Document MMpYzQ3xL3banK36OY3b17bgk

170 CHAPTER 8 1946 Guide Table 2. Infiltration Through Windows Expressed in Cubic Feet per Foot of Crock per Hour* Ttpe o Window Remarks Worn Vslocitt, Miles peb Hour 5 10 IS 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 Total for average window, non-weatherstripped, J6-in. crack and 36*in. clearance.c Windows Includes wood frame leakage^ (Unlocked) Ditto, weatheratrippedd 2 7 4 6 21 13 11 39 24 Total for poorly fitted window, non-weatherstripped, $-m. crack and %rin. clearance.* Includes wood frame leakage^- Ditto, weatheratrippedd 27 6 69 . Ill 19 34 Double-Hung Noo-weatheratripped, locked- Metal Non-weatheratripped, unlocked........ ..... Windows^ Weatherstripped, unlocked______ . 20 45 20 47 6 19 70 74 32 Rolled Section Steel Sash Windows^. Industrial pivoted, 36-in. cracks Architectural projected, kr-in. crackh_:____ Architectural projected, 36-in. crackh______ Residential casement, 16-io. crack! Residential casement, 16-in. crack* Heavy^casement.section, projected, 16-in. Heavy casement section, projected l-in. cracki 52 108 15 36 20 52 6 ,18 14 32 3 10 8 24 176 62 88 33 52 18 38 Hollow Metal, vertically pivoted window^.____ 30 88 145 20 27 35 4 56 .17 23 30 59 80 104'36 49 63 154 199 249 51 71 92 96 125 ' 154 104 137. 170, 46 60 76 244 304 372 86 - 112 139 116 152 182; 47 60 : 74 . 76 100 128 26 36 54' 72 4892 . 186 221 242 . `The values given in this table, with the exception of those for double-hung 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. The fit of the average double-hung wood window was determined as )-in. crack and $6-in. clearance by measurements on approximately GOO windows under heating season conditions.- dThe values given are the totals for the window opening tier 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 $-in. crack and clearance represent a poorly fitted window, much poorer than average. ` fWindows 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. bArchitecturally projected made of same sections as industrial pivoted except that outside 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. J6-in. crack is obtainable in the best practice of manufacture and installation, 36-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 .is obtainable in the best practice of manufacture and installation, &-tn. crack considered to represent average, practice. j Made of heavy sections. Ventilators swing in or out and stay set at any degree of opening. J^-in. crack is obtainable in the best practice of manufacture and installation, J6-in. crack considered to represent average practice. kvvith reasonable care in installation, leakage at contacts where windows are attached to steel-frame work and at mullions is negligible. With 36-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 Endows in' the table.' '' -' Air Leakage 171 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 same 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 not 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 windows3. 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 double- hung 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 alsol Table 3. Infiltration Through Outside Doors for Cooling Loads3 Expressed in Cubic Feet per Minute per Person Entering Room ' Application 1 Pair 36 in. Swinging Doors, Single Entrance*) Application Pair 36 in. Swinging Doors, Single Entrance!) Bank Barber Shop____ :_________ Broker's Office___________ Candy and Soda__ _____ Department Store.............. Dress Shop Drug Store Furrier 7.5 4.5 7.0 6.0 8.0 , 2.5 7.0 2.5 Lunch Room. .............. Men's Shop....... .................. Office....... ....______.............. Office Building________ ..... 35 5.0 3.5 3.0 2.0 2.5 25 35 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.