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BRH FrontCover_section
BRANT RADIANT HEATERS LIMITED
Existing Brochure
DO NO PRINT - FPO
What is Infrared Heating?
Infrared heating is a system or appliance that provides heat by thermal
radiation. A good example of infrared heating is the sun. The sun emits
infrared rays (thermal radiation) through cold, dark space, which is then
absorbed by objects and is converted into heat. This is made possible
through the use of the electromagnetic spectrum.
The sun generates heat energy that
travels approximately 93 million miles
through dark, cold space to heat the
earth.
Sun
Infrared Heater
Infrared energy travels by wave motion
at the speed of light – 186,000 miles per
second.
Infrared Heat Waves
Text for image
Did You Know?
Convective Heat
Concrete Floors
Heated objects then emit this energy in the form of conduction, convection
or radiation to heat the surrounding air. This is the same operating
principle for manufactured infrared heating appliances.
The Electromagnetic Spectrum
The history of discovering the
electromagnetic spectrum is a fascinating
one. Sir Isaac Newton (1643-1727) used
a prism to split sunlight, discovering that
natural white light was actually comprised
of a blend of every color of light. However,
it still took several years to learn that
visible light is only a very small portion of
the electromagnetic spectrum.
Infrared
The electromagnetic spectrum is the range of all possible frequencies of
electromagnetic radiation; it includes gamma-rays, X-rays, ultraviolet,
visible light, infrared, microwaves and radio waves.
Prism
Visible Light
Radio Waves
Microwaves
Infrared Rays
UV Rays
X Rays
Gamma Rays
Sunlight
Long Wave IR
1mm
Medium Short
Wave IR Wave IR
4um
2
0.76
Visible
Light
UV
0.38
Electromagnetic wavelengths travel through empty space, air and other
substances. Radiant heat energy is emitted from a source in the form of
electromagnetic waves in the infrared band which covers the range of 300
GHz (1mm) to 400 THz (750nm). The infrared band is located next to the
visible light band.
Sir William Herschel (1738-1822)
accidentally discovered infrared radiation
while he was taking temperatures of
the different colors of light. He placed
thermometers above the red portion of
a projected spectrum and discovered
higher temperatures.
The Theory of Infrared Heat
© 2012 Brant Radiant Heaters Ltd.
1-1
The 3 Types of Heat Transfer
Conduction:
The transfer of thermal energy between
two forms of matter in direct contact
which act to equalize temperature
differentials. Commonly described as the
transfer of energy between objects in
contact.
Convection:
The transfer of heat caused by a
temperature differential between
the heated parts of a liquid or gas.
Commonly described as the transfer of
energy between air and the object in
contact.
Radiation:
The transfer of radiant energy from the
source emitter directly to the object
without the means of an intermediary
device. Similar to visible light, radiant
energy is passed directly from the source
to the object - air is not directly heated.
Did You Know?
When electromagnetic radiation strikes
an object it is either absorbed, transferred
or reflected.
The properties of radiant heat transfer
allow for the thermostat in an area
heated by infrared to be set 5°F to
10°F lower than hot air systems while
providing comfortable temperatures at
the ground level.
Warming the Environment with Infrared Heaters
Infrared heating allows the source of heat to begin at the floor level and
not the ceiling. This makes it the most efficient and effective method in
which to heat under the diverse conditions present in most warehouses,
storerooms and even the most immense structures imaginable.
Heat the Floor Zone...
not the Ceiling...
Infrared Heating System
Forced Air System
Benefits of Heating with Infrared
A properly designed infrared heating system can offer numerous benefits
including:
Operating
Costs
Comfort
Levels
• Reduce Energy Consumption - Independent studies have confirmed
fuel savings from 20 to 50% when compared to a warm air system.
• Low Harmful Emissions - Infrared heaters burn clean thus putting off
low harmful emissions.
• Thermal Comfort- Heat the floor zone; not the ceiling. Heat energy
stored within ambient objects improves comfort levels in the space.
• Indoor Air Quality- Infrared heaters do not rely on air currents to
transfer heat. This minimizes the circulation of hazardous particles,
chemical pollutants, and cross-contamination of regularly occupied
areas.
• Flexibility- Infrared heaters can be directed where heat is needed.
• Modular Design- Individual zone controls increase personal comfort
for all building occupants.
• Air Stratification- Since it is not necessary to circulate air to heat the
inside of the building, thermal stratification is reduced.
1-2
The Theory of Infrared Heat
© 2012 Brant Radiant Heaters Ltd.
Let’s Explore Heating Options
There are various methods in which to heat many commercial and
industrial applications and it is important to understand the basic
characteristics of each. Let us explore some typical heating options.
Did You Know?
Air, water and dirt are poor absorbers of
infrared energy. Alternatively, concrete,
non-bright steel and wood are excellent
absorbers of infrared energy and allow for
the effective use of infrared heaters.
In-Floor Radiant Heat - This heating system
radiates heat into the intended space by
circulating fluids, air, or electric current
through a circuit of tubing embedded into
the floor, walls or ceiling. Pros of this
method include improved comfort and air
stratification. Cons of this method include
high first costs, upkeep, lagging response rates
and the inability to effectively spot heat.
Efficiency Standards
ASHRAE 90.1 mandates that infrared
heaters must be used when heating
unenclosed spaces.
Definitions
Unit Heaters - This heating system allows
for the transfer of warm air into a space
via a heat exchanger and a fan. Pros of this
method include reduced installation costs, and
application versatility. Cons of this method
include high operating costs, noise, heat
stratification, and reduced comfort levels.
Recirculation & Make-Up Air Heating - This
heating system conditions ventilation air
for either introduction into a space or for
replacing exhausted air with tempered air.
Commonly used in conjunction with infrared
heating, the pros of this method include an
ability to heat large spaces and to provide for
air quality and control. Cons of this method
include operation costs, high equipment costs
and stratification issues.
Indirect Fired:
Heating equipment that utilize powerful
fans to force clean, heated air through
ducts to heat the space. Products of
combustion are vented to the building
exterior and do not enter into the
building. Any heating system with a flue
is an indirect system.
Direct Fired:
Refers to heating equipment that dumps
its products of combustion directly in the
space. Direct fired units typically bring
outside air into the building, after heating
the air with an open flame.
Overhead Infrared Heating - This
heating system typically places a ceramic
or a steel emitter surface in the ceiling
of a structure for the purpose of radiant
energy transfer to the objects below. Pros
of this method include reduced building
stratification, lower operating costs,
increased comfort, quick recovery and
the ability for zone control. Cons include
clearance issues, available mounting
heights, and additional design considerations.
The Theory of Infrared Heat
© 2012 Brant Radiant Heaters Ltd.
1-3
Other Common Applications
• Farm Buildings
• Ice Rinks
• Loading Docks
• Sporting Facilities
Typical Applications
Infrared heaters are effective for a wide variety of hard-to-heat applications,
such as areas of high air infiltrations, buildings with high ceilings, or where
spot heating is preferred.
Examples of several typical applications are found below.
• Warehouses
• Agricultural Buildings
• Distribution Facilities
• Manufacturing Facilities
• Woodworking Shops
• Confinement Barns
• Pole Barns
Fire Stations
Outdoor Patios
• and Many More!
Infrared Heater Safety Council
The IRSC offers safety
guidelines for the proper
use of infrared heaters.
www.irsafetycouncil.com
Aircraft Hangars
Car Washes
Residential Garages
Sporting Facilities
Golf Ranges
Vehicle Maintenance Facilities
To view additional application photos, please visit www.reverberray.com
1-4
The Theory of Infrared Heat
© 2012 Brant Radiant Heaters Ltd.
Operating Principles of High Intensity Infrared Heaters
Gas-fired high intensity heaters are direct-fired and pass a gas-air mixture
through a porous matrix refractory material which ignites evenly across the
surface. This surface is heated to temperatures of 1350°F or above, emitting
a large concentration of infrared radiation that may be directed anywhere
heat is desired.
High intensity heaters typically operate unvented. Proper ventilation is
necessary to dissipate combustion gases released into the space.
The Types of High Intensity Infrared Heaters
Infrared Space Heaters - Infrared space
heaters are best applied in buildings with
high ceilings and areas where there is
a high demand for a heat load, such as
loading docks or bay areas.
Infrared Patio Heaters - Patio heaters are
used to provide indoor and outdoor spot
heating to applications such as restaurant
patios, decks and vestibules.
Portable Construction Infrared Heaters - Portable heaters are
generally mounted to a 20 lb., 10-inch base LP tank and are
designed for outdoor or inside areas under construction.
They are ideal when temporary heat is required or where a
permanent energy source is not available.
Did You Know?
High intensity heaters are also
referred to as spot heaters, box
heaters, ceramic heaters, and as
luminous heaters in Europe.
Operating at temperatures of 1350°F
or above, high intensity heaters
emit energy at a higher amplitude
than low intensity. High intensity
energy is in wavelengths from 1 to
6 microns and is close to the visible
light spectrum. This closeness to the
visible light spectrum is why some
energy is released as visible light.
NFPA 54, section 9.18.3.1 requires
that where unvented infrared
heaters are used, natural or
mechanical means shall be provided
to exhaust and supply at least
4-ft3/minute/1,000 BTU/h input of
installed heaters.
Most high intensity heaters are an
open flame type. Thousands of tiny
flames pass through a perforated
refractory; blanketing the surface of
the emitter.
Product Certifications/
Standards
High Intensity: ANSI Z83.19
CSA 2.35
Patio Heaters: ANSI Z83.26 CSA 5.90
Portable Heaters:ANSI Z83.7
Electric Infrared Heaters - Electric infrared heaters produce heat by running
Electric Infrared: C22.2
an electric current through a high-resistance element. They are commonly
used in areas where gas is impractical or unavailable.
Types in Infrared Heaters
© 2012 Brant Radiant Heaters Ltd.
2-1
Definitions
Atmospheric:
A unit that receives fresh air
for combustion under normal
atmospheric pressures without the
use of a blower or fan.
Key Components of High Intensity Infrared Heaters
Reflector
Emitter Surface
(typically ceramic)
Emitter Surface:
A material that is heat and corrosion
resistant, and has a porous matrix
which allows for the flow of the
gas and air mixture. It emits the
majority of the infrared heat.
Flashback:
Occurs when the fuel mixture
burns within the rayhead assembly
(behind ceramic surface) not
allowing the flame to anchor
properly on the ceramic surface
during operation. Cracked or loose
ceramics, missing gasket material or
other physical abuses can attribute
to flashback.
Rayhead:
An assembly that allows an air/
gas mixture to pass through the
perforated emitter surface, and
usually houses the venturi and
mixing tube.
Reflector:
A device configured to direct radiant
energy to the point of use in the
space while absorbing minimal
energy.
Secondary Emitter:
A device designed to re-radiate
some of the energy back to the
emitter surface, increasing the
temperature and thus increasing the
radiant output.
Re-Radiating
Rods
Ignition & Sensing Device
High intensity infrared heaters are typically enclosed, except for the
emitting surface. This exposed portion of the heater is intended to be
oriented to the load.
Operating Characteristics of High Intensity Heaters
Input Range
Clearances to Combustibles
Combustion Air
Heat Distribution
Operating Voltage
Installation
Mounting Heights
Surface Temperature
Venting
Response Time
Other Considerations
30,000 to 160,000 BTU/h
High
Atmospheric
Concentrated, intense, focused
24VAC, 120VAC or millivolt
Flexible
12 ft. to 50 ft. typical
1350°F and higher
Non-vented - indirect
Less than a minute
Wind, contact hazards, clearances
Common Uses of High Intensity
High intensity heaters are a cost effective solution for heating a variety of
application types.
Effective in high bay areas due to the intensity and ease of installation.
Cost effective and simple to install in retrofit applications.
High output per square foot makes these units excellent for spot heating.
Millivolt units provide freeze protection in the event of a power outage.
Their simplicity makes them an option for total building heating.
2-2
Types of Infrared Heaters
© 2012 Brant Radiant Heaters Ltd.
Operating Principals of Low Intensity Tube Heaters
Gas-fired infrared heaters are an indirectly fired appliance, and have a
radiating surface between the combustion and the intended load. When
there is a call for heat, a flame is ignited within an exchanger. The
exchanger is then heated to temperatures up to 1350°F, emitting infrared
energy. This energy is directed to the floor level via reflectors and is
absorbed by people and objects in its path.
A heat differential exists along the length of the heat exchanger because
more heat is produced in the first half of the tube at the burner/combustion
end, than the second half of the tube at the exhaust end. A well designed
unit minimizes this temperature differential.
The Types of Low Intensity Tube Heaters
Forced Draft Systems (Push) - A forced draft
system operates under a positive pressure,
‘pushing’ the products of combustion through
the length of the exchanger tubes. This type
of infrared heater is easy to service and install
because all of the components are housed
in one compartment. When compared to
other tube heater types, push tube heaters
offer a variety of production, installation and
operating benefits.
Did You Know?
Low intensity tube heaters are also
known as radiant tube heaters, push
tubes, tube brooders or stick heaters.
Low intensity heaters have a
radiating surface that typically
operates at temperatures below
1350°F with wavelengths of 2 to 10
microns. This is farther away from
the visible light spectrum; therefore
no light (glow) is emitted.
Tube heaters have the ability to be
direct vented or can vent into the
space as long as 4 CFM/1,000 BTU/h
of ventilation is provided.
Fresh air for combustion can be
drawn into the system and is
recommended in harsh environments
or where negative pressures exist in
the space.
Low intensity tube heaters can
be configured in a U or L shape in
order to accommodate different
applications.
Draft Induced Systems (Pull) A draft induced tube heater
operates under negative
pressure “pulling” the products
of combustion through the
length of the exchanger tubes. This type of infrared
heater offers reliable performance in high-wind applications and sometimes
can allow for extended vent runs.
Multiple Burner Vacuum System - Multiple
burner systems operate under negative
pressure “pulling” the products of
combustion through various runs of
radiant exchanger tubing via a powerful
vacuum exhauster pump. This type of
infrared heater is used when minimal
building penetrations are required, or if
extended vent runs are necessary.
Product Certifications/
Standards
Low intensity tube heaters are
Design Certified to ANSI Z83.20,
CSA 2.34b.
Select models are Design Certified
under CSA requirements for
residential use (No. 7-89).
Types in Infrared Heaters
© 2012 Brant Radiant Heaters Ltd.
2-3
Definitions
Burner Control Box:
An assembly that houses the various
control components of a tube heater
such as the gas valve, burner, ignition
system, pressure switch, etc.
Combustion Chamber:
The section of radiant emitter tubing
where the combustion occurs.
Pending surface temperatures, the
combustion chamber is typically
constructed of a higher grade
material than downstream radiant
emitter tubes.
Radiant Emitter Tube:
The section of radiant emitter
tubing following the combustion
chamber, downstream of the burner
control box. This section of tubing is
typically constructed of aluminized
or hot-rolled steel.
Reflector:
A hood-like device configured to
direct radiant energy to the point
of use in the space while absorbing
minimal energy.
Burner:
A device for the final conveyance of
the gas and air to the combustion
zone.
Baffle:
A device installed in the vent end
of the emitter tube designed to
“wring out” the most optimal
heat energy from the products of
combustion prior to venting it from
the appliance.
