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HEATINC VENTILATING AIR CONDITIONING GUIDE 1944 Table 11. Coefficients of Transmission (/) of Concrete Construction Floors and Ceilings 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 still air (no wind) conditions on both sides. TYPE OF CEILING -------------- " Metal Lath and Plaster*--Suspended or Furred................ ..... _........ .... Gypsum Board (g in.) and Plaster/-- Insulating Board Lath (Kin.) sod Plaster/ Thickness op Concrete* (Inches) 3 10 3 10 3 6 10 3 6 10 . 3 10 TYPE OP FLOORING No Flooring (Concrete Bare) | Tile" or Terrazxo Flooring on Concrete Kin- Parquet* Battleship6 Flooring Directly Mastic on on Concrete Concrete AB CD 0.69 0.65 0.45 0.45 0.59 0.56 0.41 0.41 0.50 0.48 036 036 0.62" 0.59 0.43 0.43 0.54 0.52 039 039 0.46 0.44 034 034 0.38 0.35 0.32 0.37 034 0.31 030 . '038 036 030 038 036 0.36 035 038 038 0.33 032 037 037 .0.-30 0.29 034 0.24 0.25 0.23 ' 0.22 034 0.23 031 031 031 030 0.20 0.19 . 0.19 Double Wood Floor on Sleepers'1 E' 0.25 033 032 034 0.22 031 0.19 0.18 0.17 0.19 0.18 0.17 0.15 0.15 0.14 ec s 2 1 3 4 5 6 7 8 9 to 11 12 13 14 15 "Thickness of tile assumed to be 1 in. *The figures in Column C may be used with sufficient accuracy for concrete floors covered with carpet. Thickness of wood assumed to be in.; thickness of mastic. M in- (h = 4.5). * Based onH^j in. yellow pine or fir sub-flooring and between sub-floor and concrete. in. hardwood finish flooring with an air space Thickness of plaster assumed to be % in. /Thickness of plaster assumed to be M in'- For other thicknesses of concrete, interpolate. Table 12. Coefficients, of Transmission (U) of Concrete Floors on Ground with Various Types of Finish Flooring V= 0.10a Btu per hour per square foot per degree Fahrenheit tdhperature difference between the ground and the air over the floor. ...oF"111. available, based on tests now in progress; 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 wail below grade, use the same average coefficient (0.10). A lower ground temperature should, however, be used for walls than floors as explained in Chapter 6. Forfurtherdata see A.S.H.V.E. Research Report No. 1213---Heat Loss Through Basement Walls and Floor!; by F. C. Houghten, S. I. Taimuty Carl Gutberlet and C. J. Brown (A.S.H.V.E. Transactions, VoL 48, 1942. p. 369). V' vapor will also condense whenever it comes in contact with surfaces or objects at or below the dew-point temperature. Thus two types of con densation problems are encountered; in building practice, namely (1) Surface condensation or condensation on the interior building surfaces including the. walls, ceiling (or roof) and glass, and (2) Interstitial con densation or the transmittance of the vapor through the building materials and condensation of the moisture on surfaces or voids within the materials of construction. Condensation within the construction ` as well as condensation on the interior surfaces does not necessarily occur in all buildings but only in HO CHAPTER 4. HEAT TRANSMISSION COEFFICIENTS Table 13. Coefficients of Transmission {U) of Flat Roofs Covered with Built- up Roofing. No Ceiling-tUnder Side of Roof Exposed (See Table 14 for Flat Roofs with Ceilings). These coefficients are 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 16 mph. Ill