise buildings, the slope shall be carried out and done in intervals every 5 meters to allow for daylighting and minimize the solar heat gain during peak solar time and reduce the surface temperature hence, the rising in air temperature near the roof. a) Water Purification Facility, USA c) Cascaded roof facing N-S b) Care Facility in LV in USA d) Slope facing N/E-W e) Sloped facing N/E-W Fig.102 Examples of buildings with sloped roofs in the USA and Dubai, UAE Photo credit a: Paul Warchol and b: Tom Bonner (Source: www.aia.org) and Photo credit c, d, e: Authors Refer to Appendix IVX. Criterion: Green Roofs Group: Guideline no.: Site Heat Island 5 Statement: All roofs of new buildings shall meet the standards drawn in accordance to Heat Island Effect. Roof covering shall include plantation (green) cover to reduce surface temperature, cooling loads, and using recycled water from buildings for irrigation. Intent: Controlling the overall heat gain through the building roof surface area; in-turn, lowering temperature of the air passing over these surfaces resulting in a decrease in the overall temperature of the roof area, known as a "Heat Island Effect." Green Roofs improve air quality by absorbing air pollution, collecting airborne particulates, and storing carbon. Also, lower roof’s surface temperature, reduce storm water runoff and noise transmission, and reducing the peak cooling demands for HVAC, consequently saving energy and lowering Carbon emissions. Building Types: All types of air-conditioned spaces in buildings: public services, recreation (leisure) and health, educational, religious, and residential except warehouses (industrial). Specifications: a. Use green plantation on the building’s top Roof to provide shade/shading and protect it from direct heat gain and cool the atmosphere around these roofs by evapotranspiration process, hence significantly reduce the urban heat island effect. b. Apply green roofs to improve water quality in two ways: a) by capturing, breaking down and detoxifying pollutants found in rainwater such as, nitrogen and phosphorus. This is achieved by the root systems' bacteria and fungi, which utilize the natural filtering processes of bioremediation and Phyto-remediation; and b) by acting as a sponge that captures storm water and slowly releases it over time. This reduces storm water flow that holds organic materials, chemical pollutants. c. Ensure roofing membrane is used as a critical waterproofing layer under a green roof. 80 | P a g e d. Apply a unique, root-resistant compound to prevent plant roots from penetrating beneath this waterproofing membrane. e. Install a drainage layer to grantee that excess moisture is drawn away from the roofing membrane. f. Guarantee a filter layer is included to prevent soil from clogging the drainage system, i.e., placed between the base membrane and a layer of soil while enabling water to penetrate and support the plant life. g. Apply lightweight: formulated soil to absorb and retain water in a controlled manner and to nourish the plant life h. Customize a surface layer of plant life is to meet specific functional and aesthetic requirements of individual applications. i. Install a vapour barrier or vapour retarder over the deck depending on occupancy and local conditions. j. Ensure water and root-repellent membranes are installed on top of a reinforced roof structure. k. Grantee that a soil layer is seeded with varieties of simple durable plants-sedums. l. Use green roofs to reduce sound reflection by up to 3 dB and improve sound insulation by up to 8 dB. Technical Data: • Green roofs generally include the following components: Waterproof membrane Root barrier Thermal insulation media Drainage system Filter layer Growing medium • Living plant material: 50 percent green roof or a combination of green roof and high SRI roofing materials. • Types of green roofs includes: 1. Extensive*: are shallow (less than 6"), unirrigated, light-weight roof covers offer low cost and maintenance with high performance value. These are typically planted with sedums - low drought tolerant ground covers that thrive in a shallow, rapidly draining growth media and are resistant to harsh rooftop conditions. 2. Intensive**: it is made with deep soil (greater than 6") and greater organic content to support broad variety of plant varieties. Design variations are practically limitless. Possibilities are only limited by overall weight of the system and its effect on the cost of the supporting construction. 3. Semi-intensive: It includes features of intensive and extensive green roofs. 4. Modular: it is partially congregated off-site and installed in units. It also features plastic or metal trays that are filled with growing medium and placed on the rooftop. Plants can be grown in these trays before or after installation. 5. Integrated: it is installed as a series of layers. 6. Flat: It allows for the construction of the simplest and less cost. The flat roof is never perfectly flat – enough pitch is required to facilitate positive drainage. 7. Sloped: it is only up to 45degree. • Green roof should take into consideration the following: a. Module’s size is Standard: 2x4 ft, 2ft.x2ft.x2.5in or 2ft.x2ft.x4in. 2ft.x4ft. b. Depth of modules is either as 2.5 in., 4 in., and 8 in. c. Weight of planted modules (fully saturated) do not exceed the following: i) 2 in. depth – 1113 pounds per sq. ft. (wet); ii) 4 in. depth – 18-22 pounds per sq. ft. (wet); and iii) 8 in. depth – 35+ pounds per sq. ft. (wet). d. Filter layer is a thin sheet starting from 1.2 inch thick. e. Module drainage clearance above the roof should be 0.5 inch. f. Roof membrane or any other roofing materials, as an acceptable underlying material. Modules can be placed directly on membrane or other roof materials. g. Black polystyrene tubing, as a drip irrigation system should not require for 4 in. depth modules but needed for 8 in. depth modules, based on climate & plant. h. Paver weight is 7.5 lbs./sq.ft or less. 81 | P a g e * Extensive green roofs are generally not accessible to the public. **Intensive green roofs are generally accessible to the public. Plant (vegetation) Growing medium Filter membrane Drainage layer Water proofing/root repellent layer Support panel Thermal protection layer Vapour control layer Structure support Fig.103 An image and a sketch of a green roof structure and the required layers Source: National Research Council, Institute for Research in Construction a. Extensive b. Intensive Fig.104 Types of green roofs c. Modular Image sources: www.igra-world.com / www.mngreenroofs.org/ www.furbishco.com Fig.105 Different types of green roofs Images source: www.furbishco.com Comparision of green roofs loads and those of conventional roofs (weight Kg/m2) Minimum Maximum 600 500 500 220 150 160 150 90 Gravel Surface 200 60 Paving Slabs Vehicle Surface Extensive Intensive Green Roof Green Roof 82 | P a g e Fig.106 Green roofs’ minimum and maximum structural loads ads Data source: www.ecoroofsystems.com Table 15: Green Roof performance Indicators Item Frequency Maintenance Low Periodically High Irrigation No Periodically Regularly Plant communities Moss-Sedum-Herbs and Grasses Grass-Herbs and Shrubs Lawn or Perennials, Shrubs and Trees System build-up height 60 - 200 mm 120 - 250 mm 150 - 400 mm on underground garages> 1000 mm Weight 60 - 150 kg/m 13 -30 lb/sq.ft 120 - 200 kg/m 25 - 40 lb/sq.ft Costs Low Middle Use Ecological protection layer Designed Green 2 2 2 180 - 500 kg/m 35 - 100 lb/sq.ft High Data source: www.buildinggreen.com /www.ecoroofsystems.com 83 | P a g e Appendices I-IVX (1-14) 84 | P a g e Appendix I: Grouping of Green Building Criteria: short listing Analysis No. Stakeholders’ Barriers 1. Regulatory Evaluation Criteria • • • • • Is it technically easy to be monitored? Does it require many processes for inspection? Does it incur major cost to carry out the monitoring process? Will it help in achieving their vision and mission? Does it add value and benefit them in their activity? 2. Developers • • • • • • • • • Is easy to be understood? Is it technically easy to be adopted? Does it incur extra Initial cost? Does it benefit them in reducing the operating cost? Will it increase the project’s duration? Will it benefit them in improving the life-cycle costing? Will it add value and improve the quality of their project? Will it add market value and increase sales? Will it help in achieving their mission? 3. Design Team: Architects, Consultant, Engineers, MEP, Lighting Designers, and Interior Designers • • • • • • • • Is it technically easy to be understood? Is it available? Does it require an education or a training program? Does it need many specifications to be written? Will it benefit them in producing efficient design for their project? Will it improve the life-cycle costing and quality of their project? Will it add market value to their design project? Will it add value to their profile? 4. Contractors • • • • • • • • Is it available locally? Is it technically easy to be understood? Does it require an education or a training program? Is it easy to be incorporated and built? Does it require many tests? Does it need many labors staff in construction hence, extra cost? Will it benefit them in producing better projects? Will it add value to their profile? 5. Suppliers • • • • • • • • • Is it available locally? Is it technically easy to be understood? Is it easy to be assembled or manufactured? Does it need many processes in production hence, extra cost? Does it require many tests? Is it easy to be marketed and saleable? Does it require an education or a training program? Will it benefit them in being part of completing better projects? Will it add value to their profile? 6. Facilities Managers (FM) • • • • • • • Is it technically easy to be understood? Is it easy to be operated and maintained? Does it require an education or a training program? Does it need many labors staff and processes in maintenance hence, extra cost? Does it save energy and money? Will it benefit them in offering efficient projects? Will it add value to their facility and profile? 7. End Users • • • • • Is it easy to be understood and used? Is it easy to be maintained? Does it require an awareness or education program? Does it save money? Will it improve their well being? • Will it add value to their living standards? 