Solar thermal model for kuwait challet oreintation selection and a mall with large ETFE to predict perceived operative temperature with use of all air and radiant floor cooling

1. Solar Thermal Simulation Study
Sample Project – Kuwait Challet & Mall
Prepared by Anantharaman.K, Sr. Mech Engineer, LEED AP (BD+C)
Feb 2012
Revision - 0

2. Introduction:
Aim of the solar thermal simulation is to compliment and optimize the designers selection of orientation,
shading components right from the initial stage of the design to deliver a sustainable building design to the
client with added value.
The dynamic thermal simulation software used is IES-VE, a building performance modeling tool. High
performance building designs are recommended to use software modeling tools all through the design
stages and US DOE recommends the clients to include this part of the RFP.
Feb 2012
Revision - 0

3. Challet view
from top with
ceiling made
invisible.
Mirrored
Mirrored
orientation
orientation
(Left Hall)
(Left Hall)
Existing Existing
design design
orientation
orientation
(Right Hall)
(Right Hall)
N
50
N
Play Video
– db click
on image
30
25
20
Load (kW)
Temperature (°C)
35
12
10
10
8
8
6
6
4
40
14
12
45
16
14
4
2
2
0
00:00
06:00
12:00
18:00
Date: Sun 15/Aug
The Left Hall solar peaks in the morning
while the right hall solar peaks afternoon.
Right Hall solar peak coincides with ambient
dry bulb temperature and so the Dx package
units efficiency also drops.
Dry-bulb temperature: Kuwait_KISR.fwt (Kuwait_KISR.fwt)
Solar gain: Right Reception Hall (right hall.aps)
Solar gain: Left Reception Hall (right hall.aps)
Cooling plant sensible load: Right Reception Hall (right hall.aps)
Cooling plant sensible load: Left Reception Hall (right hall.aps)
0
00:00
Gain (kW)
16

4. 50
35
Load (kW)
Temperature (°C)
40
30
14
12
45
16
14
12
10
10
8
6
Mirrored
orientation
(Left Hall)
4
25
2
20
0
00:00
8
Existing
design
orientation
(Right Hall)
06:00
12:00
6
Gain (kW)
16
4
2
18:00
0
00:00
Date: Sun 15/Aug
Dry-bulb temperature: Kuwait_KISR.fwt (Kuwait_KISR.fwt)
Solar gain reduced by ~
30% using high
performance glazing.
Solar gain: Right Reception Hall (right hall.aps)
Solar gain: Left Reception Hall (right hall.aps)
Cooling plant sensible load: Right Reception Hall (right hall.aps)
Cooling plant sensible load: Left Reception Hall (right hall.aps)
50
14
35
Gain (kW)
Temperature (°C)
40
14
12
45
16
12
10
10
25
20
8
6
6
4
30
8
4
2
2
0
00:00
06:00
12:00
18:00
Date: Sun 15/Aug
Dry-bulb temperature: Kuwait_KISR.fwt (Kuwait_KISR.fwt)
Cooling plant sensible load: Right Reception Hall (right hall.aps)
High Performance
Glazing
Cooling plant sensible load: Left Reception Hall (right hall.aps)
Solar gain: Right Reception Hall (right hall.aps)
Solar gain: Left Reception Hall (right hall.aps)
0
00:00
Load (kW)
16

5. With passive
Shading solar
load is reduced to
~ 20% which
helps in saving
energy
12
50
11
48
10
46
9
44
Gain (kW)
40
7
38
6
36
5
34
4
Temperature (°C)
42
8
32
3
30
2
28
1
26
0
00:00
06:00
12:00
18:00
24
00:00
D
ate: Sun 15/Aug
Solar gain: Right Reception Hall (right-hall1with s
hade.aps
)
Solar gain: Right Reception Hall (right hall.aps
)
Dry-bulb temperature: Kuwait_KISR.fwt (Kuwait_KISR.fwt)
Dry-bulb temperature: Kuwait_KISR.fwt (Kuwait_KISR.fwt)

6. Study of Incident Solar flux / Solar Power &
Surface temperatures for a selected surface

7. Solar exposure - area
Area of solar exposure without shade
Area of solar exposure with shade

8. CONCLUSIONS for the Challet

Thermal efficiency, Left Hall orientation is better than Right Hall orientation.

Using spectrally selective high performance glazing further reduces the solar gains to
the space.

Left hall orientation is more energy efficient.

Solar loads for worst exposure could be reduced by using spectrally selective glazing
and by using passive shading devices.

9. Mall connecting area Ph-II - Ph-III
Solar Analysis
Dynamic Thermal Modeling

10. Facing North
with
transparent
ETFE
Solar Analysis
N
Other 3
orientations
with
translucent
ETFE
Graph plotted to
understand the ambient
temperature vs chiller plant
load.

