Document 1NBo3DM93Dx0qmgvx2eGNnao

456 CHAPTER 22 1949 Guide* Table 8.' Determination of. Free Area and Pressure Loss of Register for No Deflection of Air0* d- Register Free Area in Square Inches (Upper value in each group) .Pressure Loss in Inches of Water Column (Lower value in each group) CFM Distance from Register to Opposite Wall 190,-209 19-21122-24|25-27128-30131-34135-3S 4k 62 0.02 47 0.03 37 0.04 30 0.06 02.4091 0.1185 40-49 | 50-59 160-69 CFM 660-699 Distance from Register TO Opposite Wall 35-39|40-49| HH59 160^9170-79 180-89 A' 13' 210 143 95 69 49 0.02 0.03 0.07 0.12 0.22 210-229 76 58 45 -36 29 22 0.02 0.02 0.04 0.05 0.08 0.12 700-739 236 160 107 77 54 0.02 0.03 0.06 0.11 0.21 230-249 69 53 43 34 26 0.02 0.03 .0.04 0.07 0.11 740-779 262 179 119 ' 86 61 0.02 0.03 0.06 0.10 0.18 250-269 81 63 50 40 31 21 0.02 0.03 0.04 0.06 0.09 0.18 780-819 291 198 132 95 67 0.02 0.03 0.05 0.09 0.17 270-299 93 73 59 47 36 24 0.02 0.02 0.03 0.05 0.08 0.16 820-859 320 218 145 105 74 0.02 0.03 0.05 0.08 0.15 300-339 95 77 61 46 32 0.02 0.03 0.04 0.06 0.12 860-899 352 240 160 115 81 0.02 0.02 0.04 0.08 0.14 340-379 120 97 77 59 . 40 0,02 0.02 0.03 0.05 0.10- 900-939 385 262 175 126 89 0.01 0.02 0.04 0.07. 0.13 380-419 119 95 73' 50 0.02 0.03 0:04 0.08 940-979 419 285 190. 137 97 0.01 0.02 0.04 0.07 0.12 420-459 149 114 88 60 0.02 0.03 0.04 0.07 980-1019 455 309 206 0.01 0.02 0.04 148 105 0.06 0.11 460-499 171 136 105 71 0.02 0.02 0.03. 0.06 1020-1059 493 335 223 0.01 0.02 0.03 161 113 0.06 0.11 500-539 160 123 84~ 0.02 0.03 0.05 1060-1099 530 361 241 173 123 0.01 0.02 0.03 0.06 0.10, 540-579 186 143 97 0.02 0.02 0.05 65 47 0.09 0.17 1100-1139 571 388 258 185 132 93 0.01 0.02 0.03 0.05 0.09 0.17 580-619 213 164 0.02 0.02 111 74 54 0.04 0.08 0.15 1140-1179 416 277 199 141 100 0.02 0.03 0.05 0.08 0.16 '620-659 180. .127 85. '61 0.02 0.04 0.07 0.14 1180-1219 446 -297 214 151 107 0.02 0.03 0.04 0.08 0.15 * If register selected based on distance from register to oppo site wall is unsatisfactory^on account of size or pressure loss, it is permissible to shift one or. more spaces leftor right in the tables to obtain a. moresuitable register. If requirements fall in blank space, select two registers in place of one and divide CFM capac ity between thetwo registers. ^ b Pressure loss is based on FLAT FACE ADJUSTABLE BAR TYPE and does NOT include stackhead. , - 4 Values on the rightof line A and A' should not be used in applications such as churches, auditoriums, and concert halitf ' -d Values on* right of-line B and B' should not be used in ap plications such as residential work," motion picture theaters, court rooms and schools. ' 0 For floor and baseboard registers where a velocity of ap- proiimately 300 FPM is used, the free- area =------ 1;-i-orap-- proximately, Assume a-pressure loss of'.OL.i- ,1220^1259 1260-1299 1300-1339 1340-1379 1380-1419 1420-1459 f Forany volume under 190 CFM use table 1460-1500 476 317 228 161 116 0.02 0.03 0.04 0.07 .0.14 507 338 243 172 122 0.01 0.02 0.04 0.07 0.13 539 359 258 183 r 130 0.01 0.02 0.04. 0.07 0.12 382 274 195 -138 0.02 0:04 0.07 0.12 : -403 290 206 146 0.02 0.03 0.06 0.12 - 308 0.03 ,218 0.06 o1.5io5 324 230 \ 1G3 . 0.03 0.06 0.10 A' B' Mechanical Warm Air Systems .C' V '? 457- 8. Selection of Blower. A. Determine total cfm air delivery (the sum of all branch cfm values). B. Determine static pressure requirements. a. For furnace-blower combination units it is-the sum of bonnet pressure and suction pressure. - - b. For blowers separately selected from the furnace it.is the sum of bonnet pressure, filter loss, casing Iossj losses through air washers, coils, and . other devices. 9. Selection of Furnace. , . A. Determine register delivery (the sum of roomBtu losses). B. Determine bonnet capacity. Bonnet-Capacity = (total cfm) X (temperature rise) X 1.089 C. Allowance for pick-up load. ADJUSTMENT OF SYSTEM FOR CONTINUOUS AIR CIRCULATION This procedure applies to the adjustment of an automatically fired forced warm-air heating system to provide continuous air circulation when the control arrangement is of the type, where the-room thermostat controls the . Table 9: Suggested Bonnet Phessube Inches of Water CFMTotal Through Ant One Duct 800-1000 1000-1200 ' 1200-1800 1800-2400 2400 to 3500 Suggested Bonnet Pressure Ixl Water 0.10 0.10 0.10 0.13 0.14 CMFTotal Through ^ Ant One Duct 3500 to 5000 5000 to 7500 7500 to 10,000 10,000 to 12,000 12,000 to 14,000 Suggested Bonnet Pressure In..Water 0.15 0.25 01375 0.500 0.750 - fire and theblower control (fan switch) in the furnace bonnet orwarm air plenum controls the blower operation. , This procedure s^ outlined in detail. in Manual No. 6 of the National Warm Air Healing and Air Conditioning - Association, is as follows:. 1. Adjust the fuel input in proper relation to the heat loss of the structure.-' 2. Determine the temperature rise through the furnace. 3. Adjust the air volume to produce a temperature rise through the furnace of about-100 deg. ' 4. Adjust the fan switch differential to a minimum of about 15 deg. 5. Adjust the fan switch cut-out point as low as practicable. 6. Adjust the room thermostat.temperature differential to a minimum which will cause the burner to cycle frequently. - 7. Balance the system by adjusting dampers to produce even temperature distri bution between rooms. - 8. Set the room thermostat at the desired room temperature. COOLING METHODS A slight cooling effect may be obtained under certain conditions by the circulating-basement air. A more positive cooling effect may be obtained by the use of an air washer where the temperature of the city or well water' is sufficiently low (55 F or lower), and where a sufficient volume of water can be provided., .Unless, the temperature of the leaving water is below the dew-point temperature of The indoor air at the time the washer is started; both the relative and absolute humidities will be somewhat increased.