85 | P a g e Appendix II: Glazing — SHGC, SC and LSG Introduction Glazing Performance In the summer, Low-E glass allow in VL while blocking infrared and ultraviolet solar energy that drives up cooling costs and damages curtains, window treatments, carpeting and furnishings. The solar heat transmittance of a window is measured by the solar heat gain coefficient, SHGC or SHGF. This is the fraction of incident solar radiation that enters the building as heat gain by all mechanisms. Also, the fraction of sunlight, skylight, and reflected daylight incident on a window that enters as light is measured by the visible transmittance. Hot-climate glazing’s’ systems are normally are intended to make the window pane high in VT while low in SHGC. The ratio of these two performance indicators is called the light-to-solar-gain ratio, or LSG. In general, the higher the LSG, the better the hot climate performance, with the emphasis being on lowering the SHGC value. LSG numbers greater than 1.0 should be chosen, and those exceeding 1.5 offers the best protection from the heating rays of the sun while still providing good views of the outdoors and letting in plenty of daylight. Fig.1 Glazing Performance in hot climate Typical SHGF values for representative window types* are: • • • • • • Single-pane, metal frame, clear glass .75 Double-pane, metal frame, clear glass .66 Double-pane, metal frame, bronze tint .55 Double-pane, wood-vinyl frame, clear glass .55 Double-pane, metal frame, low solar gain low-e coating .37 Double-pane, wood-vinyl frame, low-solar-gain low-e coating .31 The LSG value is seldom published by manufacturers, nor does it appear directly on window energy labels. To calculate, divide the visible transmittance of the glazing plus frame by its solar heat gain coefficient. If a window manufacturer does not publish SHGC values, but instead the older shading coefficient, SC, the results usually will be little different if SHGC is replaced by SC in the above formula. There is a caution in this, however. The NFRC values for both the VT and the SHGC apply to the whole window, including opaque framing elements. It is an area-weighted sum of the transmittances of all parts of the window, including glass, opaque frame, and semi-opaque parts. Thus, the visible transmittance value used in calculating the LSG above should be the NFRC standard one (for the whole window). When using SC in the denominator of the LSG equation, however, the numerator should contain the visible transmittance of the glass only. High-LSG glass provides the best energy and comfort performance in hot climate such as in Florida or the equivalent in Dubai. The extra initial cost for such glass can often be counterbalance by smaller air-conditioning equipment (reduced peak load) and lower monthly electric bills hence, reduced average energy use. Since high-LSG glass is most often offered only in double pane models, the extra benefits of double pane windows are a bonus. The indoor solar gain could always be reduced still further by lowering VT, while keeping LSG the same. This should not be overdone. A VT below about 0.3 to 0.35 would VT look somewhat extreme. The equation that governs the LSG is expressed below: LSG = VT / SHGC Source: www.fsec.ucf.edu * ASHRAE Handbook of Fundamentals, 1997. ** refer to the two characteristics specified by the NFRC or that published by reputable window manufacturers. 86 | P a g e Fig.2 Performance Indices Fig.3 Heat Flow through Windows Source: FSEC – Florida Solar Energy Center Fig.4 Relation between SHGC and LSG Search for LSG = TV/SHGC values of 1.40 or greater Typical values for the Total Window and Center of Glass for different types of windows are shown in Table 1. 87 | P a g e Table 1: shows SHGC, VL, LSG for different types of windows Window and Glazing Types SHGC VT LSG Single-glazed, clear 0.79 (0.86) 0.69 (0.90) 0.87 (1.04) Double-glazed, clear 0.58 (0.76) 0.57 (0.81) 0.98 (1.07) Double-glazed, bronze 0.48 (0.62) 0.43 (0.61) 0.89 (0.98) Double-glazed, glazed, spectrally selective 0.31 (0.41) 0.51 (0.72) 1.65 (1.75) Double-glazed, glazed, spectrally selective 0.26 (0.32) 0.31 (0.44) 1.19 (1.38) Triple-glazed, new low-ee 0.37 (0.49) 0.48 (0.68) 1.29 (1.39) Detailing of glazing Nevertheless, factors to consider when choosing windows are: climate, building design, building orientation, and external shading. Check with manufacturers for product specifications but consider both cooling loss and solar gain. Three Thr major things needed to be addressed when selecting the window to first ensure that your building is well well-sealed sealed with a minimum of thermal bridging. These are: • Thermal bridging across the frame • Air leakage around the frame within its opening • Edge sealing between the glazing unit and the frame The proportion of glass to frame makes a difference as the framing is often a worse (higher U value) than the glass. Warm edge edg spacer technology is a marginal help but worth considering. The bigger the window the less significant the spacer bar conductivity is. Fig.5 Low Low-E coating and thermal bridges The cause for this might be the following: 1. Complete or partial penetration of materials with different coefficients of thermal conductivity in the external construction construct 2. Different thickness of the material 3. Places of connection between two or three external constructions, or connection bet between ween external and internal construction: wall, floor, and ceiling. 88 | P a g e The influence of the thermal bridge to the rest of the compact part of the construction, according to ISO standards, extends along the construction up to 1000mm. After this, there is no heat exchange between the two neighbouring parts in the construction. The negative influence of the thermal bridge consists of increased thermal flow through it (this is not so terrible, because the loss can be compensated by decreasing the thermal flow in other parts of the construction). However, a great danger exists when the thermal bridge decreases the internal surface temperature under the point of bedewing, which causes internal condensation and formation of mould. From the above stated facts, an analysis of thermal bridges is needed for building in Dubai, regarding the intensity of thermal flows, and above all, regarding the risk of internal condensation. U-value The U-value of a glazing unit varies across its area. The centre of the unit will perform best with the lowest U-value whereas the perimeter will perform less well due to the conductivity of the spacer units. There is as yet no standard by which U-values are presented within the industry. Typical available U-values: • Single-glazing 5.0 • Double – glazing 3.0 • Triple-glazing 2.2 • Double-glazing with low-e coating 1.7 • Double-glazing with low-e coating and Argon filled 1.3 • Triple-glazing with multiple low-e coatings and Xenon filled 0.4 Typical U-Factor ranges for different window assemblies are: • Single glazed: U- factor (value) = 0.91 - 1.11 • Double glazed: U- Factor (Value) = 0.43 - 0.57 • Triple glazed: U-Factor (Value) = 0.15 - 0.33 Low-E glazing Low-E glazing has special coatings that reduce heat transfer through windows. The coatings are thin, almost invisible metal oxide or semiconductor films that are placed directly on one or more surfaces of glass or on plastic films between two or more panes (Heat Mirror Glass). The coatings typically face air spaces within windows and reduce heat flow between the panes of glass. When applied inside a double-glazed window, the low-e coating is placed on the outer surface of the inner pane of glass to reflect long wavelength energy (heat) back into the living space whilst permitting short wavelength solar energy (light) transmission through from the outside. This same coating will slightly reduce solar heat gain during the summer season. Types of Low-E glazing There are two types of Low-E (low emissivity) glass available a. Pyrolytic (hard coat) Pyrolytic (hard coat) is considered to be a medium performer, and sputtered (vacuum deposition or soft coat) is considered to be the highest performer. b. Soft-coat low-e films degrade Soft-coat low-e films degrade when exposed to air and moisture, are easily damaged, and have a limited shelf life, so they are carefully applied by manufacturers in insulated multiple-glazed windows. Hard low-e coatings, on the other hand, are more durable and can be used in add-on (retrofit) applications. The soft coats have low U-values but because they are so effective they also stop more short wave radiation. The hard Pyrolytic coats are more transparent to short wave radiation. The net effect is that the energy equation is about the same for both types. A new option is to use low iron glass in the outer pane to improve the g value (total solar heat transmission). Gas filling Filling the gap between the glass panes with low conductivity gas such as argon or krypton at atmospheric pressure improves the window performance by reducing conductive and convective heat transfer. They are mostly used in conjunction with lowemissivity coatings. One drawback though might be the long-term integrity of the fill. Vacuum double glazing (evacuated windows) Working much in the same way as a Thermos flask, the "fill" strategy with the lowest conductance is the use of vacuum between low-e coatings. Only a very small distance between the glass panes is necessary, but the long-term integrity of seals and the structural stability of the unit (due to pressure differences) are difficult to master in a cost-effective manner. Translucent glazing It is used to reduce the excessive daylight and eliminate glare and provide a pleasant working environment inside buildings in addition good distribution of daylight. 89 | P a g e a) Translucent glazing installed on a building facades (from outside) b) Translucent glazing from inside Fig.6 shows Translucent glazing to reduce excessive western solar heat, daylighting and glare (Aviation College-Dubai) Photo credit: Authors 90 | P a g e Appendix III: Insulation Materials Introduction The following are different insulation materials: Mineral Wool Insulations: Fiber Glass Insulations: • • • • • • • • • • Pipe Insulation (factory/specialty jacketing) Blanket/Board (faced/unfaced) Duct Wrap Pipe/Tank Wrap (ASJ/FSK) Duct Liner Duct Board Preformed Fittings Air Handling Systems High Temperature Fiberglass Textiles Polyvinyl Encapsulation Flexible Closed Cell Insulations: (flexible elastomeric thermal insulation) • • • • • • • • • • • • • Pipe Insulation Block Insulation Blanket Insulation Metal Mesh Blanket Preformed and Fabricated Fittings Bulk Fiber Precision Cut Pipe and Tank Wrap (ASJ/FSK) Refractory Fiber Block Safing Curtain Wall Acoustical Metal Deck Plugs Metal/PVC Fitting Covers: • • • • • • • Pipe Tubing (standard or pre-slit/preglued) Sheets/Rolls Fittings Tape Adhesive Coatings Anti-vibration Pads Fire Protection Systems: • • • • • • • Grease Duct/Plenum Wrap Mineral Wool Fire Safing Caulking/Putty Board/Block Composite Sheets Cable Tray Wrap/Cable Coating Restriction Collar Air Handling Systems: • • • • • • • • Duct Wrap Duct Liner Duct Board Rigid Plenum Liner • • • • • • • • • 90-45 Degree Elbow Covers Tee/Valve Covers Victaulic Fitting Covers Mechanical Line Couplings Flange Covers End Caps Specialty Fittings Colored Coded PVC Tank Tops Protective Coverings: • • • • • • • • Stainless Steel/Aluminum (smooth/corrugated/embossed) PVC Covering (cut and curled) Removable Covers (high temp. fiberglass cloth) FRP Jacketing Corrugated and Flat Sheeting Coils Fittings All Service Jacket (ASJ) High Temperature Fiberglass Textiles: Calcium Silicate Insulations: • Pipe Insulation Block Insulation (flat/scored/molded and curved