Document LgMK3730aoyaL3Kkj9LG28jVq

' American Society of Heating and Ventilating Engineers Guide, 1930 take the wall having the most crack; and with three or four exposed walls, take the wall having the most crack, but in no case take less than half the total crack. Methods for Determining Infiltration The determination of Q, the amount of air leaking in per hour, may be arrived at in either of two ways: (1) by assuming a certain number of air changes per hour for each room, the number of changes assumed (Table 38) being dependent upon the type, use, and location of room, or (2) by computing the infiltration taking place through the cracks around windows and doors in that side of the room which has the greatest number of feet of such crack. Chapter 2--Heat Losses from Buildings V arious T ypes of W all Construction Fig. 5. Results of Tests of Leakage through Various Parts of Window and Frame Neither of these methods for estimating the infiltration is entirely satisfactory in view of the limited amount of data available, but for th$ purposes of calculation the second (infiltration) method is to be preferred and then checked against the first (air changes per hour) method. In no case use less than one-half an air change where outside doors and windows exist. Leakage through Various Parts of Window and Frame: The results of tests of leakage through various parts of a window and frame are shown in Fig. 5. ? The principal facts brought out in these tests were that increasing the crack around the perimeter of a plain sash does not materially increase the leakage, and that weatherstripped sash, while permitting much less leakage, shows a small increase in leakage with increase in crack. These facts were established by making several hundred tests. :.Double-Hung Wood Sash Windows: Table 39, pertaining to doublehung wood sash windows, shows the amount of leakage for various wind 62 63