Document nDV4dRGMr1za4ZEYZJXbBKgw

Heating Ventilating Air Conditioning Guide 1938 Table 2. Infiltration Through Windows Expressed in Cubic Feet per Foot of Crack per Hour Ttpb or Window Remarks Wind Velocitt, Miles per Hour S 10 15 20 25 30 Around frame in masonry wall--not calkedb 3.3 8.2 14.0 20.2 27.2 34.6 Around frame in masonry wall--calkedb___ 0.5 1.5 2.6 3.8 4.8 5.8 Around frame in wood frame constructio&b_ 2.2 Double-Hung Wood Sash Total for average window, non-weatherstripped, 56-in. crack and 56-in. clearance^. Windows Includes wood frame leakaired (Unlocked) Ditto, weatherstrippedd 6.6 4.3 6.2 10.8- 21.4 39.3 15.5 23.6 16,6 59.3 35.5 23.0 30.3 80.0 103.7 48.6 63.4 Total for poorly fitted window, non-weather- stripped, 56-in. crack and 56-in- clearance. Includes wood frame leakaged 26.9 69.0 110.5 153.9 199.2 249.4 Ditto, weatheretrinnedd 5.9 18.9 34.1 51.4 70.5 91.5 Double-Hung Non-weatherstripped, locked- 20 45 70 96 125 154 Metal Non-weatherstripped, unlocked______ 20 47 74 104 137 170 Windows* Weatherstripped. unlocked__________ __ 6 19 32 46 60 76 Industrial mvoteds. V6-in. n-ank 52 108 176 244 304 372 Rolled Architectural projected, 56-in. crackh 15 36 62 86 112 139 Section Architectural projected, 56-in. crackb____ 20 52 88 116 152 182 Steel Residential casement. V.-in. erarki 6 18 33 47 60 74 Sash Windows^ Residential easement V4-ln emrki Heavy casement section, projected, 56-in. crackL ` 14 3 32. 10 52 18 Heavy casement section, projected 56-in. 76 26 100 128 36 48 8 24 38 54 72 92 Hollow Metal, vertically pivoted window*.___ .. 30 88 145 186 221 242 The values given in this table are 20 per cent less than test values to allow for building up of pressure in rooms, and are based on test data reported in the papers listed at the end of this chapter. bThe values given for frame leakage are per foot of sash perimeter as determined for double-hung wood windows. Some of the frame leakage in masonry walls originates in the brick wall itself and cannot be prevented by calking. For the additional reason that calking is not done perfectly and deteriorates with time, it is considered advisable to choose the masonry frame leakage values for calked frames as the average determined by the calked and not-calked tests. B The fit of the average double-hung wood window was determined as J-in. crack and %-in clearance by measurements on approximately 600 windows under heating season conditions. dThe values given are the totals for the window'opening per foot of sash perimeter and include frame leakage and so-called elsewhere leakage. The frame leakage values included are for wood frame construction but apply as well to masonry construction assuming a 50 per cent efficiency of frame calking. A 56-in. crack and clearance represents a poorly fitted window, much poorer than average. ^Windows tested in place in building. ^Industrial pivoted window generally used in industrial buildings. Ventilators horizontally pivoted at center or slightly above, lower part swinging out. . hArchitectural projected made of same sections as industrial pivoted except that outside framing member is heavier, and refinements in weathering and hardware. Used in semi-monumental buildings such as schools. Ventilators swing m or out and are balanced on side arms. J6*in. crack is obtainable in the best practice of manufacture and installation, 5-in. crack considered to represent average practice. . JOf.same design and section shapes as so-called heavy section casement but of lighter weight, ki-in crack is obtainable in the best practice of manufacture and installation, 56-in- crack considered to represent average practice. jMade of heavy sections. Ventilators swing in or out and stay set at any degree of opening! 56-in crack is obtainable in the best practice of manufacture and installation. 56-in. crack considered to represent average practice. With reasonable care in installation, leakage at contacts where windows are attached to steel frame- worir and at muihons is negligible. With 5fj-in. crack, representing poor installation, leakage at contact with steel framework is about one-third, and at muliions about one-siith of-that given for industrial pivoted windows in the table.. - 126 ' Chapter 6. Air Leakage i DOOR LEAKAGE Doors vary greatly in fit because of their large size and tendency to ro For a well fitted door, the leakage values for a poorly fitted doubler hune wood window may be used. If poorly fitted, twice this figure should be used. If weatherstripped, the values may be reduced one-half. A sinele door which is frequently opened, such as might be found in a store, should have a value applied which is three times that for a well fitted door This extra allowance is for opening and closing losses and is kept from being greater by the fact that doors are not used as much in the coldest and windiest weather. The infiltration rate through swinging and revolving doors is generally a matter of judgment by the engineer making cooling load determinations and in the absence of adequate research data the values given in Table 3 represent current engineering practice. These values are based on the average number of persons in a room at a specified time, which may also be the same occupancy assumed for determining the outside ventilation requirements outlined in Chapters 3 and 8. Table 3. Infiltration Through Outside Doors for Cooling loads Expressed in Cubic Feet per Minute per Person in Room Bank............................ Barber Shop............... Broker's Office.....--.. Candy and Soda....... Cigar Store................. Department Store-- Dress Shop................ Drug Store................. Furrier......................... Hospital Room._-----Lunch Room............. Men's Shop....... Office:........................... Office Buildings....... Public Building........ Restaurant..-............ Shoe Store................. Application Pair 36 in. Swinging Doors. Single Entrance^ 7.5 4.5 7.0 6.0 25.0 8.0 2.5 7.0 2.5 3.5 5.0 3.5 3.0 2.0 2.5 2.5 3.5 For doors located in only one wall or where doors in other walls are of revolving type. ^Vestibules with double pair swinging doors, infiltration may be assumed 75 per cent of swinging door values. Infiltration for 72 in. revolving doors may be assumed 60 per cent of swinging door values. SELECTION OF WIND VELOCITY Although all authorities do not agree upon the value of the wind veloc ity that should be chosen for any given locality, it is common engineering practice to use the average wind velocity during the three coldest months of the year. Until this point is definitely established the practice of using average values will be followed. Average wind velocities for the months of December, January and February for various cities in the United States and Canada are given in Table 2, Chapter 7. 127 S