radius) Fabricated Fittings Premolded Fittings • • • • • Plain, Aluminized, Vermiculite Fiberglass Cloth Silicone Coated Fiberglass Cloth Teflon Coated Fiberglass Cloth Fiberglass Tape/Rope/Tubing Fiberglass Tadpole Tape Pressure Sensitive Fiberglass Tape 91 | P a g e Urethane, Styrene, Foams: • • • • • • • • • • • • • • Cellular Glass: Preformed Pipe Insulation Board Bun Pour/Spray Froth-Paks Fittings Head Segments • • • • • Adhesives, Mastics, Coatings and Sealants • • • • • Fire-resistance Coatings Vapor Barriers Weather Barriers Finish Coatings Duct Liner Adhesive Contact Cement Silicone Caulking Preformed Pipe Insulation Block Curved Segments Head Segments Fittings Accessories and Fastening Devices: • • • • • Tapes (ASJ/FSK/PVC/foil) Metal Banding w/Wing Seals Weld Pins Stick Clips w/Speed Washers Hex Mesh and Lath (stainless steel/aluminum) Tie Wire (stainless/aluminum) Staples/Tacks Vinyl Flex Connector Vane Setter Weld-Ons Ceramic Fiber: • • • • • • • Blankets and Felts Block Bulk Fiber Rope and Brad Paper Cloth and Tape Spray Table 1: A list of different materials with the English measurement of R-value: Material R-value Hardwood siding (1 in. thick) 0.91 Wood shingles (lapped) 0.87 Brick (4 in. thick) 4.00 Concrete block (filled cores) 1.93 Fiberglass batting (3.5 in. thick) 10.90 Fiberglass batting (6 in. thick) 18.80 Fiberglass board (1 in. thick) 4.35 Cellulose fiber (1 in. thick) 3.70 Flat glass (0.125 in thick) 0.89 Insulating glass (0.25 in space) 1.54 Air space (3.5 in. thick) 1.01 Free stagnant air layer 0.17 Drywall (0.5 in. thick) 0.45 Sheathing (0.5 in. thick) 1.32 Source: Hyperphysics Georgia State University 92 | P a g e Appendix IV: Photosensors Photosensors A photo-sensor is an electronic component that detects the presence of visible light, infrared transmission (IR), and/or ultraviolet (UV) energy. Most photosensors (PS) consist of semiconductor having a property called photoconductivity, in which the electrical conductance varies depending on the intensity of radiation striking the material. The most common types of photosensors are the photodiode, the bipolar phototransistor, and the photoFET (photosensitive field-effect transistor). PS devices are essentially the same as the ordinary diode, bipolar transistor, and field-effect transistor, except that the packages have transparent windows that allow radiant energy to reach the junctions between the semiconductor materials inside. Bipolar and field-effect phototransistors provide amplification in addition to their sensing capabilities. Fig.1 Different types of photosensors Photosensors are used in a great variety of electronic devices, circuits, and systems, including: • • • • • • • • • fiber optic systems optical scanners wireless LAN automatic lighting controls machine vision systems electric eyes optical disk drives optical memory chips remote control devices Nearly all photosensors are used to decrease the electric power demand for lighting. In addition to lowering the electric power demand, dimming the lights also reduces the thermal load on a building's cooling system when the building is running its chillers, adding to the energy savings. For new building designs, the added solar heat gain that occurs when substantial amounts of daylight enters a space must be taken into account for a whole building energy usage analysis. When considering the energy savings potential from dimming fluorescent lamp luminaries, it is important to realize that fluorescent lamp systems have lower efficacy when dimmed. This loss of efficacy leads to diminished energy savings as lamps is dimmed to lower and lower levels. The figure below illustrates relative light output (dim level) as a function of power. At 20% dim level, the energy savings is approximately 60% compared to operating the lamp at full power. Ballasts that dim lamps down to less than 5% light output have a maximum energy savings of about 80% compared to full light output operation. Fig.2 Shows relative light output (dim level) as a function of power Source: www.247able.com 93 | P a g e Appendix V: Emergency Exits Lighting and Efficient Bulbs I. Efficient lighting timers In a tower with 6 flats per floor by installing 20 Watts bulbs instead of the 100 watts bulbs and using the less capacity wiring of 15mm enormous saving in electrical energy and money can be achieved (Table 1 and Figure 1). Table 1: Calculated rates, cost for electrical consumption in a typical office building in Dubai – Service staircases Bulb Rating (watts) No of floors no of lamps / floor total number of bulbs 100 5 2 10 100 7 2 14 100 12 2 24 100 60 2 120 No of working hrs consumption/ day (kwh) consumption/ year (kwh) Cost /year (AED) annual consumption annual saving annual saving of CO2 saving (kwh) (AED) emission (ton) 24 24 8760 1752 7300 1460 4.672 24 33.6 12264 2452.8 10220 2044 6.5408 24 57.6 21024 4204.8 17520 3504 11.2128 24 288 105120 21024 87600 17520 56.064 Avrage CO 2 emission saving resulting from using a light timmer in Service staircases instead of non-stop luminaers 1 = 5 flr, 2= 7flr, 3= 12 flr, 4 = 60 floors 1 6% 2 8% 3 14% 4 72% Fig.1 shows the saving in CO2 emission from reducing electrical annual consumption in service staircases using timers Note: the Ave Emission of CO2 (kg/ Kwh) was estimated at 0.64. II. Efficient lighting bulbs In a tower with 6 flats per floor by installing 20 Watts bulbs instead of the 100 watts bulbs enormous saving in electrical energy and money can be saved. Table2: Calculated rates, cost for electrical consumption in a typical residential building in Dubai – lighting bulbs Bulb Rating (watts) 100 100 100 100 No of floors 5 7 12 60 no of lamps / floor 136 136 136 136 total number of bulbs 680 952 1632 8160 No of working hrs 8 8 8 8 annual saving of annual CO2 consumption/ year consumption emission consumption/ day (kwh) (kwh) Cost /year (AED) saving (kwh) annual saving (AED) (ton) 544 198560 39712 138992 27798.4 88.95488 761.6 277984 55596.8 194588.8 38917.76 124.5368 1305.6 476544 95308.8 333580.8 66716.16 213.4917 6528 2382720 476544 1667904 333580.8 1067.459 Annual saving of electrical energy cost and CO2 Emission 1 6% 2 8% 3 14% 4 72% Fig.2 shows the saving in energy cost and CO2 emission from reducing electrical annual consumption in a typical residential tower in Dubai. Note: the Ave Emission of CO2 (kg/ Kwh) was estimated at 0.64 94 | P a g e Appendix VI: Lighting Fixtures and Motion Sensors Introduction Fluorescent Lighting: Fluorescent lamps use 25%–35% of the energy used by incandescent lamps to provide the same amount of illumination (efficacy of 30–110 lumens per watt). They also last about 10 times longer (7,000–24,000 hours). The light produced by a fluorescent tube is caused by an electric current conducted through mercury and inert gases. Fluorescent lamps require a ballast to regulate operating current and provide a high start-up voltage. Electronic ballasts outperform standard and improved electromagnetic ballasts by operating at a very high frequency that eliminates flicker and noise. Electronic ballasts also are more energy-efficient. Special ballasts are needed to allow dimming of fluorescent lamps. Improvements in technology have resulted in fluorescent lamps with colour temperature and colour rendition that are comparable to incandescent lamps. Types of Fluorescent Lamps • • Compact fluorescent lamps (CFLs) Fluorescent tube and circline lamps Efficient Electrical bulbs a. b. c. Compact Fluorescent Lamps (CFL) – 5- 28 Watts Energy Saving Halogen 11– 32 Watts Solid State Lighting (Low Emitting Diode - LED) 8– 3Watts a. CFL b. ESH c. SSL (LED) Fig.1 Different samples of efficient lighting fixtures www.Philps.com Definition Solid state lighting (SSL): SSL refers to a type of lighting that exploits light-emitting diodes (LEDs), organic light-emitting diodes (OLED), or polymer light-emitting diodes (PLED) as sources of illumination rather than electrical filaments or gas. The term “solid state” refers to the fact that light in an LED is emitted from a solid object—a block of semiconductor—rather than from a vacuum or gas tube, as is the case in traditional incandescent light bulbs and fluorescent lamps. Unlike traditional lighting, SSL creates visible light with reduced heat generation or parasitic energy dissipation. In addition, its solid-state nature provides for greater resistance to shock, vibration, and wear, thereby increasing its lifespan significantly. Fig.2 Samples of Solid State Lighting - LED bulbs Source: Illumination Engineering Society, IES A light-emitting diode (LED): LED is a semiconductor device that emits incoherent narrow-spectrum light when electrically biased in the forward direction of the p-n junction. This effect is a form of electroluminescence. An LED is usually a small area source, often with extra optics added to the chip that shapes its radiation pattern. The colour of the emitted light depends on the composition and condition of the semiconducting material used, and can be infrared, visible, or near-ultraviolet (Table 1). Fig.3 Samples of LED bulbs Source: Illumination Engineering Society, IES. Table 1: illustrates different colours of LED with potential difference in voltage 95 | P a g e Colour Infrared Red Orange Yellow Green Blue White Ultraviolet Potential Difference 1.6 V 1.8 V – 2.1 V 2.2 V 2.4 V 2.6 V 3.0 V – 3.5 V 3.0 V – 3.5 V 3.5 V Source: Illumination Engineering Society, IES a) 3 Assorted types of fluorescent lamps b & c) spiral type compact fluorescent lamp) Top: two CFLs, bottom: two regular tubes Fig.4 Standard Compact Fluorescent Lamps (CFL) Source: Illumination Engineering Society, IES a) Biax or liner CFL b) Globe CFL c) Reflector CFL d) Spiral CFL Fig.5 Different types of Compact Fluorescent Lamps (CFL) Source: Illumination Engineering Society, IES Fig.6 Compact fluorescent lamps (CFLs) come in a variety of sizes and shapes including: (a) twin-tube integral, (b and c) triple-tube integral, (d) integral model with casing that reduces glare, (e) modular circline and ballast, and (f) modular quad-tube and ballast. CFLs can be installed in regular incandescent fixtures, and they consume less than one-third as much electricity as incandescent lamps do. Source: Illumination Engineering Society, IES Table 2: Illustrates the IES illuminance categories and values for generic indoor activities Luminous flux (Light output) in lm Consumption of electricity 96 | P a g e Lifetime 90 240 400 415 505 660 700 865 900 930 1190 1230 1250 1330 1500 1700 1710 1900 2140 2990 Incandescent 240 V 1,000hr 15 W 40 W 60 W 75 W 100 W 150 W 200 W Compact fluorescent 15,000hr 5W 7W 11 W 14-15 W 20 W 23 W 30 W - - Incandescent LV Halogen 120 V 12 V Variable 4,000hr 40 W (1000hr) 60 W (1000hr) 35 W 75 W (750hr) 50 W 65 W 100 W (750hr) Source: http://catalog.myosram.com Ballasts Ballasts: Fluorescent lamps require a ballast to stabilize the lamp and to provide the initial striking voltage required to start the arc discharge. This increases the cost of fluorescent luminaries, though often ballast is shared between