Document Rp45zwxb7q6KGXqONmN29y8LX

196. -.CHAPTER 9 , i 1954 'Guide Table 18. Combined Coefficients of Transmission (U) of Unvented Pitched Roofs* and Horizontal Ceilings--Based on Ceiling Area* Coefficient* are expressed in Btu pe r (Aour) (square foot of ceiling area) (Fahrenheit degree difference * temperature between the air on the two tide*), and are bated on an outride wind velocity of 15 mph. Type of Roofing and Roof Shbathinq Ceiling Coefficients Table 12) Wood Shingles on Wood' Stbifs4 (V, 0.48) 1 In. Insu- lating Board' lating Board on Under Side of Rafters of Rafters (Ur * 0.22) (Ur 0.16) Asphalt Shingles* ob Roll Roofing on Wood Sheathing* No Roof Insulation (Rafters Exposed) (Ur = 0.53) HIn.Insu- 1 In. Insulating Board lating Board on Under Side on Under Side of Rafters of Rafters (Ur - 0.23) (Ur - 0.17) HPS ca 1 0.14 0.19 0.22 0.23 0.24 0.27 0.29 0.30 0.37 0.59 0.61 0.62 0.69 A 0.085 0.092 . 0.099 0.11 o.n 0.12 0.13 0.13 0.14 0.14 0.15 0.15 0.16 0.16 0.17 0.17 0.18 0.18 0.-19 0.19 0.20 0.21 0.22 0.22 0.23 0.25 0.29 0.29 0.30 0.31 0.31 B 0.073 0.078 0.082 0.087 . 0.091 0.096 0.10 0,10 0.11 0.11 0.11 0.12 0.12 0.12 0.13 0.13 0.13 0.13 0.14 0.14 0.14 0.15 0.15 0.15 0.15 0.17 0.18 0.18 0.19 0.19 0.19 C 0.066 0.07 0.074 0.078 0.081 0.084 0.087 0.090 0.093 0.095 0.098 0.10 0.10 0.10 0.11 0.11 0.11 0.11 0.12 0.12 0.12 0.12 0.13 0.13 0.13 0.13 0.14 0.15 0.15 0.15 0.15 O 0.087 0.094 0.10 0.11 0.11 0.12 0.13 0.13 0.14 0.15 0.15 0.16 0.17 0.17 0.18 0.18 0.19 0.19 0.19 0.20 . 0.20 0.22 0.22 0.23 0.23 0.26 0.30 0.31 0.31 0.33 0.33 E 0.074 0.079 0.083 0.088 0.093 - 0.097 0.10 0.10 0.11 0.11 0.12 0.12 0.12 0.12 0.12 0.13 0.13 0.13 0.14 0.14 0.14 0.15 0.15 0.15 0.16 0.17 0.19 0.19 0.19 0.20 0.20 F 0.067 0.071 0.075 0.079 0.083 0.086 0.089 . 0.092 0.095 0.098 0.10 0.10 o.n 0.11 o.n o.n o.n 0.12 0.12 0.12 0.12 0.13 0.13 0.13 0.13 0.14 0.15 0.15 0.15 0.16 0.16 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 (See text on p. 185.) Calculations based on } pitch roof (n 15) using the following formula: Ur X Uct U -------------7j-- Ur n U = combined coefficient to be used with ceiling area. Ut -- coefficient of transmission of the roof. [/ce =coefficient of transmission of the ceiling. n = the ratio of the area of the roof to the areaof the oeiling. Use ceiling area (not roof area) with these coefficients. * Coefficients in Columns D, E and F may be used with sufficient accuracy for tile, slate and rigid as bestos shingles on wood sheating. 4 Based on 1 x A in. strips spaced 2 in. apart. * Sheathing assumed 51 in. thick. / Values of Uc* to be used in this column may be selected from Table 12. temperatures differing greatly from the room air temperature, i.e., such cases as in sun rooms, greenhouses, and some panel heated rooms, or where there is an unusual amount of air motion in the vicinity of the glass. Although based on zero outdoor air, the values change only slightly with different design temperatures, being about 5 percent greater for a 30 F. outdoor design temperature. In computing the Table 20 values, consideration of the dependence of the indoor surface conductances upon temperature and direction of heat. ,, BnUdtof m m " ->o,,, ---------------NNoftmiminai.t,, ThsiTc''sjr>.7?>,''. Inches **" ,^ .ACTUAL THICKNESS Inches j------------------------------------Exposed Pooh 1 it 4 4 2 2i 3 , yomputed using k = i is n i* 4 4 24 2f j* 0.69 0.59 0.52 0.51 0.46 0.38 0.33 --------------------------------------------' J WmG 0.35 0.32 0.30 0.30 0.28 0.25 0.` 23 ______ __________ clear no solar radiation uxons- 0 b a*r temperature, _SECTm A-Vehtical Glass Sheets Npmbeh of Sheets Ai* Space, inches U. One None 1.13 . Two Hh 0.61 0.55 1 0.53 Sectto1B:=HoM20,nial Geabs Sheets h,,, Thbeb C-Waeeh op HollOW Gears r------- Description l it7* 1 3* ?n- thick............-------------------------------------------------------------- ^^ fi^ acrcn dividioE the cavity. Section D--Approximate Application f.TM ---~-Lr Fw G-^ uvSSSthe^;^ows 0.60 0.56 0.62 0.48 Window Description Windows with Stobm Sheets Wood Sash ' ;......... Wood Sash. ....... ??*l Sash.. A1uminum.; P- 186.) Percent4 Glass Factor 80 60 80 80 0.90 0.80 1.00* 1.10 6 From ltt* or,*reatei. 4 Onit `/Pe dcJubl?1gl^wS5?If.e?Jed by ASHVE Tech , uaapd "mra IOr two sheets with i opim. eAnndiinnygs;l.Comm. on Glass Fr "eW name,r Portions of saah concealed by W