Key Components of a Low Intensity Tube Heater
An infrared heater consists of three main components - the burner,
reflector and radiant emitter. The burner control box on a low intensity
heater typically houses all of the control components, including the burner.
Burner Control Box
Air Intake
Combustion Chamber
Burner Sight Glass
Baffle
Reflector
Radiant Emitter
Exhaust
The first 10 foot section of the tube, directly downstream of the burner
control box, is referred to as the combustion chamber. This section of
emitter tube houses the flame and is typically constructed of materials
having the capability to handle high temperatures.
Operating Characteristics of Low Intensity Tube Heaters
Input Range
Clearances to Combustibles
Combustion Air
Heat Distribution
Operating Voltage
Installation
Mounting Heights
Surface Temperature
Venting
Response Time
25,000 to 200,000 BTU/h
Minimal
Atmospheric or vented
Large area, heat differential
24VAC or 120VAC
Flexible
9 ft. to 50 ft. typical
Up to 1350°F
Vented or non-vented
2 to 5 minutes
Common Uses for Low Intensity Tube Heaters
Low intensity heaters are a cost effective and energy efficient solution for
heating a variety of application types.
Effective in low bay areas and often used for total building heat.
Cost effective and simple to install in retrofit applications.
Durable and reliable, they are an excellent choice for car washes.
Patios and vestibules are a common application for low intensity infrared.
The soft heat patterns have proven well in agricultural applications.
Fresh air intake and exhaust options provide versatility.
2-4
Types of Infrared Heaters
© 2012 Brant Radiant Heaters Ltd.
General Design Principles
Definitions
Regardless of heater type, it is important that the design meets the
application requirements in order to achieve the best comfort levels and to
maximize efficiencies.
Choosing the right heating solution is accomplished with knowledge of
the facility that is to be heated. It is best to plan thoroughly and design an
infrared heating layout that will ensure optimal performance. Improper
equipment application can result in undesired results.
Basic Application Guidelines
1. Conduct A Building Survey
When designing an infrared system, a proper building survey will help
to ensure its optimal performance. An accurate heat loss calculation
with an emphasis on air changes must be conducted. The strategic
location of the burners will allow for added heat in areas where it is
most needed. Vent location, air intake, gas supply and operational
obstacles must also be considered.
2. Discuss Performance Expectations
Understanding your customer’s needs is paramount to the overall
satisfaction of the installation. Remember that many people do not
fully understand the operating characteristics of an infrared heater and
it is important to help educate them. The following questions should be
reviewed prior to the installation:
··
··
What is the overall heating objective (spot heat, freeze control, etc.)?
What are the expectations of the infrared system?
Is the temperature differential acknowledged?
Will the clearances to combustibles always be maintained?
3. Review Recommended Mounting Heights
While mounting heights are not mandatory to follow, they are critical
in the proper application of the appliance. Mounting heights are one of
the most important factors in the selection process as they are directly
correlated to the radiant footprint and overall comfort levels.
Air Change:
The introduction of new, cleansed
or recirculated air into a space. The
method of measuring the amount
of air movement into or out of a
space in terms of the number of
building volumes or room volumes
exchanged in unit time.
Flux Density:
The rate of radiant energy transfer
across a given surface per unit area
in unit interval of frequency or
wavelength.
Heat Load:
The amount of heat to be generated,
usually measured in BTUs. Factors for
determining heat load include:
1. Floor and wall area.
2. Windows and doors.
3. Air changes.
A formal heat loss calculation
will most accurately provide the
necessary BTU loading requirements.
For estimating purposes, however,
a figure of 35 to 50 BTU’s per square
foot is sometimes used in the preplanning stages. If spot heating,
a figure of 100 to 200 BTU’s per
square foot may be used. Generally,
the larger the building, the less
the per square foot BTU loading
requirements.
Like Visible Light
2’
20’
12’
5’
24’
40’
General Design Principles 3-1
© 2012 Brant Radiant Heaters Ltd.
Design Tips
Additional BTU’s per square foot are
generally required to keep people
warm in spot heating applications or
small areas which quickly lose heat to
the surrounding area.
Some applications can benefit from
using a combination of heat types.
Infrared heaters are commonly used
by combining several heaters to
achieve larger heated areas.
The effective infrared surface
temperature of a person or object
may be diminished with wind in
excess of 5 mph. In this case, wind
barriers may be required.
Ventilation
For proper ventilation, a positive air
displacement of 4 CFM/1000 BTU/h of
gas consumed must be provided.
Where insufficient air movement
exists, induced air displacement
is required. A balanced system is
essential to avoid negative building
pressure which causes excessive
infiltration, unfavorable drafts and
effects combustion efficiency.
Let’s Explore Designing with High Intensity Heaters
To better understand designing with high intensity heaters, let’s first review
the operating characteristics. High intensity heaters place a large amount of
heat into a small area of space due to the 1600-1800°F ceramic emitter surface.
Hot Gas Roll-out
Ceramic Emitter
Intense Heat Zone
The heat output pattern of a high intensity heater is focused and intense.
This intense heat output has many application advantages; however, it
requires adequate mounting heights and increases the clearance to
combustibles considerations. Designed as a direct fired appliance, these units
cannot be directly vented and require adequate indirect building ventilation.
Frequently Asked Questions
Q: What type of applications are best suited for high intensity infrared?
A:High intensity heaters are found in a wide variety of applications
but have proven themselves to be very effective in high ceiling, spot
heating and retrofit applications.
Q: Do high intensity heaters have other advantages?
Consider This
Are high intensity heaters perfectly
energy efficient as all of their energy
is released into the space?
A:Yes, when compared to other systems these heaters tend to be lower
in cost, relatively simple to install and have proven to need minimal
maintenance.
Q: When would I choose a high intensity heater over a tube style heater?
A:This question is often asked and really boils down to your application
and your design objectives. If your application requires a focused
more intense heat signature and can withstand the height, clearance
and ventilation requirements then the right choice is likely a high
intensity product.
Q: When applying a high intensity heater what other considerations exist?
A:Higher clearances to combustibles, the need for appropriate building
ventilation, protective guarding in select applications and the use of this
product in windy areas are all items worthy of additional consideration.
3-2 General Design Principles
© 2012 Brant Radiant Heaters Ltd.
Total Building Heat with High Intensity
Design Scenarios
Bad Design:
Heating an overall area with infrared heaters is particularly suited for
buildings with large air volumes or high rates of air movement where
convection (air heating) methods are grossly ineffective.
Sample Heater Layout
C
A
B
Good Design:
- High intensity heater
Dim A- Recommended mounting height
Dim B- Distance between heaters
Dim C - Distance between heater rows
Recommended Mounting Heights (in feet)
BTU/h Input
Stnd. Refl.
Dim A.
Parabolic Refl.
Dim A.
Dim B.
Dim C.
Distance Between
Heater & Wall
30,000
12-14
12-15
8-30
10-70
6
60,000
14-16
18-21
15-43
15-90
12
90,000
16-18
21-25
20-55
20-110
12
130,000
21-24
26-32
22-65
23-140
14
160,000
24-28
29-35
25-70
25-160
14
Wrong Installation:
Failure to place control end down
will result in damaged controls.
Spot Heat with High Intensity
BTU/h
Input
Approx.
Coverage
30,000
12’ x 12’
9’ to 14’
5’
120 cfm/h
60,000
18’ x 18’
12’ to 18’
7’
240 cfm/h
90,000
24’ x 24’
16’ to 20’
10’
360 cfm/h
130,000
30’ x 30’
18’ to 20’
12’
520 cfm/h
160,000
35’ x 35’
20’ to 30’
16’
640 cfm/h
B
A
Recommended Mounting Distance Behind Person
Height (Dim. A)
or Work Station (Dim. B)
Required
Air Changes
Right Installation:
20° - 35°
Heater must be mounted level side
to side and at a 20-35° angle from
horizontal with the control end
down.
General Design Principles 3-3
© 2012 Brant Radiant Heaters Ltd.
Construction Considerations
Every tube heater has a minimum
and maximum length which
is dictated by the BTU’s of the
appliance. For example a 100,000
BTU heater has a minimum 20-ft
and a maximum 50-ft length.
A turbulator baffle is sometimes
inserted into the last pipe(s) to
increase operating efficiencies and
maximize heat transfer at the end of
the heater.
Temperatures on the combustion
chamber may exceed 1200°F while
temperatures at the exhaust end of a
tube heater are often below 300°F.
“U-Tubes”
U-shaped heaters are often the
best solution when heating people
or when tackling a spot heat
application. By design, a “U-tube”
will place the hottest tube directly
adjacent to the coldest tube for
optimal comfort levels.
Don’t be fooled...
...by the promise of a perfectly even
heat output or an operating method
that implies superior performance.
Construction standards and
efficiency guidelines as described on
page 6-3 better explain why such
claims can be misleading.
Let’s Explore Designing with Low Intensity Heaters
To better understand designing with low intensity heaters, let’s first explore
its operating principles. Hot gases produced at the burner pass through
a steel tube exchanger cooling as they reach the exhaust - creating a
temperature differential along the tube run.
Typical flame properties & heat pattern
Hotter
Cooler
Slow
Fast
Tube heaters feature a burner, radiant tubes and reflectors. A flame
originates from the burner and travels approximately 2-6 feet in length
leaving the hot gasses to heat the remaining radiant pipe. This results in
the infrared energy being directed to the floor level in a disproportionate
amount. What is commonly referred to as “temperature differential”
should be highly considered during the design phase.
Frequently Asked Questions
Q: What type of applications are best suited for tube heaters?
A:Tube heaters are used in a wide variety of applications and are a
preferred solution for total building heat in newly constructed
applications. When properly designed, tube heaters have proven
effective in commercial, industrial, patio, agricultural, warehouse and
spot heat applications.
Q: Do low intensity heaters have other advantages?
A: Yes, tube heaters have proven to be quite versatile and rugged. This
is due to the low intensity heat signature and construction features
that allow for direct ventilation and the consumption of outside
combustion air.
Q: What design considerations exist when applying a tube heater?
A:When applying a tube heater, first remember the fundamentals which
include heat load, coverage, clearances and mounting heights. Then
account for the temperature differential by strategically locating burner
boxes in the areas of the greatest heat loss or highest desired heat zone.
3-4 General Design Principles
© 2012 Brant Radiant Heaters Ltd.
Low Intensity Heater Application Guidelines
Design Scenarios
Bad Design:
When designing for total building heat, the concern is to replace heat loss
with heat input, maintaining the most uniform heat pattern as possible.
Placing the hotter end of the heater in colder areas of the building helps
in achieving better heat distribution. Optimize heat patterns by moving
the heater toward the center of the space as it reaches perimeter walls. This
avoids wasting energy through the wall.
Proper model selection and good layout practices will result in increased
efficiencies and comfort levels.
Good Design:
Low Intensity Application Chart
Model
Length
20 Ft.
30 Ft.
40 Ft.
50 Ft.
60 Ft.
70 Ft.
80 Ft.
B
BTU/h Range
Recommended
Mounting Height
Coverage
Dim A
Dim B
Dim C
50-65 MBH
75-100 MBH
50-65 MBH
75 MBH
100-125 MBH
50-65 MBH
75-125 MBH
150-175 MBH
100-125 MBH
150-200 MBH
125 MBH
150-200 MBH
175-200 MBH
200 MBH
10’ - 16’
12’ - 20’
10’ - 16’
12’ - 20’
13’ - 20’
10’ - 16’
12’ - 20’
16’ - 30’
15’ - 25’
16’ - 30’
16’ - 25’
17’ - 40’
17’ - 40’
18’ - 45’
20’ x 12’
22’ x 15’
30’ x 14’
33’ x 18’
33’ x 18’
40’ x 16’
44’ x 21’
45’ x 26’
55’ x 24’
56’ x 30’
66’ x 27’
67’ x 34’
78’ x 38’
89’ x 42’
10’ - 20’
20’ - 30’
10’ - 20’
20’ - 30’
20’ - 30’
10’ - 20’
20’ - 30’
30’ - 40’
20’ - 30’
30’ - 40’
20’ - 30’
30’ - 40’
30’ - 40’
30’ - 40’
20’ - 40’
30’ - 50’
20’ - 40’
30’ - 50’
30’ - 50’
20’ - 40’
30’ - 50’
40’ - 60’
30’ - 50’
40’ - 60’
30’ - 50’
40’ - 60’
40’ - 60’
40’ - 60’
16’
18’
17’
20’
20’
20’
20’
25’
25’
25’
25’
25’
30’
30’
A
Wrong Installation:
Right Installation:
C
C
Dim A- Distance between heaters; Dim B - Distance between heater rows; Dim C - Distance between heater and wall
Note: This application chart is provided as a guideline. Actual conditions
may dictate variation from this data. Dimensions A, B & C are based upon
heaters hung at the factory recommended mounting height.
General Design Principles 3-5
© 2012 Brant Radiant Heaters Ltd.
Heard on the Street
“...infrared heaters are well suited for
a wide range of applications...”
“...designing with infrared is more of
an art and less of a science...”
“...there are no absolute right ways
to apply an infrared heater; however,
there are absolute wrong ways...”
“...a well designed infrared system
is one not even noticed during its
operation...”
“...I should have put this type of
heating system in years ago...”
Design Tools
The Infrared Heater Selector slide
chart will help determine the best
heater selection for the application.
Detroit Radiant Products Co.
Infrared Heater
Selector
Founded in 1955, Detroit Radiant Products company is
the foremost manufacturer of gas fired infrared heating
equipment in the world.
We offer the most complete line of infrared heating
products including; unvented high intensity heaters, low
intensity tube heaters, multiple-burner vacuum systems,
decorative outdoor patio heaters and portable
construction heaters.
Characterized by our
exclusive line of
Re-Verber-Ray brand
name products, Detroit
Radiant Products
Company has
established a reputation
for delivering quality
products in a cost efficient manner. We attribute our
success to the fact that our primary focus has always
been on infrared technology.
www.reverberray.com
Please visit our website to access the latest and most
comprehensive source of information available for
Re-Verber-Ray products.
This selector is provided as a reference only. Data posted on heater
warning labels takes precedence over the data in this selector.
NOTE: All heaters ship FOB Warren, MI 48089 - Class 85
DETROIT RADIANT PRODUCTS
21400 Hoover Road
Warren, Michigan 48089
Phone: 586.756.0950
Fax: 586.756.2626
sales@drp-co.com
Ten Steps to Designing an Infrared Heating System
1. Contact your local factory representative. Local representatives are
factory trained and will provide a complete no-charge design analysis.
2. Determine the type of application. Infrared heaters are ideal for use
in fire stations, warehouses, auto body shops, sporting facilities, pole
barns, garages and much more. Infrared heaters are not explosionproof and may not be placed in a Class1 or Class 2 Explosive
Environment, such as a paint booth.
3. Discuss performance expectations. Discuss the customer’s
expectations. What temperature do they wish to maintain? What
is the environment used for? Where are the work and storage
areas? Do they seek even heat distribution? What are the available
mounting heights?
4. Calculate the heat loss. Determine the heat loss of the building using
standard ASHRAE guidelines. Determine design temperature and
desired temperature rise. Pay particular attention to the air changes
per hour.
