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CHAPTER 13
1956 Guide
Table 10 Total Equivalent Temperature Differentials for Calculating
Heat Gain Through Sunlit and Shaded Walls-
_______
Son Time
Nobth Latitude
Wail Facing
P.M.
Exterior color of Wall--D = dark, L light d I l|d| l 1 d I l|d|l|d!l|d|l|d|l|d| l|d|l
Sooth Latitude
Wall Facing
NE E SE S
SW W NW N (Shade)
NE E SE S
SW w NW N (Shade)
NE E SE S
SW w NW N (Shade)
NE E SE S
SW w NW N (Shade)
NE E SE S
SW w NW ' N (Shade)
NE E SE S
SW w NW N (Shade)
-4 -4
24 4
12 18 16
0
14 32
28 22
10 16 18 12
12 10 14 14 14 14 10 10 12 12 14 14 14 14 10 10 24 16 16 14 14 14 10 10 30 20 26 20 16 14 10 10
6 6
6 6
4 6
6
2
2
--2 -4 -4 -2 -2
6 6
6 4
4 6 4
4
26 22 40 '28 42 28 24 20 20 12 40 2 48 34 22 22 12 10 24 20 40 26 34 24 10 10 14 14 12 12 8 8
6 8
6 4
4
8 4 4
2
2
SE E
NW W SW
4 In. Brick or Stone Veneer + Frame
-2 2 2
-4
1 11
24 12 30 14 20 10 -2 -2
20 31 28 12
10 17 16
6
10 14 26
6 14
16
12 12 18
10 12 14
14 14
14
14 14 14
12 12
12
12 12 12
10 10 10
10 8 8
24 16 26 18 20 16 12 12 8 8
6 6 6 4
0 -2 0 -2 0 -2 0 0 -4 -4 -2 -2 -4 -4 -2 -2
2 4 2 0
2 2 2
0
12
10 8 6
8 32 22 36 26 34 24 10 8 6
8 6 6
26 12
10
18 12 10
40 30 12
28
22 12
42 34 12
28 24 12
16 12
8
14 . 6
10 6 84
4
6 6 6 4
SE E NE N
NW W SW S (Shade)
8 In. Hollow Tile or 8 In. Cinder Block
0 4 2 0
00 2 12 02
00
0 4
0 0
20 24 16
2
10 12
8 0
16 26
20 12
10 10 14 20 12 20
6 24
6 12 14 14
12 12
14 26
10 10 12 16
14 12 12 10 8 14 12 14 .10 10 14 12 12 10 8 20 14 12 10 8
8 8
6 6
202020 424242 000020 -2 -2 -2 -2 -2 -2
6 6 4 0
4 4
12 10
10 8
26 18
18 14
30 20 30 22
26 32
18 22
8 18
6 14
2 0
8 6
6 12 10 22 18 30 22 10 6 10 10 10 10 10 10 6
8 6
SE E NE N
NW W SW S (Shade)
8 In. Brick or 12 In. Hollow Tile or 12 In. Cinder Block
22
86 8> 4 42
2 8
6 4
2 10 6 14 46 24
2 8 4
16 18 14
8 10 10
14 18 18
8
10 12
10 14 16
6 8 12
10 14 12
8 10 10
10 14 12
10 10 10
10 12 12
8 10 10
2 4 2 10 e 16 10 16 12 12 10 10 8
8 8
2 0
4 4 2
0
6
6 2 0
4 4
2 0
6 6 2 0
4 6 2
0
8 4 10 G 12 20 12 24 16 20 14
G 10 G 14 20 16 24 16 24 16
C
2 0
G 2
4 2
G
G 10 f
16 14 1 14 G6
SE E NE N
NW W SW S (Shade)
12 In. Brick
8
12 10 8
68 8 12 6 10 68
68 8 12 6 10 66
4 8
6 4
8 10
10 6
4 10 6 12 6 10 46
4 12 6 12 6 10 6 10 8 14 10 14 10 14 8 14 6 12 8 14 10 14 10 12 4 8 4 10 6 12 8 12
6 SE 8E * 8 NE 8- N
___ _
10 12
8 4
6 10 8 12 68 42
6 10 8 12 68 22
6 8 4 2
10 10
8 2
6 10 6 10 48 22
6 10 6 10 48 22
8 10
6 10 48 22
8 12 6 12 6 10 24
8 14 10 8 16 10 6 10 6 466
NW W SW s (Shade)
8 In. Concrete or Stone or 6 In. or 8 In. Concrete Block
4 6
6 2
24
4 14 26 12
0
8 4
1
16 24
16 4
8 12 10
1
14 24
18 12
8 12
12
6
10
18 18
16
6
10 12
12
12 14 14
18
8 12 10 14
12 12 121 14
10 10
10 12
10 12
12 10
8
10 10
8
8
10 10
8
6 8
8 6
1 86
6 4
0
2 4
2 0
4 6 4
0
2
4 0
0
6
6 4 0
2 4
2
0
8 8
4 2
4 6 4 2
14
12 6 4
10 8 6 4
22
20
12 6
16 14 10
24 28 20
16 18
14 8
22 26
22 6
16 18 16
6
10
14 8
4
8
10
6 4
SE E N NE
NW W SW , . 8 (Shade)
Cooling Load
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Table 10. JTotal Equivalent Temperature Differentials for Calculating Heat Gain Through Sunlit and Shaded Walls--Concluded.
