Document 9EZ67BRVRQo0Qy8ZRNYQVZ3p

Heating Ventilating Air Conditioning Guide 1939 --------------------- -------------------------------------------------------------------- ] buildings by an amount ranging from 5 per cent to 20 per cent. This extra ' heating surface is required only on the windward side and on windy days I and hence automatic temperature control is especially desirable with sucti installations. In stair-wells that are open through many floor levels although closed ; off from the remainder of each floor by doors and partitions, the strati- fication of air makes it advisable to increase the amount of heating surface : at the lower levels and to decrease the amount at higher levels even to the point of omitting all heating surface on the top several floor levels. One - rule is to calculate the heating surface of the entire stair-well in the usual way and to place 50 per cent of this in the bottom third, the normal i amount in the middle third and the balance in the top third. ; HEAT EQUIVALENT OF AIR INFILTRATION Sensible Heat Loss The heat required to warm cold outside air, which enters a room by infiltration, to the temperature of the room is given by the equation: where Ha = 0.24 Q d (ft - <o) (3) Ha = heat required to raise temperature of air leaking into building from to to Btu per hour. 0.24 = specific heat of air. Q = volume of outside air entering building, cubic feet per hour. d = density of air at temperature to, pounds per cubic foot. <1 = room air temperature, degrees Fahrenheit. to -- outside air temperature, degrees Fahrenheit. Latent Heat Loss When it is intended to add moisture to air leaking into a room for the '> maintenance of proper winter comfort conditions, it is necessary to ! determine the heat equivalent to evaporate the required amount of water vapor, which may be calculated by the equation: (4)j where j Hi = heat required to increase moisture content of air leaking into building from ; Mo to Mi, Btu per hour. ; Q -- volume of outside air entering building, cubic feet per hour. ; d = density of air at temperature ti, pounds per cubic foot. ! Mi -- vapor density of inside air, grains per pound of dry air: Mo = vapor density of outside air, grains per pound of dry air. L = latent heat of vapor at Mi, Btu per pound. I 5 It is sufficiently accurate to use d = 0.075 lb, in which case equation 3 \ reduces to 5 and if the latent heat of vapor is assumed for general condi- J tions as 1060 Btu per pound Equation 4 reduces to 6. ' I Ha = 0.018 Q (ti - to) Hi = 0.0114 Q (Mi - Mo) - (5) (6) Changing the temperature and vapor subscripts in Equations 5 and 6 to (to -- t,:) and (M0 -- Mi) permits the use of these same formulas for determining the sensible and latent heat gains due to infiltration in cooling load computations. Chapter 6. Air Leakage . -Miner has more than one room which is divided by interior walls If a Dm a g suffic;entiy accurate to use half of the total infiltration or PartJ,, determining the total heat requirements. Where buildings losses tor wans> the infiltration losses are calculated by using haVhalf of the total crack, in which case the entire infiltration loss should be considered. c u v E Research Reports: A* N* o. R6Q8&ftl--AAiruLLeea^kagge^,, b^y Fi.g2C4. |Hpou1g0h5t)en and C. C. Schrader (A.S.H.V.E. Trans- No 704-Air Leakage Around Window Openings, by C. C. Schrader (A.S.H.V.E. Transactions, Vol. 30, 1924, p. 616). xr No. *77q8c6_-iMn fIilttrraattiioon^ThrMouag^haPrelat sItnegreedls a(And.s.HUn.vp.lEas.teTrerdansBarcictkionWsa, lVlso, l.b3y3,F1.92C7., ono_Air^ Leakage on Metal Windows in a Modern Office Building, by F. C. No. 80J^u^en|nd M. E. O'Connell (A.S.H.V.E. Transactions, Vol. 34, 1928, Oi o__Air^ Leakage Through a Pivoted Metal Window, by F. C. Houghten and No. 81a-rt,r Lea ,cBonnell (A s.H.V.E. Transactions, Vol. 34, 1928, p. 519). XT,, OOR__A;r Infiltration Through Various Types of Brick Wall Construction, by No. 8^^irLlnLarson, D. W. Nelson and C. Braatz (A.S.H.V.E. Transactions, Vol. 35, 1929, p. 183). No 851--Air Infiltration Through Various Types of Wood Frame Construction, N by G L Larson, D. W Nelson and C. Braatz (A.S.H.V.E. Transactions, Vol. 36, 1930, p. 99). No 909--Air Infiltration Through Double-Hung Wood Windows, by G. L. Larson,. D. W. Nelson and R. W. Kubasta (A.S.H.V.E. Transactions, Vol. 37, 1931, p. 571). No 936--Investigation of Air Outlets in Class Room Ventilation, by G. L. Larson, D W. Nelson and R. W. Kubasta (A.S.H.V.E. Transactions, Vol. 38, 1932, p. 463). ^^ No. 994--Wind Velocities Near a Building and Their Effect on Heat Loss, by F. C. Houghten, J. L. Blackshaw and Carl Gutberlet (A.S.H.V.E. Transactions, Vol. 40, 1934, p. 387). Neutral Zone in Ventilating, by J. E. Emswiler (A.S.H.V.E. Transactions, Vol. 32, 1926, p. 59). Effect of Frame Calking and Stprm Sash on Infiltration Around and Through Windows, by W. M. Richtmann and C. Braatz (A.S.H.V.E. Transactions, Vol. 34, 1928, p.547). The Weathertightness of Rolled Section Steel Windows, by J. E. Emswiler and W. C. Randall (A.S.H.V.E. Transactions, Vol. 34, 1928, p. 527). Pressure Differences Across Windows in Relation to Wind Velocity, byj. E. Emswiler and W. C. Randall (A.S.H.V.E. Transactions, Vol. 36, 1930, p. 83). Flue Action in Tall Buildings, by H. L. Alt (Heating, Piping and Air Conditioning, May, 1932). Air Infiltration Through Steel Framed Windows, by D. O. Rusk, V. H. Cherry and L. Boelter (Heating, Piping and Air Conditioning, October, 1932). Influence of Stack Effect on the Heat Loss in Tall Buildings, by Axel Marin (A.S.H. V.E. Transactions, Vol. 40, 1934, p. 377). Fuel Saving Resulting from the Use of Storm Windows and Doors, by A. P. Kratz and S. Konzo (A.S.H.V.E. Transactions, Vol. 42, 1936, p. 87). The Infiltration Problem of Multiple Entrances, by A. M. Simpson and K. B. Atkinson (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, June, 1936). Infiltration Characteristics of Entrance Doors, by A. M. Simpson (Refrigerating Engineering, June, 1936). Heating Requirements of an Office Building as Influenced by the Stack Effect, by F. C. Houghten and Carl Gutberlet (A.S.H.V.E. Journal Section, Healing, Piping and Air Conditioning, July, 1937). 129