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Fan selection Chart

Centrifugal Blower CFM Chart : ( CFM Values at different pressures for 960 RPM Motor )

Press.in inches W.G. 1 2 3 4 5 6 8 10 12 16 20 24 28 32 36 48 50
RPM Motor H.P. Approximate capacity in Cu. Feet / Minute. at N.T.P.
960 0.25 1000 500 300 200 100 - - - - - - - - - - - -
960 0.5 2000 1000 700 500 400 300 100 - - - - - - - - - -
960 0.75 3000 1600 1100 800 600 400 200 - - - - - - - - - -
960 1 4000 2200 1500 1100 800 600 400 300 300 100 - - - - - - -
960 1.5 5600 3200 2200 1700 1300 1000 700 400 400 200 - - - - - - -
960 2 6200 4100 2900 2200 1800 1400 1000 700 500 300 200 - - - - - -
960 3 - 6100 4300 3400 2700 2200 1600 1200 900 500 400 300 200 100 - - -
960 5 - 10100 6900 5600 4600 3800 2800 2100 1700 1100 700 600 500 400 200 - -
960 7.5 - 14400 10300 8200 6800 5800 4300 3300 2700 1800 1300 900 800 600 600 400 300
960 10 - 17800 13800 11600 8900 7300 5800 4600 3700 2500 1900 1300 1000 900 800 500 500
960 12.5 - - 17000 13000 11100 9400 7200 5700 4700 3400 2500 1900 1400 1100 1000 700 600
960 15 - - 20000 15500 13000 11200 8700 7000 5700 4200 3100 2400 1800 1400 1200 900 800
960 20 - - 27300 20700 17000 14700 11500 9400 7800 5700 4400 3500 2700 2100 1700 1200 1200
960 25 - - 31400 26000 20700 18100 14300 11700 9800 7300 5700 4600 3700 2900 2300 1600 1500
960 30 - - 32900 30200 24800 21400 16800 13900 11700 8800 7000 5600 4600 3700 3000 1900 1900
960 40 - - - 39000 33100 27700 22100 18300 15600 11900 9500 7800 6500 5400 4500 2700 2500
960 50 - - - 47900 40500 34500 27200 22600 19300 15000 12000 9900 8300 7100 6000 3600 3300
960 60 - - - 50900 47700 41500 32200 26900 23000 18000 14600 12000 10200 8700 7500 4700 4300
960 75 - - - - 53000 51000 39100 33100 28500 22400 18400 15300 13000 11200 9700 6300 5900
960 100 - - - - - 53000 51800 44200 37300 29700 24600 20700 17600 15300 13400 9100 8600

 



CFM Values at different pressures for 1400 RPM Motor

Press.in inches W.G. 1 2 3 4 5 6 8 10 12 16 20 24 28 32 36 48 50
RPM Motor H.P. Approximate capacity in Cu. Feet / Minute. at N.T.P.
1400 0.25 1000 500 300 200 100 - - - - - - - - - - - -
1400 0.5 1900 1000 700 500 400 300 200 100 - - - - - - - - -
1400 0.75 2800 1600 1100 800 600 500 300 200 - - - - - - - - -
1400 1 - 2000 1400 1100 800 700 500 300 300 100 - - - - - - -
1400 1.5 - 3000 2100 1700 1300 1100 800 600 400 200 - - - - - - -
1400 2 - 4000 2800 2200 1800 1500 1000 800 600 400 200 100 - - - - -
1400 3 - 5800 4100 3300 2700 2200 1700 1300 1000 700 400 300 200 100 - - -
1400 5 - 8400 6800 5300 4400 3700 2800 2300 1800 1300 900 600 500 400 300 200 -
1400 7.5 - - 9900 8300 6400 5500 4300 3500 2800 2000 1500 1100 900 700 600 400 200
1400 10 - - 12800 10300 8400 7200 5700 4600 3800 2900 2200 1700 1300 1000 800 600 500
1400 12.5 - - 15400 13100 10300 8900 7000 5800 4800 3600 2800 2200 1800 1400 1100 700 700
1400 15 - - - 14900 12400 10600 8400 6900 5800 4400 3400 2700 2200 1800 1500 900 900
1400 20 - - - 19300 16400 13700 10900 9100 7700 5900 4700 3800 3200 2600 2200 1100 1100
1400 25 - - - 24800 20000 17200 13500 11200 9600 7400 5900 4900 4100 3400 2900 1700 1600
1400 30 - - - - 23600 20600 16000 13300 11400 8900 7200 5900 5000 4300 3600 2300 2100
1400 40 - - - - 30400 26700 20700 17400 15000 11800 9700 8100 6800 5900 5100 3400 3100
1400 50 - - - - 32900 32800 25900 21400 18500 14700 12200 10200 8700 7500 6600 4400 4200
1400 60 - - - - - 38300 31200 25000 21900 17700 14600 12300 10500 9100 8000 5600 5300
1400 75 - - - - - 43500 38100 31100 27200 21600 18100 15400 13300 11600 10200 7300 6900
1400 100 - - - - - - 49200 41500 35100 28400 23900 20500 17900 15700 13800 10100 9600

