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American Society of Heating and Ventilating Engineers Guide, 1928.
Table 9-C. Coefficients of Transmission (17) of Various Types of Floors and Ceiling
Note.--These coefficients are expressed in B.t.u. per hour per square loot per l.deg. fahr. difference in temperature between the ground and the air over the floor and are based on still air (no wind) conditions.
CbUCilETE COliSTIZUCTlONi Okl CG.OUUD *
The values of U tn this: Table- are based, on the
ybllowmq Internal ConduckiviktesCC) which are expressed, in 6.t.u. per Ur. per Sq. ft. per (*F
Tile or Terraco
10.00 per l*
Concrete (3tane l:Z4<niO 8.30 per 1"
Cinder Concrete
5.20 per 1*
Wood. (Yellow Pine)
1.00 per V
Wood (Maple)
1.20 per l*
Fiber In^ulabon (frxrA/bnn) 0.33 per l*
Cort board
0.30 per t"
Typical Construction
Y - Thickness o/ Insulation m Inches <here specified Insulation bebmen Z membrane Waterprot/mq Course?;
Type of Insulation (between Cinder 4 X) 5tone Concrete ) 1
u 8 u-
04 Uo Insulation 05
206 07,
208 Fiber Insulation 09 (fcoard /army
710
ZI.I
717 Corb board
717 '214
215
Type
Floorirvq
f Yellow Pine tyl Maple or Oat 1" Terraco
> X Vlo Floorinq Floorinq on Floorinq on l* or Tile
tt<nn
V&
min c07
(Concrete bare) Wood.. "Sleepers Yellow fine Sub- Floorinq on
embedded, err Floonaqon Wood Concrete
Concrete
Sleepers embedded
JoUr o
in Concrete
f_--H h--
a
b
C
d
O' 4*
0. 550
0.388
0.308
0.526,
o' 5'
0.5ZI
0.370
0.Z97
0.49 5
O' ' O'
0.490
0.355
0.286
0.467
O' , 8\
0.439
0.327
0.268
0.420
l' . 4'
0. 207
0. 178
0.159
0.203
r S'
0.202
0.174
0.156 ,
0.198
C O'
0.197
0.17 1
0.153
a 193
r 8'
0,188
0.164-.
0.148.
0.185
2' r 4'
r S'
0.11,8 0.116
0.108 0.107
6.101 0.100
0.117 . 0.115. .
T O'
V 8'
0.115 0.112
0.105 0.103
0.098 0.096
0.113
o. no;
Assume ground temperature to be 50 deg. fahr.
fMembrane water proofing neglected in calculations.
JThe figures in column "b" may be used with sufficient accuracy for maple or oak flooring on wood sleepers embedded in concrete.
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Chapter i--Calculating the Heat Losses from Buildings
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39
*Pre cast cement.
tNom inal thicknesses specified--actual thicknesses used in computations.
,, ' .
IN o built-up roofing. The value for corrugated iron is obtained by assuming that the surface area is increased 50 per cent.