5. Determine the heater type. There are a variety of heater types. Select
high or low intensity heaters. If selecting low intensity, determine
whether it is to be in a straight or U-shaped configuration, negative or
positive pressure, unitary or system design. Multiple heaters of lower
BTU’s are preferred over single, large BTU models.
6. Review the minimum and maximum mounting heights.
CRITICAL! All infrared heaters have a minimum and maximum
recommended mounting height. This is established to ensure
effective and comfortable heat patterns at the floor levels.
7. Observe clearances to combustibles. WARNING! Clearance
to combustibles distances must be maintained at all times. Pay
particular attention to storage areas, overhead doors and car lift areas.
Signs are recommended for safety and also in accordance with the
ANSI Z83.20/CSA 2.32 Standard.
8. Review coverage. Infrared heaters are best applied in an outer
perimeter design pattern. Place burners in the areas of greatest heat
loss, opposite of each other and spaced equally.
9. Make heater selections. Select single or two-stage models. Specify
heater inputs, gas type and voltage. Utilize upgrade options based
on the application. Review construction features and pricing of each
model to make the best selection.
10. Other related considerations include venting, controls, guards, signs
and whether to utilize outside combustion air.
3-6 General Design Principles
© 2012 Brant Radiant Heaters Ltd.
Heating Safely with Gas-Fired Infrared Heaters
Infrared heating systems have a long history of safe use in a wide variety
of commercial and industrial applications. Safety should be a top priority
of the design and installation phases.
Your Role & Making a Difference
A safe and effective infrared application represents the collective efforts of
many industry professionals. Let’s explore the roles of the following trades
and their typical duties in providing or using an infrared heater.
The Manufacturer is legally responsible for the construction of
a “reasonably safe” appliance. Most manufacturers will have
their products certified to a national standard which validates
performance and safety design aspects. Premier manufacturers
will utilize strict quality control measures and provide clear warnings and
instructions.
The Specifying Engineer is responsible for the design of the
system within the building environment. Many engineers
will research the manufacturing community and specify the
best available products. Engineers will conduct the heat loss
calculations and place product in a manner that will provide satisfactory heat
patterns, comply with any codes and avoid any hazards.
The Contractor is the professional party or parties responsible for
the installation of the equipment. A mechanical contractor will
often hang, pipe, and vent the appliance according to the local
codes and the manufacturer’s instructions which they should be
quite knowledgeable of.
The Distributor is sometimes known as a manufacturer’s
representative or as a wholesaler. The distributor is often factory
trained and provides a great resource for specific application
concerns or guidance. Premier distributors will provide technical
support, conduct surveys, stock product and replacement parts and be
associated with supporting regional associations.
The Inspector is found in many parts of the country and is
responsible for the review and approval of the installation prior
to initial operation and issuance of approval certificates. A
good inspector will possess a basic knowledge of the product
operation, the key hazards and the local codes. Some inspectors will
proactively locate and utilize other knowledge resources in the pursuit of a
safe and quality installation.
I nfrared Heater Safety
Council (IRSC)
The Infrared Heater
Safety Council
represents a
gathering of the
leading manufacturers of gas-fired
infrared heaters with a stated
purpose of educating the public on
the safe use of our products.
To learn more about the IRSC, please
visit www.irsafetycouncil.org.
A brochure highlighting information
on the proper use of infrared heaters,
clearance factors and proper
ventilation is available on this web
site.
Codes
Designers and installers of gas-fired
infrared heating systems should be
familiar with local codes and the
National Fuel Gas Code (NFPA-54)
ANSI Z223.1, or the Canadian Gas
Association (CAN/CGA B149.1)
which is continually updated to
maintain safe use of gas appliances
in applications.
Are you Aware… …that some manufacturers
provide an extensive online AutoCad
library with product and detailed
installation depictions? Using this
resource will allow the conveyance
of clear instructions to the field.
The End User, or the customer, is the party who will utilize the
product in their space. The end user should acquaint themselves
with the owners manual and use and maintain their product as
instructed. The end user should pay particular attention to the
clearances to combustibles and conduct an annual maintenance review.
Safety
© 2012 Brant Radiant Heaters Ltd.
4-1
Clearance Considerations
•
•
•
•
•
•
•
•
Canvas
Combustible materials
Flammable liquids
Insulated ceilings
Paper products
Racking
Wiring in conduit
Wood
Clearance to Combustibles
Clearance to combustibles, or the required distance for safe operation, are
common with many space heating products. Combustibles are materials
which may catch on fire and include common items such as wood, paper,
rubber and fabric. Clearances to combustibles distances are prominently
displayed on the product and must be maintained at all times to ensure
safety.
Operational Considerations
•
•
•
•
•
•
•
Car wash equipment
Hoses
Overhead cranes
Overhead doors
Parked vehicles
Sprinkler systems
Vehicle lifts
Responsibility of the Installer and Users
Ensure that building materials with a low heat
tolerance are protected to prevent degradation.
“...in locations used for storage of combustible materials,
signs shall be posted to specify the maximum permissible
stacking height to the combustibles.”
This is quoted from the National Fuel Gas Code (ANSI Z223.1), and the Standard
for Gas-Fired Low-Intensity Infrared Heaters (ANSI Z83.20)
ANSI Z83.20 further states “...and
such signs must either be posted
adjacent to the heat thermostat or in the absence of such
thermostat in a conspicuous location.”
4-2
Safety
© 2012 Brant Radiant Heaters Ltd.
How Clearances to Combustibles are Derived
Did You Know?
ANSI Standards govern the method by which clearances to combustibles
are derived. A low intensity tubular heater will undergo the following steps
during its certification process:
1. Identify the hot spot on the heater.
2. Place the hottest portion of the heater into a test apparatus and identify
the registered temperatures with the goal of finding a 90°F temperature
rise. Record the distance.
Black Board Test Apparatus
160°F
Brant Radiant Heaters Ltd. provides
clearance to combustibles data for
its tube heaters at a 20-ft. mark
downstream of the burner. This
allows for added flexibility in the
design and application of the
heating system.
The European Standard for testing
clearances allows for a 117°F
temperature rise and therefore a
small clearance to combustible
envelope.
6”
24”
160°F
24”
81”
• Keep gasoline or other
combustible material including
flammable objects, liquids, dust
or vapors away from the heater or
any other appliance.
Sample 40 ft.-150,000 Btu/h heater
• Maintain clearances from heat
sensitive material, equipment and
workstations.
160°F
Embedded Thermocouples
160°F
Sample 70°F room temperature
3. Perform tests at a 0° and 45° mounting angles and any other
configuration desired by the manufacturer. Display data on product
and in the installation, operation, maintenance and parts manual.
Top
Top
Behind
Side
Front
Side
Below
Below
0° Mounting Angle
45° Mounting Angle
Top
Top
Front
Behind
Read, Understand and Follow
These Guidelines:
Side
Below
0° Mounting Angle
0° Mounting Angle
• Maintain clearances from
swinging and overhead doors,
overhead cranes, vehicle lifts,
partitions, storage racks, building
construction, etc.
• Hang heater in accordance with
the suspension requirements.
Side
Below
• Maintain clearance from heat
sensing devices, such as sprinkler
systems, and make sure these
devices are not overheated.
• Do not run gas pipe or conduit in
the area of exhaust products or in
the clearance zone.
Safety
© 2012 Brant Radiant Heaters Ltd.
4-3
Gas Connection
• When connecting an infrared
heater to the supply line,
allowances for expansion are
required.
• A flexible connector of approved
type must be used.
• The gas piping system shall not
bear any weight of any appliance.
• Gas conversions must be done
by a qualified person or agency
following the manufacturer’s
conversion instructions.
• Reference NFPA 54/ANSI Z2223.1
National Fuel Gas Code, or
Canadian CSA B149.1 Installation
Codes latest revision.
Other Considerations
Proper Gas Connection
Connect a heater to the gas supply using proper equipment as set forth by
ANSI, NFPA, CAN/CSA and the manufacturer.
Shut-off
Movement
Burner Control Box
Drip tee
Type 1 Rubber
hose
Improper Gas Connection
Never connect the gas supply line directly to the heater inlet. Never use
copper piping to connect unit to the gas supply.
Failure to properly connect the gas supply to the unit may result in leaks,
improper heater operation and possible system failure including explosion
or fire.
Movement
Ventilation
• Provide proper fire guarding
(thimbles, flashing, etc.) when
venting through a combustible
wall.
• Provide mechanical or natural
ventilation of 4 CFM/1000 BTU/h of
input when operating unvented.
• Provide fresh air for combustion
when operating in harsh
environments.
• Use a single control when
common venting multiple units.
Burner Control Box
Proper Ventilation
Heaters must be vented per all applicable codes. All infrared heating
manufacturers provide a variety of vent terminations and piping.
Rooftop Vent Cap
Double-Wall B-Vent
• Provide adequate separation from
the heater to the air intake.
• Verify vent line(s) are free of
obstructions and debris.
• Use approved sidewall vent caps
as specified by the manufacturer.
4-4
Safety
© 2012 Brant Radiant Heaters Ltd.
Sidewall
Vent Cap
Heater
Heater
Double-Wall B-Vent
For specific ventilation requirements, reference the manufacturer’s
Installation, Operation and Maintenance manual.
Construction Properties
Key Components
Let’s examine a low intensity tube heater.
Reflector
Combustion Chamber
Radiant Emitter
Radiant Emitter
Radiant Emitter
An infrared tube heater is made up of a series of interconnected emitter
tubes with a reflector(s) placed over the top. Collectively, these elements
emit and direct heat for use in the intended space. Not all heaters are made
alike and an understanding of the core components is important when
selecting the product.
Radiant Heat Exchanger - What Matters
Tube exchanger material selection plays a vital role in the comfort,
performance and longevity of a low intensity infrared heater. Let’s examine
the following product design considerations.
• Thermal Conductivity: The ability to transfer heat through a material,
allowing for a greater transfer of heat energy.
• Cost: The material cost must be practical and economical, without
sacrificing quality.
• Corrosion Resistance: Exchanger(s) should not fail prematurely under
normal operating conditions.
• Emissivity: The material utilized in the exchanger of a low intensity
tube heater must have the ability to release heat in the form of radiant
energy, which is measured in emissivity.
Exchanger Thickness Diagram
The tubes and
reflectors utilized
on an infrared tube
heater constitute
key system components and often
govern most of the operational
aspects of the heater itself.
Did You Know?
Thermal Saturation Rate: The
rate of full energy transfer from the
source to the emitter. This rate is
impacted by burner design, tube
material and tube wall thickness.
When testing to satisfy ANSI
Z83.20 the manufacturer must
provide a minimum 15 minute
saturation period before conducting
performance testing.
The Norm: A 10-foot x 4-inch x
16-gauge emitter tube is most
commonly used within the infrared
industry as it represents the best
balance between performance,
responsiveness, safety and price.
Gauge: A measurement of the
wall thickness of an object (see
chart below). Note that while the
gauge of the emitter tube impacts
performance and longevity so does
the exchanger material, arguably to
a greater degree than the gauge.
Schedule 40
Let’s review the various material utilized in the marketplace.
12 ga.
14 ga.
16 ga.
18 ga.
20 ga.
22 ga.
20 Gauge
26 Gauge
(overheated)
14 Gauge
16 Gauge
Sample exchanger surface temperatures after 10 minutes of operation.
24 ga.
Schedule 40
(underheated)
26 ga.
[not to scale]
Construction Properties
© 2012 Brant Radiant Heaters Ltd.
5-1
Radiant tubes are constructed of
stainless steel, titanium stabilized
steel, aluminized steel and hot rolled
steel. Different tubes have different
tolerances to heat and corrosion.
Each material will also have its own
emissive characteristics.
Unlike cold rolled steel, hot rolled
steel is formed at a temperature
above the recrystalization point of
carbon to prevent work hardening.
Did you Know?
Stainless steel is broken down into
three basic categories:
1. Austenitic (300 Series). Low iron.
Non magnetic. Superior rust
resistant properties.
2. Ferritic (Low 400 Series). Higher
Iron. Magnetic. Able to be
titanium stabilized.
3. Martinstitic (High 400 Series).
Higher Iron. Magnetic. Able to be
hardened.
A Recipe for Steel
All steels share
iron as their
core common
denominator. The
modest addition of different alloys
including carbon, magnesium,
sulfur, copper, nickel, chromium, etc.
will dictate the different grades and
characteristics of the final product.
Material Types
Hot Rolled Steel: A common commercial grade ferritic steel that
is heated to high temperatures then formed through a rolling
die. This material is naturally dark in color, producing moderate
emissive values. Characteristics of hot rolled steel include low cost, limited
corrosion resistance and lower heat tolerances.
Aluminized Steel: A common hot rolled steel that is coated
with an aluminum-silicon alloy by the utilization of the hot-dip
process. This alloy material is naturally silver in color, thereby
reducing the emissive capacity of the finished product. This in turn,
warrants a special treatment for increased heat output (see page 5-3).
Characteristics of aluminized steel include a higher cost, greater corrosion
resistance and an increased heat tolerance.
Titanium-Stabilized Aluminized Steel: An enriched version
of aluminized steel. The base metal, or substrate, is treated
with a small amount of titanium to afford superior strength and
heat tolerance. The aluminum-silicon coating is the same as the standard
aluminized steel. Characteristics of this material include a superior ability to
withstand vigorous cyclic service of higher temperatures, a greater corrosion
resistance and a notable cost premium due to materials and availability.
Stainless Steel: A higher end commercial grade steel containing
substantive amounts of chromium and nickel. The higher
cost of stainless steel limits its use to primarily harsh or humid
environments where it exhibits superior corrosion resistance. 304 Series
stainless is commonly utilized due to its superior corrosion resistance,
however it is susceptible to warping at high temperatures due to reduced
heat transfer properties. A titanium-stabilized 409 Series stainless steel has
a higher heat tolerance than the 304 Series, but can exhibit surface rust. Left
without a highly emissive surface coating, both materials demonstrate lower
output values.
Material Characteristics
Steel Type
Construction Properties
© 2012 Brant Radiant Heaters Ltd.
Est. ε
Value
Cost
Pros
Cons
409 1450°F .64 to
Titanium stabilized
$$$$
Stainless
.68
High heat tolerance
Can show surface rust
High cost & low emissivity
304
Stainless
May distort under high heat
High cost & low emissivity
.62 to
Corrosion resistant
$$$$$
.66
High heat tolerance
Titanium
Stabilized
.72 to
.74
$$$
Enhanced heat tolerance Availability
Corrosion resistant
Higher cost & low emissivity
Aluminized
.72 to
.74
$$
Medium heat tolerance
Corrosion resistant
Not suitable for high heat
Higher cost & low emissivity
.80 to
.82
$
Low cost
Highly emissive
Susceptible to corrosion
Low heat tolerance
Hot-Rolled
5-2
Max.
Temp
850°F
Exploring Emissivity
Pyromark 1200 Paint®
Emissivity is a measure of the ability of a material to radiate energy. It is
quantified by the ratio of the radiating ability of a given material to that of a
black body.
ε = 0.0
1.0
Perfect
Heat transfer through radiation takes place in form of electromagnetic
waves mainly in the infrared region.
Some objects in nature have almost completely perfect abilities to absorb
and emit radiation - these objects are called black bodies. A black body is
a hypothetical object that is able to completely absorb all wavelengths of
thermal radiation that falls on its surface. A true black body would have an
ε = 1.0 while real objects will yield values less that perfect.
