Fan Temperature Correction Calculator
Correct fan pressure and BHP rating for high or low air temperature.
Enter your values
ⓘ Live results
Results
- Corrected static pressure
- 1.743 in wc
- Corrected brake horsepower
- 3.487 hp
- Correction factor
- 0.697
Quick answer
Fan pressure and power scale directly with the ratio of standard absolute temperature to actual absolute temperature.
Correction factor = (460+70) / (460+T_actual)
How to use the Fan Temperature Correction Calculator
- 1Enter the fan's rated static pressure and horsepower, typically given at standard 70F air.
- 2Enter the actual continuous operating air temperature.
- 3Read the corrected pressure and power the fan will actually produce and draw at that temperature.
Worked example
Using the values the calculator loads with:
Inputs
- Rated static pressure (at 70F)2.5 in wc
- Rated brake HP (at 70F)5 hp
- Actual air temperature300 F
Results
- Corrected static pressure1.743 in wc
- Corrected brake horsepower3.487 hp
- Correction factor0.697
Frequently asked questions
Why does hot air reduce pressure?
Hot air is less dense, so the same fan wheel speed moves the same volume but less mass, producing less pressure and requiring less power.
Is this the same for cooling air below 70F?
Yes, the same ratio applies — colder, denser air increases both pressure and power above the 70F rating.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.