Document x51kqx1y8wzNLzEVa500mDgk6

T a b l e 12. C o e f f ic ie n t ^ o f T r a n s m is s io n (17) o f P it c h e d R oofso ' Coefficients are expressed in B tu per hour per square foot per degree Fahrenheit difference in temperature between the a ir on the two sides, and are based on an outside w ind velocity o f 16 mph. , . HEATING' VENTILATING AIR CONDITIONING GUIDE 1943 sac . 2 dwfa0 o? . Go M fc Si >Q aj <an.. ! 0.060 | | 890*0 ( Ul pus rm ) pieoq^>Q . coi h) pa* ( ni HD P"OSV<>0 X C"! H) pm ( oj i) uot^epsoi piSiy o (01 H) "Wd Pn* ( "1M) nojj^nmii pifta fa (u| J{) aoiisjnsaj pjfty fa |1 0 .2 1 1 0.16 1 0.12 \ 0.10. | 0.092 |! 0.078 atoo S o .j 0.086 | 0.083 | 0.083 | 0.076 | 0.075 | 0.13 | 0.12 | 0.12 | 0.11-* |I o . i i 0.22. 1 | 0.29 aaissid po poo^ Q 1| 0 .2 9 Cat K) pas (*nn) preoq^ssid O 0.46 | 0.30 pas q* pr(j*|s\?%ajq) fa 1 (pModig ora,j*H) 2uJPO ON < 6 25 - 0.21 | o o I to 0.070 0.070 0.064 0.064 0.057 0.052 0.047 0.34 | 0.32 | 0,24 | 0.23 | 0.17 | 0.13 | 1 1:0 0.095 | 0.080 0.071 o 1o o 0.079 | 0.078 | <0 do 0 .1 3 '| 0.11 | 0.072 | o o 0ro0d 0.087 | 0.24 | 1 C IO CO s o' o 0.13. | 0o000 CO oo | 99*0 j ts 00 O' 0.062 1| 0.056 0.059 | 0.053 j 0.048 None | B rig h t A lu m in u m Foil* | 1 In. Flexible* | 2 in. Flexible* | None | B rig h t A lu m in u m Foil* | 2 in. Flexible* | INSULATION BETWEEN ROOF RAFTERS i Jj- 3 I fa - fa d G CO oo & tua o fa d eo S heathing/ Roofing4 on Wood Slate o r T ile tlo n Roofing, or. Shingles, Com posl- R ig id Asbestos A sphalt Shingles, Wood Shingles on Wood S trips6 >' TYPE OF ROOFING AND ROOF SHEATHING 1 : i TYPICAL CONSTRUCTION j JL. i : 114 -* * ' 6Based on 1 In. b y 4 in. strips spaced 2 in. Figures based on tw o a ir spaces. Insulation may also be applied to under side of roof rafters w ith fu rrin g strips between. ^Roofing fe lt between roof sheathing and slate or tile neglected in calculations. "Computed from factors marked tiy *. in Table. . 2. Nos.. 6 to 10; inclusive, based on J j In. thick slate. Assumed 3 /Sheathing a%s isun.mtehdic k% based on the in; thick. actual w id th of 2 in. by 4 in. rafters. These coefficients are corrected fo r the effect of studs. ; *A lr space faced on one side w ith b rig h t alum inum fo il applied to plasterboard. CHAPTER 4. HEAT TRANSMISSION COEFFICIENTS Table 13. Coefficients of Transmission (U) of Doors, Windows, Skylights v and Glass Block Walls Coefficients are based on a wind velocity of 15 mph, and are expressed in Btu per hour per square foot per degree Fahrenheit difference in temperature between the atr inside and outside ofthe door, window, skylight or wau Section A. Windows and Skylights Description U 1.13a. 0.45. * 0.281. Nominal Thickness Inches i .mmw 2 3 Section B. Solid Wood Doorsb. Actual Thickness Inches U Exposed Door u* With Glass Storm Door % We . Wwwe 2X 2VS 0.69 . 0.59 0.52 0.51 0.46 0.38 0.33 - . 0.42 0.38 0.35 0.35 0.32 0.28 0.25 . Section C, Hollow .Class Block Walls Description Smooth surface glass blocks 7% x 7% x 3% in. thick Ribbed surface glass blocks 7% x 7J4 x in. thick u Still Air Both Sides 0.40 0.38 u Still Air Inside, . 15 mph Outside 0.49 i . 0.46 See Heating. Ventilating and Air Conditioning, by Harding and Willard, revised edition, 1932. `Computed using C 1.15 for wood;/j.= . 1.65 and/o 6.0. # .... , It is sufficiently accurate to use the same coefficient of transmission -for doors containing thin wood ; panels as that of single panes of glass, namely, 1.13 Btu per hour per square foot per degree difference - between inside and outside air temperatures. , *These values may also be used with-sufficient accuracy for wood storm doors. Neglect storm doors if loose and use values for exposed doors. Air spaces assumed to be in. or more in width. Basement Floor and Wall Coefficients The dirt in contact with basement floors and walls below grade has an appreciable insulating value. The exact thickness or depth of the dirt which may contribute to the heat resistance of floors and walls in contact therewith is a variable and indeterminate quantity. Tests at. the A.S.H.V.E. Research Laboratory5 indicate that the rate of heat flow through basement floors, even without insulation, does not exceed 0.10 Btu per square foot per degree Fahrenheit temperature difference between the air above the floor and the soil under the floor at the point of maximum diffusion of the heat from the basement. As indicated in the footnote of Table lOj this coefficient is recommended for use whenever it is desirable *A S H V E Research Paper--Heat Loss Through Basement Walls and Floors, by F. C. Houghten, S. 1. Taimuty. Carl Gutberlet and C. J: Brown (A.S.H.V.E. Journal Section. Heating, Pipingand Air Conditioning, January. 1942, p. 69). ;