two or more lamps. Electromagnetic ballasts with a minor fault can produce an audible humming or buzzing noise. Electrical ballast: is a device intended to limit the amount of current flowing in an electric circuit. a) An automotive (ignition system) b) Electronic Ballasts of a CFL ballast resistor Electronic ballasts Fig.7 Different types of Compact Fluorescent Lamps (CFL) Source: Illumination Engineering Society, IES Fig.8 Shows garden light can use stored Solar Power due to such low power consumption of the LED Source: http://peswiki.com/index.php/Directory:Light Emitting Diodes Lighting level • In interior offices or residential buildings, illuminance levels shall range between 10 -100 FC (100 & 1000 Lux). • In exterior situations, levels may range from 100 to 10,000 FC (1000Lux – 100,000 Lux) or more. Ensure good lighting is achieved in interior spaces to save energy. This depends on more than just illuminance levels: • Direction, 97 | P a g e • • • Distribution, Colour temperature, and Colour rendering index of the source all contribute to effective lighting (and visibility). The task reflectance and contrast also contribute greatly. The determination of target illuminance levels are generally considered however to be a starting point of any effective lighting design. Illumination levels are generally dictated by the needs of the visual task. Typically, the more light available, the easier it is to perform a specific task. But how much light is enough? Illuminance levels are influenced by: a.) details of task a.) reflectance and contrast (task and background) b.) the eye - (age and condition) c.) importance of speed and accuracy ILLUMINANCE LEVELS Provide appropriate lighting levels for the required task(s). It is also equally important to NOT under light a task. There is generally little value in under lighting a task where human performance is concerned. The electrical energy saved is often offset by a far greater loss in human performance or productivity. As the eye ages, it requires more light to see the same detail with the same speed and accuracy. For this reason lighting systems must be designed with specific human needs in mind. a. A classroom designed for children might require only 40 foot-candles, while the same classroom designed for adult activities might require 80 foot-candles or more. b. Lighting levels in the home, school or office may range from 20 to 100 foot-candles or more. Illumination Index: Illuminating Engineering Society (IES) has published illuminance recommendations. These tables cover both generic tasks (reading, writing etc), and 100's of very specific tasks and activities (such as drafting, parking, milking cows, blowing glass and baking bread). All tasks fall into 1 of 9 illuminance categories, covering from 20 to 20,000 Lux, (2 to 2000 FCs). The categories are known as A–I; and each provide a range of 3 illuminance values (low, mid and high). Table 3: IES Illuminance categories and values for generic indoor tasks Activity Category Lux Public spaces with dark surroundings Simple orientation for short temporary visits Working spaces where visual tasks are only occasionally performed Performance of visual tasks of high contrast or large size Performance of visual tasks of medium contrast or small size Performance of visual tasks of low contrast or very sm size Performance of visual tasks of low contrast or very sm size over a prolonged period Performance of very prolonged and exacting visual tasks Performance of very special visual tasks of extremely low contrast A-C for Illuminance over a large area (i.e., lobby space) Footcandles A B 20-30-50 50-75-100 2-3-5 5-7.5-10 C 100-150-200 10-15-20 D 200-300-500 20-30-50 E 500-750-1000 50-75-100 F 1000-1500-2000 100-150-200 G 2000-3000-5000 200-300-500 H 5000-7500-10000 500-750-1000 I 10000-15000-20000 1000-1500-2000 D-F for localized tasks G-I for extremely difficult visual tasks Source: IES IES recommendations 1. Define visual task and visual plane. 2. Select illuminance CATEGORY (use IES tables or Table 3 above) 3. Determine illuminance RANGE. (Table 3). 4. Select WEIGHTING factors: for category A-C use 'Table 3a for category D-I use 'Table 3b Table - 3a - (for Categories A-C) Room and Occupant Characteristics -1 Weighting Factor 0 +1 98 | P a g e Occupant ages Average room surface reflectance below 40 more than 70% 40-55 30-70% over 55 less than 30% INSTRUCTIONS for Table 3a: Add both weighting factors algebraically. If the total factor is -2 use the low illuminance value. If the total factor is +2 use the high illuminance value. If the total factor is 0 use the middle illuminance value. Table–3b- (for Categories D-I) Room and Occupant Characteristics Occupant ages Importance of speed Average room surface reflectance -1 below 40 not important more than 70% Weighting Factor 0 40-55 important 30-70% +1 over 55 critical and/or accuracy less than 30% INSTRUCTIONS for Table 31b: Add all 3 weighting factors algebraically. If the total factor is -2 or -3 use the low illuminance value. If the total factor is +2 or +3 the high illuminance value otherwise use middle illuminance value. Case study: What illuminance is recommended for an adult aged 56, performing detailed accounting tasks of medium contrast or small size? Use 'Table 3' to identify CATEGORY' E' as the appropriate category. Use 'Table 3' to also identify the illuminance RANGE as 50-75-100 FC. From 'Table 3b' calculate the weighting factor: AGE - 56 IMPORTANCE OF SPEED AND ACCURACY - (important) BACKGROUND REFLECTANCE - (medium contrast, about 40%) factor +1 factor 0 factor 0 +1 In accordance with 'Table 1b' instructions, use a weighting factor of +1 and then select the middle value of 75 foot-candles for the task. Use IES method of determining target illuminance values. Select appropriate illuminance level from TABLE 4. Then, multiply by appropriate "weighting" factor from TABLE 4a. Table 4: TASK CATEGORIES AND REFERENCE ILLUMINANCE LEVELS ILLUMINANCE CATEGORY DIFFICULTY OF VISUAL TASK A B C D E IMPORTANCE OF SPEED & ACCURACY Non-critical / critical MOVEMENT THROUGH PUBLIC SPACES 50 - 75 Lux (5 - 7 FC) INFREQUENT READING OR WRITING; 100 - 150 Lux High contrast & large size (9 – 14 FC) FREQUENT (& easy) READING OR WRITING; 200 - 300 Lux High contrast & large size (19 – 28 FC) (e.g., typewritten page) MODERATELY DIFFICULT READING OR WRITING; 300 - 450 Lux Low contrast or small size (28 – 42 FC) (e.g., pencilled mechanical drawings) DIFFICULT READING OR WRITING; 500 - 750 Lux Low Contrast & Small size (46 - 70 FC) (e.g., poor copy of a blueprint) Source: M.S. Rae, the IES Journal V17#1, 1988. Table 4.a ADJUSTMENTS TO REFERENCE ILLUMINANCES (For different task background reflectance and worker ages) TASK BACKGROUND REFLECTANCE (R) R > 0.8 0.8 - 0.6 0.6 - 0.4 0.4 - 0.2 0.2 or less > 30 1.0 1.2 1.7 2.5 5.0 AGE (A, in years) 30-40 40-50 1.2 1.5 1.5 1.9 2.0 2.5 3.0 3.8 6.0 7.6 50-60 2.0 2.6 3.4 5.1 10.2 60+ 3.1 3.9 5.2 7.8 15.6 99 | P a g e Appendix VI: Swimming Pools – Covering Materials Swimming Pool Covers Swimming pool heating/cooling costs can be significantly reduced by using a pool cover. The use of a pool cover also can help in reducing the size of a solar pool heating/cooling system, hence save money. Swimming pools lose energy in a variety of ways, but evaporation is by far the largest source of energy loss. Evaporating water requires tremendous amounts of energy. It only takes 1 Btu (British thermal unit) to raise 1 pound of water 1 degree, but each pound of 80ºF water that evaporates takes a whopping 1,048 Btu of heat out of the pool The evaporation rate from an outdoor pool varies depending on the pool's temperature, air temperature and humidity, and the wind speed at the pool surface. The higher the pool temperature and wind speed and the lower the humidity, the greater the evaporation rate. In windy areas, windbreak—trees, shrubs, or a fence— can be added to reduce evaporation. The windbreak needs to be high enough and close enough to the pool that it doesn't create turbulence over the pool, which will increase evaporation. Under this condition make sure windbreaks are no causing shades or shading on the pool from the sun, which helps heat it. Indoor pools aren't exposed to the environment, but a swimming pool can lose a lot of energy from evaporation. It even requires room ventilation to control indoor humidity caused by the large amount of evaporation. The ventilated air also must be conditioned, which adds to the energy costs. In hot climate such as that of Dubai, outdoor pools gain heat from the sun, absorbing 75%–85% of the solar energy striking the pool surface. This is an important contribution to the pool's heating needs. A pool cover will decrease the solar gain contribution to some extent, depending on what type you use. A transparent bubble cover (Fig 1) may reduce pool solar energy absorption by 5%–15 %. A completely opaque cover will reduce it by 20%–40%. Covering a pool when it is not in use is the single most effective means of reducing pool heating costs. Savings of 50%–70% are possible. Pool covers on indoor pools not only can reduce evaporation but also the need to ventilate indoor air and replace it with unconditioned outdoor air. You can also shut off exhaust fans when an indoor pool is covered, which saves even more energy. Types of Pool Covers The simpler form swimming pools covers are a large sheet of plastic. Plastic meets the requirement of being a vapour barrier. Use a cover designed specifically for swimming pools such as: • • • UV-stabilized polyethylene, Polypropylene, Vinyl. Also, swimming pools covers can be transparent or opaque. Covers can even be light or dark coloured. Different types at low cost are: o Bubble (or solar) cover: Bubble covers are similar to bubble packing material except they use a thicker grade of plastic and have UV inhibitors. o Vinyl covers: It consists of a heavier material and has a longer life expectancy than bubble covers o Insulated vinyl covers: a thin layer of flexible insulation sandwiched between two layers of vinyl. Fig.1 Different types of swimming pool covers Source: eere.energy.org 100 | P a g e There are three operation systems: • • • Manual Semi –automatic Automatic Manual: cover can be manually pulled and the cover on and off, fold it, and place it somewhere out of the way. Semi-automatic: cover uses a motor-driven reel system. It also use electrical power to roll and unroll the cover, but usually require someone to pull on the cover when unrolling, or guide the cover onto the reel when rolling up the cover. Semi-automatic covers can be built into the pool deck surrounding the pool, or can use reels on carts. Automatic: cover has permanently mounted reels that automatically cover and uncover the pool at the push of a button. Use a Pool Cover Pool covers should be used during your swimming season. If you use your pool only at night, the effectiveness of a pool cover will depend on whether the evaporation and other losses prevented by the cover exceed the solar gain reduction caused