Inline Duct Booster Fan Calculator
Size an inline booster fan for extra duct run pressure loss.
Enter your values
ⓘ Live results
Results
- Booster fan duty point
- 150 CFM @ 0.7 in wc
- Added static from booster run
- 0.4 in wc
- Recommendation
- Select a booster fan whose curve meets or exceeds this point at design CFM
Quick answer
A booster fan should be sized to deliver the design CFM against the additional pressure drop of the extended or restrictive duct run, on top of existing static.
Booster duty = CFM at (existing SP + added run SP)
How to use the Inline Duct Booster Fan Calculator
- 1Enter the design CFM required at the register or outlet.
- 2Enter the existing system static pressure and the additional pressure loss from the extended or restrictive run.
- 3Select a booster fan whose performance curve delivers the design CFM at the combined static pressure.
Worked example
Using the values the calculator loads with:
Inputs
- Design airflow150 CFM
- Existing system static0.3 in wc
- Added duct run static0.4 in wc
Results
- Booster fan duty point150 CFM @ 0.7 in wc
- Added static from booster run0.4 in wc
- RecommendationSelect a booster fan whose curve meets or exceeds this point at design CFM
Frequently asked questions
Where should the booster fan go?
As close to the source (or as centered in the run) as practical, with straight duct both upstream and downstream for best performance.
Can a booster fan replace a bad duct design?
It can compensate for extra length or fittings, but very undersized ducts should still be corrected where possible.
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.