Energy Efficient Building Design
College of Architecture
Illinois Institute of Technology, Chicago
HEAT GAINS and LOSSES : WINDOWS and SKYLIGHTS (Glass) The heat gain components through glass consists of solar radiation and conduction. Solar radiation is considered in two parts – direct and diffuse (or scatter). Diffuse radiation is the solar radiation that is absorbed, stored and scattered in the atmosphere. The glass can be in the sun (direct and diffuse radiation) or in the shade (diffuse or scatter radiation). Conduction heat gain occurs due to the difference in temperature on either side of the glass. Conduction heat gain is positive if the outdoor air temperature is greater than indoor air temperature and it is negative (heat loss from the space) if the indoor air temperature is greater. Solar radiation is always positive.
Window
Sun
Overhang
N Sun
WINDOW
Altitude
I
Azimuth Glass in Shade diffuse radiation
Wall-Solar Azimuth
Window
Component of Solar
Side Fin
Radiation perpendicular Glass in Sun
to Wall-Window Surface
direct and diffuse radiation
Figure ? Direct solar radiation is the vector component of the absolute (total) solar radiation that is perpendicular to the glass surface. The Solar Cooling Load (SCL) Factor for a window is based on this value. So for any given hour, the SCL values for windows with different azimuth and tilt angles will have different SCLs although the absolute solar radiation is the same for all windows. Q-solar = A * SC * SCL Q-cond = A * U * CLTD A = Glass Area , SC = Glass Shading Coefficient, U = Glass heat transfer coefficient. CLTD = Cooling Load Temperature Difference. CLTD for glass depends mainly on the difference between indoor and outdoor temperatures but as with walls and roofs it is affected by the mass and properties of the glass material. When solar radiation strikes a glass surface, some of it is transmitted, some of it is absorbed and some of it is reflected. The absorbed component increases the temperature of the glass and the heat is slowly conducted (released) to the outside and inside depending on the difference in temperature. Unlike walls that are thick and have high densities, the absorbed portion of the solar radiation is relatively small compared to transmitted and reflected components. Instructor: Varkie C. Thomas, Ph.D., P.E.
Skidmore, Owings & Merrill LLP
ARCH-551 (Fall-2002) ARCH 552 (Spring-2003)
F13 - 1
Energy Efficient Building Design
College of Architecture
Illinois Institute of Technology, Chicago
For example, a particular tinted glass has a transmissivity of 0.6 (60% of radiation is transmitted), reflectivity of 0.3 (30% of radiation is reflected) and absorbtivity of 0.1 (10% of radiation is absorbed). The direct solar radiation value is the component of the absolute solar radiation that is perpendicular to the glass surface. Shading Coefficient (SC) is the ratio of the solar heat through a given glass type under specific conditions to the solar heat gain through a standard reference unshaded glass that was used to determine Solar Cooling Load (SCL) factors. The reference glass is one-eighth thick inch clear double strength single glass and it has an SC = 1 under the specific conditions. SC = Solar heat gain through given glass type Solar heat gain through reference glass type Solar Heat Gain Coefficient (SHGC) is the ratio of the measured solar heat through a given glass type to the incident solar heat on the glass. The measured values are affected by the air films on either side of the glass, absorbtivity and by other factors. SHGC is therefore less than SC (about 10% to 15%). SHGC values are used in manual calculations. Input to energy computer programs is usually SC, and the program calculates SHGC based on conditions on either side of the glass. ASHRAE Standard 90.1 specifies SHGC values for different climates because it is based on tested measured values of different glass types and not on theoretical values. Radiant heat entering through the glass does not directly affect the room space air through which it passes. The radiant heat is first absorbed by the interior surfaces (walls, floor, ceiling) of the space and the contents (furniture and other objects) in the space. The absorbed heat is released to the air in the space through conduction and convection due to the difference in temperature. Solar Cooling Load (SCL) factors are based on the solar radiation heat gain entering through the glass and the effect of the room surfaces and furnishings in absorbing and transmitting the radiant heat. There is therefore a time lag between the solar radiation entering the space through the glass and when it affects the temperature of the air in the space. Visible Light Transmission (VLT) factor is the ratio of amount of light (lumens) transmitted through the given glass type to the amount of light transmitted by the standard reference glass type. Visible light and radiation heat are part of the electromagnetic spectrum and vary from each other in wave length. The is therefore a correlation between SC and VLT for different glass types but they are not the same. For building energy efficiency in summer you want to reduce the SC and increase the VLT. This reduces the cooling load due to radiation heat gain and reduces it even further by reducing the heat gains from lighting. Glass manufacturing research and technology tries to develop glass that optimizes the properties of glass for building energy efficiency. In summary, energy efficient glass depends on it’s U-value, SC, SHGC and VLT. Glass manufacturer’s data provides this information. ASHRAE tables for Solar Cooling Load (SCL) factors are therefore based on approximate groups and combinations of different types of room surfaces and furnishings. It is also based on floor levels (ground, middle, top) since this affects the inside surfaces of the space.
