How much power is needed to run a centrifugal fan 50% faster?

Question

I have a 2000rpm, 1/12 HP AC motor driving a centrifugal fan. I want to use a 3000rpm AC motor and a VFD to drive the same fan in the range of 2000 - 3000rpm. Can I determine how much HP is needed for the new motor?

Answer 1

*Learn and digest affinity laws for centrigugal fans:

http://www.engineeringtoolbox.com/fan-af...

P1 / P2 = (n1 / n2)^3 (d1 / d2)^5

where,

P = power (W, bhp, ..)

For example:

100 : q1 - volume capacity - (m^3/s, gpm, cfm, ..)

100:  dp1 - head or pressure (m, ft, Pa, psi, ..)

5 :    P1 - power (W, bhp)

2000 : n1 - initial wheel velocity (rpm)

3000 : n2 - final wheel velocity (rpm)

Final volume capacity : 150

Final head (pressure) : 225

Final power : 16.9 w