by the cover. The type of cover and the climate affects this balance. Climate relates issues a) In dry and/or windy conditions, the evaporation rate of the pool increases. Therefore, it is generally beneficial to have a transparent or bubble cover on during daylight hours. b) In warm, humid conditions such as Dubai the evaporation rate decreases. In this case, it may be more beneficial to leave the cover off during the daytime. Benefits from covering swimming Pools Further to energy savings, pool covers also do the following: • • • Conserve water by reducing the amount of make-up water needed by 30%–50% Reduce the pool's chemical consumption by 35%–60% Reduce cleaning time by keeping dirt and other debris out of the pool. 101 | P a g e Appendix VIII: Solar Water Heating Systems Introduction Solar water heating could typically provide 60-70 Percent of domestic hot water needs. A solar water heater has it main component a collector. The collector could be copper absorber plate or evacuated tube collector. The function of the collector is to capture the sun’s rays and impinging on its surface in the form of heat energy to the fluid in the collector. The indirect circulation system is the most common. The process composes of heat absorber, heat transfer fluid, pump, hot water cylinder, and then to the source of water supply (taps). Heat absorber Heat transfer fluid Hot water cylinder taps Pump Collector Cold water Fig.1 Schematic showing the function of a solar water heater Solar water heating systems include storage tanks and solar collectors. There are two types of solar water heating systems: A. Active, which have circulating pumps and controls B. Passive Cold water Cylinder Hot water Collector Pump Collector Cylinder Active circulation Passive circulation Fig.2 Two types of Solar Water Heating Systems There are two types of active solar water heating systems: • Direct Circulation Systems Pumps circulate household water through the collectors and into the home. They work well in climates where it rarely freezes. • Indirect Circulation Systems Pumps circulate a non-freezing, heat transfer fluid through the collectors and a heat exchanger. This heats the water that then flows into the home. They are popular in climates prone to freezing temperatures. Also, there are two basic types of passive systems: 102 | P a g e • Integral collector-storage passive systems These work best in areas where temperatures rarely fall below freezing. They also work well in households with significant daytime and evening hot-water needs. • Thermosyphon systems Water flows through the system when warm water rises as cooler water sinks. The collector must be installed below the storage tank so that warm water will rise into the tank. These systems are reliable, but contractors must pay careful attention to the roof design due to the tank’s heavy storage capacity. They are usually more expensive than integral collector-storage passive systems. Passive solar water heating systems are typically less expensive than active ones, but they're usually not as efficient. However, passive systems can be more reliable and may last longer. Most solar water heaters require a well-insulated storage tank. Solar storage tanks have an additional outlet and inlet connected to and from the collector. In two-tank systems, the solar water heater preheats water before it enters the conventional water heater. In one-tank systems, the back-up heater is combined with the solar storage in one tank. Types of Solar Collectors Solar collectors used for residential applications falls into 3 types: a. Flat-plate collector b. Integral collector-storage systems c. Evacuated-tube solar collectors Fig.3 A Flat-plate collector Source: Green specs • Flat-plate collector Glazed flat-plate collectors are insulated, weatherproofed boxes that contain a dark absorber plate under one or more glass or plastic (polymer) covers. Unglazed flat-plate collectors—typically used for solar pool heating have a dark absorber plate, made of metal or polymer, without a cover or enclosure. • Integral collector-storage systems (known as ICS or batch systems) It features one or more black tanks or tubes in an insulated, glazed box. Cold water first passes through the solar collector, which preheats the water. The water then continues on to the conventional backup water heater, providing a reliable source of hot water. This type should be installed only in mild-freeze climates not in Dubai. • Evacuated-tube solar collectors They include parallel rows of transparent glass tubes. Each tube contains a glass outer tube and metal absorber tube attached to a fin. The fin's coating absorbs solar energy but inhibits radiant heat loss. These collectors are used more frequently for commercial applications. Fig.4 Evacuated-tube solar collectors Source: Green specs • Flat Plate v Evacuated tube Despite being much more expensive than flat plate collectors, evacuated tube collectors achieve both higher temperatures and 103 | P a g e efficiencies. They perform well in both direct and diffuse solar radiation similar to that of Dubai. This characteristic, combined with the fact that the vacuum minimizes heat losses to the outdoors. Because of the circular shape of the evacuated tube, sunlight is perpendicular to the absorber for most of the day. For comparison, in a flat-plate collector that is in a fixed position, the sun is only perpendicular to the collector at noon. Heat Distribution Solar heating primary circuits transfer heat from the solar collectors to the pre-heat cylinder. They may be ‘Direct’ or ‘Indirect’: Direct - Direct circuits are those that directly heat the water that flows from the household taps. Advantages: • Simplicity and increased efficiency over secondary circuits through reduction of heat transfer loss. Disadvantages: • They are subject to freezing unless the water is drained-back when the pump switches off, which puts constraints on the positioning of the collectors in relation to the feed tank. • As new water continually flows through the collectors, they can be prone to ‘furring’ in the collector waterways resulting in loss of efficiency. Fig.5 Direct and indirect circuits of solar water heating systems Source: Green specs Indirect Indirect circuits use a separate ‘heat-transfer fluid’ circuit to transfer heat from the collectors to the pre-heat cylinder. Their main advantage is that they can employ a wide range of materials and fluids as part of the circulation. There many types, namely, pumped indirect circuits which incorporate a heat-transfer fluid including anti-freeze and corrosion inhibitor. The pump, controlled by a differential temperature controller, circulates the heat-transfer fluid from the collector panels through the heat exchanger in the hot water cylinder and back to the solar collectors for re-heating. The temperature sensors of the differential temperature controller are situated at the solar collector and on the hot water cylinder. This type ensures that fluid is only circulated when the fluid in the collectors is hotter than in the cylinder. Advantages: • Integral protection against freezing • Overheat control • Heat is delivered from the collector at optimal rate • Greater choice of collector and pipe layout • Reduces heat loss through pipes Disadvantages: • Increased complexity • Pump requires electricity (though this can be alleviated by PV supply) • More expensive The pre-heat configuration for the typical solar water heating system can be achieved in two ways, a separate pre-heat cylinder may be placed between existing cold water feed and the normal hot water storage, or the existing hot water storage cylinder can be replaced with a larger double heat exchange coil cylinder. Whichever design is chosen, extra storage volume is required. The space available to accommodate this extra storage capacity will often be the determining factor in the choice of system and also in the location of the storage cylinder. a. b. c. Solar twin coil system Solar pre-feed system to combi-boiler with heat store Solar pre-feed system to combi-boiler Fig.6 Meters for the water cylinder Source: Green specs Sizing 104 | P a g e 1. Selecting the type of storage cylinder Vented, mains pressure or thermal store. Mains pressure (un-vented) cylinders and thermal store cylinders are more expensive, but they enable the hot water to be maintained at the same pressure as the mains supply. 2. Selecting the collector type and system (see above) • Choose the type of collector- usually a flat plate or evacuated tube. • Choose a direct or indirect distribution system (normally direct in Dubai) • Choose gravity or pumped circulation • Determine a pre-heating storage strategy – basically the choice is between a single cylinder with twin coils or the placement of a distinct pre-heat tank before the conventional cylinder. Fig.7 A (Stiebel) twin coil cylinder Source: Green specs The Position of the collector The collector position to give optimum all year round energy collection is roughly south facing and at a tilt of 35 degrees to the horizontal. The orientation and tilt angle will usually be determined by the roof angle. Collectors can face anywhere between south, south east and south west and have tilt angles commonly found on roof of UK houses i.e., 15 – 50 degrees without losing more than 5% of optimum annual energy collection. However, a steeper angle might be considered to optimize spring and autumn performance at the expense of summer surplus. Shading from trees, buildings etc. can produce significant losses in system efficiency and should be avoided Fig.8 Pipes line Fig.9 A system pump Source: Green specs The Size of pipe line Piping is required to route and control the flow of heat transfer fluid between various components of the solar subsystem. The objective of the piping design is to accomplish all these functions with the best compromise between minimum parasitic power requirements and minimum capital costs. The pipe size should be determined according to the flow rate required for the solar heating system, maximum allowable flow velocity as well as economic aspect. A lot of heat can be lost in a conventional solar water heating system because the pipes used can be wide. Issues to consider here include both surface area and pipe volume. Reducing surface area means reducing thermal losses. Using narrow micro-bore pipes in conjunction with low flow pumps instead of wider pipes will typically cut heat loss from pipes by over 50%. The Circulation pump sizing Pumps should circulate heat transfer fluid at the design flow rate with minimum expenditure of electrical energy. Analysis of the complete pipe work will allow a total system head to be determined, describing variation of the total pressure drop of the system with operating flow rate. A suitable pump should provide the required flow rate at the necessary head while operating at or near its best efficiency. Sizing a Solar Swimming Pool Heating System 105 | P a g e In general, the surface area of your collector should