Atrium - TU Wien

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Atrium - TU Wien

2nd Central European Symposium on Building Physics, Vienna, Austria, September 9-11, 2013
Thermal environment
in detached houses with atrium
Towards proper utilization of atrium space in traditional
dwellings “Kyo-machiya”
Chiemi IBA, Shuichi HOKOI & Daisuke OGURA: Kyoto University, Japan
Shihono ITO: Takenaka Corporation, Japan
2
INTRODUCTION
Atrium space in modern houses
Atrium space ,which is open to
rooms or a corridor on the upper
floor (sometimes connected to
staircase) has been preferred in
modern detached houses.
An open, spacious and
bright space.
Residents who stay
upstairs and downstairs
can easily communicate
with each other.
However…
It is quite difficult to design
air conditioning system
effectively for such modern
houses with an atrium.
3
INTRODUCTION (continued)
Traditional townhouses “Kyo-machiya” in Kyoto, Japan
They generally have atrium space, which is expected to be a path of
breeze and daylight.
In traditional “Kyo-machiya”, atrium usually doesn’t open to the rooms on
the upper floor, but open atrium spaces have increased by renovation.
The influences of such atriums on the thermal environment in traditional
houses have not been clarified.
Exterior of Typical “Kyo-machiya”
Atrium space in Living room
(view from 2nd floor )
INTRODUCTION (continued)
4
Purpose of this study
To clarify the effect of atrium space on the indoor thermal
environment.
Major goal of our research
To propose proper ways of living, which can realize both
comfortable indoor environment and saving energy.
Main target is traditional townhouse.
This presentation includes…
Measurement of indoor environment in two real-scale
detached houses with an atrium both in summer and in
winter (in modern houses)
CFD analysis corresponding to the measurements
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INDOOR ENVIRONMENT
IN SUMMER
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INDOOR ENVIRONMENT IN SUMMER
Measurement outline
Date: August 18th, 2009
Cite: Two-story gabled house in Kyoto, Japan (House A)
Feature: 2nd floor corridor faces to atrium, 2nd floor rooms can be open to
atrium
Air conditioner 2
Air conditioner 1
1st floor center
Staircase
Living room
1st floor plan
2nd floor
near AC
2nd floor center
Atrium
2nd floor plan
South Elevation
7
Measurement of indoor environment
Measurement patterns
Pattern
Windows
on 1st floor
on 2nd floor
Air conditioners
on 1st & 2nd floors
1
CLOSE
CLOSE
ON
2
OPEN
OPEN
OFF
3
CLOSE
OPEN
OFF
Remarks
Cooling by air-conditioner
(set at 27 °C)
Natural ventilation
(Outdoor temperature was
kept at about 32°C)
expected to bring comfortable
breeze to living space
8
Case of Cooling by air-conditioner : Pattern 1
The cooler air from the AC on 2nd floor flowed downward to 1st floor.
Airflow distribution
Temperature profile
(Pattern 1)
(Cooling set temperature is 27 °C.)
9
Case of Natural ventilation: Pattern 2
Temperature profile
(Pattern 2 & 3)
Pattern 2
Pattern 3
10
Case of Natural ventilation: Pattern 3
In the case of natural ventilation, the airflow direction mainly depends on
the outside wind direction, and changes frequently.
Temperature profile
(Pattern 2 & 3)
Pattern 2
Pattern 3
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CFD Analysis of indoor airflow
The case of natural ventilation was analyzed by using STAR-CD 4.10.
Calculation conditions
Standard k-ε turbulence model is used.
40 x 40 x 40 grid cells
Boundary conditions: measured data
Inlet air: 32 °C, 1.0m/s
External walls: 32 °C, no-slip condition
Partition walls: no-slip and no-heat flux
conditions
Simulation Model
for House A
(Pattern 3)
N
12
Airflow distribution on 2nd floor for Pattern 3
Main stream occurred along the corridor.
Strong airflow observed near the outlet window.
Calculated
Measured
Although there were
some difference in the
low-air-speed area,
calculated directions
generally agreed with
the measured directions.
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Influence of atrium space on indoor airflow
Effect of cross ventilation: Comparison between with and without atrium
With Atrium
on 2nd floor
on 1st floor
Vertical distribution
of airflow
Inlet
Inlet
Window-8
Window 8
Outlet
Outlet
Window
1
Window-1
Atrium
Atrium
Without Atrium
Breeze in Living space
Inlet Inlet
Window-8
Window 8
Outlet
Outlet
Window 1
Window-1
No
atrium
No
Atrium
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Summary
1. When the air conditioner was working, the cool air from the upper floor
went down to the lower floor. As a result the upper floor was not
sufficiently cooled, while the lower floor was overcooled. Such airflows
can make the undesirable situation in terms of both indoor comfort and