Instructor: Varkie C. Thomas, Ph.D., P.E.
Skidmore, Owings & Merrill LLP
ARCH-551 (Fall-2002) ARCH 552 (Spring-2003)
F13 - 2
Energy Efficient Building Design
College of Architecture
Illinois Institute of Technology, Chicago
ZONE TYPES The ASHRAE Cooling Load Temperature Difference (CLTD), Solar Cooling Load (SCL) and Cooling Load Factor (CLF) method was developed so that heating and cooling loads can be calculated manually. It consists of building performance tables for different latitudes and different building configurations. The tables were generated using the DOE2 computer program that used more intensive and accurate calculation procedures (example Transfer Function Method for Walls). These tables are published in the ASHRAE 1981 Handbook. Room or space zone types were developed for: Solar Heat Gain through Glass Internal Heat Gains from People, Lights, and Equipment MULTI-STORY BUILDING ROOF
BUILDING FLOOR TYPES (1) Single Story (ground floor and roof) (2) Top Floor (multi-story with roof) (3) Middle Floor (multi-story without ground & roof)
(4) Ground Floor (multi story) (5) Interior Zones (6) Exterior Zones
Ceiling
TOP Floor
Ceiling (a) None (b) With Window Glass
MIDDLE Floor without Ceiling
Inside Shades (a) None (b) Half (c) Full Lights
Number of Interior and Exterior Walls (a) one or two (b) three © four or more
Concrete Partition Equipment
People Floor Covering (a) None (b) Vinyl (c) Carpet
Floor (a) 2.5 inch concrete (b) 1 inch wood
Ceiling
Partitions (a) Gypsum (b) Concrete Block
MIDDLE Floor SINGLE-STORY BUILDING INTERIOR Zone Ceiling
GROUND Floor
Instructor: Varkie C. Thomas, Ph.D., P.E.
PLAN VIEW OF BUILDING ( ZONES )
ROOF NW
N
NE
W
INT
E
SW
S
SE
Ceiling
GROUND Floor
Skidmore, Owings & Merrill LLP
ARCH-551 (Fall-2002) ARCH 552 (Spring-2003)
F13 - 3
Energy Efficient Building Design
College of Architecture
Illinois Institute of Technology, Chicago
ASHRAE Zones for Solar Cooling Load (SCL) Factors for Glass are based on: A. Floor Level and Room Location 1. Single Story Building (Table 8.8-A) 2. Top Floor (Table 8.8-B) 3. First / Ground Floor (Table 8.8-C) 4. Middle Floor (Table 8.8-D) 5. Interior Rooms (Table 8.8-E) B. C. D. E. F. G.
Number of Walls in the Space ( 1 & 2 or 3 & 4 or greater) Floor Type ( Concrete or Wood ) Ceiling Type ( With or Without Suspended Ceiling ) Floor Covering ( Carpet or Vinyl ) Partition Type (Gypsum or Concrete Block ) Inside Shades ( Full, Half or None )
The figure below shows space heat gain time delay.
