Document v6RymZ4a08RGkNDDbveZ03n99
American Society of Heating and Ventilating Engineers Guide, 1930
Chapter 2--Heat Losses from Buildings
Table 35. Coefficients of Transmission (j Iof Pitched Roofs with Unheated Attics
i J*Note.--ThB FIGURES ON THESE PAGES ARE THE COMBINED COEFFICIENTS of TRANSMISSION OF FlTcftJ I
FOOT OF ROOF AREA PER 1 DEG. FAHR. DIFFERENCE IN TEMPERATURE BETWEEN THE AIR UNDERNEATH
UNHEATED ATTICS, AND TOP-FLOOR CEILINGS, AND ARE EXPRESSED IN B.T.U. PER HOUR PER SQUARE rvG AND THE OUTSIDE AIR. AN AVERAGE WIND EXPOSURE OF 15 MILES HAS BEEN ASSUMED. THESE
COEFFICIENTS ARE BASED* ON ONE-THIRD PITCHED ROOFS. BUT ARB SUFFICIENTLY ACCURATE FOR
JSSciNG FROM ONE-QUARTER PITCH TO ONE-HALF PITCH.
The values of Uin this Table are based on thefollawinq Internal Canduc-
-tmties or Conductances which are expressed in B.tu.per Uk perSqFfc per IT
Asphalt or Composition Roofinq
6.50 as applied
Asbestos Shmqles
6.00 as applied
Slate Shmqles
|0.n per r
Wood. ( Yellow Pine or Fir)
1.00 per 1"
Wood. Lath < Plaster
2.00 ,, applied
Plaster board
3.13 peri"
Plaster (Gypsum)
2.32 perf*
E-iqid Insulation (Board form)
0.33 per l`
Flexible Insulation
0.27 per' lm
Cork, board
fl.30 per 1"
Cellular Gypsum (I8R)
0.S4 per 1"
Flaked Gypsum, Dry (18*)
0.34 per. I"
Typical Construction
Goof Sheathinq-. _^^^!p^/^^tJnheoAed Attic ^ S----- Attic Floormq
PlasterCeilinq-^ '
base
hio Attic Floormq
(Zoofmq LV and Boof
Insulation
Wood {^Piaster { Ciqtd rRiqid
between Ceilmq Lath and board | Insulator Insulation
Sbeathmq Joists
Plaster .Plaster 4 Plaster $ Plaster
D Ceilmq Ceilmq Ceihnq Ceilmq 2
A Bc 0
tw Yellow Pine Attic Floormq c
Ik'Cork- r Cork- Wood V Plaster t C*qi4 reiqtd ll Cork- Z" Cork.board 4 board t Lath and board t Insulation Insolation boardl boards Plaster Plaster Plaster Plaster 4 Plaster 4 Plaster Planter Plaster Ceilmq Ceilmq Ceilmq Ceilmq Ceilmq Ceilmq 6eilinq Ceilmq
E F G u i j K. L
i hione
2 Wood
j* Flexible b
3
Shmqles on Wood Strips4
2- Cellular 4 Gypsum
4
V flawed Gypsum
5 Asphalt
Mone
fc SWinqles or Flexible b
Composition
7 fcoofmq on
Wood
V Cellular 4 Gypsum
8 Sheathing
2" Flaked Gypsum
<1 Klone
Hiq id Asbestos
10 Shmqles on Flexible. b
Wood
II Shealhwiq
2* Cellular 4 Gypsum .
V flaked 11 Gypsum
13 Ktcne
14 and Coot inq Flexible b
15 SlaealVunq lb
V. Cellular Gypsum r Haked Gypsum
d
0.143 0.764 0.140 0.141. a 141 0.141 0.116 0.046 O.llfc' 0.176 0.107 0.040 0.047 0.047 O.O&l 0.071 0.277 0.773 0.144 0.143 a 143 QI43 0.118 0.047 0.178 0.178 0.108 0.040 0.043 6.043 0.081 0.011 0.7r 71 0.777 0.144 0.1430.143 0.143 0.118 0.047 0.I7& 0.178 0.108 0.040 0.043 0.043 0.081 0.011 0.780 0.281 0.148 0.1/15 0.145 0.145 0,120 0.098 0.130 0.130 0.109 0.090 0.043 0.043 0.082 0.072 `
a 106 0.088 0.172 an 7 ai36 0.109 0.081 0.074
0.078 0.068 0.109 0.109 0.044 0.080 00)68 0.060 0.074 0.064 0.101 0.101 0.088 0.076 0.064 0057 0.061 0.054 0.078 0.018 0.070 0.062 0053 0044 0.107 0.088 0.175 0.175 0.138 0.110 0.087 0.075 0.074 0-068 0.110 0.110 0.045 0.081 0.068 0.060 0.015 0064 0.102 0.102 0.088 0.016 0.064 0.057 0.061 0.054 0.078 0.078 0.070 0.061 0.054 0.044 0.101 0.088 0.115 0.115 0.138 0.110 0.087 0.075 0.014 0.068 0.110 0.110 0.045 0.081 0.068 0.060
0.015 0.064 0.102 0.102 0.088 0.016 0.064 Q057
0.061 0054 0.018 0.018 0.070 0.067 0.054 0.044 0.108 0.084 0.114 0.174 0.140 0.(11 0.088 0.076 0.080 0.068 O.ttl 0.111 0.046 0.081 0068 0.060 0.076 0.065 0.103 0.103 0.089 0.076 0.065 0058 0.061 0.054 0.018 0.078 0.070 0.067 0054 0044
aBased on 1 in. by 4 in. spaced 2 in.
'*7
bCan also be applied to. underside of ceiling joistawitb furring strips between insulation and ceilin*
oBased on actual thickness of 1 in. lumber of approximately in.
/^
dThe coefficient used for cellular gypsum, 0.59 is for 18 lb. weight--weights as low as 12 lb. may be used.
58 V: '
Baaed on 1 in. by 4 in. spaced 2 in.
--
bCan also be applied to underside of,ceiling joists with furring strips between insulation and ceiling.
Based on actual thickness of 1 in. lumber of approximately Hfa in. dThe'coeffident used for cellular gypsum. 0.59 i&for 18 lb. weight--weights as low as 12 lb. may be used.
59