Document 4JeZVqED23EqXaeZV9xe7XzQe

HEATINC VENTILATING AIR CONDITIONING CUIDE 1944 diffusion of the heat from the basement. As indicated in the footnote of Table 12, this coefficient is recommended for use whenever it is desirable to make allowance for the small basement floor heat loss, as may be the case with heated basements. Using this coefficient (0.10) the total heat loss per square foot of floor area will amount to only 2.0 Btu per square foot per hour, based on a temperature difference of 20 F between the air in the basement above the floor and the.minimum soil temperature below the basement. The same coefficient (0.10) may be used for calculating the heat loss through basement walls below grade but a somewhat higher temperature difference should be used for reasons explained in Chapter 6. Thus the total heat loss through basement walls will be greater than that through floors. According to present available data the unit wall heat loss will be approximately twice the floor heat loss under average conditions in northern latitudes or about 4.0 Btu per hour per square foot (total, not per degree temperature difference) between the basement air and the ground at a level corresponding to the mid-height of the basement wall. Until further data are available, this value may be used with reasonable accuracy for calculating heat losses through basement walls of heated basements. CONDENSATION IN BUILDINGS The water vapor in buildings will be transmitted through many types of building construction if there is a difference in the vapor pressures on the two sides1 of the structure9 (see Table 11, Chapter 7). Such water 'Methods of Moisture Control and Their Application to Building Construction, by F. B. Rowley, A. B. Algren and C. E. Lund. (University of Minnesota Engineering Experiment Station Bulletin No. 17). T able 10. Coefficients of T ransmission V) of F rame Construction Ceilings and Floors( Coefficients ore expressed in B tu Per hour per square foot per degree Fahrenheit difference in temperature between the a ir on the two sides y and ore based on s till a ir (no w ind) conditions on both sides. INSULATION BETWEEN, OR ON TOP OF, JOISTS (No FlooringAbove) WITH FLOORING (On TopopCeiling CHAPTER 4. HEAT TRANSMISSION COEFFICIENTS Joists) None iraswQfsj | "I C4 CO Tt lO | Koe> 0.34 z So5oSoSoS oooo Double Wood Floor* ill 3In. 4 In. VermiculiteInsula Mineral Wool Insula tionBetweenJoists tion BetweenJoists _i * Nd- dz CO S3 C4 a 3 In. 15J> 5. ik III*.*5,.3 -2 a d C4 hi dO |tii d o Ije- d 5 CO < 0.45. 0.093 0.092 0.092 0.092 0.006 0.066 0.065 0.065 owoeoawocoo wOooSooOs--ooOs--oooi NCJNN OOOO ~*ooo OOOO OOOO oDaor-t- ,, oooo oooo os os o o oooo OS 00 OO 00 oooo o Co4oNCo4oCI ooro.No-oo1 0.10 0.12 0.092 0.11 0.091 0.10 0.080 0.089 CCOOIONMONHMO OvOOtOQOOOQOOiiOOAn OCOOSMOOQOCOOCO4OONN r. mOOhOhOO OOOO OOo)OGoOOoOCOoS Co41 o-HoOCoOOOS 00)0(4 oooo COOOC4 oooo So3 o2o2o2 OlNOCO oooo o O X) 151 m go 5 1^-2 SoR o6*u q%_ (<*-a1^o *3.f3c.'2oo-' 'oo?* * St2 -S = is8 s-it 3 Bv c-0 3- .. 9 oO 3 3*1 B oa Zaj o "oo _ gl z-% S Ss | a. NoCellififl...............................................................-.... - 0.24 GMyetpsaluLmatBhoaarndd(PlHaistn.)er*.Pl..ai..n...or....D.e.c..or..at. .e.d...................................................-........... WGyoposduLmatLhatahn(d$iPlian.st)er.Pl..a.s.t..er..e.d.*....................................................................................... IIIPlnnnysssuuulllwoaaatttioiidnnn(gggMBBBioooaanar.rr)dddLLPlaaltaiihhnn(.o)Q1rii iPlnD.n)ea.i)cnoPlroPlaartsatesteDdr.ee.rec..edo*.r.d.".a..t....e.....d..........................................................................................--.....................- TYPE OF CEILING S H a OJJ2 a cl^cs g&fl 8 S-l 5 -If3 a a-gji * a Jl-sjj <H3 o <A8ca 233.i;-3!". a-g3a S-S % -g a "5i CD g s i i! Ct tliis BS S llsz "o " c v o Ha "a2 " Uo' 109