Highly Emissive Object
NASA’s space
program applies the
Pyromark 2500®
Series paint to the
shroud of the Space
Shuttle to reject high temperatures
seen during re-entry.
Different materials are subject to
different tolerances to heat and
corrosion. However, when tube
exchangers are coated with a highly
emissive black tube coating, infrared
heat output is enhanced - achieving
an emissive value of .95.
Poorly Emissive Object
In general, good emitters of radiation are also good absorbers of radiation
at specific wavelength bands. Likewise, weak emitters of radiation are also
weak absorbers of radiation at specific wavelength bands.
Swaged Design
A swaged interlocking tube design provides a tube-on-tube overlap that
helps to ensure structural integrity, ensures a tight seal, and is easier to
install. The clamp is designed to merely hold the secured tubes in place.
Swaged Tube
Pyromark® Series 1200 flat black
paint, manufactured by Tempil
Division, is highly absorptive and
emissive. It achieves uniform
emissivity for maximum heat
diffusion and can withstand
temperatures up to 1200°F.
Non-Swaged Tube
On the other hand, a non swaged tube design means that the clamp will
act in part as the heat exchanger. The use of a large stainless steel clamp is
often utilized to mask the fundamental problems that exist with this lesser
securing method.
Did you Know?
That an untreated “silver” 40-foot
150,000 BTU tube heater will exhibit
stack temperatures 150°F to 200°F
hotter than a duplicate model with
treated ‘black’ tubes. This difference
directly correlates to increased
radiant outputs.
Upon each start of a heating cycle,
water vapor condenses momentarily
until the unit heats up to operating
temperatures. Swaged tubes retain
any condensation, allowing it to
quickly evaporate from the full cycle
of the heater.
A heater featuring a
swaged tube design
will typically reduce the
installation time by 1-2 hours (when
compared to non swaged tubes).
Construction Properties
© 2012 Brant Radiant Heaters Ltd.
5-3
When Infrared Energy Strikes
an Object:
1. It is absorbed as heat, such as when the sun shines on our skin.
2. It is reflected, such as when light
reflects off of a piece of glass.
3. It is transferred, such as the sun
shining through a window and
warming up a room.
The following formula may be used to
quantify the process defined above:
Exploring Reflectivity
Core reflector material is an important variable when evaluating reflector
design. When radiant energy strikes a surface, it is either absorbed,
reflected or transmitted through the material.
α+τ+ρ=1
α = fraction of radiant energy absorbed.
τ = fraction of radiant energy transmitted.
(τ=0 when dealing with solid materials)
ρ = fraction of radiant energy reflected.
The “Perfect” Reflector
Because infrared
waves share the same
physical properties
as visible light on
the electromagnetic
spectrum, it is best to compare how
well light is reflected from a highly
polished surface versus a dull surface.
Theoretically, the perfect reflector
exhibits mirror like properties capable
of a 100% reflective value.
Reflector Material
% Reflectivity
*Absorption Value
Stainless Steel (Polished)
60% to 90%
0.10 to 0.40
Aluminum (Polished)
60% to 90%
0.10 to 0.40
Aluminum (Dull or Mill Finish)
35% to 60%
0.40 to 0.65
*Absorptance for solar radiation taken at 1000°F.
Source: Table 3; Section 3.8. 1993 ASHRAE Fundamentals Handbook.
Highly polished, mirror-finished aluminum reflector material is most
effective in delivering infrared heat energy to the floor levels. Polished
aluminum has a very low absorption value; therefore, it has a very high
reflective value.
Reflector Design Theory
In Summary
Properly choosing a quality infrared
heater requires an understanding of
the different tube and reflector types.
Too often these key construction
features are overlooked and a lesser
quality product is selected on price
alone. In nearly every situation the
upgrade to higher quality materials is
a minimal incremental investment to
the entire job itself.
5-4
Construction Properties
© 2012 Brant Radiant Heaters Ltd.
The shaded areas represent the sections of tube
that emit infrared which reaches the space
below. The sum of the angles of these sections
is 315°. Dividing this number by 360° gives a
percentage of the infrared which reaches the
space below. This percentage is 87.5.
Note that the energy not reaching the space
below (white) is absorbed by the tube and
re-radiated.
Reflector design refers to the geometric
shape of the top shield. This shape is
mathematically engineered to allow for
optimal focus of the infrared waves, similar
to how light is focused from ballasts. The
design is directly correlated to the heat
pattern of the appliance.
Another important function of the reflector
is to capture a significant amount of the
appliance’s convective heat output. This
heat energy is absorbed by the appliance
and then re-radiated in the form of infrared
energy.
While reflector design is an important consideration in the design process
of an infrared heater, it is typically secondary to the considerations placed
on material type which have a greater impact on reflectivity.
Efficiency
The Four Efficiencies of
Infrared
Heating with infrared technology is an excellent method to reduce energy
costs. However, the fact that infrared technology is fundamentally
different than traditional means of heating requires special attention when
evaluating an infrared appliance for its efficiency.
Combustion Efficiency: A measure
of how complete an appliance
converts fuel into heat energy.
Efficiency = What you get out ÷ What you put in
Thermal Efficiency: A measure of all
energy (conductive, convective and
radiant) captured by the heater.
There are several different efficiencies that can be utilized when comparing
infrared heaters. Understanding how these efficiencies are derived and how
they apply will aid in selecting the proper unit for an application.
Combustion Efficiency
Pattern Efficiency: A measure of
how effectively an appliance delivers
radiant energy into a heat pattern.
Bernoulli’s Principle
Combustion efficiency is a measure of how complete an appliance converts
the supplied fuel into heat energy. 100% combustion efficiency, or
stoichiometric combustion, is achieved when the exact amount of oxygen
required to burn a specific amount of fuel is supplied to the reaction; no
more, no less. This is also commonly referred to as perfect combustion.
Stoichiometric Combustion
At standard temperature and
pressure, there are approximately
761,300,000,000,000,000,000,000
molecules in one cubic foot of gas.
Every molecule would have to come
into contact with an oxygen molecule
at exactly the right time and place for
100% combustion of this gas to occur.
Radiant Efficiency: A measure of all
radiant energy leaving the heater.
Stoichiometric equation for natural gas: CH4 + 2O2
CO2 + 2H2O
In practice, “perfect combustion” is nearly impossible to achieve. In fact,
this is unfavorable in most heating appliances because the slightest change
in the environment could easily starve the flame of oxygen, resulting
in high levels of noxious gasses. Therefore, most heating appliance
manufacturers adjust the air-to-fuel ratio to allow for a small amount of
excess air. This will minimize the pollutants created, and still maximize
the efficiency. The graph above depicts the combustion process, and
demonstrates the relationship between its products when changing the
amount of air supplied.
States that when
there is a decrease
in pressure there
must be an increase
in velocity at
Daniel Bernoulli
[1700–1782]
the same rate
that the pressure was decreased.
This principle is most commonly
attributed to the theory of lift, as
generated by an airfoil, but it also
plays a role in burner design.
Increased Velocity
Good burners will utilize a venturi,
or a tube with a narrowed passage,
for the purpose of increasing velocity
through the tube. This results in
better aeration, better mixing,
better flame stability and better
combustion efficiency.
Venturi Burner Design
Non-Venturi Burner Design
Efficiencies
© 2012 Brant Radiant Heaters Ltd.
6-1
Your Next Paycheck...
When cashing your
next paycheck, think of
thermal efficiency. Your
gross pay (energy in)
reflects what you earned. Your net
pay (energy out) reflects what you
take home.
Thermal Efficiency
Thermal efficiency is the measure of all energy — conductive, convective
and radiant — captured by the heater. Thermal efficiency is currently the
industry standard used to measure the efficiency of an infrared heater in
the United States of America and Canada.
Thermal efficiency is a measure of the total heat energy captured by an
appliance which is available for useful output. The Sankey diagram below is
a good visual depiction of this process.
Sankey Diagram
The Infrared Industry
Currently the infrared industry and
the American National Standards
Institute (ANSI) and Canadian
Stanards Association (CSA) use
thermal efficiency as the sole
method to measure the efficiency of
the appliance.
While this measure of efficiency may
be suitable for appliances such as
unit heaters or boilers, it does not
depict the total efficiency of infrared
heaters.
As a result, this current efficiency
standard has allowed some
manufacturers to produce a cheaper,
lesser quality heater with low
radiant output exchangers and less
reflective reflectors.
Various industry standard
committees recognize this problem
and are working to develop a radiant
efficiency standard to accurately
measure the efficiency of infrared
heaters.
Considering Electric?
While often promoted as being
100% efficient, remember that
most electric heaters are powered
by upstream, gas-fired power
generators subject to significant
energy transmission losses.
FLUE LOSSES
GROSS
INPUT
APPLIANCE
AVAILABLE
HEAT ENERGY
The gross input is the total amount of heat energy supplied to the
appliance through the combustion process. The majority of that energy
is captured within the appliance, but some escapes through the flue,
which is counted as a thermal loss. Once the available heat energy is
captured within the appliance, it can be emitted in three different forms;
convection, conduction, and radiation. Every infrared heater is required
to pass a minimum thermal efficiency rating. A well designed infrared
heater maximizes the radiant output while minimizing the convection and
conduction thermal movements.
Oftentimes, infrared heating solutions are sold on thermal efficiency claims
alone, and generally claims that cannot be fully attained. The additional
cost to achieve optimal thermal efficiency far outweighs any theoretical
payback when utilizing an infrared appliance.
Thermal Energy of an Infrared Heater
The diagram below demonstrates the three forms of heat energy leaving a
tube style heater. Note the convective energy in yellow, the radiant energy
in red and the conductive energy in orange.
Convection
Radiant
Energy
6-2
Efficiencies
© 2012 Brant Radiant Heaters Ltd.
A specific type of flow diagram,
in which the width of the arrows
is shown proportionally to the flow
quantity. They are typically used
to visualize energy or material
transfers between processes.
Conduction
The Testing Process
Certification Guidelines
ANSI Z83.20 is the recognized standard governing the certification of an
infrared tube heater. The Standard is over 140 pages in length and details
all of the required tests and regulatory procedures for a gas fired low
intensity infrared heater.
The diagram shown below highlights the key variables in testing for the
rated thermal efficiency of the appliance. As you can see, the efficiency
rating is a measurement of both the CO2 (combustion efficiency) and the
stack temperature (flue loss).
1
FLUEGases
GASES %%
CO2CO2
inINFlue
2
4
3
5
6
7
8
Exhaust temperature above
480°F results in an excessive
loss of usable heat and could
potentially compromise vent ducts
or terminations. Temperatures
below 200°F will yield poor radiant
performance and are subject to
condensation.
9 10 11 12
NATURAL
GASFlue
FLUE LOSS
Natural
Gas
Loss%%
60
50
40
30
25
20
The Construction and Operation
Standard for Low Intensity Heaters
(ANSI Z83.20/CSA 2.23) dictates
a maximum allowable exhaust
temperature of 480°F plus the
ambient temperature, a minimum
70% thermal efficiency value, and no
more than 400ppm carbon monoxide
(CO) in an air free sample.
15
GAS
TEMPERATURE - ROOM
TEMPERATURE
Flue GasFLUE
Flue
Temperature
- Room
Temperature
F 900 800 700
600
500
400
300
200
100
20-Ft., 100,000 BTU/h
C 500
400
300
200
100
100
50-Ft., 100,000 BTU/h
Thermal Efficiency Rating Diagram
Tube Heaters are Unique
Two heaters with the same combustion efficiency (CO2) can have very
different thermal efficiencies by the addition of radiant pipe to the
appliance. This must be done with careful consideration as a longer
infrared tube heater will have pronounced temperature differentials
and emit very little heat towards the exhaust end. Very often, the best
performing heater may fall in the middle of the range of available lengths
for a particular BTU model. This model is often representative of both
good thermal and radiant performance characteristics.
20’-100 BTU/h Differential
70% T.E.*
480°F + Ambient
Consider This
Oftentimes, vacuum systems are
promoted as being more efficient
than the unitary push tube.
Surprisingly, this is only achieved
when the system is installed at
maximum allowable lengths and is
allowed to condense.
Another often overlooked factor
between a unitary push tube and
vacuum system is the vacuum
pump's high electrical consumption.
This should be considered when
calculating overall system
efficiencies.
For additional information on
vacuum system efficiencies, please
see pages 7-2 & 7-3.
50’-100 BTU/h Differential
86% T.E.*
200°F + Ambient
* Theoretical value only.
Efficiencies
© 2012 Brant Radiant Heaters Ltd.
6-3
Some History
Radiation formulas such as the
Stefan-Boltzmann Law have been
in existence since the 1800’s. These
formulas along with other pertinent
radiant data are found in the
ASHRAE Fundamentals Handbook.
Developing an accurate radiant
efficiency standard has been
sought after for many years with
little success. Various infrared
manufacturers have funded
campaigns for the development of
a radiant efficiency standard to no
avail.
Presently, the domestic infrared
industry conducts certification
testing by using only a thermal
efficiency method. Radiant
effectiveness is conveyed by using
known physics and lows which help
to distinguish a product and its
performance.
Radiant Efficiency
Radiant efficiency is a measure of how much thermal energy is emitted
as radiant heat energy. This form of thermal transfer is fundamentally
different from conduction or convection in that it does not require an
intermediary device to transfer the heat energy. This greatly reduces the
transmission losses, because it sends the heat directly to the intended load.
Thus, heating with radiant energy is a more effective and efficient means of
heating over traditional forced warm air systems.
Stefan-Boltzmann Law
The theoretical radiant output of a surface can be calculated by utilizing
the Stefan-Boltzmann law. According to this Law, a small increase in the
temperature of a radiating body results in a large amount of additional
radiation being emitted.
The following equation describes this law mathematically:
w = AєσT4, where
w = Total radiant output
A = Area
є = Emissive Value
σ = Stefan-Boltzmann constant
T = Absolute temperature
For example, an exchanger tube at a temperature of 1200°F has nearly twice
as much radiant output as a similar exchanger tube at 900°F.
Certification of Europe
European Standard
BS EN 416-2 is the
leading authority in
the quantification of rational use of
radiant energy. Infrared products
bearing the CE mark will have been
tested to this Standard.
Appliances tested to the European
Standard must meet a minimum
thermal and radiant efficiency value
and are rated accordingly. This is a
more objective method to properly
evaluate the total performance of
the appliance.
When comparing two identical tube heaters (for instance, a 40-ft., 150,000
BTU/H model) with different surface temperatures, it is simple to see how
drastically the surface temperature effects the radiant output (shown below).
Heater A
Heater B
900°F
A
є
σ
T
=
=
=
=
153.2m2
0.90
5.6704 x 10-8Js-1m-2K-4
755°K
1200°F
A
є
σ
T
=
=
=
=
153.2m2
0.90
5.6704 x 10-8Js-1m-2K-4
922°K
To calculate the percent reduction in radiant output, simply divide
Heater A by Heater B, as shown:
Heater A Output: [(153.2)(.90)(5.6704 x 10-8)(755)4]
.45 or a 55% reduction of radiant output.
=
Heater B Output: [(153.2)(.90)(5.6704 x 10-8)(922)4]
6-4
Efficiencies
© 2012 Brant Radiant Heaters Ltd.