be equal to at least 50 percent of the pool's surface area. Sizing a solar swimming pool heating system involves many factors: • • • • • • • • Pool size Length of swimming season Average regional temperatures Desired pool temperature Site's solar resource Collector orientation and tilt Collector efficiency Use of a pool cover. In cooler and cloudier areas, you may need to increase the ratio between the collector area and the pool surface area. Adding collector square footage also lengthens the swimming season. In hot humid climate such Florida or Dubai, a 15-by-30-foot outdoor swimming pool may typically requires a collector that equals 100% of the pool's square footage to accommodate yearround use. This equals 450 square feet of collectors. If the outdoor pools to be used for 6–8 months per year, so they typically size their systems at 60%–70% of the pool's surface area. In any climate, you can usually decrease the required collector area by using a pool cover. Sitting a Solar Swimming Pool Heating System's Collector Collectors can be mounted on roofs or anywhere near the swimming pool that provides the proper exposure, orientation, and tilt toward the sun. Both the orientation and tilt of the collector will affect your solar pool heating system's performance. Make sure that these are well considered during in installation for site's solar resource and sizing the right system. Collector Orientation Solar pool heater collectors should be oriented geographically to maximize the amount of daily and seasonal solar energy that they receive. In general, the optimum orientation for a solar collector in the northern hemisphere is true south. However, recent studies have shown that, depending on your location and collector tilt, the collector can face up to 45º east or west of true south without significantly decreasing its performance. Factors such as roof orientation should be considered (if the collector to be mounted on the roof), local landscape features that shade the collector daily or seasonally, and local weather conditions (foggy mornings or cloudy afternoons), as these factors may affect your collector's optimal orientation. Fig.10 Swimming pools solar water heating systems, orientation and tilting angle Source: www.eere.energy.org Collector Tilt The angle at which a collector should be tilted varies based on your latitude and the length of your swimming season (summer or year-round). Ideally, collectors for summer-only heating should be tilted at an angle equal to current latitude minus 10º–15º. Collectors for year-round heating should be tilted at an angle equal to your latitude. However, studies have shown that not having a collector tilted at the optimum angle will not significantly reduce system performance. Evaluating Your Site's Solar Resource for Solar Water Heating Prior to installing a solar water heating system, consider the site's solar resource first. The efficiency and design of a solar water heating system depends on how much of the sun's energy reaches your building site. If the site and building has not been shaded and generally faces south, it's a good case for a solar water heating system. Although the optimal tilt angle for your collector is an angle equal to your latitude, fixing the collector flat on an angled roof will not result in a big decrease in system performance. 106 | P a g e Appendix IX: Water Fixtures Introduction Water efficiency covers much more than just low flow fixtures. Domestic fixtures do account for a significant portion of water use, especially in areas with heavy cooling loads such as Dubai and arid climate this can be equal or outweighed by cooling water and landscape uses. It should also be remembered that the building stock consists of much more than office buildings such as hospitals, laboratories, industrial manufacturing, and parks. These non-office building facilities will have heavy process water uses. Saving water in these processes might be only the beginning. Savings from chemical, energy and labour usually eclipses water savings in these building types. As shown in Figure 1, domestic water account for 41% and cooling/heating 27%, landscaping 20% and the rest 12%. Watrer Use distribution in a typical office building Domestic (toilets, urinals, faucets, etc.), cooling/heating, and landscaping uses 9% 41% 20% 2% 1% 27% Domestic Kitchen cooling /heating once through cooling lanscaping Misc./UAF Fig.1 Domestic water uses that represent the best opportunities to conserve water in an office building Source: www.mri.org Low Flow fixtures: Summary The use of toilets that use no more than 1.6 gallons of water per flush are called efficient and low flow ones. Low-flow plumbing fixtures including toilets, faucet aerators and showerheads shall be used to ensure water saving in buildings and proved to save substantial amounts of water compared to conventional fixtures while providing the same utility. Different types of low-flow toilets use various technologies aimed at making the toilet more functional. Some toilets have large drain passages, redesigned bowls and tanks for easier wash down. Others supplement the gravity system with water supply line pressure, compressed air, or a vacuum pump. Conventional faucet aerators don't compensate for changes in inlet pressure, so the greater the water pressure, the more water you use. New technology compensates for pressure and provides the same flow regardless of pressure. Aerators are also available that allow water to be turned off at the aerator itself. Standard kitchen and bathroom water faucets shall use 4 to 7 gallons of water per minute (gpm). This means that a single incidence of washing dishes may consume up to 120 gallons of water. Non-conserving showerheads use 5 to 8 gpm, consuming up to 40 gallons of water for a single five-minute shower. It has been indicated that by simply installing a high-efficiency showerhead and faucet aerator will save about 7,800 gallons of water per year in an average household. An easy-to-install faucet aerator will reduce both the flow rate (from 4 to 7 gpm to 1 to 2.75 gpm) and splashing while increasing areas of coverage. This conserves water and improves faucet performance at the same time. Low-flow heads save more than 12 gallons per shower (a savings of 44% over non-conserving showerheads). Ultra-low-flow heads conserve even more, using only .8 to 1.5 gpm, reducing the average five-minute shower's water usage from 40 to 7.5 gallons. Source: http://www.fypower.org). 107 | P a g e Fig.2 A sample of an efficient and low-flow Showerhead Showerheads use similar aerator technology and multiple flow settings to save water: • Low-flow shower heads use about 2½ gallons of water per minute compared to between four and five gallons per minute used by conventional heads. • Low-flow faucet aerators can cut the water usage of faucets by as much as 40% from 4 gallons per minute to 2½. • Low-flow toilets use a maximum of 1.6 gallons of water /flush compared with 3.5 gallons of water used by a standard one. Laminar flow fixtures Controls for laminar flow fixtures deliver a precise volume of water at faucets, showerheads, and hose outlets, typically 1.5 to 2.2 gallons per minute (gpm). Fixtures equipped with laminar flow controls deliver a constant rate, unlike conventional water-saving fixtures that deliver varying flow rates in response to varying line pressure. Under the same flow rate/pressure conditions, aerated streams actually tend to feel “lighter” because they mix air and water; laminar streams are heavier (water only) and feel stronger. a. Laminar flow controls work differently than faucet aerators. Aerators add air to the water stream to make stronger flow. b. Laminar flow controls, on the other hand, work by producing dozens of parallel streams of water. When the faucet is open, water flows in a clear, solid-looking stream, and does not splash. High efficient toilets fixtures with Low flow - Summary High efficiency toilets (HETs) designed for water conservation have been defined according to the Environmental Protection Agency (EPA) as those that use an average of 20 percent less water per flush than the industry standard of 1.6 gallons (or, 1.28 gallons). 1. Using a high efficiency unit (in place of 1.6 gallon flush units) can save up to 8,760 gallons of water each year for a family of four with average daily flushes of six each. This is the target to achieve in climates were water is scares. Types of apparatus: New innovation lead to 10% greater savings in total bathroom water usage than market leading Smart flush® technology and even greater savings when compared to single flush 11L or standard 6/3L dual-flush toilet suites used in combination with separate hand basin. www.caroma.com.au 1. Dual-Flush Toilets — designed for light and heavy flushes, dual-flush toilets tend to average less than 1.2 gallons per flush. They meet HET criteria of 1.28 gallons per flush or less (HET criteria for a dual flush toilet identifies the effective flush volume as the 108 | P a g e average of one high flush and two low flushes). Dual flush models are available from many well well-known known manufacturers with light flush capacities from .8 to 1.1 gallons and heavy flush capacities from 1.3 to 1.6 gallons per fl flush. ush. These toilets typically operate with a handle that can move up or down, or a two button system. One direction or button will activate the lower flow flush, while w the other will activate the higher flow flush. a. residential b. commercial water conversation fixture* Fig.3 Residential esidential and commercial type’s toilet fixtures Source: ASSE and Tool bases 2. Pressure Assist Toilets — Pressure assist, or pressurized tank, toilets are another high perfo performance, rmance, low consumption alternative. These toilets use either water line pressure or a device in the tank to create additional force from air pressure pressur to flush the toilet. The device in the tank could either be a storage device with compressed air that wou would ld require replacement or a tank that creates pressure when the tank is being filled. These toilets typically average 1.1 to 1.2 gallons per flush. Some pressure press assist systems move a greater volume of water at a significantly lesser volume of sound. 3. Power Assist Toilets — Power assist toilets operate using a pump to force water down at a higher velocity than gravity toilets. Power assist toilets require a 120V power source to operate the small fractional horsepower pump. Typical flush volumes are between 1 and 1.3 gallons per flush and dual--flush models are also available. 