saving energy.
2. When the windows were opened for natural ventilation, effective cross
ventilation did not necessarily occur between floors.
(This can be partly because the balustrade by the atrium prevented airflow. )
3. Under certain conditions, more agreeable indoor ventilation might be
obtained in the house without atrium.
We should consider the negative aspect of natural ventilation…
The hotter outside air can make the indoor air higher.
We should open or close the windows at the proper time.
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INDOOR ENVIRONMENT
IN WINTER
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INDOOR ENVIRONMENT IN WINTER
Measurement outline
Date: January 16th, 2011
Cite: Two-story gabled house in Kyoto, Japan (House B)
Feature: Large atrium, Staircase connected to atrium, Floor
radiant heating system installed between 1st floor and 2nd floor
Staircase
Living room
Staircase
Atrium
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When the doors on 2nd floor were closed
0.14m/s
(820mm high)
0.14m/s
0.10m/s
(410mm high)
0.10m/s
INDOOR
ENVIRONMENT
IN WINTER
Measurement
of
indoor
airflow
0.25m/s
(1,230mm high)
Airflows could not be
detected on 2nd floor.
0.22m/s
(1,640mm high)
0.22m/s
0.07m/s
(on the beam)
0.05m/s
(on the beam)
corridor
Wind speed
increased.
When the doors on 2nd floor were open
0.19m/s
(1,800mm high)
0.41m/s
(820mm high)
0.41m/s
0.25m/s
(410mm high)
0.25m/s
0.14m/s
(on the beam)
0.35m/s
(1,640mm high)
0.35m/s
0.05m/s
(on the beam)
Inner
Inner
garden
garden
0.22m/s
(2,650mm high)
0.05m/s
(1,000mm high)
0.40m/s
(100mm high)
0.05m/s
(550mm high)
0.17m/s
(on the beam)
3. INDOOR ENVIRONMENT IN WINTER
18
Simulation Model for House B
Kitchen
Dining room
Japanese
room
洋室1
Room
1
廊下
Corridor
Atrium
吹抜け
洋室2
Room
2
Living room
Closet
クロー
1st floor plan
ゼット
Room 1
Living リビング
room
Room 2
洋室3
Room
3
和室
Japanese
解析モデル（住宅C
解析モデル（住宅C ) room
Staircase
Wall surface temperature [°C]
1st floor
Atrium
2nd floor
floor
wall
ceiling
floor
wall
partition
ceiling
22.0
21.5
25.5
22.0
18.5
20.0
19.0
Closet Room 3
2nd floor plan
19
Airflow distributions
1st floor
2nd floor
Vertical
2nd floor
Vertical
Temperature distributions
1st floor
3. INDOOR ENVIRONMENT IN WINTER
20
Summary
1. A cold draft occurred through the atrium and the staircase
even though there was little vertical temperature
difference.
2. The atrium and the staircase should be separated to
prevent this cold draft.
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CONCLUSIONS
The influence of an atrium and a staircase on the indoor thermal
environment both in summer and in winter was investigated
mainly concerning airflow distribution.
Atriums and staircases don’t necessarily have good influence
under certain conditions.
Particularly in winter, the combination of atrium and staircase
can cause undesirable cold draft.
If some partitions are installed in proper position and are
operated reasonably, such undesirable airflow can be avoided.
22
Now we’re doing measurement in traditional townhouses
in Kyoto…to propose the reasonable utilization technique
of atrium space.
Thank you for your attention !
23
Supplemental materials
1. INTRODUCTION (continued)
24
A major goal of our research is…
To propose proper ways of living, which enable comfortable and
energy-saving indoor environment in traditional dwellings.
In this paper…
We focus on the effect of atrium space on the indoor thermal
environment, particularly focusing air flows in a house.
1. Indoor environmental factors (temperature and airflow rate) were
measured in two real-scale detached houses with an atrium.
2. The airflow and the temperature distributions in the house were
simulated by using CFD analysis.
3. The analysis model was verified by comparing the calculation results
with the measurement results.
4. By using this analysis model, the cases with and without an atrium
were calculated.
CONTENTS
25
1.
INTRODUCTION
2.
3.
4.
5.
CFD analysis of indoor airflow
CFD analysis of indoor airflow
DISCUSSIONS
CONCLUSIONS
2. INDOOR ENVIRONMENT IN SUMMER
26
Calculated temperature distribution
in Pattern 3
31.3°°C
32.0°°C
32.0°°C
31.3°°C
31.4°°C
31.4°°C
31.4°°C
31.4°°C
30.5°°C
30.2°°C
Vertical
Horizontal
25
27
P4(Japanese style room)
3. INDOOR
ENVIRONMENT
IN WINTER
Temperature[°C]
20
P1 (Living room)
P3(Kitchen)
P2(Dining room)
P6(Utility)
15
P5(Entrance)
10
5
Outside
15:30
15:00
14:30
14:00
13:30
13:00
12:30
12:00
11:30
10:30
11:00
0
Measurement
of
Time
indoor
temperature
25
P11(near window)
P7(Room 1)
Temperature[°C]
20
15
P9(Room 3)
P8(Room 2)
P10(Closet)
10
5
Outside
15:30
15:00
14:30
14:00
13:30
13:00
12:30
12:00
11:30
11:00
10:30
0
Time

Atrium - TU Wien

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