Document RJbk5Qm854Roe8Jdjv8dgEVmk
American Society of Heating and Ventilating Engineers Guide, 1931
Chapter 3--Heat Losses by Transmission,
Table 32. Coefficients of Transmission
with Unheated Attics
Notr.--The FIGURES ON THESE PAGES ARE THE COMBINED COEFFICIENTS of TRANSMISSION
PITCHED ROFS
mooE CEILINGS, and are expressed in b.t.u. per hour per SQUARE
FOOT OF ROOF AREA PER 1 DEG. FAHR. DIFFERENCE IN TEMPERATURE BETWEEN THE AIR UNDE^?
tuwaTED ATTICS. AND TOfjT^MAGE WIND EXPOSURE OF 15 MILES HAS BEEN. ASSUMED. These
COEFFICIENTS ARE BASED ON ONE-THIRD PITCHED ROOFS, BUT ARE SUFFICIENTLY ACCURATE
^^OUTS^XI>E AIR-p.--nr.Half PrTCH.
The values of U in this Table are based or? tb following Internal Conduc-
-t vities or Conductances which areexpressed in B.t.u.per Ur.perSq.Ft per IT
\spbalt or Composition Goofmq
fc.so as applied
aslsabteestSohsmSahmleqstes VVv^ooooddL(aYthe4lloPwlaPsinteeror fir)
4.00 as applied . 10.37 per p \lM00 Derap1*plied
F laster board CFf-aiqsidteIrns(Gulyaptsiounm)(feoarJdf_orm)% F Uxible Insulation
3.13 peri*
2.32 per fo.33 per f o.27 per l"
C.ork. board C-ellular Gypsum (Id*) F laked Gypnum, Dry (IB*)
0 30 per l" o.S* per 1*
O.Mperf
fcaofinq
b and Goof
_D e
Sheathing
3
2
No Attic Flooring
Insulation between Ceiling Joists .
Wood i Plaster i R.iqid 1' (tiqid
Lath and board $ Insulatio 1 Insulation Plaster Plaster t Plaster 4 Plaster Ceilinq Ceilinq Ceilinq Ceiling
A Bc0
i None
2 Wood
f Flexible b
3
Wood. Strips*
2" Cellular 4 Gypsum
.4
2" Flaked Gypsum
5 Asphalt
fa Shingles or Composition
7 Goofinq on Wood
8 Sheathing
None
^ Flexible b
V Cellular Gypsum
2* Plaked Gypsum
4
4 None C.iqid Asbestos
10 Shmqles on 5 Flexible
Wood II Sheathinq
2" Cellular <* Gypsum
12
r Flaked Gypsum
13 None Slate or Tile
14 and Cool inq flexible
felt on Wood
15 Sheathing
Z. Cellular Gypsum
16
V flaked Gypsum
b d
0.263 0.264 0.140 0.141 0.141 0.141 0.116 0.04fa 0.12fa 0176 0.107 0.040 0.047 0.042 0.081 0.071 0.272 0.273 0.144 0.143 0.143 0.143 0,118 0047 0.128 0.128 0.108 0.04D 0.043 0.043 0.081 0071 0.71 \ 0.272 o.m 0.143 0.143 0.143 0.118 0.047 0.128 0.128 0.108 0.040 0.043 0.043 0.081 0.071 0.780. 0.781 0.148 0.145 0.145 0.145 0.120 0.048 0.130 0.130 0.104 0.040 0.043 0.043 0082 0072
Typical Construction (Looting -
Goof Sheathing
Unheeded Attic Atttc flooring
Plaster Ceiling-"
VW Yellow Pine Attic floor in q
l\*Corkboard 4 Plaster Ceilinq
2* Corkboard i Plaster Ceiling
Wood I Ptast|[t Gvqid l* Giqid (\ Cork-
Lath and' board ^ \mulahsn| Insulation board 4 Plaster Plaster 4 Raster 4 Plaster] Plaster Ceding Ceitmq Ceding Ceding Ceding
V Cork
board 4 Plaster Ceding
WI
KL
0.106 0.088 0.172 0.078 0,068 0.104 0.074 0.064 0.101
0.172 0.104 0.101
0.136 0.104 0.087 0.074 0.044 0.080 04)68 0.060 0.088 0.076 0.064 0.057
0.04,1 0.054 0.078 0.078 0.070 0.062 0.053 0.044 0.107 0.088 0.175 0.175 0.138 0.110 0.087 0.075 a 074 0.068 o.uo 0.110 0.045 0.081 0.068 0.060 0.015 0064 .0.102 0.102 0.088 0.076 0.064 0.057 O.Ofct 0.054 0.078 0.078 0.070 0.062 6054 0.044
0.107 0.088 0.175 0.115 0.138 0.110 0.087 0.075
0.074 0.068 0.110 0.110 0.045 0.081 0.068 0.060
0.075 0.064 0102 0.102 0.088 0.016 0.064 0.057
O.Ofal . 0.054 0.078 0.018 0.070 0.062 0.054 0.044
0.108 0084 0.174 0.174 0.140 am 0.088 0.076
0.080 0.068 O.ltl O.lll 0.046 0081 0.068 0.060
0.076 0.065 0.103 0.103 0084 0.076 0.065 <2458
0061 0054 0.078 0.078 0.070 6.062 0.054 0.044
aBased on 1 In. by 4 In. spaced 2 in.
aBased on 1 in. by 4 in. spaced 2 .in. * .
bCan also be applied to underside of ceiling joists with furring strips between. insulation and c [ bCan also be applied to underside of ceiling joists with furring strips between insulation and celling.
Ill oBased on actual thickness.of 1 in. lumber of approximately in. *
cBased on actual thickness of 1 in* lumber of approximately
-,
jdThe coefficient used for cellular gypsum, 0.59 is for 18 Ib. weight-^weights as low as 12 lb. may k.fl dThe coefficient used for cellular gypsum. 0.S9 is for 18 lb. weight--weights as low as 12 lb. may be used.
68. 69
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