Laminar Flow Hood CFM Calculator
Airflow for a clean bench or flow hood.
Enter your values
ⓘ Live results
Results
- Required blower
- 600 CFM
- At 1.0 in wc static
- 690 CFM rating advised
- Filter face area
- 6 sq ft
- Air changes in a 4x2x2 ft work zone
- 2250
Quick answer
Laminar flow hoods run at about 100 feet per minute across the filter face, so CFM equals filter area times 100.
CFM = w x h / 144 x 100
How to use the Laminar Flow Hood CFM Calculator
- 1Measure the HEPA filter face you plan to use.
- 2Keep face velocity at 90-110 FPM for sterile work.
- 3Choose a blower rated for that CFM at 1.0-1.5 in wc, since a loaded HEPA is restrictive.
Worked example
Using the values the calculator loads with:
Inputs
- Filter width36 in
- Filter height24 in
- Face velocity100 FPM
Results
- Required blower600 CFM
- At 1.0 in wc static690 CFM rating advised
- Filter face area6 sq ft
- Air changes in a 4x2x2 ft work zone2250
Frequently asked questions
Why 100 FPM?
It is fast enough to sweep contaminants away but slow enough to stay laminar and not disturb plates.
Horizontal or vertical?
Horizontal suits mycology and plant culture; vertical is better when you need to protect the operator too.
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.