Document 6br9ydQx58pe7DEqb5eaw5vb1
V 142
Chapter 7
1945 Guide
Table 4. Solar Radiation (Direct plus Sky) Impinging Against Walls Having Several Orientations and a Horizontal Surface
For 40 Deg North Latitude on August 1
Sun Time
Northeast
. Intensity of Solar Radiation, Btu per Sq Ft per Hour
East
Southeast South Southwest West
Northwest
Horizontal Surface
4:50 5:00 6:00
700 8:00 9:00
10:00 11:00 12:00
IKK) 2:00 3KX)
4K)0 5 K)0 6KK)
7.-00 7:10
00
56 49 56
123 162
137 211 102 195
54 152 28 94 26 26
25.5
25.5
23.5
23.5
21 . 21
17. 11
4.5
17 11 4.5
2.5 2.5 00
0 4' 32
109 166 181
171 144 98
41 23.5 21
17 11 4.5
2.5
0
0 2.5 4.5
11 29 74
103 124 128
124 103
74
29 11 4.5
2.5
0
0 2.5 4.5
11 17 21
23.5 41 98
144 171 181
166 109 32
4
0
0 , 2.5
4.5
11 17 21'
23.5 25.5 26
94 152 195
211 162 56
6 0
0 2.5 4.5
11 17 21
23.5 25.5 26
28 54 102
137 123 49
5
0
0 5 20
85 160 212
244 . 281 290
281 244 212
160 85 20
5
0
Table 5. Solar Radiation (Direct plus Sky) Impinging Against Walls Having Several Orientations and a Horizontal Surface
For 46 Deg North Latitude on August 1
Sun Time
Northeast
Intensity of Solar Radiation, Btu per Sq Ft per Hour
East
Southeast
South
Southwest West
Northwest
Horizontal Surface
4:25 5K)0 6:00
7:00 8KX) 9:00
10KX) 11:00 12:00
IKK) 2:00 3.00
400 500 600
700 7:35
0 22 87
151 144 100
46 28 .26
25.5 23.5 21
17 12 5.5
3.5 0
0 20 99
192 237 199
153 94 26
25.5 23.5 21
17 12 .5.5
3.5 0
0 17 56
134 188 197
184 158 116
63 23.5 21
17 12
5.5
3.5
0
0 3.5 5.5
12 48 93
121 146 156
146 121 93
48 12 5.5
3.5 0
0 3.5 5.5
12 17
21
23.5. 63 116
158 184 197
188 134 56
17 0
0 3.5 5.5
12 17 21
23.5 25.5 26
94 153 199
237 192 99
20 0
0 3.5 5.5
12 17 21
23.5 25.5 26
28' 46 100
144 151 , 87
22 0
0 9
27
89 156 205
243 259 281
259 243 205
156 89 27
9
0
Cooling Load
143
as given in Fig. 1 and Table 4; outdoor design temperature reaching a maximum of 95 F as shown by the temperature curve in Fig. 2 and an indoor temperature of 75 F.
Curves in Fig. 3 were prepared by the A.S.H.V.E. Laboratory from recent tests made there and show the heat flow through the inside surface of three types of walls for various orientations6. The results are given for the following conditions: 90 per cent of the solar radiation given in Fig. 1 and Table 4 for 40 deg north latitude on August 1; outdoor design tem perature reaching a maximum of 93 F as shown by the temperature curve in Fig. 3 and an indoor temperature of 78 F and 50 per cent relative humidity.
The heat flow shown in Figs. 2 and 3 is a combination of normal trans mission and solar radiation transmission and is the total heat flow through the wall or roof. Due to the heat capacity of wall? and roofs there is a
Fig. 2.
SUN TIME. AUGUST 1
Relation Between Time and Heat Flow Through Inside Surface of Horizontal Roofs Corrected to Design Day of August 1
time lag6 in the transmission of heat through them as shown by the curves. For the types of construction covered in Figs. 2 and 3 and for the con ditions indicated, the heat flow through the inside surface at any given time can be read directly. For other types of construction, the curves may be used as a guide in estimating the heat flow. The time lag for other types of construction is included in Table 6 which was prepared by the ^A.S.H.V.E. Laboratory from data collected by it and by other authorities.
Solar Radiation Transmitted Through Glass
Windows present a problem somewhat different from that of opaque walls, because they permit a large percentage of the solar energy to pass
`A.S.H.V.E. Research Report No. 1195--Heat Gaia Through Walls aad Roofs as Affected by Solar Radiation, by F. C. Houghten. E. C. Hach. S. I. Taimnty and Carl Gutberlet (A.S.H.V.E. Transactions, Vol. 48. 1942, p. 91).
`Loc. Cit. Note 2.