Document 85myanonbnQJXR5dj8kkLr2Xa

74 CHAPTER 5 Table 7.... Required Size of Extended-Plenum Cfa Handled by Plenum Fiorina Dinmntiato Inches Cfai Handled by Pteaoa Plenum Dintensoai Inches Dp to 300 301 to 400 401 to 500 501 to 600 601 to 700 8x8 10 r 8 12x8 14 x 8 16x8 701 to 800 801 to 900 901 to 1000 1001 to 1100 1101 to 1200 20x8 22x8 24x8 26x8 28 x 8 tures. When either higher bonnet pressures or temperatures, or both, are to be used, care must be taken to ascertain that the furnace employed is capable of meeting the required conditions. INSIDE WALL DELIVERY SYSTEMS The concept of warm-air perimeter heating is relatively new. The older methods of introducing warm air into spaces use other outlet locations. One of the most common of these has been the use of register locations on a warm or inside wall. For such systems, the combinations of parts selected as standard by the National Warm Air Heating and Air Con ditioning Association are shown in Tables 9 and 10. A simplified method for selecting the combinations of branches, boots, stacks, and registers, is given in Manual 7 of the National Warm Air Heating and Air Conditioning Association* In this method, the sizes of the branch ducts are obtained from two tables giving their Btu capacities. The proper combination of parts for each branch can be deter mined if the following information is available. 1. Location of room, that is, whether on first or second story. 1962 Guide And Data Book 2. Actual horizontal length of duct from bonnet to boot, ia feet. 3. Btu loss from room to be heated. 4. Equivalent lengths in feet of all fittings and of the register. Fig. 7 mows the values of equivalent l*ngtha of fittings com. monly used for domestic systems. This simplified method is applicable to structures having heat losses not in excess of approximately 120,000 Btu per hour. The capacities shown in Tables 9 and 10 are based upon the most reliable data pertaining to friction losses and temperature drops in ducts. They are also based upon a 100 deg temperature rise of the air, and a static pressure available for overcoming friction loses in the external duct system alone of 020 in. of water. The use of this method requires that the fan in the fan-furnace assembly will be capable not only of overcoming the resistance of the external duct system alone, but also the resistances imposed by the blower inlet, the filter, and the furnace caring. Tables 9 and 10 are applicable for the selection of both warm air and return air branches. A depth of S in. has been adopted as the standard for trunk ducts, and where a branch joins the trunk the required increase shown in the last line of Table 9 or Table 10 refers to an 8-in. trunk duct. Where two branches form a trunk the longer bdkich is considered to be the trunk and its equivalent width (for 8-in. depth) is increased as required. DESIGN PROCEDURE FOR LARGE SYSTEMS11 For buildings having a heat loss in excess of 120,000 Btu per hour, the design procedure given in Manual 9 of the National Warm Air Heating and Air Conditioning Associa tion, may be used. Work sheets 9a, 9b, and 9c are available to simplify calculations.11 The procedure consists of: t. Calculation of design heat losses from individual spaces Actual Ft Table 6 .... Required Size of Return Air Grille and Duct for Pmtwt Drop Allowance of 0J0S In. of Wafer Up fo 10 FI n fo 20 FI 21 fo 30 Ff 31 fo 40 FI GrfS* Free No. of 90 Dog fth* 23456 23456 1 234 5 6 Dud Free Area 2 3 4 56 16 5,000 14 17 20 23 26 28 15 19 .22 25 27 28 17 20 23 25 27 29 18 31 24 27 28 30 32 10,000 27 32 37 42 46 49 29 34 39 43 47 49 31 38 41 45 48 51 33 38 43 47 49 51 CT47 15,000 37 44 50 55 60 64 40 46 52 57 61 65 43 49 54 58 63 67 45 51 56 61 64 67 63 20,000 46 54 61 66 73 78 49 63 69 75 79 53 GO 65 71 77 82 55 62 68 74 78 83 79 25,000 54 64 72 79 86 92 58 68 75 82 88 94 .62 71 78 84 91 96 66 74 80 87 92 98 95 30,000 62 73 82 89 97 104 67 78 85 93 100 106 71 80 88 95 102 108 75 84 91 99 104 110 111 35,000 69 82 92 101 111 119 74 85 95 106 114 121 79 91 99 108 117 124 84 94 103 113 119 126 126 40,000 77 90 100 110 121 130 82 94 105 116 124 132 87 99 109 118 128 137 92 103 113 123 130 140 158 50,000 89 105 119 132 146 158 95 111 124 138 150 161 102 117 129 142 155 166 108 123 135 148 158 170 190 60,000 100 122 139 154 170 161 111 129 145 161 174 184 119 137 151 165 178 189 126 143 158 172 181 193 221 70,000 117 139 158 174 191 1203 127 