Nortek R8GE Series, Installation Instructions Manual

Page: 23 / 28

23
Gas Information
Table 11. Gas Pipe Capacities
CAPACITY OF BLACK IRON GAS PIPE (CU. FT. PER HOUR)
FOR NATURAL GAS (SPECIFIC GRAVITY - 0.60)
NOMINAL PIPE
DIAMETER (IN.)
LENGTH OF PIPE RUN (FEET)
10 20 30 40 50 60 70 80
1/2 130 90 75 65 55 50 45 40
3/4 280 190 150 130 115 105 95 90
1 520 350 285 245 215 195 180 170
1 1/4 1,050 730 590 500 440 400 370 350
1 1/2 1,600 1,100 890 760 670 610
NOTE: The cubic feet per hour listed in the table above must be greater than the cubic feet per hour of gas flow required by
the furnace. To determine the cubic feet per hour of gas flow required by the furnace, divide the input rate of the furnace by
the heating value (from gas supplier) of the gas.
Cubic Feet Per Hour Required =
Input To Furnace (Btu/hr)
Heating Value of Gas (Btu/Cu. Ft.)
Table 12. Gas Flow Rates
GAS FLOW RATES
(CUBIC FEET PER HOUR)
TIME FOR
ONE REVOLUTION
(SECONDS)
CUBIC FEET PER
REVOLUTION OF GAS METER
1 5 10
10 360 1,800 3,600
12 300 1,500 3,000
14 257 1,286 2,571
16 225 1,125 2,250
18 200 1,000 2,000
20 180 900 1,800
22 164 818 1,636
24 150 750 1,500
26 138 692 1,385
28 129 643 1,286
30 120 600 1,200
32 113 563 1,125
34 106 529 1,059
36 100 500 1,000
38 95 474 947
40 90 450 900
42 86 429 857
44 82 409 818
46 78 391 783
48 75 375 750
50 72 360 720
52 69 346 692
54 67 333 667
56 64 321 643
58 62 310 621
60 60 300 600
62 58 290 581
64 56 281 563
GAS FLOW RATES
(CUBIC FEET PER HOUR)
TIME FOR
ONE REVOLUTION
(SECONDS)
CUBIC FEET PER
REVOLUTION OF GAS METER
1 5 10
66 55 273 545
68 53 265 529
70 51 257 514
72 50 250 500
74 49 243 486
76 47 237 474
78 46 231 462
80 45 225 450
82 44 220 439
84 43 214 429
86 42 209 419
88 41 205 409
90 40 200 400
92 39 196 391
94 38 191 383
96 38 188 375
98 37 184 367
100 36 180 360
102 35 176 353
104 35 173 346
106 34 170 340
108 33 167 333
110 33 164 327
112 32 161 321
114 32 158 316
116 31 155 310
118 31 153 305
120 30 150 300