Document k96kmwYemk27p43VyLpM3ZBxV

HEATING VENTILATINC AIR CONDITIONING GUIDE 1942 Table 11. Coefficients of Transmission (/) of Various Types of Flat Roofs Covered with Built-Up Roofings TYPICAL CONSTRUCTION WiTBotrr Ckilikqs Wrra Metal Lath and Plaster Ceilings* TYPE OP ROOF DECK Thickness . or Roor Deck (Inches) No. HQSftHCj A/PPJ(tT/^ RflOflNtf, /flLL *T/urro.T/jr' Precast Cement Tile l H tfWUtATlM/ coricutTC. m/OLATuw, R0F1N4 / ["HniininiimiifflW R`: CJMCRtTfc' lil>l CEtUtM?^ Concrete Concrete Concrete lN/ULATlOH/ lOOFUHj / wrnmwm utovs |41/UULLAATTl9lvnn>t ROOFlflfii I woep Wood Wood Wood Wood l 1M* :2` 4 Irtfuurriott/ M,W"SC...A t'trjvrcy.-. t.y.f nzzzzzzzzezzzzal fLA/TS*. tOW' -m/ULAtll HOPFlHCj FLA/TCIL MAILS' wjouTwiti RPOF tWtf^ Re.**- j Gypsum Fiber Concrete* (2 in.) on Plasterboard (H in.) Gypsum Fiber Concrete* (3 in.) on Plasterboard (H in.) Gypsum Fiber Concrete* (2 in.) on Rigid Insulalation Board <H in.) Gypsum Fiber Concrete* (2 in.) on Rigid Insula tion Board (1 in.) Flat Metal Roofs Coefficient of transmis sion of bare corrugated iron (no roofing) is 1.50 Btu per hour per square foot of projected area per degree Fahrenheit dif ference in temperature, based on an outside' wind velocity of 15 mph. `2M 3M 2H 3 Computed from factors marked by * in Table 2. `Nominal thicknesses specified--actual thicknesses used in calculations. 'Gypsum fiber concrete--87per cent gypsum. 12^ per cent wood fiber. 108 CHAPTER 4. HEAT TRANSMISSION COEFFICIENTS AND TABLES Coefficients are expressed in Btu per hour per s ware foci per degree Fahrenheit difference in temperature between the air on the two sides, and ore based on an outside wind velocity of lo mph. WITHOUT CEILING--UNDER SIDE OF ROOF EXPOSED WITH METAL LATH AND PLASTER CEILINGS* ja 5 _d 1d N _a 3 | o Z _ao 3 3a -g 2 a 39a o `5 2 ao 39a la 2 'a .2 39 3 I at _d 1 Oo d 5 _d CM TS *2 1J MM Oo Oo d 5 a ap0 3 1 1, -9 e Z. 2 J3 _ao 3 3a 3*S 2 ja 5 aa 3a9 a 2 Rigid Insulation (2 In.) .d .S 1 -a ? jQSo p 2 O O' O A B C D E . F G H I* J K L M N o _d N T J Jd Oe P 0.84 0.37 0.24 0.18 0.14 0.22 0.16 0.13 0.43 0.26 0.19 0.15 0.12 0.18 0.14 0.11 0.82 0,37 0.24 0.17 0.14 0.22 0.16 0.13 0.42 0.26 0.19 0.15 0.12 0.18 0.14 0.72 0.34 0.23 0.17 0.13 0.21 0.16 0.12 0.40 0.25 0.18 0.14 0.12 0.17 0.13 0.64 0.33 0.22 0.16 0.13 0.21 0.15 0.12 0.37 0.24 0.18 0.14 0.11 0.17 0.13 0.11 0.11 0.11 0.49 0,28 0.20 0.15 0.12 0.19 0.14 0.12 0.32 0.21 0.16 0.13 0.11 0.15 0.12 0.10 0.37 0.24 0.18 0.14 0.11 0.17 0.13 0.11 0.26 0.19 0.15 0.12 0.10 0.14 0.11 0.095 0,32 0.22 0.16 0.13 0.11 0.16 0.12 0.10 0.24 0.17 0.14 0.11 0.097 0.13 0.11 0.092 0.23 0.17 0.14 0.11 0.096 0.13 0.11 0.091 0.18 0.14 0.12 0.10 0.087 0.11 0.096 0.082 0.40 0.25 0.18 0.14 0.12 0.17 0.13 0.11 0.27 0.19 0.15 0.12 0.10 0.14 0.12 0.097 0.32 0.22 0.16 0.13 0.11 0.15 0.12 0.10 0.23 0.17 0.14 0.11 0.097 0.13 0.11 0.091 0.26 0.19 0.15 0.12 0.10 0.14 0.11 0.10 0.20 0.16 0.13 0.11 0.09 0.12 0.10 0.087 0.19 0.15 0.12 0.10 0.09 0.12 0.10 0.08 0.16 0.13 0.11 0.09 0.08 0.10 0.09 0.077 0.95 0.39 0.25 0.18 0.14 0.23 0.17 0.13 0.46 0.27 0.19 0.15 0.12 0.18 0.14 0.11 *These coefficients may be used with sufficient accuracy for wood lath and plaster, or plasterboard and plaster ceilings. It is assumed that there is an air space between the under side of the roof deck and the upper side of the ceiling. 109