147 164 182 195 206 135 155 171 186 200 213 144 162 178 193 203 216 252 80,000 128 155 175 191 208 222 140 164 182 198 214 225 151 172 188 203 219 231 160 179 195 211 222 235 284 90,000 141 168 188 205 225 244 IS3 177 195 213 232 248 164 186 201 218 240 256 173 183 209 229 244 263 316 100,000 154 180 200 221 247 265 166 189 209 233 252 270 176 198 217 239 258 277 1S5 206 227 250 265 285 Note: When multiple number of return sir duets fain to*ether, add the individual duet free artaa together to determine the free arte <d duet to be used from tbs* point to the return air plenum d furnace. Warm Air Heating Systems 75 Eqsf*. length of FBIkjs and Registers Table 9..., Capacity and Sizing Table--First Story far Warn Air and Return Air Stock, Brooch, and Regitten fforicMtfaf length fume* fo Register Ducts* instated A/lic Dncfs Firxt Story Boom Hoof loss--Sfuh Cato Op to 70 Eq Ft CeLb Up to 7 8-12 13*17 18-25 26-35 36-45 46-55 Cot. c Up to 5 6-9 10-13 14-18 19-25 26-35 36-45 46-55 CoL d 7,200 6,700 6,100 5,600 4,800 4,100 3,500 3,000 Cot. e 12,500 11,700 10,800 9,900 8,500 7,400 6,400 5,500 CoL f 16,000 15,000.14,000 13,000 11,000 9,900 8,700 . 7,700 CoL g 19,100 18,000 17,000 16,000 14,200 12,500 11,000 9,600 CoL h 25,000 23,400 21,600 19,800 17,000 14,800 12,800 11,000 CoL i 32,000 30,000 28,000 26,000 22,600 19,800 17,400 15,400 CoLi 80,000 75,000 70,000 65,000 56,500 49,500 43,500 38,500 71 to 100 Eq Ft Up to 7 8-12 13-17 18-25 26-35 36-45 46-55 Up to 5 6-9 10-13 14-18 19-25 28-35 36-45 46-55 5,500 5,100 4,800 4,500 3,900 3,400 3,000 2,600 9,900 9.200 8,600 8,100 7,100 6,200 5,400 4,600 13,100 12,300 11,600 10,900 9,7008,500 7,500 6,500 16,300 15,400 14,500 13,700 12,200 10,800 9,500 8,300 19,800 18,400' 17,200 16,200 14,200 12,400 10,800 9,200 26,200 24,600 23,200 21,800 19,400 17,000 15,000 13,000 65,500 61,500 58,000 54,500 48.50& 42,500 37,500 33,500 101 to 130 Eq Ft Up to 7 8-12 13-17 18-25 26-35 36-45 46-55 Up to 5 6-9 10-13 14-18 19-25 28-35 36-45 46-55 4,600 4,300 4,100 3,800 3,300 3,000 2,700 2,300 8,500 7,900 7,409 6,900 6,100 5,300 4,700 4,000 11,300 10,600 10,000 9,400 8,400 7,400 6,500 5,400 14,300 13,500 12,700 11,900 10,500 9,300 8,300 7,000 17,000 15,800 14,800 13,800 12,200 10,600 9,400 8,000 22,600 21,200 20,000 18,800 16,800 14,800 13,000 10,800 56,200 52,600 50,200 47,300 42,000 37,000 32,400 27,000 131 to 165 Eq Ft Up to 7 8-12 13-17 18-25 26-35 36-45 46-65 Up to 5 6-9 10-13 14^18 19-25 26-35 36-45 46-55 4,100 3,800 3,600 3,400 2,900 2,600 2,300 2,000 7,300 6,900 6,400 6,000 5,300 4,700 4,200 3,600 9,800 9,100 8,600 8,100 7,200 6,400 5,600 4,700 12,300 11,700 11,000 10,300 9,100 8,100 7,100 6,000 14,600 13,800 12,800 12,000 10,600 9,600 8,400 7,200 19,600 18,200 17,200 16,200 14,400 12,800 11,200 9;400 49,200 45,800 41,900 40,300 36,000 31,800 28,100 23,500 166 to 200 Eq Ft Up to 7 8-12 13-17 18-25 26-35 36-45 46-55 Up to 5 6-9 10-13 14-18 19-25 26-35 36-45 46-55 3,800 3,500 3,300 3,100 2,700 2,400 2,100 1,700 6,500 6,100 5,700 5,400 4,800 4,300 3,800 3,000 8,800 8,200 7,700 7,200 6,400 5,7005,000 3,900 11,000 10,500 9,900 9,300 8,300 7,300 6,4005.100 13,000 12,200 11,400 10,800 9,600 8,600 7,600 6,000 17,600 16,400 15,400 14,400 12,800 11,400 10,000 7,800 44,100 51,500 38,800 36,000 32,000 28,200 24,700 19,500 Combination Number 41 42 43 44 45 46 47 Stacks*: No. (in parenthesis) and Size (1) 10x3)< <D 10x3){ (1) 12x3>f (1) 14x3Ji (2) 10i2} (2) 12x3# - Rectangular Branch Size Round Branch 8ize (Dram) 3x8 4x8 5x8 6x8 8x8~ 10x8 15x8 5 6 7 8 9 10 12 Number of Joist Spaces' and .Minimum DepthReturn Air ' 1 at 3 I at 3 1 at 4 1 at 5 1 at 6 or 1 at 7 or 1 at 9 or 2 at 3 2 at 4 2 at 5 Registers: Low Wall, High Wall, or Baseboard 10x6 10x6 12x6 14x6 , (2)10x6 or (1) 24x6 (2)12x6 (1) 30x6 -- Registers: Floor-Warm Air 8x10 8x10 9x12 9x12 or longer 10x12 12x14 - Registers: Floor-Return Air 6x10 or 6x10 or 6x12 or 4x14 4x14 6x14 6x14 6x30 6x30 8x30 Trunk Duct Increase, Inches 1 2 3 4 5 7 12 b ^MiiMumco gucxe in neatea tcucee ana mauiatea qucte in uaacaseo spacca.- . Note: pgr return air a MxZH m. stud space may b* used of lux3H & stack. When 12x3H in. or 14x3M in. stack is required, a Ux$H in. stud space may. 0*ed only when inside of stud space b smooth and without protruding plaster keys. The number of iobt spaces far combination 47 b based on in. foists. One *1*ny fie used with 2x10 in. josta. toe limiting factor In a duet la the stack capedty.