Pattern Efficiency
Pattern efficiency is the measure of how effectively an appliance directs
radiant heat energy into a usable heat pattern. This pattern, coupled
with the proper application of the product, influences the system's total
effectiveness.
Mounting height, reflector design, material, and application all determine
whether or not the desired pattern will be prevalent. This pattern is often
measured in BTU/h per square foot; also known as Effective Radiant Flux.
Did you Know?
Similar to lighting a space, the goal
of infrared heating is to obtain
highly efficient heat by directing the
infrared energy in a specific pattern.
Poor Pattern
100W x3
Poor Pattern
Efficiency
Poor Pattern
Efficiency
Poor Pattern Efficiency
300W
Poor Pattern Efficiency
Ideal Pattern
100W
100W
100W
Good Pattern Efficiency
This step in the 'gas-to-useful heat' process is critical because it is a good
indicator of the distribution of heat energy. Even the most efficient radiant
heaters my prove ineffective if applied improperly, resulting in poor pattern
efficiency.
The effective application of the
pattern to the thermal load
influences the system’s total
effectiveness.
What is Radiant Flux Density?
Radiant flux density is the power of electromagnetic radiation falling on or
emanating from a body, measured as watts per square meter.
Flux has a primary mathematical definition in terms of a surface integral
which uses the vectors that represent the force which is causing the flux
being studied:
Flux = ∫∫s F ∙ dS = ∫∫R F ∙ <− ∂z , − ∂z , 1 > dxdy
∂x ∂y
Efficiencies
© 2012 Brant Radiant Heaters Ltd.
6-5
Let’s Review
•
Combustion Efficiency is important as it is a direct indicator of the
performance of the burner operating within the appliance.
•
Thermal Efficiency is the recognized North American testing method
and is important as it is a measurement of all energy leaving the
appliance.
•
Radiant Efficiency is of significant importance when discussing the
performance of a radiant tube heater.
•
Pattern Efficiency attempts to quantify the flux density of coverage of
the pattern of the heater.
Collectively all of these known efficiencies should be considered when
weighing the overall performance of the infrared heater.
European Standards
Radiant
Efficiency
Two Stage Operation
Two stage infrared heaters operate
in a high (100%) or a low (65%)
output mode according to demand.
This technology will result in
additional fuel savings and bottom
line energy savings. To learn more
about two stage operation, please
see page 10-1.
The Bottom Line
Recognize the difference between
system efficiency and device
efficiency. Infrared systems have
been proven to outperform most
‘device efficient’ appliances.
Accordingly, the overall operating
efficiency of an infrared system
should be the most important
criterion when selecting a heating
solution.
6-6
Efficiencies
© 2012 Brant Radiant Heaters Ltd.
Thermal
Efficiency
The European Test Standard necessary for CE
Certification recognizes the importance of
rational use of energy when weighing the overall
efficiency of an appliance. This method will
most likely be adapted in the North American
marketplace.
Conclusion
•
Many factors contribute to the performance of an infrared system; it is
unwise to select a system based on a single criterion.
•
Radiant efficiency and thermal efficiency should be given equal
consideration.
•
The simple addition of excess radiant pipe to an infrared heater can
raise the thermal efficiency. However, this may not be productive or
yield favorable performance results.
•
Definitive radiant claims within the North American market should
be viewed with skepticism as no recognized test method exists to
substantiate such claims.
•
A short length high BTU tube heater will display higher radiant and
lesser thermal efficiency ratings. On the other hand, a long length
low BTU tube heater will display higher thermal and lesser radiant
efficiency ratings. Choose your models carefully.
Engineered Vacuum Systems
Common Applications
of Vacuum Systems
Engineered vacuum systems represent a small but important segment of
the infrared market. More commonly found in larger applications, these
systems offer potential operating benefits that are not easily obtainable with
traditional infrared tube heaters.
While the benefits of choosing an engineered vacuum system are worth
noting, so are the complexities. Therefore, careful consideration to the
design, installation, operation and investment of an engineered vacuum
system should be made.
Aircraft Hangars
Operating Theory
An engineered vacuum system emits low intensity infrared heat just like
any other type of tubular heater. What makes these systems unique is
the method in which they operate as well as their expanded operational
boundaries.
Distribution Facilities
An engineered vacuum system typically consists of the following
components:
Emitter Pipe
Burner
Vacuum Exhauster
Vehicle Storage
Baffle
Reflector
While each manufacturer will have their own design parameters, the
theory behind vacuum system design is rather universal. The design
goal of a vacuum system is to connect emitter tube extending from one
or more burner assemblies to a vacuum pump. This is best achieved by
applying the fundamentals of infrared design (Chapter 3) with the required
manufacturer’s application design criteria (see page 7-6).
Fire Station Apparatus Bays
The operational objective of a vacuum system is to simply move hot
gases from the burner(s) to the pump. This movement heats the emitter
pipes, which in turn heat the building via infrared energy. This operation
typically requires a higher capacity vacuum pump, capable of providing
expanded system utility, as further described on the following pages.
Engineered Vacuum Systems
© 2012 Brant Radiant Heaters Ltd.
7-1
Burner Control Assembly
Some vacuum burners are limited in
their BTU offering. Carefully choose
inputs appropriate to your available
mounting height and design needs.
Some vacuum burners utilize filters to
avoid clogging of an internal ceramic
burner. Changing burner filters is
periodically required and can be a
difficult and costly task. Outside
combustion air in lieu of a filtered air
intake design is recommended.
Vacuum Pump
Strategically locate the vacuum pump
in an area where noise will not be
of concern. Avoid the placement of
pumps in contaminated, harsh or
moisture laden environments.
Vacuum pumps are not created
equally and often represent the
most expensive and vital system
component. Take time to learn the
product, notably the horsepower,
housing material, bearing type, shaft
and impeller.
Key System Components
Vacuum Pump
Burner Control Assembly
Damper
Radiant Emitter/Tailpipe
Burner Control Assembly
The burner control assembly will house key combustion components
including the gas valve, safety switches, igniter and the burner. Typically,
burner inputs range from 40,000 to 200,000 BTU’s and have a minimum
and maximum emitter length.
Vacuum Pump
The vacuum pump or exhauster is the device that transfers hot gases
through the system by inducing a regulated suction onto the system.
Typical vacuum pumps range from 0.5 to 1.25 HP and are selected
according to total system BTU’s and emitter lengths.
Emitter Pipe
Emitter or radiant pipe is the tubing that connects the burner assemblies to
the pump. Typically 4 to 6 inches in diameter, this tubing is covered by a
reflector and may be made of hot rolled, aluminized or titanium stabilized
steel. Condensing systems will utilize ceramic coated or stainless steel pipe
(aka “tailpipe”) designed to withstand the corrosive condensate that forms
during normal operation.
Emitter Pipe
The investment in a vacuum system
warrants the use of quality tubes.
Protect your investment by utilizing
aluminized, titanium stabilized or
stainless steel tubes and avoid less
costly hot rolled or light gauge steel
tubes.
Sample Vacuum System Application
Graphic Legend:
HLV-100/80
HLV-100/80
HLV-100/80
HLV-100/80
Tee Fitting
HLV-100/80
HLV-100/80
HLV-100/80
HLV-100/80
HLV-100/80
Unlike ceramic coated hot rolled steel,
stainless steel tailpipe will not crack
and offers superior longevity and
protection.
A swaged tube design will ensure
system integrity and avoid the
possibility of a clamp acting as the
heat exchanger or as an unwanted
condensate catch.
90° Elbow
Damper
Cross Fitting
HLV-100/80
HLV-100/80
HLV-100/80
HLV-100/80
HLV-100/80
HLV-100/80
Color Legend:
Blue: Burner Box; Red: Combustion Tube; Black: Radiant Exchangers
Green: Stainless Steel Tailpipe; Orange: Vacuum Pump; Purple: Heater Accessories
7-2 Engineered Vacuum Systems
© 2012 Brant Radiant Heaters Ltd.
Burner Assembly
Vacuum Pump
Vacuum System Pros
·
Operating Efficiencies. A vacuum system can be designed to achieve
·
·
·
improved thermal efficiencies (see 6-2). This is due to the fact that the
system can be designed to condensate.
Reduced Vent Penetrations. A vacuum system can tie multiple
burners onto a single vacuum pump. Accordingly, the number of vent
penetrations within the space may be reduced.
Extended Tube Lengths. A vacuum system will best accommodate
a design that employs extended runs of radiant emitter. This may
be desirable in large applications or in applications where the vent
penetration is a long distance from the pump.
Elevation Changes. A vacuum system will allow for a design that
requires an elevation change of the system itself. This may be necessary
in unique, pitched or obstacle ridden applications.
Vacuum System Cons
·
·
·
·
·
Costly. Vacuum systems are typically 30 – 50% more costly than a
similar “push” tube design. A vacuum system requires a lot more
components as well as a considerable installation and maintenance
premium.
System Dependency. A vacuum system is dependent upon a single
pump. Should this pump fail, the entire system will be out of
commission until a repair or replacement is completed.
Noise. A vacuum pump typically generates noise that may be
problematic in select applications. Considerations for this noise must
be addressed in the design stages to avoid a future problem.
Complexities. The design and installation complexities adherent
to a vacuum system are many. Only a person knowledgeable of
vacuum system designs should attempt to layout a system, conduct an
installation, and perform a system start-up.
Electrical Consumption. Higher horsepower, higher amp, vacuum
pump motors consume more electrical energy than a push tube
system. This should be considered when selecting a system and when
measuring overall operating efficiencies.
Considerations
Engineering: Most manufacturers
offer an extensive vacuum system
design guide that is necessary to
follow carefully when designing
an engineered vacuum system.
A working knowledge of the
manufacturer’s guidelines is highly
suggested when applying a vacuum
system.
Environmental: By design, an
infrared system offers energy saving
benefits; most notably a reduction
in fuel consumption. A condensing
vacuum system offers the ability to
achieve higher thermal efficiencies.
However, consideration must
be made for the disposal of the
condensate, if generated.
Comfort: A properly designed
infrared system (see Chapter 3) will
result in optimal comfort levels.
Considerations should be made
when determining the location of
the burner boxes, the condensate
piping, and the vacuum pump.
Location of these critical items
impact the total comfort in the
space.
Installation: The installation of a
vacuum system is more complex
than typical “push tube” systems.
Notable differences may include
starting the installation at the pump
and building backwards, slope
consideration, elevation changes,
damper locations, tees, elbows and
many other peripheral items.
Start-Up: A vacuum system requires
a thorough and proper start-up by a
professional. The start-up includes
system balancing, establishing
proper box pressures and control
programming.
Engineered Vacuum Systems
© 2012 Brant Radiant Heaters Ltd.
7-3
Consider This...
A vacuum system operating at
maximum lengths will likely
condensate and requires the use of
condensate pipe or “tailpipe”. Tailpipe
is often one of the most expensive
portions of a vacuum system, yet it
yields minimal radiant output.
Our normal body temperature is
98.7°F. Tailpipe will operate at a
similar temperature if the system is
condensing. Commonly mounted
30-feet in the air, one must ask how
effective the radiant output is of this
portion of the system.
Dry Systems
A dry system would be defined as a system that maintains operating
stack temperatures above the point of condensation. The following
characteristics are typical to a dry system:
··
··
Shorter burner to pump lengths.
System completely covered by reflectors.
A more even radiant heat emittance from the system.
Lower thermal efficiencies.
System A: Non-Condensing System
Hot
1100°
Burner
Pump
30’
Cold
Economic Example
Assumptions:
Cost p/ Therm - (100k BTU) @ $1.00
Degree Days - 2270 (Detroit @ 45°F)
No Night Setback
100% Building Occupancy
·
·
·
·
System A (Dry):
Acquisition Cost: $20,000
Thermal Eff.: 82%
BTU Input:
400,000
BTU Output: 328,000
Operating Cost: $11,073 p/annum
Condensing Systems
A wet system would be defined as a system that maintains operating
stack temperatures below the point of condensation. The following
characteristics are typical to a wet system:
··
··
·
Longer burner to pump lengths.
Uncovered condensate or tailpipe.
A sloped system with a condensate trap.
A less even radiant heat emittance from the system.
Higher thermal efficiencies.
System B: Condensing System
Hot
1100°
System B (Wet):
Acquisition Cost:$32,000
Thermal Eff.: 90%
BTU Input:
400,000
BTU Output: 360,000
Operating Cost: $10,089 p/annum
Payback:
Difference A vs. B:
$12,000
Annual Savings A vs. B:
$984
Payback in Years:
12.20
7-4 Engineered Vacuum Systems
© 2012 Brant Radiant Heaters Ltd.
Too cool
80°
Burner
Pump
In-Series vs. Tandem Burner Design
Other Considerations
“In-series” burners describe a system footprint where the burners are
physically located inline with the emitter pipe. Tandem burners emulate an
in-series design, but are purposely located directly adjacent to the emitter
pipe for operating purposes.
Dampers:
A primary damper is used in every
system and is placed before the
vacuum pump.
Secondary dampers are required
when there are variances in burner
gas input and/or radiant tube runs.
These are necessary to balance the
system’s exhaust flow.
In-Series Design
Features
Design Parameters
Burner Filters
Tandem Design
In Series
Tandem
Flexible per Design Guide
Flexible per Design Guide
Pending Burner Design
Typically Not Required
Upstream Gases
Will Impact Upstream Burner
Will Bypass Upstream Burner
BTU's
Typically Small to Mid Range
Typically Small to Large Range
Primary Damper
Secondary Dampers
Positive vs. Negative Pressure Operation
Infrared tube heaters employ both
negative and positive pressure to move
their products of combustion. Both
methods will yield similar operating
results and operating efficiencies. When
choosing one method over the other
one should carefully consider the overall
design objectives and choose the system
type best able to complete the intended
purpose.
-
-
-
+
+
+
Negative System
+
+
+
+
+
+
+
+
Condensate Traps:
Condensate traps are required on
wet systems that are vented through
the roof. They are not required when
venting through the sidewall unless
specified by the local body having
jurisdiction.
Venting & Air Intake:
Positive System
Rooftop Venting
Features
Negative
Positive
Condensing Option
Optional with Tailpipe
Not Available
Elevation Changes
Optional
Not Typical
Fixture Efficiency
70% Min. to 92% Max.
70% Min. to Typ. 86% Max.
Safety
Certified to ANSI Z83.20
Certified to ANSI Z83.20
Unvented Use
Optional
Optional
Venting Lengths
Longest Length
Shorter Lengths
Venting Pipe
Under Positive Pressure
Under Positive Pressure
Sidewall
Venting
Condensate disposal.
Vacuum systems allow for a reduced
number of roof penetrations.
Provide fresh air for combustion
when negative building pressure or
chemicals are present in the space.
Engineered Vacuum Systems
© 2012 Brant Radiant Heaters Ltd.
7-5
Design for Non-Condensing Systems
Design Definitions
Calculated Maximum Run:
The longest allowable ‘Calculated
Run’ from any burner to the vacuum
pump, including condensing pipe.
System tube lengths are determined by the gas input (BTU/h) of each
burner. The chart below illustrates sample system design parameters for
each burner model used in each system. When calculating tube lengths, do
not add in elbow and tee fittings as they have been accounted for.
