Document peRjgzzg6LQZxNXrgmOKjg9xX

HEATING VENTILATING AIR CONDITIONING GUIDE 1943 Table 11. Coefficients of Transmission (U) of Various Types of Flat Roofs Covered with. Built-Up Roofing^ TYPICAL CONSTRUCTION Without Ceilings Plasteb Ceilings* TYPE OF ROOF DECK Thickness or * Roof - Deck (Inches) No. /ttsr KOortHCj /Tut SjcifeEp ,tktr /Till laiBSSESM Precast Cement Tile lIIWVUU LtfATUtONN>f HOOHHGj '-r-COWatTtr ?/.(, ; cetLiricj/ f Concrete Concrete Concrete 22 43 64 lN/ULtflMI/ tOOHHff. / lipM wTopT i ` tfljuuTiffi. ROlFlttij Wood Wood Wood Wood 5 6 7 4` 8 : . Ifl/UL/ffltftt/ f 6tf/u>yy.-*y' ~ riAjreit sataop * - ItlJULAlUfy- - aSimi/ f. ?LA/TCR,D#AR-V^ * CElLlKd? Gypsum Fiber Concrete* . (2 in.) on Plasterboard 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.) MiouTMit/ . RPOTMKfii 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. "Computed from factors marked by * in Table 2. . `Nominal thicknesses specified--actual thicknesses used in calculations. `Gypsum fiber concrete--87H per cent gypsum, 12H per cent wood fiber. 2H 3H m 3 112- 9 10 11 12 , CHAPTER 4; HEAT TRANSMISSION COEFFICIENTS Coefficients ore expressed in Btu per hour per square foot per degree Fahrenheit difference in temperature, between the air'on the two sides, and are based on an outside .wind velocity of 15'mph. \ WITHOUT CEILING--UNDER SIDE OF ROOF EXPOSED : . .. ' WITH METAL LATH AND PLASTER CEILINGS* ja" i ja .' _d 5- J3 N j3 c | S d 5 ja' <s .d' 3B 1 a o vs _Bo | *a joa 9 a a = oa S3 9 a jj - a "B a -5 ~a 22 jj 6 S' ja - a JO 1 id .Ad O O' e O O 55 I I 9 ~a a 2 B *5 a s 2 ao - 9 a ;a a: OB *3 JS -a mte 2 .5 1 2 t o 5 i .3 O o ja oh. O AB CbE FGH 1 j K LMN o 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 0.11 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 0.11 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 0.49 0.37 0.32 0.23 0.28 0.24 0.22 0.17 0.20 0.18 0.16 0.14 015 0.14 ai3 0.11 0.12 0.19 0.11 0.17 0.11 0.16 0.096 0.13 0.14 0.13 0.12 0.11 0.12 0.32 0.11 0.26 0.10 0.24 0.091 0.18 0.21 0.19 0.17 0.14 0.16 0.15 0.14 0.12 0.13 0.12 0.11 0.10 0.11 0.15 0.10 0.14 0.097 0.13 0.087 0.11 0.12 0.10 0.11 0.095 0.11 0.092 0.096 0.082 0.40 i 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 0jl2 0.10 o:o9. 6.12 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, dr plasterboard and plaster ceilings. It is assumed that there is an air space between the underside of the roof deck and the upperside of the ceiling. 113 .