CLTD/SCL/CLF Method
Heat Balance Method
TETD Method Convection HEAT
COOLING
GAIN
LOAD
Radiation
HEAT EXTRACTION
Convection with Time Delay Furnishings Structure and other Variable Heat Storage Plus / Minus Swing
The tables show : Direct solar radiation intensities for different vertical surface azimuths and for a horizontal surface for 24o North latitude on July 21st and January 21st. Note that solar radiation on the south surface peaks in winter. Heating energy can be reduced by increasing the percent glass on the south. how the SCL (time delayed) values vary for different vertical surface azimuths and for a horizontal surface for 24o North latitude on July 21st.
Instructor: Varkie C. Thomas, Ph.D., P.E.
Skidmore, Owings & Merrill LLP
ARCH-551 (Fall-2002) ARCH 552 (Spring-2003)
F13 - 4
Energy Efficient Building Design
College of Architecture
Illinois Institute of Technology, Chicago
EXAMPLES OF ZONE TYPES for Glass SCL and People, Equipment & Lights CLF No. of
Mid-Flr Type
Walls
Ceiling
Floor
Partition
Inside
Glass
People
Type
Cover
Type
Shade
Solar
Equipt
ZONE TYPE
TOP FLOOR 1 or 2
2.5" Concrete
Lights
With
Carpet
Gypsum
Full
A
A
B
3
A
B
B
4
A
A
B
ZONE TYPE
GROUND FLOOR 1 or 2
2.5" Concrete
With
Carpet
Gypsum
Full
A
C
B
3
A
C
B
4
A
B
B
ZONE TYPE
MIDDLE FLOOR 1 or 2
2.5" Concrete
With
Carpet
Gypsum
Full
B
B
C
3
B
B
C
4
B
C
C
No. of
Mid-Flr Type
Walls
Ceiling
Floor
Partition
Inside
Glass
People
Type
Cover
Type
Shade
Solar
Equipt
ZONE TYPE
TOP FLOOR 1 or 2
2.5" Concrete
Without
Vinyl
Cncr Blck
None
3 4
Gypsum
B
A
C
B
A
B
A
A
B
ZONE TYPE
GROUND FLOOR 1 or 2
2.5" Concrete
Without
Vinyl
Cncr Blck
None
3 4
Gypsum
D
D
D
C
D
C
B
C
C
ZONE TYPE
MIDDLE FLOOR 1 or 2
2.5" Concrete
Lights
Without
Vinyl
Cncr Blck
3 4
Instructor: Varkie C. Thomas, Ph.D., P.E.
Gypsum
Skidmore, Owings & Merrill LLP
None
C
C
C
C
C
C
B
A
C
ARCH-551 (Fall-2002) ARCH 552 (Spring-2003)
F13 - 5
Energy Efficient Building Design
College of Architecture
Illinois Institute of Technology, Chicago
Building
Direct Solar Radiation Intensities on Vertical & Horizontal Surfaces o
JANUARY 21st
Latitude : 24 North
Rad = Absolute Solar Radiation BTUH
Month/Day : January 21st
Glass
NW W SW
N Inter S
NE E SE
Direct Solar Radiation Intensities for Hours 7:00 AM to 6:00 PM
Azim
7
8
9
10
11
12
13
14
15
16
17
18
N
2
12
18
23
26
27
26
23
18
12
2
1
NE
21
41
23
24
26
27
26
23
18
12
2
1
E
62
190
190
144
73
29
26
23
18
12
2
1
SE
63
218
253
245
211
160
95
38
19
12
2
1
S
25
114
166
200
220
227
220
200
166
114
25
12
SW
2
12
19
38
95
160
211
245
253
218
63
31
W
2
12
18
23