Calculated Minimum Run:
The shortest allowable ‘Calculated
Run’ from any burner to the vacuum
pump, including condensing pipe.
Designing a non-condensing system can be fairly straightforward given
the following steps are properly applied. In addition to these steps, an
understanding of the design definitions is critical.
Calculated Run:
Calculated run is determined by
adding the total ‘Single Flow’ plus
one-half of the ‘Common Flow’ of
tubing or pipe.
1. Begin by designing a tentative layout without regard to design Calculated Starting Point of
Condensing:
The point in the ‘Calculated Run’
where condensing pipe must begin.
Minimum Distance to Fitting:
The minimum allowable distance
from a burner to the first elbow or
intersection.
Run:
The total actual length of tube or
pipe from an individual burner to
the vacuum pump.
Common Flow:
The tube or pipe in a run between
the first intersection and the vacuum
pump. ‘Common Flow’ begins at the
point where two or more burners
share common tube or pipe.
Single Flow:
The tube or pipe in a run from the
burner to the first intersection.
Single and Common Flow Diagram
75,000 Btu
Burner
Single Flow
Common Flow
Vacuum Pump
20 ft.
30 ft.
Single Flow
30 ft.
75,000 Btu
Burner
parameters. Use this approach to place each burner and the vacuum pump where most desired.
2. Once a tentative layout has been established, confirm that each run in
the system meets the criteria for ‘Calculated Minimum Run’. ‘Calculated
Minimum Run’ is determined by adding the total ‘Single Flow’ plus onehalf of the ‘Common Flow’.
·
·
If the system does not meet the ‘Calculated Minimum Run’,
length must be added to the run until all burners meet the design
parameters.
If the run exceeds the ‘Calculated Maximum Run’, it will be
necessary to either make the system a condensing system or shorten
the runs which exceed this criteria.
3. Confirm the following applies (non-condensing systems only):
a) A maximum of two elbows per run are allowed.
b) A maximum of three intersections (tees or crosses) are allowed per system.
c) All elbows and intersections less than 20 feet from a burner require a reflector.
Sample Design Parameters
Minimum Distance
to Elbow or
Intersection
Calculated
Minimum Run
40-60
10 ft.
75-80
10 ft.
90-100
Burner
MBH Input
Calculated Starting
Point of Condensing
Calculated
Maximum Run
30
45
85
35
50
95
10 ft.
40
55
105
110-125
10 ft.
45
60
110
140-150
15 ft.
50
65
120
170-180
200
15 ft.
20 ft.
55
60
70
75
130
140
For complete design information, refer to the HLV Series Design Manual (F/N: LIOHLV).
7-6 Engineered Vacuum Systems
© 2012 Brant Radiant Heaters Ltd.
Infrared Heaters Offer Green Benefits
Long before the importance of the environment was widely understood,
fuel efficient heaters for industrial and commercial use were available in the
marketplace. Gas-fired infrared heaters offer a solution to the global effort
for businesses to design, build and operate facilities that are ecologically
friendly.
Infrared heaters allow for a lower temperature setting, resulting in lower
fuel costs. On average, infrared heaters can save the customer 23% to
50%. Two-stage technology can reduce energy costs by another 12% and
benefit customers with faster heat loss recovery, improved comfort and a
significant reduction in equipment cycles.
Today more than ever, infrared heaters are getting the recognition they
deserve for their many green benefits they bring to business, including:
•
•
•
•
•
Proven fuel savings.
Possible rebates from local gas companies.
Low levels of harmful emissions.
Improved air quality because airborne particles are not circulated.
Increased comfort levels.
‘Green’ Characteristics of Infrared Heaters
Topic
BTU/h Range
Energy Savings
Heating with gas fired infrared heating appliances have proven fuel
savings over traditional forced air systems. Documented cases have
confirmed a savings of up to 50%.
Rebates
Numerous gas companies recognize the energy savings associated
with infrared heaters and encourage the installations by offering
rebates of up to $500 for each installed unit. Check with your local
supplier.
Tax Credits
Emissions
The Energy Act of 2005 allows commercial buildings a tax credit of
up to $1.80 per sq. ft. for buildings that demonstrate a total energy
savings greater than 50% of an established baseline. Infrared heating
can help to achieve an overall energy efficient building. LEED®
Platinum Certification automatically qualifies.
Reducing the energy consumption of your heating appliance will
reduce the amount of CO2 released into the atmosphere.
Furthermore, infrared heaters are low emitters of other noxious gases
such as NOx, Carbon Monoxide and VOC’s.
Air Quality
Infrared heaters do not use air currents to transfer the heat. This will
help minimize the exposure of hazardous particles, chemical
pollutants, and cross-contamination of regularly occupied areas.
Thermal Comfort
Individual zone controls increase the thermal comfort for all
occupants. Heat energy stored within ambient objects rather than the
air improves the heater’s energy efficiency.
Advanced
Technology
Features such as two-stage technology, black coated emitter tubes,
highly polished reflector material, and an advanced burner design all
contribute to increasing the heater’s energy efficiency.
Proven Infrared Savings
Reduced fuel requirements of
radiant heaters allow them to be
installed with a rated input of 80
to 85% of the total calculated heat
loss. Source: ASHRAE HVAC Systems and
Equipment.
“Additional energy savings of 25% to
30% were associated with operation
of the two-stage infrared system…”
Source: ASHRAE Technical Paper 4643.
“…for total building heating...
complete [radiant heating]
systems... produce a most effective
and efficient means of utilizing
energy for space heating.” Source:
ASHRAE Systems Handbook.
“...annual fuel savings as high
as 50%.” Source: ASHRAE Systems
Handbook Chapter 15.
Two-stage technology has a proven
35% less cycles and an additional
12% fuel savings over single-stage
operation. Source: Braneida Study
October 1993.
Did You Know?
USA fossil fuel consumption in BTU’s.
• Dec. 2009 - 58.7 Quadrillion
• Dec. 2008 - 62.8 Quadrillion
• Dec. 2007 - 64.6 Quadrillion
Source - US Department of Energy
Green and LEED®
© 2012 Brant Radiant Heaters Ltd.
8-1
Definitions and References
LEED®: An acronym that stands
for “Leadership in Energy and
Environmental Design”. This is a
third party certification program for
design, construction, and operation
of high performance green buildings.
Visit www.usgbc.org/LEED.
LEED® AP: An accredited
professional who has demonstrated
a thorough understanding of green
building practices, principles of
green, and the LEED® Rating System
through a standardized test. Consult
with LEED® AP when planning to
build an energy efficient, green
building. Visit www.gbci.org.
ASHRAE: An acronym that stands
for “American Society of Heating,
Refrigeration, and Air-Conditioning
Engineers”. A technical society
to advance the arts and sciences
of heating, ventilation, air
conditioning, and refrigeration. Visit
www.ashrae.org.
USGBC: An acronym that stands
for “US Green Building Council”, a
non-profit trade organization that
oversees the LEED® Certification
program. Visit www.usgbc.org.
The USGBC
Energy efficiency is recognized by LEED® as a significant
contributing factor to a green environment. An infrared
heating system design with multiple units allows for
greater control over comfort. Infrared allows for overall
lower temperatures, yet units can be controlled separately
for higher or lower temperatures in each area.
The U.S. Green Building Council (USGBC) is a non-profit organization
that oversees LEED®, and the Green Building Certification Institute (GBCI)
handles the credentialing of professionals who demonstrate a thorough
understanding of LEED® principles. Those individuals can earn an
“Accredited Professional” certification – LEED® AP – title­.
Customers should consult a LEED® AP when beginning a new building
project or making enhancements to an existing facility.
Taking the "LEED®"
Businesses worldwide are taking the steps to build office buildings,
manufacturing plants and commercial shops with efforts toward higher
efficiencies and lower operating costs by going “green.”
Leadership in Energy and
Environmental Design (LEED®)
is a third-party certification
program and an internationally
accepted benchmark for the design, construction and operation of highBENEFITS
performance,
environmentally friendly buildings. LEED® provides the tools
to create and sustain a building’s LEED® rating, and recognizes performance
in seven key credit categories:
• Sustainable Site
• Water Efficiency
• Energy and Atmosphere
• Materials and Resources
• Environmental Quality
• Innovation and Design
• Regional Priority
Energy Savings Recognition & Reward
LEED® and related logo is a trademark
owned by the U.S. Green Building Council
and is used by permission.
8-2
Green and LEED®
© 2012 Brant Radiant Heaters Ltd.
The continued emphasis on the use of energy saving appliances has resulted
in numerous programs designed to encourage the use of infrared heaters.
Federal tax credits (see page 8-1) and/or generous utility rebate programs
(see page 10-1), designed to promote the use of ‘green’ technologies, are
presently available in many parts of the United States.
LEED® Points Breakdown
Areas Where Infrared Can
Contribute
Regional
Innovation Development
4% & Design 6%
Sustainable Sites
26%
Indoor Environmental Quality 15%
Materials &
Resources 14%
LEED ® Credits
Based on LEED® for new construction.
Water
Efficiency 10%
Energy & Atmosphere 35%
When implementing the LEED® NC (v.3.0) process, there are seven credit
categories in which up to 100 total points are earned. The application of
infrared heaters can contribute up to 22 points in three of the qualifying
categories.
EA
Sustainable Sites
Water Efficiency
Energy & Atmosphere (up to 19 points)
MR
Materials and Resources
EQ
Indoor Environmental Quality (up to 2 points)
Innovation and Design (up to 1 point)
Regional Priority
SS
WE
Qualifying Credit Categories
when Using Infrared Heaters
ID
RP
Energy & Atmosphere (EA): Category point total = 35 points. Establishes
energy efficiency and system performance, optimizes energy efficiency,
supports ozone protection protocols and encourages renewable/alternate
energy sources.
Indoor Environmental Quality (EQ): Category point total = 15 points.
Establishes minimum indoor environmental quality performance to
prevent the development of indoor environmental quality problems in
buildings.
Innovation & Design (ID): Category point total = 6 points. Project teams
are encouraged to apply for innovation credits if the energy consumption
of non-regulated systems are also reduced. One point can be credited if at
least one project team participant is a LEED® Accredited Professional (AP).
Contributes up to
22*pts.
• Reduced fuel
consumption rates up to
50%. (EA Credit 1)
• Reduced electrical
energy consumption.
(EA Credit 1)
• Increased thermal
comfort levels by design
in the space.
(EQ Credit 7.1)
• Improved individualized
comfort zones through
modular design.
(EQ Credit 6.2)
• Exemplary performance
in energy conservation.
(ID Credit 1)
• Consulting a LEED® AP
can potentially earn an
additional credit.
(ID Credit 2)
* Out of 100 total points.
Four Levels of Certification
Certified:
Silver:
Gold: Platinum:
40-49 pts.
50-59 pts.
60-79 pts.
80+ pts.
Green and LEED®
© 2012 Brant Radiant Heaters Ltd.
8-3
Did You Know?
There are several LEED approved
energy modeling software programs
from which to choose. Below is a
list of some of the more popular
programs:
• US DOE®
• Trane TRACE®
• Carrier HAP®
• eQUEST®
• Energy 10®
• TRNSYS®
• EnergyPlus®
• EnergyPro®
• VisualDOE®
• BLAST®
• Energy Pro®
Consider This...
The information that is provided
from the energy modeling does not
represent the actual energy costs
after construction. Many extraneous
factors such as variable occupancy,
building operation and maintenance,
weather, and changes in energy rates
can all play a factor in the actual
outcome.
As with any calculation,
the results are only as
good as the information
provided. The old antic dote ‘garbage
in, garbage out’ even applies when
utilizing energy modeling tools.
Energy Modeling and Infrared Heaters
What is Energy Modeling?
Energy modeling is the process in which a building is evaluated through
a software program for total building efficiency. This is accomplished by
utilizing specialized software with complex algorithms, specific design
variables, and weather data. The benefit of performing an energy modeling
simulation is that a building can be compared to several different design
alternatives prior to the start of construction. This allows the owner and the
design team to select the optimal design.
Energy Modeling and LEED®
The LEED® rating system typically utilizes energy modeling to award
points based on a percentage of improvement over a theoretical baseline
building. The amount of points awarded is dependent on the percentage
of improvement. The energy modeling must be in conformance with
ASHRAE 90.1-2004, and the calculation for improvement is taken from
appendix G; seen below.
100 x
(Baseline Building Performance – Proposed Building Performance)
Baseline Building Performance
=
Percentage
Improvements
How to Utilize Infrared in an Energy Model
In order to represent the maximum efficiency of infrared, a few key items
must be considered prior to entering data into the calculation. These
following tips are provided to help maximize the points scheme for a
project utilizing infrared.
TIP #1: According to the ASHRAE Handbook HVAC SYSTEMS AND EQUIPMENT, when
utilizing infrared heating, it is recommended to reduce the required heat energy to 80% to
85% of the total heat needed according to the calculated heat loss. This reduction in fuel
consumption will increase the overall efficiency of the baseline building model.
This allowable reduction in required heat is unique to infrared because of
its overall high system efficiency.
TIP #2: ASHRAE 90.1-2004 Section 6.5.8 states that radiant heating SHALL be used when
heating unenclosed spaces. (Examples: loading docks, patios, valet areas, etc.)
Infrared heats objects directly without heating the air first – which makes it
ideal for areas with high air infiltration.
TIP #3: Because infrared is a very unique method of heating, it is addressed separately in
ASHRAE 90.1-2004 under Section 6.5.8. Therefore, do not look for infrared in Tables 6.8.1
Minimum Efficiency Requirement, as there is no clause for infrared heaters.
Because of the fundamental method in which infrared heats objects, a
thermal efficiency rating does not fully depict the effectiveness of the unit
(see Chapter 5).
8-4
Green and LEED®
© 2012 Brant Radiant Heaters Ltd.
Common Installation, Operation & Maintenance Practices
Proper Use:
Infrared heaters are designed to provide warmth and comfort for
commercial, industrial and some approved residential applications.
Most infrared heaters are not approved for:
•
•
•
Residential indoor living or sleeping areas.
Process heating, such as paint booths, grain bins, material drying.
Hazardous (class 1 or 2) environments.
A Qualified Technician:
Infrared heaters must be installed by a qualified person or agency per
applicable codes and the manufacturer’s Installation, Operation and Service
manuals. Also, an installer shall:
•
•
•
•
•
Install the heater in accordance with the published minimum clearances to combustibles and other heater specifications.
Provide access for servicing.
Give a copy of the manufacturer’s Installation, Operation and Service manual to the owner.
Ensure there is adequate air circulation around the heater.
Ensure the heater is placed in an approved application.
Installation Considerations:
•
•
•
•
•
Proper design
• Chemicals or vapors in the space
Gas supply and pressure
• High moisture/harsh environment
Mounting heights
• Venting lengths and locations
Clearance to combustibles
• Reflector angle
Burner box location
• Necessary guarding
Specialty Applications:
Certain applications may require additional design and installation
considerations. Contact the factory or your local representative for
assistance when applying infrared heaters in applications such as:
•
•
•
•
•
•
High altitude sites
Residential applications
Areas with non-standard gas
CNG bus stations/service garages
Agricultural applications
Outdoor patios
Applicable Standards and
Codes
Installation must comply with
national and local codes and
requirements of the local gas
company.