North Latitude
Wall Facing
NE E SE S SW W NW N (Shade)
Son Time
A.M.
P.M.
8 1 10
12 2 4 1 3 8 10
Exte:rior color of Wal --I> - dark, L light
12
Sooth
Latitude Wall
Facing
D D L D D L D L D L D lL D lL D
12 In. Concrete or Stone
6
4
6
2
6 6,
2
6 4
14 18
8 10
14 1
8 12
10 16
8 1C
10 12
8 10
12 14
10 10
10 14
8 10
SE E
14 8 1G 10 16 10 14 10 12 10 12 10 NE
-1
4 2 10 6 14 10 16 12 14 10 10 8 N
8
4 *
8
4
6
4
6 10 6
48 6 10 46
6 10
6 12 48
8 18 14 20 14 18 12 8 16 10 24 14 22 14 6 10 8 18 12 20 14
0022 4 4 668 8 66
NW W SW S(Shade)
NOTES FOR TABLE 10
(Total heat-transmission from solar]
Explanation: Iradiation and temperature difference! [between outside and room air, Btu|
[per (hr) (sq ft wall ares)
,J
NOTES:
[Equivalenttemperature Heat transmission] I differential from above Y coefficient for wall,!
| table
, Btu per (hr) (eql
ft) (P deg)
]
cauy true. Uaric colors on exterior surface of walls have been assumed to absorb 90 percent of solar radiation and reflect 10 percent; White colors absorb 50 percent and reflect 50 percent. This includes some allowance for dust and dirt since clean, fresh white paint normally absorbs only 40 percent of solar radiation. '
2. APPblCA T10N. These values may be used for all normal air conditioning estimates, usually with out corrections, when the load is calculated for the hottest weather. Correction for latitude (Note 3) is neces sary only where extreme accuracy is required. There may be jobs where the indoor room temperature is considerably above or below 80 F, or where the outdoor design temperature is considerably above 95 F, in which caseit may be desirable to makecorrection tothe temperature differentials shown. The solar intensity
on all walls other than east and west varies considerably with time of year.
, 3. CORRECTIONS. Outdoor minus room temperature. If the outdoor maximum design temperature minus room temperature is different from the base of 15 deg, correct as follows: When the difference is greater (or less) than 15 deg, add the excess to (or subtract the deficiency from) the above differentials.
Outdoor daily range temperature. If the daily range of temperature is less than 20 deg, add 1 deg to every 2 deg lower daily range; if the daily range is greater than 20 deg, subtract 1 deg for every 2 deg higher daily range. For example, the daily range in Miami, Florida is 12 deg, or 8 deg less than 20 deg; therefore, the cor rection is +4 deg.
Color of exterior surface of wall. Use temperature differentials for light walls only where the permanence of the light wall is established by experience. For cream colors use the values for light walls. For medium colors interpolate half*way between the dark and light values. Medium colors are medium blue, medium
peen, bright red, light brown, unpainted wood, natural oolor concrete, etc. Dark blue, red, brown, green,
etc., are considered dark colors.
v
Forlatitudes other than 40 deg north; and in other months. These table values will be approximately correct (or the east or west wall in any latitude (0 deg to 50 deg North or South) during the hottest weather. In the lower latitudes when the maximum solar altitude is approximately 80 deg to 90 deg (the maximum occurs at
&oon) the temperature differential for either a south or north wall will be approximately the same as a north,
or shade wall. The temperature differential (fx) for any wall facing, and for any latitude for any month may he approximated ss follows:
= -ffxiiw-tt)
h maximum solar radiation intensity transmitted through glas3, Btu per (hr) (sq ft) for particular wall facing, in July, 40 deg north latitude (note: this is maximum value irrespective of time).
It a same as A except use the maximum value for wall facing, for month, and latitude desired for tx.
tw = temperature differential for particular wall facing, for the desired time of day from above table.
(Note that this makes adjustment only for solar radiation, and that there may be additional correction for outdoor temperature.) * FOR INSULATED WALLS use same temperature differentials as used for uninsulated walls.