Operating instructions

3
FF Note: The blower will not operate properly if
ductwork is not attached. The ductwork supplies static
pressure to give the blower motor a load to work against.
Blower motors may overheat if run for an extended period
of time without ductwork attached.
Table 1 - Duct Sizing Chart
Acceptable Branch Duct Sizes Acceptable Main or Trunk Duct Sizes
CFM Round Rectangular Round Rectangular
50 4" 4x4
75 5" 4x5, 4x6
100 6" 4x8, 4x6
150 7" 4x10, 5x8, 6x6
200 8" 5x10, 6x8, 4x14, 7x7
250 9" 6x10, 8x8, 4x16
300 10" 6x14, 8x10, 7x12
350 10" 6x20, 6x16, 9x10
400 12" 6x18, 10x10, 9x12 10" 4x20, 7x10, 6x12, 8x9
450 12" 6x20, 8x14, 9x12, 10x11 10" 5x20, 6x16, 9x10, 8x12
500 10" 10x10, 6x18, 8x12, 7x14
600 12" 6x20, 7x18, 8x16, 10x12
800 12" 8x18, 9x15, 10x14, 12x12
1000 14" 10x18, 12x14, 8x24
1200 16" 10x20, 12x18, 14x15
1400 16" 10x25, 12x20, 14x18, 15x16
1600 18" 10x30, 15x18, 14x20
1800 20" 10x35, 15x20, 16x19, 12x30, 14x25
2000 20" 10x40, 12x30, 15x25, 18x20
2200 22" 10x45, 15x28, 18x22, 20x20
Tables calculated for 0.05 to 0.10 inches of water friction per 100’ of duct. At these duct design conditions, along with the pressure drop through the filter,
the total design external static pressure is 0.20 inches of water. Normal airflow at 0.20 inches of water should then be used for these calculations.
Table 2 - Fan Performance Data
UNIT FAN External Static Pressure - in WG
SIZE SPEED 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.50
Low 550 520 490 460 445 430 410 385
GV/GH/180/181 Medium 610 580 550 530 510 480 460 440
High* 675 650 625 600 580 560 525 480
Low 760 710 680 650 625 600 580 560
GV/GH/230/231 Medium 860 800 775 750 735 710 650 590
High* 950 900 870 855 830 800 760 720
Low 870 825 800 775 750 735 710 650
GV/GH/290/291 Medium 980 935 900 870 845 830 800 760
High* 1090 1050 1000 965 940 920 865 840
Low 1005 965 935 890 855 815 805 740
GV/GH/360/361 Medium* 1140 1100 1065 1010 965 935 915 840
High 1210 1150 1110 1070 1030 985 960 895
Low 1005 965 935 890 855 815 805 740
GV/GH/420/421 Medium 1140 1100 1065 1010 965 935 915 840
High* 1210 1150 1110 1070 1030 985 960 895
Low 1325 1275 1235 1200 1165 1135 1105 1055
GV/GH/520/521 Medium 1505 1450 1415 1375 1320 1275 1245 1185
High* 1685 1625 1550 1500 1435 1405 1360 1305
Low 1500 1450 1410 1360 1325 1310 1250 1210
GV/GH/590/591 Medium 1700 1645 1595 1555 1500 1480 1410 1380
High* 1900 1850 1800 1740 1680 1625 1590 1510
Low 1900 1850 1800 1750 1690 1660 1600 1560
GV/GH/670/671 Medium* 2220 2185 2150 2110 2050 2000 1960 1880
High 2410 2370 2325 2250 2200 2150 2110 2030
Low 2510 2390 2270 2200 2110 2070 2030 1980
GH980 Medium 2840 2720 2600 2520 2430 2380 2330 2280
High* 3040 2920 2800 2730 2640 2590 2550 2480
Low 3020 2940 2860 2780 2710 2650 2600 2550
GH1200 Medium 3220 3140 3060 2970 2900 2890 2800 2710
High* 3530 3430 3340 3260 3170 3100 3040 2960
*Denotes Factory Setting