Gas Codes:
Refer to National Fuel Gas Code, ANSI
Z223.1 (same as NFPA 54) or CAN/CGA
B149.1-latest revisions.
Aircraft Hangars:
Refer to Standard for Aircraft Hangars,
ANSI/NFPA 409 or CAN/CGA B149.1–
latest revisions.
Public Garages:
Standard for Parking Structures NFPA
88A – latest revision or the Code
for Motor Fuel Dispensing Facilities
and Repair Garages, NFPA 30A or
CAN/CGA B149.1– latest revision
Electrical:
Refer to National Electrical Code®,
ANSI/NFPA 70 or CSA C22.1 Canadian
Electrical Code-latest editions.
Venting:
The venting must be installed
in accordance with the unit’s
Installation, Operation and Service
manual and the following codes.
Refer to NFPA 54/ANSI Z223.1,
National Fuel Gas Code or CAN/
CGA B149.1 Canadian Standards
Association-latest revisions.
Did You Know?
The effectiveness of an
infrared surface to a
person or object may be diminished
with wind speeds above 5 mph. The
use of adequate wind barrier(s) may
be required.
When possible, locate
the thermostat in a
neutral location to avoid
a false sensing scenario.
Avoid direct placement
on outside cold walls.
Common Practices
© 2012 Brant Radiant Heaters Ltd.
9-1
Did You Know...
Source D.O.E.
Tips for Improved Infrared Operating Efficiencies
Energy Star: Install an Energy Star rated programmable controller
and have an automatic setback during times of zero occupancy.
Most applications can recover from a setback within 20-30 minutes.
...that 30% of a building’s total
energy is used inefficiently or
unnecessarily?
...that 20 billion dollars could
be saved annually if the energy
efficiency of all commercial buildings
improved by 10%?
...that improving the energy
efficiency of commercial and
industrial buildings by 10% can
significantly reduce greenhouse gas
emissions?
Do Your Part!
Gas fired infrared heating appliances
are a great method to efficiently
heat many applications when
properly applied and maintained.
By actively following the tips listed
here, infrared heaters can potentially
increase a building’s overall
efficiency ratio, reduce the output
of greenhouse gases, and increase
comfort levels in the building.
Do your part and own an energy
efficient building!
1
2
70°F
Two-Stage: Utilize two-stage technology in your heating appliances.
This will lower annual fuel consumption, reduce greenhouse gas
production, and increase comfort levels in the space.
Controls: Utilize advanced control options. Today’s climate control
technology provides an excellent means to directly monitor and
improve your building’s overall efficiency and can also allow for
individualized zoning. Consider using programmable thermostats,
locking guards, remote sensors and in some cases, advanced DDC
controls.
Insulation: Evaluate the soundness of your structure. Air leaks, poor
or missing insulation, and degraded weather-stripping increases
the amount of energy needed to maintain a constant temperature.
Adding additional insulation will help to maximize your building’s
energy efficiency.
Maintenance & Cleaning: Clean and maintain your current units.
Dust and debris can accumulate on the reflector and internal
components, inhibiting the overall efficiency of the unit. Routine
maintenance can help to keep your unit running at its optimal
efficiency.
Replace Older Units: Replace older units with a more efficient one.
The advancement of technology has yielded more efficient heating
appliances. Also, as older units wear down, the efficiency may decay,
thus requiring more energy consumption to heat a desired area.
Educate: Inform staff of the high costs associated with poor energy
management practices. Discourage leaving dock doors open for
extended periods of time. Also, instruct staff members that setting
back the thermostat by just 2°F can save up to 6% on your heating
costs.
Barriers: Seal off any areas where excessive air leaks are present.
Isolate unoccupied areas with partitions. Areas that contain
excessive air leaks can increase fuel consumption.
Rebates: Get rewarded! A wide array of government, state and
local gas companies offer initiatives in the form of rebates and tax
credits to encourage energy savings and green building. Conduct an
energy audit and then contact your local gas providers to determine
eligibility.
9-2
Common Practices
© 2012 Brant Radiant Heaters Ltd.
www.reverberray.com
Distribution Network
Our acclaimed and expansive website, www.
reverberray.com, caters to engineers, contractors
and end-users seeking information and access
to our many lines of infrared heaters. Online
tools include product brochures, specifications,
manuals, a CAD library, a parts locator program,
wiring diagrams, distributor information,
troubleshooting guides and much more.
Aftermarket Parts Replacement
During the cold winter months, the importance
of properly providing and supporting
aftermarket parts is critical. A custom database
parts program, containing over 2000 items,
is part of the Re-Verber-Ray® solution to this
need. Browse our parts list or search for a
specific part by product name, part number or via a
reference library. Learn more about your applicable
part including technical details, photographs, historical
usage, list pricing and much more. Share this web based
resource with your network for ease in identifying and
obtaining the necessary components. Visit
www.reverberray.com/parts.
Online CAD Library
6"
4"
4"
6"
4"
HLV-120/96
6"
HLV-120/96
4"
6"
6"
HLV-120/96
6"
4"
HLV-120/96
4"
HLV-120/96
6"
6"
6"
6"
6"
HLV-120/96
6"
4"
6"
4"
HLV-120/96
PB-9
HLV-120/96
4"
4"
LEGEND:
BLUE= BURNER
BOX
RED= COMBUSTIO
N TUBE WITH REFL.
BLACK= ALUMINIZED
TUBES WITH REFL.
GREEN= S.S. TAIL
PIPE WITH REFL.
PURPLE= HEATER
ACCESSORIES
RE-VERBER-RAY
4"
4"
DETAILS:
6"
DETROIT RADIANT
21400 HOOVER RD
CORROSION
DRAWN BY:
CHECKED
BY:
SCALE:
DATE:
1:1
PRODUCTS
WARREN, MI 48089
CONTROL
HANGAR
PROJECT:
DRAWING
NO:
1
Looking to design an infrared project and in
need of a technical drawing? Try visiting our
website to learn more about our free AutoCad
compatible product CAD library. Download an
extensive inventory of drawings consisting of
assorted symbols, heaters, installation details,
etc. in four commonly accepted file formats.
Save time, money and ensure technical accuracy
by visiting www.reverberray.com/cad.
Detroit Radiant Products Co. offers a
local distribution network designed
to assist in pre and post sale support.
Local representatives are factory
trained to provide design assistance,
quotations, technical support and
aftermarket parts.
Local Representative. Your local
representative may be found by
entering your zip code online at
www.reverberray.com/locator.
Master Part’s Distributor. A factory
authorized national distributor able
to provide support, as listed below,
for your Re-Verber-Ray® heater.
• Toll-free staffed assistance
(Mon.-Fri., 9am-5pm local time).
• Technical troubleshooting assistance.
• Stocked Re-Verber-Ray® parts.
• Visa and MasterCard services.
• 24-hour shipping, via UPS, anywhere
in the USA.
• Fair and competitive parts pricing with
Trade discounts.
• Visit www.reverberray.com/locator/
mpdist.html.
W.W. Grainger, Inc. A leading
business-to-business distributor
of MRO and HVAC equipment.
Dayton® brand infrared heaters, as
manufactured by Detroit Radiant
Products Co., were first introduced
in the late 1960’s and are presently
available at any of the 440+
Grainger branch outlets.
Did You Know?
That re-sellers of
Re-Verber-Ray®
Series 3 tube
heaters may display their logo and
contact information on the product.
Enroll in our personalized label
program at www.reverberray.com/
labels.
Distributed by:
ABC MECHANICAL COMPANY, INC.
1234 Anywhere Street
Some City, MI 12345
(123) 456-7890
http://www.website.com
ID: ABCI
Place company mission or other statement here.
Common Practices
© 2012 Brant Radiant Heaters Ltd.
9-3
Maintenance Tips
The fan is a critical tube
heater component and
must be kept clean.
When cleaning the fan, be sure to
clean each fin on the impeller fan
(squirrel cage) to ensure proper air
movement. Oil the motor annually
using SAE 20 or SAE 30 Motor Oil.
A heater that hangs in a dirty
or moist operating environment
should be covered or removed
during the summer months.
A dirty reflector will adversely impact
the output and performance of an
infrared heater. Clean reflectors
annually using a wet rag or sponge.
If your aluminum reflector is stained
or discolored, try cleaning it with
Alumiprep 33 by Henkel Technologies.
To avoid blockages in
the venting from birds
nesting, a screen can be installed on
your vent cap with squares spaced
1/4 to 1/2 inches across.
If using high pressure air to clean a
ceramic heater DO NOT exceed 30
psi or you risk removing the gasket
material that lines each ceramic.
High pressure air should be applied
carefully and from a distance of 3 to 5
feet. DO NOT apply high pressure air
to a gas valve or air pressure switch
as this will rupture the component’s
internal diaphragm.
When checking the
combustion chamber
noted on the annual
inspection checklist, pay particular
attention to the integrity of the top
portion of the tube nearest the burner
(the first 10-feet) as this is where the
failure risk is greatest.
9-4
Common Practices
© 2012 Brant Radiant Heaters Ltd.
Infrared Heater Inspection Checklist
For optimum performance and safety, it is recommended that all installation,
service and annual inspection be performed by a qualified person or agency.
Make sure that:
☐☐ Clearances to combustibles warning signs are posted as described in Chapter 4.
☐☐ The manufacturer’s Installation, Operation and Service manual is legible. Keep
manual in a clean, dry place. Contact the manufacturer for replacement labels
or manuals.
☐☐ All warning labels are attached and legible.
☐☐ The area around the heater is free of combustible materials.
☐☐ Reflector is in good condition and free of dust and debris. Clean outside
surface with a damp cloth, if needed. Reflector must be properly resting on
mounting brackets and not the tube itself.
☐☐ Vent pipe and outside air inlet are free of dirt, obstructions, cracks, gaps in the
sealed areas or corrosion. Look for bird or insect nests. Remove any carbon
deposits. Tubes are connected and suspended securely. There should be no
holes, cracks or distortion on any part of the tube, especially the top.
☐☐ Gas line has no gas leaks. Check gas connection and verify proper inlet
pressures are satisfied; refer to the manufacturer’s Installation, Operation and
Service manual.
☐☐ Combustion chamber and burner observation windows are clean and free of
cracks or holes.
☐☐ Blower impeller fan and motor are clean.
☐☐ Burner and orifice are clean.
☐☐ Igniter and electrode are not cracked, broken, eroded or showing signs of wear.
Replace as needed.
☐☐ Thermostats, sensors and control devices have no exposed wire nor damage
to the device or its wiring. Verify that clearance to combustible placards are
posted and in accordance with manufacturer's requirements.
☐☐ Suspension of the heater is secure and in accordance with manufacturer's
requirements. Look for signs of wear on the chain or ceiling.
☐☐ Pump and blower inlets and outlets are free of blockage or soot.
☐☐ Ceramic tiles in burner assembly are not operating in a flashback condition
(burning behind grids).
☐☐ Ceramic tiles are not cracked. Ceramic burner assembly gaskets must be in
place. Do not clean with high pressure air.
For a complete checklist, reference the manufacturer's Installation, Operation
and Maintenance manual.
The Key Benefits of Infrared
ASHRAE Paper of the Year
Regardless of brand type or features, an infrared heater will typically save
energy when compared to traditional methods of heating. The overall
operating efficiencies of an infrared system are proven and measurable.
When selecting an infrared tube heater, there are several key features that
contribute to the overall quality and effectiveness. Items such as two-stage
technology, burner design, exchanger tube properties and reflector material
all have a vital role to play in the makings of an exceptional infrared heater.
Independent Evaluation of Infrared vs. Forced Air Heating
A 2-½ year study (Oct. 1999 – March 2002) was conducted at a commercial
facility to compare the effectiveness of a two-stage infrared heating system
verses a forced air heating system. The study was recognized and published
by ASHRAE in 2003 (see ASHRAE Paper 4643). A summary of the key
findings is noted below.
of up to 23% over a conventional
forced air heating system.
• The two-stage infrared heat
system ran on low fire longer
than the forced air unit per
on-cycle, resulting in reduced
temperature swings and
improved comfort.
• The thermal flywheel effect in
the concrete slab contributes to
energy use efficiency.
Forced Air vs. Infrared Energy Usage.
35
Average m3/day
• The results yielded a fuel savings
30
Forced Air
Infrared
% savings expressed as IR over FA
(-5.3)%
25
23.0%
19.5%
20
10
5
Test 1
10/1/99-2/17/00
FA= 26.7; IR= 28.2
Test 2
2/18/00-2/28/00
FA= 26.6; IR= 21.4
Test 3
10/18/00-10/12/01
FA= 37.7; IR= 29.0
A growing number of gas utilities have formally recognized the energy
saving benefits of infrared and have included them in sponsored rebate
programs. A list of known programs is provided below.
Ontario
Quebec
Amount Company
Contact Information
$100
Enbridge
www.enbridgegas.com/businesses
$300
Union Gas
www.uniongas.com/business
$500
Gaz Metro
$100-$250 Gazifere
• Proven Savings: 20-50% over
conventional forced air units.
• Flexibility: Heaters can be
placed where they are most
needed.
• Superior Comfort: Reduced
stratification and increased
perceived comfort.
• Durability: Low maintenance
and quality components ensure
a long life cycle.
• Quiet and Clean: No noisy air
blowers pushing dirt and dust
around.
Utility Rebate Programs
Location
Benefits of Infrared
• Modular Design: Unitary
systems are excellent for spot
heating or for total building
heat.
15
0
In 2003, Agviro Inc.
was recognized by
ASHRAE for their
efforts in publishing
Paper No. 4643 “Evaluation of an
Infrared Two-Stage Heating System
in a Commercial Application”. Agviro
Inc. has researched and authored a
number of scientific, technical and
informational papers on the subject
of energy efficiency.
www.gazmetro.com
www.gazifere.com
Listed programs apply to natural gas, low intensity infrared heaters only.
Energy Conservation
ASHRAE Handbook -2008 HVAC Systems & Equipment.
“Infrared heaters are effective for
spot heating. However, because of
their efficient performance, they are
also used for total heating of large
areas and entire buildings (Buckley
1989). Radiant heaters transfer heat
directly to solid objects. Little heat is
lost during transmission because air
is a poor absorber of radiant heat.”
Key Features 10-1
© 2012 Brant Radiant Heaters Ltd.
Ever Wonder...
Why your car gets
better gas mileage
when driving on the
expressway? This is primarily due
to a reduction of start – stop cycles
prevalent to city driving. A two-stage
heater also conserves energy by
reducing its on/off cycles.
Two Stage Technology
Two-stage infrared technology is characterized by a high fire (typ. 100%)
and a low fire (typ. 65%) operating mode. Because high fire is typically only
needed 5-10% of the season, the dominant operating mode will be low fire.
Annual Heating Hours for Major Cities
5000
10.2%
4000
3000
14.9%
89.8%
85.1%
High Fire Operation
7.4%
7.7%
92.6%
92.3%
5.2%
94.8%
Hrs/Yr
2000
Two-Stage Operation
0
Don’t be fooled by
claims of reduced
thermal efficiencies
when considering two-stage
technology. The key to two-stage
operation is the reduction in
cycles which directly translates
to an overall improved operating
efficiency.
