Document wjoB4047ELgmkM1732ooJgYQ

/ 152 CHAPTER 8______________ 1948 GuiJe Table 2. Infiltration Through Windows Expressed in Cubic `Feet per Foot of Crock per Houra Ttp* or Window Rehabxs Wind Velocity, Miles per Boob s 10 15 . 20 25 30 , Around frame in masonry wall--not calkedb 3 ,8 14 Around frame in masonry wall--calkedb____ 1. 2 3 Around frame in wood frame construction*^ Double-Hung Wood Sash T<2J iats window, non-weather-- . stripped, fa-\n. crack and 56~in. clearance c Windows Includes wood frame leakage^_________: (Unlocked) Ditto, weatherstriDDedd 2 7 4 6 . 11 21 .39 13 24 Total for poorly fitted window, non-weather- atripped, 56*w- crack and 56-in. clearance.* includes, wood frame Iralrsurpd .27 69 111 Ditto, weatherstrinnerid Double-Hung Non-weatherstriDDed. toebni Metal Non-weatheretriDDed. nnlnHrpH Window^ WeatberetriDDed unlivlr^d 6 19 20 45 20 47 .6 19 34 70 74 32 Industrial pivoted. Krtn. cradr. 52 108 176 Rolled Architectural projected. fa-in. crackb 15 36 62 . Section Architectural projected, 56-in. crackb______ 20 52 Steel . - Residential casement. 16-in. enudri 6 18 Sash. Windows* Residential casement. WUin Heavy casement section, projected, itrin. cracki.. H^caeement section, projected JfrST 14 3 32 10 88 33 52 18 ,8 24 38 Hollow Metal,; vertically pivoted windowf 30 88 .145 20 4 17 59 36 154 51 96 104 46 244 86 116 47 76 26 ;54 186 27 35 5 6 23 30 80 . 104 49 63 199 249 71 92 125 137 60 154 170 76 304 112 152 . 60 100 36 : 72 372 139 182 74 128 48 92 ' 221 242 ; "The values given In this table, with the exception of those foi double-hiing and hollow metal windows, 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 in chapter footnotes. 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 non-calked tests. rj .cThe fit of,the average double-hung wood window'was determined as 3-iii. crack and 56-in. clearance by measurements on approximately 600 windows under besting season conditions. ' <*Tbe 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 butapply as well to masonry construction assuming a 50 per cent efficiency of frame calking. -.. eA $4n..crack and clearance represent a poorly fitted window, much poorer than average. I ^Windows testedin place in building. ^ ', ^Industrial pivoted window generally used in industrial buildings. Ventilators horizontally pivoted at'center or slightly above, lower part swinging out. ^Architecturally projected made ofsame sectionsas industrial pivoted exceptthatoutside framing member Is heavier, and it has refinements in weathering and.hardware. Used in semi-monumental buildings such as schools. Ventilators'swing in or out and are balanced on side arms. 16-in. crack is obtainable in the best practice of manufacture and installation, %-in. crack considered to represent average practice. - . Of same design and-section shapes as so-called heavy section casement but of lighter weight. !-in: crack isobtainable in the best practice of manufactureand installation, 56-in. crack considered to represent average practice. * ./ - ?jMade of.beavy sections. Ventilators swing in or out and stay set at any degree of opening. 26-in. crack is obtainable in:the best.practice of manufacture and installation, fa-in.,crack considered to represent average practice. kWith reasonable care in installation, leakage at contacts where windows are attached to steel frame work and at mullions is negligible. With 56-in. crack, representing poor installation, leakage at contact with steel framework is about one-third, and at mullions about one-sixth of that given for industrial pivoted windows in the table.' `, Air'Leakage 153 generally decreases its. leakage, but in some cases may push the meeting rail members apart and increase the leakage. On windows with large 'clearances, locking will usually reduce the leakage. Wood casement windows may be assumed to have the eame unit leakage as for the average double-hung wood window when properly fitted. Locking, -a normal operation in the closing of this type of window, maintains the crack at a low value. For metal pivoted sash, the length of crack is the total perimeter of the movable or ventilating sections. Frame leakage on steel windows may be neglected when they are properly grouted-with cement mortar into brick work or concrete. When they are hot properly sealed, the linear feet of sash section in contact with steel work at mullions should be figured at 25 per cent of the values for industrial pivoted windows as given in Table 2. When storm sash are applied to well fitted windows, very little re duction in infiltration is secured, but the application of the sash does give an air space which reduces the heat transmission and helps prevent the frosting of the windowss. By applying storm sash to poorly fitted windows, a reduction in leakage of 50 per cent may be obtained, the effect so far as air leakage is concerned being roughly equivalent to that obtained by the installation of weatherstrips.. Door Leakage Doors vary greatly in fit because of their large size and tendency to warp. For a well fitted door, the leakage, values for a poorly fitted doublehung wood window may be used. If poorly fitted, twice this figure should be used. If weatherstripped, the values may be reduced one-half. A single 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 practice4. These values are based on the average number of persons in a room at a.specified time, which may also Table 3. Infiltration Through Outside Doors for Cooling Loads* Expressed in Cubic Feet per Minute per Person Entering Room ' Application Pair 36 in. Swinging Doors, Single ENTRANcsb Application Pair 36 in. Swinging Doors, Single Entrance Bank_________ _ _____ . 7.5 Hospital Room 3.5 4.5 5.0 7.0 3.5 Candy and Soda_____ ;____ Department Store________ Dress Shop ... __ . 6.0 Office1 -3.0 8.6 Office Building___ ________ 2.0 2.5 Public Building___ _______ 2.5 Drug Store_______________ 7.0 Restaurant.......................... .. 2.5 Furrier __ _. . . 2.5 Shoe Store.i 3.5 For doors located in only one .wall or where doors in other walls are of revolving type. bVestibules 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. .