 



CFM Values at different pressures for 2800 RPM Motor

Press.in inches W.G. 1 2 3 4 5 6 8 10 12 16 20 24 28 32 36 48 50
RPM Motor H.P. Approximate capacity in Cu. Feet / Minute. at N.T.P.
2800 0.25 600 400 300 200 200 100 100 - - - - - - - - - -
2800 0.5 - 1000 700 500 400 300 200 100 - - - - - - - - -
2800 0.75 - 1400 1000 800 600 500 300 300 200 - - - - - - - -
2800 1 - 1900 1400 1000 900 700 500 400 300 200 100 - - - - - -
2800 1.5 - - 2000 1500 1300 1000 800 600 500 300 200 100 - - - - -
2800 2 - - 2600 2100 1700 1400 1100 900 700 500 400 200 200 100 - - -
2800 3 - - 3700 3000 2400 2100 1600 1300 1100 800 500 400 300 300 200 - -
2800 5 - - - 4800 4000 3400 2700 2200 1900 1400 1100 800 600 600 400 200 200
2800 7.5 - - - 5900 5900 5100 3900 3300 2800 2100 1700 1300 1100 1000 800 400 400
2800 10 - - - - 7500 6600 5100 4300 3600 2900 2300 1900 1600 1400 1200 700 700
2800 12.5 - - - - 8200 8100 6400 5300 4500 3600 2900 2500 2000 1700 1500 1000 900
2800 15 - - - - - 9500 7700 6200 5400 4300 3500 3000 2500 2100 1800 1200 1200
2800 20 - - - - - 10800 10000 8200 7100 5500 4700 3900 3400 2900 2500 1800 1700
2800 25 - - - - - - 12200 10200 8700 7000 5900 5000 4400 3800 3300 2300 2200
2800 30 - - - - - - 14300 12200 10400 8400 7000 6000 5200 4600 4100 2900 2800
2800 40 - - - - - - 16600 15900 13900 11000 9200 7900 7000 6100 5400 4000 3800
2800 50 - - - - - - - 19500 17200 13500 11400 9900 8600 7700 6800 5100 4900
2800 60 - - - - - - - 22500 20400 16100 13600 11700 10300 9200 8300 6100 5900
2800 75 - - - - - - - - 25000 20300 16700 14500 12900 11500 10300 7800 7500
2800 100 - - - - - - - - 28500 26600 22000 19100 16900 15100 13700 10500 10100


Motor Selection

The shaft power (H) lines shown on each performance curve indicates the input power at the fan shaft in kW. To determine the minimum motor power required to drive the fan, this fan shaft power H has to be multiplied by a safety coefficient which accounts for power losses in belt drives and a reasonable safety margin. The recommended values for the safety coefficient are as under: Safety Coefficient = 1.20 for H upto 10 kW = 1.12 for H over 10 kW The reasonable safety margin mentioned above takes care of any small change in the operating point or fan speed, which may be due to possible minor inaccuracies in calculation of system pressure drop or a pulley ratio slightly different from the design value. For conversion to horsepower (hp), 1 hp = 0.746 kW. With motors larger than 7.5 kW (10 hp), the use of a star/delta (Y/Δ) starter is highly recommended.