26
29
73
144
190
190
62
31
NW
2
12
18
23
26
27
26
24
23
41
21
10
Horiz
5
55
121
172
204
214
204
172
121
55
5
2
Rad
71
239
288
308
317
320
317
308
288
239
71
25
NW W SW
N Inter S
NE E SE
Building
Direct Solar Radiation Intensities on Vertical & Horizontal Surfaces JULY 21st
Latitude : 24o North
Rad = Absolute Solar Radiation BTUH
Month/Day : July 21st
Glass
Direct Solar Radiation Intensities for Hours 7:00 AM to 6:00 PM
Azim
7
8
9
10
11
12
13
14
15
16
17
18
N
45
41
37
39
41
42
41
39
37
41
45
26
NE
168
176
150
104
58
42
39
36
32
26
18
6
E
190
213
195
149
83
43
39
36
32
26
18
6
SE
101
128
129
108
73
45
40
36
32
26
18
6
S
18
27
34
39
44
46
44
39
34
27
18
6
SW
18
26
32
36
40
45
73
108
129
128
101
50
W
18
26
32
36
39
43
83
149
195
213
190
95
NW
18
26
32
36
39
42
58
104
150
176
168
85
Horiz
73
141
198
243
270
278
270
243
198
141
73
13
Rad
186
241
265
278
284
286
284
278
265
241
186
81
Instructor: Varkie C. Thomas, Ph.D., P.E.
Skidmore, Owings & Merrill LLP
ARCH-551 (Fall-2002) ARCH 552 (Spring-2003)
F13 - 6
Energy Efficient Building Design
College of Architecture
Illinois Institute of Technology, Chicago
Building
ZONE Type A : SOFT Rad = Absolute Solar Radiation BTUH
Latitude : 24o North
Standard Glass with NO Shades
Month/Day : July 21st
Inside Surfaces and Furnishings : Soft
NW
N
NE
W
Inter
E
SW
S
SE
Glass
Solar Cooling Load (SCL) Factors for Hours 7:00 AM to 6:00 PM
Azim
7
8
9
10
11
12
13
14
15
16
17
18
N
35
36
36
38
40
42
42
40
38
39
43
32
NE
124
150
144
115
78
58
49
44
38
32
25
14
E
130
177
180
154
107
68
54
46
40
33
25
14
SE
74
104
114
106
83
59
50
44
38
32
25
14
S
15
23
30
35
40
43
43
40
37
32
24
14
SW
15
23
30
35
39
42
61
88
110
118
105
62
W
15
23
30
35
39
41
67
116
160
186
184
118
NW
15
23
30
35
39
41
51
83
122
151
158
106
Horiz
55
113
170
218
253
271
273
258
225
176
115
54
N Inter S
NE E SE
Building
ZONE Type B : MEDIUM SOFT Rad = Absolute Solar Radiation BTUH
Latitude : 24o North
Standard Glass with NO Shades
Month/Day : July 21st
NW W SW
Inside Surfaces and Furnishings : Medium Soft
Glass
Solar Cooling Load (SCL) Factors for Hours 7:00 AM to 6:00 PM
Azim
7
8
9
10
11
12
13
14
15
16
17
18
N
30
32
32
35
37
39
40
39
37
39
42
33
NE
105
128
126
106
78
62
55
50
44
38
31
20
E
118
151
158
141
105
74
63
55
48
41
33
22
SE
63
89
100
95
78
60
53
48
43
37
30
20
S
13
20
26
31
36
39
40
38
36
32
26
17
SW
13
20
26
31
35
38
55
79
98
106
98
63
W
14
21
27
32
35
38
61
102
141
165
167
115
NW
14
21
27
32
35
38
47
75
108
134
142
102
Horiz
48
97
146
190
224
244
251
243
219
181
130
78
Instructor: Varkie C. Thomas, Ph.D., P.E.