11. 32
90
30
80
28
Percentage (%)
48
46
44
42
40
38
36
34
32
30
28
26
24
Temperatures
are within 28
deg C and it is
acceptable for
this application.
70
60
26
50
24
40
22
30
20
20
18
10
16
00:00
06:00
12:00
18:00
Date: Thu 15/Jul
Mean radiant temperature: Lakes GF (lakes with stratification.aps)
Dry resultant temperature: Lakes GF (lakes with stratification.aps)
Solar altitude: Kuwait_KISR.fwt (Kuwait_KISR.fwt)
Dry-bulb temperature: Kuwait_KISR.fwt (Kuwait_KISR.fwt)
People dissatisfied: Lakes GF (lakes with stratification.aps)
0
00:00
Angle (deg.)
Temperature (°C)
Temperature prediction at occupied GF level

12. Cooling plant load with and without stratification assumptions.
2000
48
1500
46
1900
46
1400
1800
44
1300
1700
42
1200
44
40
1500
38
1400
36
1300
34
1200
1100
40
1000
38
900
36
800
34
700
1100
26
00:00
06:00
12:00
500
28
400
800
28
600
30
900
30
32
1000
32
26
00:00
700
00:00
18:00
Sys load (kW)
1600
Sys load (kW)
06:00
12:00
18:00
300
00:00
Date: Thu 15/Jul
Date: Thu 15/Jul
Dry-bulb temperature: Kuwait_KISR.fwt (Kuwait_KISR.fwt)
Dry-bulb temperature: Kuwait_KISR.fwt (Kuwait_KISR.fwt)
Room cooling plant sens. load: (lakes1.aps)
Room cooling plant sens. load: (lakes with stratification.aps)
Chillers load: (lakes1.aps)
Chillers load: (lakes with stratification.aps)
48
Without
stratification single
zone 23 deg C
2000
46
1800
44
1600
42
1400
40
38
1200
36
1000
34
800
32
600
30
400
28
26
00:00
06:00
12:00
18:00
Date: Thu 15/Jul
Dry-bulb temperature: Kuwait_KISR.fwt (Kuwait_KISR.fwt)
Dry-bulb temperature: Kuwait_KISR.fwt (Kuwait_KISR.fwt)
Room cooling plant sens. load: (lakes1.aps)
Room cooling plant sens. load: (lakes with stratification.aps)
200
00:00
Sys load (kW)
Temperature (°C)
Temperature (°C)
42
Temperature (°C)
48
With stratification at
high level, 32 deg C

13. Ground floor solar flux and solar power with surface temperature
90
32
90
80
31
80
70
40
30
Temperature (°C)
Angle (deg.)
50
60
29
50
28
40
27
30
26
20
20
25
10
0
Radiation flux (W/m²)
60
70
30
10
24
00:00
06:00
12:00
18:00
0
00:00
Date: Thu 15/Jul
Solar altitude: Kuwait_KISR.fwt (Kuwait_KISR.fwt)
Int surface incident solar flux: External floor (lakes gf surface temp.aps)
70
350000
60
Surface temperature: External floor (lakes gf surface temp.aps)
400000
300000
50
40
Heat flow (W)
80
Angle (deg.)
450000
31
30
29
250000
28
200000
30
20
100000
10
27
150000
50000
0
32
0
00:00
26
25
06:00
12:00
18:00
Date: Thu 15/Jul
Solar altitude: Kuwait_KISR.fwt (Kuwait_KISR.fwt)
Surface temperature: External floor (lakes gf surface temp.aps)
Int surface incident solar power: External floor (lakes gf surface temp.aps)
24
00:00
Temperature (°C)
90

14. People dissatisfied comparison
All air (vs) Radiant chilled floor @ 19 deg C
32
90
48
30
80
46
28
44
70
22
20
18
Angle (deg.)
24
42
60
40
50
38
40
36
34
30
16
14
12
10
Temperature (°C)
Percentage (%)
26
32
20
30
10
0
00:00
28
06:00
12:00
18:00
26
00:00
Date: Thu 15/Jul
People dissatisfied: Lakes GF (lakes with stratification.aps)
People dissatisfied: Lakes GF (lakes radiant.aps)
Dry-bulb temperature: Kuwait_KISR.fwt (Kuwait_KISR.fwt)
Dry-bulb temperature: Kuwait_KISR.fwt (Kuwait_KISR.fwt)
Solar altitude: Kuwait_KISR.fwt (Kuwait_KISR.fwt)
Solar altitude: Kuwait_KISR.fwt (Kuwait_KISR.fwt)
Here the percentage dissatisfied
considerably reduces from 26 % to
14% by using radiant floor cooling.

15. With internal shading at 10m high level

16. People dissatisfied % with and without internal shading
15.5
15.0
14.5
Percentage (%)
14.0
13.5
13.0
12.5
12.0
11.5
11.0
10.5
10.0
00:00
06:00
12:00
18:00
Date: Thu 15/Jul
People dissatisfied: Lakes GF (lakes shades.aps)
People dissatisfied: Lakes GF (lakes radiantjune.aps)
00:00