Fan Efficiency

Fan efficiency, abbreviated as \(\eta_f\) (Greek symbol eta), a dimensionless number, is the ratio of input and output power.

 

Fan Efficiency formula

\(\large{ \eta_f = \frac{ P_{out} }{ P_{in} } }\)

Where:

\(\large{ \eta_f }\)  (Greek symbol eta) = fan efficiency

\(\large{ P_{in} }\) = input power (watt)

\(\large{ P_{out} }\) = output power output (watt)

\(\large{ I }\) = current

\(\large{ V }\) = volt

\(\large{ p }\) = air pressure (\(inch\; H_2 O\))

\(\large{ Q }\) = air flow (cfm)

Solve for:

\(\large{ P_{in} = V \; I  }\)

\(\large{ P_{out} = \frac{ p \; Q  }{ 8.5 }  }\)