Document G6K9BB5yadGXbZRovEVa7m0Xq

190 ,1 I ih :: tt f! % t CHAPTER 9 1950 Guide 32 o e .2 .3 52 sa S- J* o$ zr S'-r 5 S3 g gg.2 a*2 <=> I&* fia o a 3S fsl g 3 3d --a *uo Hg~ 2 o SO $ aa S f- 3 g -2-S 111! 'a'^ 1111 *e3 J3 2 2 ^ o > a * %* 3 g MS * 3 -2-` e Z -g e 3 3O g -S^s y dO^B b S5" * S 3 .0-3 *SP 5d 3a %~a38 , eg . 3 .2 s gfu X J3 <a o * 3.0 T3 a c* S c o.o 21 a-J Si. rlil * a >si 1 |JI !gfJ-i 3 a oM o s )SiE 0. CQ fc.~ -o * *9 - v, -g. ,, S Heat Transmission Coefficients of Building Materials 191 Table 12. Coefficients of Transmission (17) of Concrete Construction Floors and Ceilings Coefficients are expressed in Btu per {hour) (square foot) (Fahrenheit decree difference in temperature between Ike air on die two aide*), andjar* 6aeed on slvU air (no wnd) conditions on bot& sides. type op ceiling TYPE OF FLOORING Tmcrmcss or Concrete (Inches) $$ in. Raster Applied to Underside of Metal Lath and Plaster*--Suspended or Fur Gypsum Board Qi in.) and Plaster/-- Insulating Board Lath (Hin.) and Plaster/ 8 6 10 3 6 10 3 6 10 3 6 10 3 0 10 No Flooring (Concrete Bara) Hie* or Terrazso Flooring on Concrete A 0.6S 039 050 0.62 0.54 0.46 038 035 032 036 083 080 085 083 082 ooo OOO 1 B 0.65 *086 0.48 . 087 084 081 eoo feiste iaphalt Tile* Directly on Concrete Parquet* flooring In Mastio on Concrete CD 0.66 0.45 088 0.41 0.49 086 080 0.43 083 089 0.45 084 087 080 085 088 082 086 085 083 0.30 088 0.27 084 0.25 ' 081 0.23 080 082 0119 Double Wood Floor on Seepers* *E 085 083 082 084 082 081 0.19 0.18 0.17 0.19 0.18 0.17 0.15 0.15 0.14 s i * 1 2 3 4 6 0 7 8 9 10 11 12 13 14 15 Thickness of tile assumed to be 1 in. 6 Conductivity of Asphalt Tile assumed to be 3.1. * Thickness of wood assumed to be H in-; thickness of mastic, | in. (t = 4J5). Col. D may *! be used for concrete covered with carpet. d Based on H in. yellow pine or fir sub-flooring and H in. hardwood finish flooring with an air space be tween sub-floor and concrete. Thickness of plaster assumed to be f in. ./ Thickness of plaster assumed to be | in. 0 For other thicknesses of concrete, interpolate. Table 13. (U)Coefficients of Transmission of Concrete Floors on Ground with Various Types of Finish Flooring U = 0.10 Btu per (hour) (square foot) (Fahrenheit degree temperature difference between the ground and the air over the floor). v Until more complete data are available, it is recommended that a coefficient of 0.10 be used for all types of concrete floors on the ground, with or without insulation. For basement wall below grade, use the same average coefficient (0.10). A lower ground temperature should, however, be used for walls than floors as ex plained in Chapter 11. For further data see A.S.H.V.E. Research Report No. 1213--Heat Loss Through Basement Walls and Floors, by F. C. Houghton, S. I. Taimuty, Carl Gutberlet and C. J Brown (A.S.H.V.E. Transactions, Vol. 48, 1942, p. 369). of the ground, on the material constituting the wall or floor, and on the conductivity of the surrounding earth. The conductivity of the earth will vary with local conditions, and is usually unknown. Tests8 at the A.S.H.V.E. Research Laboratory indicate a heat flow of approximately 2.0 Btu per (hour) (square foot) through an uninsulated concrete base ment floor, with a temperature difference of 20 F between ground tem perature and the air temperature 6 in. above the floor. Based on this result, a coefficient of 0.10 Btu per (hour) (square foot) (Fahrenheit degree difference) is recommended for calculation where it is desirable to allow for the small basement floor heat loss, e.g., for heated basements. For basement walls the same coefficient may be used, but due to closer proximity to the surface of the ground, the temperature difference for win ter design conditions will be greater than for the floor. The test results