4. Gravity Fed Single Flush Toilets — Gravity fed single flush toilets operate the same way as any standard toilet, however, they use less total capacity per flush. Typical flush capacities that are available for these models are 1.1 and 1.28 gallons. Additional guidelines: Type of fixtures Water efficient showerhead using conventional aerator or venturi technology for flow rate <2.5 gpm Standard number 2 per fixture Water-efficient efficient sink faucets/aerators <2.2 gallons/minute 2 per fixture Ultra low flow, (<1.6 gpm/ flush) toilets installed: Power-assist Dual flush 4 6 Note: Commercial water conversation fixture are also HETs, flush with 20% less water than Afwallâ™ FloWise and Maderaâ™ FloWise. Like the residential FloWise toilet, the Afwall toilet and Madera toilets don’t. 109 | P a g e Appendix X: Operable Windows and Ventilation Systems II. Operable Windows The following images illustrate operable windows on building’s facades in Dubai. Fig.1 Operable windows in different commercial (Residential) buildings in Dubai Photo Credit: Authors III. Ventilation Systems The ventilation system is independent of the heating/cooling system and supplies outdoor air to all offices. The main air-handling unit has two heat exchangers, two fans and a heating/cooling coil. Fresh air from the air-handling unit is delivered via displacement ventilation that places the air close to occupants. Displacement ventilation uses 100% outdoor air. Ventilation air is introduced at floor level, rises as it warms, and is exhausted at ceiling level. CO2 levels are typically 450 ppm in offices. Incoming ventilation air passes through a desiccant-coated energy recovery wheel, a cooling coil (in summer only) and a second heat exchanger before delivery. Ventilation system operates at full capacity 20 hours a day at two rates. The normal rate is 10L/S/person. The high flow rate is used when additional fresh air is needed or when free cooling is provided by outdoor air. A. Displacement Ventilation It is an air distribution system in which incoming air originates at floor level and rises to exhaust outlets at the ceiling. Fig.2 A schematic diagram of an efficient ventilation system (Displacement Ventilation) Source: www.advancedbuildings.org Incoming air is delivered to interior rooms by way of floor-level vents. This incoming air displaces upper air, which is exhausted through ceiling-level vents. Because displacement ventilation systems typically use 100% outdoor air, air pollutants generated within the building are removed at source and are not re-circulated. In addition, heat generated by ceiling level lights is removed, and thus heat is not included when estimating building cooling loads. Displacement ventilation is applied in several different ways, depending on the method used to deliver incoming air. In a typical design, air is released from wall ducts that run under windows. Air is exhausted through ceiling plenums. If the office is more than five metres wide, one air supply may be insufficient. Additional air supply would be required from interior partitions. 110 | P a g e In another application of displacement ventilation, air is supplied through floor plenums with in-floor fans, or from above-floor fans associated with workstation air outlets. A third method uses ceiling jets to send a vertical column of conditioned air to the floor. This method is often used as a means of personal temperature control. Types of buildings that shall use Displacement Ventilation are: • • • • • • High-rise office and Low-rise offices High-rise and Low-rise apartment s Retail Food service Institutional Arena Benefits DV removes internal heat gains and entrain pollutants captures and removes air pollutants at source Limitations It may add complexity to supply air ducting, it is more difficult to incorporate free cooling more difficult to remove sensible and latent heat gains because of higher air temperatures Application Displacement ventilation is typically used in offices and industrial plants. The Scandinavian concept is applied successfully in offices with double-loaded corridors. The temperature of incoming air must not be much lower than room temperature in order to avoid chilling the occupants. This factor has implications for building energy use. In some conditions, additional air volume must be circulated in order to capture internal sensible heat gains and in order to cool air for dehumidification purposes. B. Personal Temperature Control Fig. 3 A schematic diagram of a ventilation system with Personal Temperature Control Source: Awarded ASHRAE Technology Award, Division 2 (1997) Types of buildings that shall use temperature control systems are: • • • high-rise and low-rise office retail food service Limitation: Installations that include overhead jets may require a minimum pressure of 100 Pascals in the air distribution ducts. Some installations require a raised-floor supply air plenum. Source: Awarded ASHRAE Technology Award, Division 2 (1997) 111 | P a g e Appendix XI: Indoor Air Quality (IAQ) Definition According to a famous IAQ standard in USA (ASHRAE Standard 62-2007) an acceptable IAQ can be defined as: (a) Air in which there are no known contaminants at harmful concentrations; and (b) Air with which a substantial majority (80% or more) of the people exposed do not express dissatisfaction. This definition implies compliance is required with both objective criteria (such as measured concentration of contaminants) to prevent illness and subjective criteria (such as odour panels) to provide comfort. Like the criteria in thermal comfort, the level of satisfaction and acceptability (80%) indicates that conditions do not have to be unanimously or universally applicable. The purpose of the AQI is to help you understand what local air quality means to your health. Table 1: Seven classes of indoor air pollutants Pollutant class Typical examples Combustion products Volatile organic chemicals Respirable particulates Respiratory products Biologics and bioaerosols Radionuclide Odours Carbon monoxide, nitrogen dioxide, sulphur dioxide, carbon dioxide, tobacco smoke components Pesticide and fungicide components, alcohols, benzene, esters, chloroform Asbestos, fiber glass, inorganic and organic dusts, frayed materials, pollen Water vapour, carbon dioxide Molds and fungi, bacteria, viruses, nonviable microbial particulates Radon, radon progeny Odours associated with any of the above Source: USEPA Table 2: New Materials: Furnishings and construction materials can have odors associated with formaldehyde and VOCs. Common products with odorous chemicals include: Material Chemical New carpet 4-phenylcyclohexane New woods Butyric acid Fiber glass Trim ethylamine Permanent press textiles Formaldehyde Vinyl wall covering Methyl isobutyl ketone and styrene Plastics and resins Phenols Floor leveler Phenoxyethanol and phenol Cleaner Butoxyethanol and limonene * Odors can result from ozone and VOCs such as styrene and other aromatic hydrocarbons. Carbonless copy paper, transparencies, and labels result in additional odors. Source: www.usepa.org Adhesive products: According to California EPA 10 chemicals are required to meet the threshold as adhesive products for emission levels, plus 5 additional chemicals. The 15 chemicals are as follows: • Acetaldehyde • Benzothiazole • 2-Ethyl-1-Hexanol • Formaldehyde • Isooctylacrylate • Methylbiphenyl • 2-Methyl-Pyrrolidinone • Naphthalene • Phenol • 4-Phenylcyclohexene (4-PCH) • Styrene • Toluene • Vinyl Acetate • Vinyl Cyclohexene • Xylenes (m-,o-,p-) Source: Carpets and Rugs Institute, USA Carpet products: 112 | P a g e According to California EPA, 7 chemicals are required to meet the threshold for emission levels (IAQ) plus 6 additional chemicals as required by CRI. The 13 chemicals are as follows: • Acetaldehyde • Benzene • Caprolactam • 2-Ethylhexanoic Acid • Formaldehyde • 1-Methyl-2-Pyrrolidinone • Naphthalene • Nonanal • Octanal • 4-Phenylcyclohexene • Styrene • Toluene • Vinyl Acetate Chemicals of Concern: Table 3: Chronic Reference Exposure Levels for organic chemicals with possible indoor Sources, based on the California OEHHA list as of September 2002 No. Substance Chronic Hazard Index (CAS #) Inhalation REL 3 (µg/m ) Target(s) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Acetaldehyde* (75-07-0) Acrolein (107-02-8) Acrylonitrile (107-13-1) Ammonia (7664-41-7) Arsenic (7440-38-2) & arsenic compounds Benzene (71-43-2) Beryllium (7440-41-7) and beryllium compounds Butadiene (106-99-0) Cadmium (7440-43-9) & cadmium compounds Carbon tetrachloride (56-23-5) Carbon disulfide (75-15-0) Chlorinated dioxins (1746-01-6) & dibenzofurans (5120-73-19) Chlorine (7782-50-5) Chlorine dioxide (10049-04-4) Chlorobenzene (108-90-7) Chloroform (67-66-3) No. Substance (CAS #) 18 Chromium hexavalent: soluble except chromic trioxide 9 0.06 Respiratory system Respiratory system; eyes 5 Respiratory system 200 Respiratory system 0.03 Development; Cardiovascular system; Nervous system 60 Hematopoietic system; development; nervous system 0.007 20 0.02 Respiratory system; immune system Reproductive system Kidney; respiratory system 40 Alimentary system; development; nervous system 800 Nervous system; reproductive system 0.00004 0.2 Alimentary system (liver); reproductive system; development; endocrine system; respiratory system; hematopoietic system Respiratory system 0.6 1000 Respiratory system Alimentary system; kidney; reproductive system 300 Alimentary system; kidney; development Chronic Hazard Index Inhalation REL 3 (µg/m ) Target(s) 0.2 Respiratory system 113 | P a g e 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 Chromic trioxide (as chromic acid mist) Cresol mixtures (1319-77-3) Dichlorobenzene (1,4-) (106-46-7) Dichloroethylene (1,1) (75-35-4) Diesel Exhaust* Diethanolamine (111-42-2) Dimethylformamide (N,N-) (68-12-2) Dioxane (1,4-) (123-91-1) Epichlorohydrin (106-89-8) Epoxybutane (1,2-) (106-88-7) 0.002 Ethylbenzene (100-41-4) Ethyl chloride (75-00-3) Ethylene dibromide (106-93-4) Ethylene dichloride (107-06-2) Ethylene glycol (107-21-1) Ethylene glycol monoethyl ether (110-80 Ethylene glycol monoethyl ether acetate (111-15-9) Ethylene glycol monoethyl ether (109-86-4) Ethylene glycol monoethyl ether acetate (110-49-6) Ethylene oxide (75-21-8) Formaldehyde (50-00-0) Glutaraldehyde (111-30-8) Hexane (n-) (110-54-3) Hydrazine (302-01-2) Hydrogen chloride (7647-01-0) Hydrogen cyanide (74-90-8) Hydrogen sulfide (7783-06-4) Isophorone (78-59-1) Isopropanol (67-63-0) Maleic anhydride (108-31-6) Manganese & manganese compounds Mercury & mercury compounds (inorganic) Methanol (67-56-1) 2,000 No. Substance (CAS #) 53 Methyl chloroform (71-55-6) Methyl isocyanate (624-83-9) 54 600 800 Respiratory system 70 5 3 Nervous system Nervous system; respiratory system; alimentary system; kidney Alimentary system Respiratory system Cardiovascular system; nervous system 80 Alimentary system ; respiratory system 3,000 Alimentary system; kidney; cardiovascular system 3 Respiratory system; eyes 20 Respiratory system; cardiovascular system 30,000 Development; alimentary system (liver); kidney; endocrine system Development; alimentary system 0.8 Reproductive system 400 400 Alimentary system (liver) Respiratory system; kidney; development 70 300 Reproductive system; hematopoietic system Development 60 Reproductive system 90 Reproductive system 30 Nervous system 3 Respiratory system; eyes 0.08 7000 0.2 Respiratory system Nervous system Alimentary system; endocrine