Paint Booth Face Velocity Calculator
Cross-draft or downdraft face velocity for a paint booth.
Enter your values
ⓘ Live results
Results
- Required airflow
- 9,600 CFM
- Face area
- 96 sq ft
- Target velocity
- 100 FPM
- Filter loading margin
- Size fan 15-20% above clean-filter CFM
Quick answer
Cross-draft paint booths are typically designed for 100 FPM face velocity, downdraft booths for 50-100 FPM, per NFPA 33 guidance.
CFM = face area x target velocity
How to use the Paint Booth Face Velocity Calculator
- 1Measure the open booth cross-section (width x height).
- 2Choose the booth airflow pattern and its NFPA 33 target velocity.
- 3Add a margin for filter loading over the service life of the media.
Worked example
Using the values the calculator loads with:
Inputs
- Booth opening width12 ft
- Booth opening height8 ft
- Booth typeCross-draft (100 FPM)
Results
- Required airflow9,600 CFM
- Face area96 sq ft
- Target velocity100 FPM
- Filter loading marginSize fan 15-20% above clean-filter CFM
Frequently asked questions
Why does downdraft need less velocity?
Downdraft uses gravity to help pull overspray down and away from the work, needing less horizontal sweep.
What happens if velocity is too low?
Overspray and solvent vapours are not captured, creating fire and finish-quality risks.
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.