Minneapolis, Los Angeles,
Minnesota
California
Denver,
Colorado
Atlanta,
Georgia
90.2%
18.2%
88.8%
Detroit,
Michigan
9.8%
93.8%
11.2%
1000
Low Fire Operation
6.2%
81.8%
St. Louis,
Missouri
New York,
New York
Dallas,
Texas
Seattle,
Washington
This graph shows how many hours
per year a two-stage heater would
run at 70% (low fire) and 100%
(high fire).
This graph also shows the high and
low fire as a percentage of total
annual operating time.
Unlike single stage heaters, two-stage operation allows for a 35% reduction
in on/off cycles and has a documented 12% fuel savings over single stage
heaters. Oftentimes, a 20% savings is realized. Two-stage heaters provide
enhanced comfort levels and perform to the demands of the space. The two
stage operation also allows for faster heat recoveries, design flexibility and
improved comfort levels.
Braneida Study
Buckley and Seel
Buckley and Seel (1987) compared
energy savings of infrared heating
with those of other types of
heating systems. Recognizing the
reduced fuel requirement for these
applications, Buckley and Seel
(1988) noted that it is desirable for
manufacturers of radiant heaters
to recommend installation of
equipment with a rated output
that is 80 to 85% of the heat loss
calculated by methods described
in Chapters 29 and 30 of the 2005
ASHRAE Handbook - Fundamentals.
A six month study (Oct. 1993 - April 1994) was
conducted to evaluate the operation of two-stage
and single stage infrared heaters. The study was
recognized and published by RDM Engineering
in July 1994. A summary of the key findings is
noted below.
• Fuel Savings. A 12% additional fuel savings was observed.
• Cycle Reduction. A 35% reduction of on/off cycles directly correlates
to fuel savings as it avoids the wasteful over-cycling nature of single
stage appliances.
• Superior Comfort. The ability to operate in low fire for prolonged
periods of time results in less intense, improved comfort levels.
• Design Flexibility. Two-stage technology allows one to design for the
“worst case” scenarios, yet perform to the “normal” daily demands.
• Faster Heat Recoveries. An appliance operating at 65% will obtain full
output (100%) much faster than an appliance that starts from off.
• Reduced Carbon Dioxide Emissions. Less energy consumption will
result in less emissions.
• Improved Product Life. A reduction in operating cycles and
temperatures yields less stress on the equipment thereby extending its
life cycle.
10-2 Key Features
© 2012 Brant Radiant Heaters Ltd.
9-2 Quality
Advanced Burner Design
Definitions
There are many different shapes, styles and configurations of burners in
infrared appliances. A well designed burner has the ability to achieve
complete combustion through a wide range of inputs without producing
an unstable, noisy or incomplete burn. There are several key design
characteristics that affect the performance of a burner in an infrared
appliance.
Key design characteristics include:
•
•
•
•
A true venturi.
Separated primary and secondary combustion air.
All stainless steel construction.
Specialized flame arrestor designed to inhibit flashback or liftoff.
Emissivity: The ratio of the radiant
energy emitted by a surface to that
emitted by a black body at the same
temperature. Perfect black body
emissivity is 1. A perfect reflector
is 0.
Venturi: A venturi burner with a
tapered throat follows Bernoulli’s
Principle that states, “where there is
a decrease in pressure, there must be
an increase in velocity at the same
rate that the pressure decreases.”
• Vortex inducing fins increase thermal heat transfer.
Did You Know?
Vortex “Swirl” Burner
Cup-style Burner
Heat Exchanger Tubes
The exchanger tubes of a low intensity infrared
heater are a critical part of the heater. Many
criterions must be met in order to achieve
the maximum thermal radiant output. For
additional information on tube construction
and design see Chapter 5.
• 16-gauge construction for improved performance and longevity.
• Overlapping swage design to ensure a continuous seal.
• Various material offerings to meet the needs of any application.
• Specially formulated silicon-resin coating increases radiant output.
Emissive Values for Common Industry Heat Exchangers
Highly emissive silicone-based resin coating: ε = .95
Heat-treated exchanger: ε = .80
Untreated exchanger: ε = .70
The Stefan-Boltzmann Law states
that the total energy radiated from
a body is directly proportional to
the fourth power of the black body’s
thermodynamic temperature, T (also
called absolute temperature), and
can be calculated by the following
formula:
w = AεσT4 (total radiant output)
A = Area of emitting surface
ε = Emissive Value
σ = Stefan-Boltzmann constant
T = Absolute temperature
A high
temperature black
resin coating
(aka/ Pyromark)
enhances the
ability of a radiant emitter tube to
emit infrared energy. This black
coating is the same material used
by NASA on the nose of the space
shuttle to disperse heat away from
the space shuttle during re-entry
into the Earth’s atmosphere.
Key Features 10-3
© 2012 Brant Radiant Heaters Ltd.
Quality 9- 3
Labor Savings:
A heater featuring a
swaged tube design
is far easier to install
than a non-swaged design and will
typically reduce the comparable
installation time by 1-2 man hours.
Interlocking Tube Design
Brant Radiant Heaters Ltd. utilizes a unique interlocking tube design
that overlaps each tube by four inches. This is accomplished by swaging
(pronounced “swedging”) one end of the tube to fit into the next. The
benefits of this design include structural integrity, a better seal, assurance
that the clamp will not act as a heat exchanger, and labor savings on the
initial installation.
Reflectivity:
Reflectivity is a
material’s ability to
radiate energy to
the floor. The best
example of this is to
compare how well a flashlight is
reflected from a highly reflective
surface verses a dull surface.
Despite the availability of bright
aluminum, most reflectors used in
the infrared industry are constructed
of a mill finish aluminum that only
provides a 60-70% reflectivity value.
Did You Know?
Brant Radiant Heaters performs a
100% function test on each unit
prior to its approval for shipment
from the factory. This dedication to
quality ensures that the end user
will receive a quality product able
to consistently serve their heating
needs for many years to come.
Quality Reflectors
Aluminum reflectors that have a highly polished, mirror-like finish — with
85% to 95% reflectivity — are most effective in reflecting infrared heat
energy to people and objects at the floor level. This manufacturing detail is
optimal for targeting the heat energy to specific areas.
When radiant energy falls on a reflector’s surface, it is either reflected or
absorbed. Aluminum has a low absorption value and when combined with
a polished surface, it will have a very high reflective value.
Reflector Grade
Mill Grade
Polished Aluminum
Reflectivity
60 - 70%
85 - 95%
Absorption Value
.40 - .65
.10
Radiant Energy on
Reflective Surface
35 - 60%
90%
Quality Components
In addition to the enhanced key components outlined in this chapter, Detroit
Radiant Products Co. utilizes many other quality components, such as:
•Reliable ignition systems.
•Fully digital controls.
•Industry proven gas controls.
•Various upgrade options.
•Service friendly designs.
•Flexible control and voltage options.
•Quality accessories for custom configurations.
10-4 Key Features
© 2012 Brant Radiant Heaters Ltd.
9-4 Quality
About Brant Radiant Heaters Limited
Mission Statement
For more than half
a century, Brant
Radiant Heaters
Limited has been
setting the standard
for high quality, cost
effective, energy
efficient infrared heaters. Our Re-Verber-Ray® brand products are recognized
as a solution for most commercial, industrial and specialty applications.
Our Paris, Ontario manufacturing facility includes an in-house quality
control system that performance tests each heater, and a “blueprint” of every
single valve-train, before leaving our ultra-modern facility. We are supported
by a global network of associate companies which collectively provide an
unparalleled production platform.
Brant Radiant Heaters Limited has a trusted and talented network of
employees and representatives. Our attention to detail and customer
satisfaction has helped to make us a recognized leader of energy-efficient
infrared heating products.
Trademarks and Associations
Produced since 1965, quality infrared heaters
by Detroit Radiant Products Company.
Produced since 2001, quality infrared heaters
dedicated to the wholesale marketplace.
Custom ID
Produced since 1972, quality infrared
heaters for W.W. Grainger Inc.
Brant Radiant Heaters Ltd. is dedicated
to providing high quality energy
efficient infrared heating equipment at
reasonable prices with good delivery
and courteous service.
Re-Verber-Ray® Products Are
Found In...
U.S.A
Canada
Mexico
Ireland
Korea
China
Russia
Poland
Bulgaria
Ukraine
Israel
Turkey
By request, quality infrared heaters for private
brand name arrangements.
Contact Us
Local Dealer Relationships
Factory trained Re-Verber-Ray® representatives work with engineers,
contractors and installers to develop efficient design plans for each
application, ensuring the customer that the right products are selected to
meet maximum efficiency.
Brant Radiant Heaters Limited
34 Scott Ave.
Paris, On N3L 3R1 CAN
(519) 442-7823 voice
(800) 387-4778 toll free
(519) 442-7321 fax
sales@brantradiant.com
www.brantradiant.com
Company
© 2012 Brant Radiant Heaters Ltd.
11-1
Associations
American National
Standards Institute (ANSI)
www.ansi.org
American Society of
Heating, Refrigerating and
Air-Conditioning Engineers
(ASHRAE) www.ashrae.org
Canadian Standard
Association (CSA)
www.csa.ca
Certification of Europe (CE)
www.iti.co.uk
Gas Appliance
Manufacturer’s Association
(GAMA) www.gamanet.org
Green Building
Certification Institute
(GBCI) www.gbci.org
Infrared Heater Safety
Council (IRSC)
www.irsafetycouncil.org
National Fire Protection
Association (NFPA)
www.nfpa.org
National Society of
Professional Engineers
(NSPE) www.nspe.org
Underwriters Laboratory
(UL) www.ul.com
US Green Building Council
www.usgbc.org
Product & Factory Audits Include:
• Quarterly CSA Inspection
• Annual CE Inspection
• Annual 17025 Inspection
• OSHA Inspections
• Local City/State Inspections
11-2
Company
© 2012 Brant Radiant Heates Ltd.
Rewards and Recognitions
A world-class manufacturer of gas-fired infrared heaters, Detroit Radiant
Products Company has received recognition as a leader in the industry.
In addition to active memberships in trade associations, Detroit Radiant
Products Co. has received several awards, including:
Product of the Year
Heating and Heat Exchange
Plant Engineering
Multiple CFQ1 Top Supplier Awards
W.W. Grainger
AE’s Top 50 Product
Agricultural Engineering
Multiple Patents
For innovative product initiatives.
On-Site Testing Laboratory
An on-site ISO/IEC 17025 certified testing
laboratory enables research of the latest
technological advancements as well as in-house
CSA product certification and review. This
resource allows for continuous research and
development efforts enabling Detroit Radiant
Products Company to stay at the forefront of infrared and other modern
day energy technologies.
Dedication to Education
The proper application of an infrared heater
requires a working knowledge of the basic
principles of infrared. Detroit Radiant Products
Company is committed to continuous educational
efforts. Annual training seminars may focus
on the ABC’s of infrared, the development of
our distribution network, safety and/or specialized classes designed for
professional installers or licensed state inspectors.
Additional Resources
• Award Winning Technical Studies.
• White Paper Library.
• Annual Training Seminars.
• Resourceful Web Site.
• Associate Foreign Operations.
• Dedicated and Available Staff.
• ISO/EIC 17025 Approved Laboratory. • On-Site Educational Classroom.
1 U.S. gal. No. 4 oil = 144 000 Btu or 42.20 kWh
1 ton refrigeration = 12 000 Btu or 3.5172 kWh
www.brantraiant.com
© 2012 Brant Radiant Heaers Ltd.
to obtain:
kWh
3.6
MJ
kWh
3412
Btu
MJ
947.8
Btu
Btu
0.001055
MJ
Heat emission or gain
W/m2
0.317
Specific heat
kJ/kgK
0.2388
Heat flow rate
W
3.412
Btu/h
U-value, heat transfer coefficient
W/m2K
0.1761
Btu/sq. ft. h °F
Specific volume
Conductivity
W/mK
6.933
Btu in./sq. ft. h °F
Velocity
Quantity of heat
www.brantradiant.com
Multiply:
by
to obtain:
Calorific value (mass)
kJ/kg
0.4299
Btu/lb.
Calorific value (volume)
MJ/m3
26.84
Btu/cu. ft.
Pressure
bar
14.50
lb./sq. in. (psi)
bar
100
kPa
Btu/sq. ft.
bar
0.9869
std. atmosphere
Btu/lb. °F
mm Hg (mercury)
133.332
Pa
ft. of water
2.98898
kPa
m3/kg
16.02
cu. ft./lb.
m/s
3.281
ft./s
© 2012 Brant Radiant Heaters Ltd.
Ph:
519.442.7823
Fax:
519.442.7321
E-mail: sales@brantradiant.com
by
34 Scott Ave.
Paris, On. N3L 3R1 Canada
www.brantradiant.com
Multiply:
®
Conversion Factors
®
1 mechanical horsepower = 2 545 Btu/h or 0.7459 kW
Ph:
519.442.7823
Fax:
519.442.7321
E-mail: sales@brantradiant.com
1 boiler horsepower = 33 480 Btu/h or 9.812 kW
1 imperial gal. No. 2 oil = 168 130 Btu or 49.27 kWh
®
34 Scott Ave.
Paris, On. N3L 3R1 Canada
www.brantradiant.com
Ph:
519.442.7823
Fax:
519.442.7321
E-mail: sales@brantradiant.com
Global Provider of Energy Efficient Heating Solutions Since 1965
1 U.S. gal. No. 2 oil = 140 000 Btu or 41.03 kWh
BRANT RADIANT
HEATERS LIMITED
1 imperial gal. No. 6 oil = 182 540 Btu or 53.50 kWh
Global Provider of Energy Efficient Heating Solutions Since 1965
1 U.S. gal. No. 6 oil = 152 000 Btu or 44.55 kWh
1 m3 of natural gas = 35 310 Btu or 10.35 kWh
BRANT RADIANT
HEATERS LIMITED
1 cu. ft. of natural gas = 1 000 Btu or 0.2931 kWh
34 Scott Ave.
Paris, On. N3L 3R1 Canada
www.brantradiant.com
1 imperial gal. No. 4 oil = 172 930 Btu or 50.68 kWh
Global Provider of Energy Efficient Heating Solutions Since 1965
1 Therm = 100 000 Btu or 29.31 kWh
BRANT RADIANT
HEATERS LIMITED
Useful Values
Gas-Fired Infrared Heating Equipment
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☐ Other_ ______________________________________________
Name:_ ________________________________________________________________
Address:________________________________________________________________
City:____________________________ State:_________________ Zip:_______________
Phone:_ _________________________ E-mail:_ ________________________________
Gas-Fired Infrared Heating Equipment
☐☐ I would like to be included on a quarterly educational mailing list.
☐☐ Please have a local distributor contact me.
☐☐ I have a pending project that I would like to discuss.
☐☐ I have a specific literature request. Provide details below:
I am a: ☐ Engineer
☐ Contractor ☐ Dealer/Wholesaler ☐ End User
☐ Other_ ______________________________________________
Name:_ ________________________________________________________________
Address:________________________________________________________________
City:____________________________ State:_________________ Zip:_______________
Phone:_ _________________________ E-mail:_ ________________________________
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Brant Radiant Heaters Limited
34 Scott Ave
Paris, On N3L 3R1
(519) 442-7823
(519) 442-7321 Fax
brantradiant.com