Document wr7E0XdYy58NenY5MLMJbVM4Q

CHAPTER 9 1956 Guide 170 Table 1. Conductances (C) fob Surfaces and Aib Spaces All conductance values expressed in Btu per (hr) (sq fi) (F deg temp diff) Section A. Surface Conductances for Still Air*_______________________ Surface Emissivity Horizontal........ Sloping--45 deg Vertical............. Sloping--45 deg................. Horizontal.............................................. . Downwara i \ ' \ 1----------- ------------ , 1 --j;_ __ havina an emissivity equal ence oi iwr a ior surittwc --- -^^nTThcmal ------------ ---_-_-_--_-_-_-_--_-_-_-_-_-_-_-_-_--_-_-_r_.__n__<_____.___--a:---* s---m----m---*-- Thermal Resistance-E. li i* __________________ Notes: 4b SWphaeceres oa fraunngifeoormf ththicickknneessssi,abgoiuvnedne, dthbeygmivoednecroantedluycstamnocoethisstuhrfeacaevse.rage over the range; extreme c Ivnatleurepsowlaitihoinn, tahnedrmanogdeerdaitfefeerxthraepreoflraotmionb, yoflecsosntdhuacntan10cepevarclueenst.are permissible for other values of mean temperature, temperature difference and effective emissivity E. d Effective emissivity of space, B, is given by--- -- + -- -- 1 where pi and es are the emissivities js ej ci f Tohf tehceosnudrufacctaenscoefsthoei haoiriszpoanctea.l sp(SaceesSwecitthionheCa.t fbloewlowd)o.wnward are substantially independent of * Based on National Bureau ofStandards data presented in Housing Research Paper No. 32, Housing and temperature difference. Home Finance Agency, 1954 (U. S. Government Printing Office, Washington, D- C.) Section C. Reflectivity and Emissivity Values of Various Surfaces4 sod Effective Emissivities of Air Spaces Reflectivity IN PERCENT Aluminum foil* bright... Aluminum sheet........................ , , Aluminum coated paper, polished Steel, galvanized, bright Aluminum paint.......................... Building materials: wood, paper, glass, masonry, non-metallic paints.............. * See also Chapter 5, Table 3. 92 to 97 80 to 95 75 to 84 70 to 80 30 to 70 5 to 15 Average Emissivity * 0.05 0.12 0.20 0.25 0.50 0.90 of Air sfacb |Witb one sur With both face haying surfaces of . emissivity e emissivity * and other 0.90| 0.05 0.12 0.20 0.24 0.47 0.82 0.03 0.06 0.11 0.15 0.35 0182 Heat Transmission Coefficients of Building Materials 171 Table 2. Conductivities (k). Conductances (C) and Resistances (R) of Building and Insulating Materials ' (Design Values)4 These constants are expressed in Btu per (hour) (squarefool) (Fahrenheit degree temperature difference). Conductivities (k) are per inch thickness and, conductances (C) are for thickness or construction stated, not per inch thickness Conductivity or Conductance Resistance (R) AIR SPACES'1 AIR SURFACES Still Air 15 uPH Wind 754 mph Wind BUILDING BOARD*1 Boards, Panels, Sheathing, Etc. Description Density (Lb. per CuFt) See Table 1--Section B. Position Heat Flow Thickness Horizontal.............Up........................................54-4in. Sloping (45).........Up..................................54-4 in. Vertical.................. Horizontal.................... H-4 in. Sloping (45).........Down.................................. 54-4in. Horizontal.............Down...................................... Hin. Horizontal.............Down.................................... 154in. Horizontal.............Down........................................4in. Horizontal.............Down........ ...................... 8 ia. See Table 1--Section A Position------ Heat Flow Horizontal............................................................ Up Up Sloping (45)................................................ Up Vertical....................................................Horizontal Sloping (45).................................................. Down Horizontal..................................................... Down Any Position--Any Direction.......................... Any Position--Any Direction.......................... Asbestos-cement board...................... Asbestos-cement board..................... 54 in. Gypsum or plaster board................. 54 in- Gypsum or plaster board-- .......... 54 in. Plywood................................................................ Plywood...................................................................54in. Plywood.................................................................. 54m. Plywood..................................... 54 in. Plywood or Wood Panels.................................... 54in. Wood fiber board, laminated or homogeneous. A Wood fiber--hardboard type............................. Wood fiber--hardboard type.............................. 54in. Wood--fir or pine sheathing..................... *54z in. 50 50 34 34 34 34 26 31 65 65 (k) 0.80 0.42 0.50 1.40 .2 -a (C) paj' ,g fe 8.S 1CL o H*-* C* (i) a) 1.18 1.11 1.03 0.97 0.98 0.87 0.81 0.80 0.85 0.90 0.97 1.03 1.02 1.15 1.23 1.25 1.83 1.60 1.46 1.32 1.08 6.00 4.00 0.61 0.62 0.68 0.76 0.92 0.17 0.25 33 3.10 2.25 3.20 2.12 1.60 1.07 5.60 1.02 2.38 2.00 0.72 0.03 0.32 0.45 0.31 0.47 0.63 0.94 0.18 0.98 building PAPER Vapor--permeable felt.................................. Vapor--seal, 2 layers of mopped 15 lb felt.... Vapor--seal, plastic film...................................... 16.70 8.35 flooring MATERIALS * insulating materials Blanket and Batt Board Asphalt tile.............................................................Win- Carpet and fibrous pad.......................................... Carpet and rubber pad..................................... Ceramic tile.............................................................1in. Cork tile................................................................ Cork tile..................................................................54in. Felt, flooring........................... ............................ ; . Floor tile or linoleum--av. value.......................54in. Linoleum........... ......... 54 in. Plywood subfloor.................................................. 54in. Rubber or plastic tile.......................................... 54in. Terrazzo.................................................... . -- I in. Wood subfloor......... ...................................*54* in- I JWood, hardwood finish........................................ 54inEEffective Emissivity Cotton fiber6........................................................ Mineral wool, fibrous form, processed from rock, slag, or glass6.................................................... 1.5-4.0 Wood fiber............................................................... 3.2-3.6 Wood fiber, multilayer, stitched expanding6-- 1.5-2.0 Glass fiber......................................... Wood or cane fiber Acoustical tile*............................... ....... 54 in. Acoustical tSe*............ ;................ ....... 54 in. Interior finish (plank, tile, lath).................. Interior finish (plank, tile, lath)............. 54 in. Sheathing (impreg. or coated)..................... Sheathing (impreg. or coated) .................54 in. Sheathing (impreg. or coated).............*54* in. 15.0 15.0 20.0 20.0 20.0 24.80 0.48 0.81 12.50 3.60 16.70 20.00 12.00 1.28 42.40 12.50 1.02 1.47 0.27 0.25 0.27 0.25 0.35 0.38 3.70 4.00 3.70 0.84 1.19 0.56 78 2.86 2.63 0.76 1.32 0.49 2.06