Skidmore, Owings & Merrill LLP
ARCH-551 (Fall-2002) ARCH 552 (Spring-2003)
F13 - 7
Energy Efficient Building Design
College of Architecture
Illinois Institute of Technology, Chicago
Building
ZONE Type C : MEDIUM HARD Rad = Absolute Solar Radiation BTUH
Latitude : 24o North
Standard Glass with NO Shades
Month/Day : July 21st
Inside Surfaces and Furnishings : Medium Hard
NW
N
NE
W
Inter
E
SW
S
SE
Glass
Solar Cooling Load (SCL) Factors for Hours 7:00 AM to 6:00 PM
Azim
7
8
9
10
11
12
13
14
15
16
17
18
N
31
31
30
32
35
36
36
35
34
36
39
31
NE
104
120
114
92
65
53
50
47
43
38
32
23
E
117
143
143
123
88
62
56
51
47
42
35
26
SE
64
85
92
85
68
51
47
44
40
36
30
21
S
14
20
25
29
33
36
36
34
32
29
24
15
SW
17
23
28
32
34
37
53
75
92
97
87
53
W
20
25
30
34
36
38
60
99
132
152
150
97
NW
19
24
29
33
35
37
45
72
103
125
129
87
Horiz
57
102
145
181
208
223
226
217
194
160
115
71
N Inter S
NE E SE
Building
ZONE Type D : HARD o
Rad = Absolute Solar Radiation BTUH
Latitude : 24 North
Standard Glass with NO Shades
Month/Day : July 21st
NW W SW
Inside Surfaces and Furnishings : Hard
Glass
Solar Cooling Load (SCL) Factors for Hours 7:00 AM to 6:00 PM
Azim
7
8
9
10
11
12
13
14
15
16
17
18
N
27
27
27
29
31
33
33
33
33
34
37
30
NE
86
100
97
82
63
54
52
49
46
42
37
29
E
97
118
121
108
83
64
59
56
52
47
41
33
SE
53
71
77
74
62
50
47
45
42
38
33
26
S
13
18
22
25
29
32
32
31
30
28
24
18
SW
18
22
26
29
31
34
47
64
79
84
78
53
W
22
26
29
32
34
36
53
84
112
130
130
91
NW
20
24
28
31
33
34
41
63
88
106
111
80
Horiz
55
90
124
154
178
193
199
196
181
156
122
88
Instructor: Varkie C. Thomas, Ph.D., P.E.
Skidmore, Owings & Merrill LLP
ARCH-551 (Fall-2002) ARCH 552 (Spring-2003)
F13 - 8
Energy Efficient Building Design
College of Architecture
N
Illinois Institute of Technology, Chicago
WINDOWS and SKYLIGHTS
100 ft
24oN Latitude
Example
Building: 100'L x 100'W x 300'H (100% Glass)
E
300 ft
Calculate Solar Heat Gain for:
S
(1) Zone Type A ( SOFT Interior ) (2) Zone Type D ( HARD interiors )
100 ft
July
ZONE TYPE A (SOFT)
July
ZONE TYPE D (HARD)
Hour
Solar Cooling Load (SCL) Factors
Hour
Solar Cooling Load (SCL) Factors
No.
N
E
S
W
RF
No.
N
E
S
W
RF
6
19
57
5
5
10
6
17
46
7
17
29
7
35
139
15
15
55
7
27
97
13
22
55
8
36
177
23
23
113
8
27
118
18
26
90
9
36
180
30
30
170
9
27
121
22
29
124
10
38
154
35
35
218
10
29
108
25
32
154
11
40
107
40
39
253
11
31
83
29
34
178
12
42
68
43
41
271
12
33
64
32
36
193
13
42
54
43
67
273
13
33
59
32
53
199
14
40
46
40
116
258
14
33
56
31
84
196
15
38
40
37
160
225
15
33
52
30
112
181
16
39
33
32
186
176
16
34
47
28
130
156
17
43
25
24
184
115
17
37
41
24
130
122
18
32
14
14
118
54
18
30
33
18
91
88
19
11
6
6
44
24
19
17
27
13
50
71
20
6
3
3
21
12
20
15
24
11
42
62
21
3
1
1
11
6
21
13
21
10
36
56
Instructor: Varkie C. Thomas, Ph.D., P.E.