system 9 Respiratory system 9 Nervous system; endocrine system; cardiovascular system 10 Respiratory system 2000 Development; liver 7,000 Kidney; development 0.7 0.2 0.09 4,000 Respiratory system Nervous system Nervous system Development Chronic Hazard Index Inhalation REL Target(s) 3 (µg/m ) 1,000 Nervous system 1 Respiratory system; reproductive system 114 | P a g e 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 Methyl t-butyl ether (1634-04-4) Methylene chloride (75-09-2) Methylene dianiline (4,4'-) (101-77-9) Methylene Diphenyl Isocyanate (101-68 Naphthalene (91-20-3) Nickel & compounds (except nickel oxide) Nickel oxide (1313-99-1) Phenol (108-95-2) Phosphine (7803-51-2) Phosphoric acid (7664-38-2) Phthalic anhydride (85-44-9) Propylene (115-07-1) Propylene glycol monoethyl ether (107-98-2) Propylene oxide (75-56-9) Selenium and selenium compounds (other than hydrogen selenide) Styrene (100-42-5) Sulphuric acid (7664-93-9) Tetrachloroethylene* (perchloroethylene) (127-18-4) Toluene (108-88-3) Toluene diisocyanates (2,4-&2,6-) Trichloroethylene (79-01-6) Triethylamine (121-44-8) Vinyl acetate (108-05-4) Xylenes (m-, o-, p-) 8,000 Kidney; eyes; alimentary system (liver) 400 Cardiovascular system; nervous system 20 0.7 9 Eyes; alimentary system (hepatotoxicity) Respiratory system Respiratory system 0.05 Respiratory system; hematopoietic system 0.1 Respiratory system; hematopoietic system 200 Alimentary system; cardiovascular system; kidney; nervous system 0.8 Respiratory system; alimentary system; nervous system; kidney; hematopoietic system Respiratory system 7 20 3,000 Respiratory system Respiratory system 7,000 Alimentary system (liver) 30 Respiratory system 20 Alimentary system; cardiovascular system; nervous system 900 Nervous system 1 Respiratory system 35 Kidney; alimentary system (liver) 300 Nervous system; respiratory system; development 0.07 600 Respiratory system Nervous system; eyes 200 Eyes 200 Respiratory system 700 Nervous system; respiratory system Source: California Environmental Protection Agency CEPA, Office of Environmental Health Hazard Assessment (OEHHA) Note: The most recent list shall be used for this specification as published at http://www.oehha.org/air/chronic_rels/allChrels.html 115 | P a g e Calculation of VOCs Concentration The concentration of a compound in the building shall be calculated using the following Equation; Concentration = (Emission factor) * (Loading factor) (Air change rate) 2 For this equation, the units are: μg/m3 = 2 3 (μg/m hr) * (m /m ) -1 (h ) This can be simplified as follows: Concentration = Emission rate Air change rate Note: the weekly average air change rate must be used in the calculations of concentrations of contaminants. Smoke exposure limits Tobacco smoking can also cause a small increase in indoor CO concentrations. Short-term exposures to highly elevated concentrations of CO can cause brain damage or death. Lower concentrations can exacerbate the heart disease, angina. Current indoor exposure guidelines (WHO 2000) are set in relation to exposure durations is shown in Table 4. Table 4: Smoke Exposure limits inside buildings CO Limits Exposed time 100 mg/m3 15 minutes* 60 mg/ m3 30 minutes* 30 mg/ m3 60 minutes* (1 hour) 10 mg/ m3 8 hour Note *: exposures must be limited to these time periods and must not be repeated within eight hours. Source: www.who.org/ /www.yourbuilding.org 116 | P a g e Appendix XII: Cool Roof Materials and Solar Reflectance Index Introduction Cool roofs are a highly reflective and emissive material that remains 50 to 60 degrees F cooler in the summer sun, hence, reducing energy costs, improving occupant comfort, cutting maintenance costs, increasing the life-cycle of the roof, and contributing to the reduction of urban heat islands and associated smog. If the building have a dark-colored roof, it will be hotter than if it had a light-colored roof. Cool Roofs are roofs consisting of materials that very effectively reflect the sun's energy from the roof surface outwards. Cool materials for low-slope roofs are mainly bright white in color, although non-white colors are starting to become known and available for sloped roof applications. Cool Roofs must also have high emissivity, allowing them to emit infrared energy. Cool roofs reduce the roof surface temperature by up to 100 degrees Fahrenheit, thereby reducing the heat transferred into the building below. White Metal Roofing Coated aluminum sheets covering Cool roof : white coating b) Cool roof by using aluminum covering Fig.1 Cool roof applications – Aviation College, Dubai Photos: Authors Cool roof by using aluminum covering Fig.2 Cool roof application – DCCI building, Dubai Photos: Authors Cool roof materials have two important surface properties: a high solar reflectance– or Albedo– and a high thermal emittance. Solar reflectance is the percentage of solar energy that is reflected by a surface. Thermal emittance is defined as the percentage of energy a material can radiate away after it is absorbed. Cool roofs reflect heat well across the entire solar spectrum, especially in the infrared and visible wavelengths. The less solar radiation materials absorb, the cooler they are. In addition to absorbing less heat, the coolest roofing materials radiate away any absorbed heat. Cool roofs keep your building cooler in the summer, reducing air conditioning bill. A cool roof installation not only reduces energy costs, but will also benefit in terms of: • • • Save up to 10% on electricity bills during the summer months by reducing air conditioning use Save peak electricity demand costs if you have time-of-use metering Increase indoor comfort by decreasing indoor temperatures during the summer months 117 | P a g e • • Reduce the heat island effect in cities and suburbs Reduce air pollution and smog formation The following chart illustrates the cool roof materials of different Albedo reflectance indices. Fig.3 Roof Cool and materials’ characteristics (SRI) Source: ASHRAE Green Guide White-topping: White-topping is a cool paving technique in which an existing pavement is covered by a layer of light-colored concrete. It involves adding a four to eight inch thick layer over the asphalt base or the roof base cover (concrete). However, a new method called ultra-thin white topping requires only two to four inches of concrete. Cool roof Performance • • • The performance of cool roofs is affected by the accumulation of dirt. Dirt accumulation can be reduced if roof surfaces slope at least 0.25 in./ft. When liquid-applied coatings are used, carefully select coatings that is compatible with the underlying substrate. Liquid-applied cool roof coatings should comply with ASTM Standard 6083-97 for durability and elongation and have a minimum thickness of 20mils. 118 | P a g e Appendix XIII: Bright (Light) Colour Materials for Pavements Introduction To reduce the heat island effect materials should stay cool in sunlight on at least half of the site’s non-roof impervious surfaces, such as sidewalks, courtyards, plazas and parking lots (hardscape). The material’s solar reflectance index (SRI) must be at least 29. Where paved surfaces are required, using materials with higher SRI will reduce the heat island effect, consequently saving energy by reducing demand for air conditioning, and improve air quality. Concrete and concrete pavers are ideally suited to meet this requirement. Ordinary Portland cement concrete has an SRI in the range of 38 to 52, although it can vary. New concrete made with white Portland cement has an SRI of 86. It can also be achieved with concrete, specifically white cement tiles, with an SRI of 90. The threshold for the roof credit is 75% of the roof with an SRI of 78 or better for low-slope and 29 or better for steep-slope. However, concrete surfaces can help in reducing surface temperature. The following table illustrates cool materials for pavements. Table 1: Solar reflectance (Albedo), Emittance, and Solar Reflective Index (SRI) of select material surfaces Material surface Solar Reflectance* Emittance SRI* Black acrylic paint New asphalt Aged asphalt “White” asphalt shingle Aged concrete New concrete (ordinary) New white Portland cement concrete White acrylic paint 0.05 0.05 0.1 0.21 0.2 to 0.3 0.35 to 0.45 0.7 to 0.8 0.8 0.9 0.9 0.9 0.91 0.9 0.9 0.9 0.9 0.0 0.0 6 21 19 to 32 38 to 52 86 to 100 100 * SRI Solar Reflectance Index Table 2: Solar Reflectance and Thermal Performance of Asphalt Shingles Product Solar Reflectance Infrared Emittance Temperature Rise (F) White ISP K-711 White ISP K-711 White Shasta White Generic White Generic Grey Antique Silver Aspen Gray Ocean Gray Gray Beachwood Sand Light Brown Medium Lt. Brown Medium Brown Autumn Brown Dark Brown Green Surf Green Onyx Black Island Brown Weathered Wood Coral Saddle Tan Desert Tan Generic Black Black 0.21 0.36 0.31 0.26 0.25 0.22 0.20 0.17 0.12 0.08 0.20 0.19 0.10 0.12 0.10 0.08 0.19 0.16 0.03 0.09 0.08 0.16 0.16 0.12 0.05 0.05 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 68 55 59 64 64 67 69 71 76 79 69 70 77 76 77 79 70 72 83 78 79 72 72 76 82 82 Solar Reflectance 21 40 34 27 26 22 19 17 9 4 19 18 7 9 7 4 18 14 -2 6 4 14 14 9 1 1 Source: LNBL, USA 119 | P a g e Appendix IVX: Sloped/Cascaded (Staggered) Roof Introduction Slope Roof A slope roof is a roof surface with an inclination towards North to reduce the impact of solar intensity normally during noon time by reducing and reduce the altitude angle and making the solar beam less perpendicular. Sun Highest intensity of solar radiation beam at 12 noon Sloped roof at 45° 45° 90° Building roof flat Fig.1 A schematic drawing for a sloped roof at 45 and compared with a flat roof with the heist solar intensity This appendix highlights some examples of sloped/cascaded roofs of buildings. Some of these examples are being built in the City of Dubai. It also illustrates examples of ill-oriented sloped roofs. st nd Fig.2 Examples of 2 buildings with sloped roofs: 1 is Whitney Water Purification Facility in New Haven, CT; and 2 is an Animal Care Facility in Las Vegas, NV, USA (Source: www.aia.org) Photo credit: Paul Warchol Photo credit: Tom Bonner a) Cascaded roof facing N-S (Jumeirah) b) Sloped roof facing N/E-W (Jumeirah) c) Sloped roof facing N/E-W (Burjman office) Fig.3 Examples of 3 commercial buildings with sloped/cascaded roofs in Dubai (a hotel and 2 office buildings) Photo credit: Authors 120 | P a g e a & b a sloped roof facing north-south south near DIC c. Steeped roof facing N-S d. A steeped roof facing north-East north Fig.4.. Examples of Sloped roofs of commercial (residential and office) buildings near DMI and Marsa, Dubai Photo credit: Authors Fig.5. Examples of Sloped roofs facing north - south of commercial (residential) buildings Umm Sequim - Jumeirah, Dubai Photo credit: Authors a) ill-oriented oriented sloped roof facing south south-west b) ill-oriented sloped roof facing west though it is cool roof Fig.6. Example of ill ill-oriented sloped roof in Sheikh Zayed Road and Deira, Dubai Photo credit: Authors 121 | P a g e