Skidmore, Owings & Merrill LLP
ARCH-551 (Fall-2002) ARCH 552 (Spring-2003)
F13 - 9
Energy Efficient Building Design
College of Architecture
Length (ft) =
Building
100
Width (ft) =
Illinois Institute of Technology, Chicago
100
Height (ft) =
300
Wall Glass (ft2) =
30,000
Roof Glass (ft2) =
10,000
Wall Glass SC =
1.0
Roof Glass SC =
1.0
Calculate Solar Gains at: (1) 8:00 AM (2) 12:00 Noon (3) 4:00 PM (4) 8:00 PM (5) 12:00 Midnight Heat Gain (btu/hr) = Area * SC * SCL
July Hr.No.
NORTH SCL
MBH
EAST SCL
MBH
MBH = 1000 btu/hr
SOUTH
WEST
ROOF
TOT
SCL
MBH
SCL
MBH
SCL
MBH
MBH
ZONE TYPE A (SOFT) 8
36
1080
177
5310
23
690
23
690
113
1130
8900
12
42
1260
68
2040
43
1290
41
1230
271
2710
8530
16
39
1170
33
990
32
960
186
5580
176
1760
10460
20
6
180
3
90
3
90
21
630
12
120
1110
Peaks at 4 PM
ZONE TYPE D (HARD) 8
27
810
118
3540
18
540
26
780
90
900
6570
12
33
990
64
1920
32
960
36
1080
193
1930
6880
16
34
1020
47
1410
28
840
130
3900
156
1560
8730
20
15
450
24
720
11
330
42
1260
62
620
3380
Envelope
Solar Radiation BTUH
Solar
Heat Gain
Zone Type A (Soft Interior)
Radiation
MBH
Zone Type D (Hard Interior)
BTUH
Peaks at 4 PM
10000 MBH 300 BTUH 8000 MBH
6000 MBH
200 BTUH
4000 MBH 100 BTUH 2000 MBH
8:00
12:00
4:00
8:00
AM
Noon
PM
PM
Instructor: Varkie C. Thomas, Ph.D., P.E.
Skidmore, Owings & Merrill LLP
ARCH-551 (Fall-2002) ARCH 552 (Spring-2003) F13
- 10
Energy Efficient Building Design
College of Architecture
Illinois Institute of Technology, Chicago
Conduction Heat Gain through Glass (Windows and Skylights) Q = A * U * CLTD Q = conducted heat gain through glass A = glass surface area U = U-value of glass CLTD = Cooling Load Temperature Difference for glass CLTD for Glass
AM
Hour
1
2
3
4
5
6
7
8
9
10
11
12
CLTD
1
0
0
0
0
0
0
0
2
4
7
9
CLTD for Glass
PM
Hour
13
14
15
16
17
18
19
20
21
22
23
24
CLTD
12
13
14
14
13
12
10
8
6
4
3
2
The glass CLTD values in the table above are for based on the following conditions: Indoor Room Temperature = Outdoor Design High Temperature = Average Outdoor 24-Hour Day Temperature = Daily Temperature Range =
78oF 95oF 85oF 21oF
ASHRAE design weather conditions give T-maximum and T-daily_range. T-average can be calculated from: T-average = T-maximum - (T-daily_range) / 2 CLTD values have to be corrected for location conditions other than the values shown above. CLTD (corrected) = CLTD (table) + ( 78 – T-room ) + (T-average – 85 ) T-room = Actual design temperature of the room T-average = Actual average summer design temperature of the location. Example: Location = Dubai. Design outdoor temperature = 115oF, Daily range = 20oF , T-average = 115 – 20/2 = 105 Design indoor temperature = 72oF, CLTD (corrected) for hour 3:00 PM = CLTD(table) + ( 78 – 72 ) + ( 105 – 85 ) = 14 + 6 + 20 = 40oF
Instructor: Varkie C. Thomas, Ph.D., P.E.
Skidmore, Owings & Merrill LLP
ARCH-551 (Fall-2002) ARCH 552 (Spring-2003) F13
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Energy Efficient Building Design
College of Architecture
Illinois Institute of Technology, Chicago
EXAMPLE: Cooling Load through Building Envelope (Walls and Windows) Cooling Load Temperature Difference (CLTD) for Light Construction
Solar Cooling Load (SCL) Factors for Soft Zone
HR
N
Qw-N
E
Qw-E
S
Qw-S
W
Qw-W
HR
N
Qgs-N
E
Qgs-E
S
Qgs-S
W
Qgs-W
8
5
800
16
2,560
0
0
1
160
8
32
7,680
151
36,240
20
4,800
21
5,040
9
8
1,280
29
4,640
2
320
3
480
9
32
7,680
158
37,920
26
6,240
27
6,480
10
11
1,760
39
6,240
5
800
6
960
10
35
8,400
141
33,840
31
7,440
32
7,680
11
14
2,240
45
7,200
9
1,440
9
1,440
11
37
8,880
105
25,200
36
8,640
35
8,400
12
16
2,560
46
7,360
13
2,080
13
2,080
12
39
9,360
74
17,760
39
9,360
38
9,120
13
19
3,040
43
6,880
18
2,880
17
2,720
13
40
9,600
63
15,120
40
9,600
61
14,640
14
21
3,360
40
6,400
22
3,520
24
3,840
14
39
9,360
55
13,200
38
9,120
102
24,480
15
24
3,840
37
5,920
25
4,000
34
5,440
15
37
8,880
48
11,520
36
8,640
141
33,840
16
26
4,160
35
5,600
26
4,160
46
7,360
16
39
9,360
41
9,840
32
7,680
165
39,600
17
29
4,640
33
5,280
26
4,160
56
8,960
17
42
10,080
33
7,920
26
6,240
167
40,080
18
30
4,800
30
4,800
26
4,160
62
9,920
18
33
7,920
22
5,280
17
4,080
115
27,600
Example Glass Conduction Heat Gain HR
Table
Corrct
Qgc
HR
N
E
Building : 120'L x 120'W x 20'H
Latitude : 24oN
Total for Walls and Windows S
W
Month/Day : July 21st
8
0
16
5,120
8
13,600
43,920
9,920
10,320
Room Temp (Tr oF)
9
2
18
5,760
9
14,720
48,320
12,320
12,720
o
Outside Temp (To F)
105
10
4
20
6,400
10
16,560
46,480
14,640
15,040
Daily Range (DR oF)
20
11
7
23
7,360
11
18,480
39,760
17,440
17,200
Avg Temp (Ta oF)
95
12
9
25
8,000
12
19,920
33,120
19,440
19,200
CLTD (corr) = CLTD(table) + (78-Tr) + (Ta-85)
13
12
28
8,960
13
21,600
30,960
21,440
26,320
14
13
29
9,280
14
22,000
28,880
21,920
37,600
Qw =A*U*CLTD
Aw =
1600
Uw =
0.1
15
14
30
9,600
15
22,320
27,040
22,240
48,880
Qgs = A*SC*SCL
Ag =
800
SC =
0.3
16
14
30
9,600
16
23,120
25,040
21,440
56,560
17
13
29
9,280
17
24,000
22,480
19,680
58,320
Zone
N
E
S
W
18
12
28
8,960
18
21,680
19,040
17,200
46,480
HR
17
9
15
17
Instructor: Varkie C. Thomas, Ph.D., P.E.
Skidmore, Owings & Merrill LLP
72
Peak Envelope Loads
N W
E S
Qgc = A * Ug * CLTD
Ug =
ARCH-551 (Fall-2002) ARCH 552 (Spring-2003) F13
0.4
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