Chemical Storage Ventilation Calculator
Exhaust airflow for a flammable/chemical storage room.
Enter your values
ⓘ Live results
Results
- Required exhaust
- 200 CFM
- Air changes per hour
- 6.7
- Exhaust point
- Within 12 in of floor (heavier-than-air vapours)
- Fan rating
- Explosion-proof / spark-resistant fan required
Quick answer
Flammable liquid storage rooms typically require continuous mechanical exhaust of at least 1 CFM per square foot of floor area, with a minimum of 150 CFM.
CFM = max(area x 1, 150)
How to use the Chemical Storage Ventilation Calculator
- 1Enter the storage room floor area and height.
- 2Apply 1 CFM per sq ft with a 150 CFM minimum, per IFC/NFPA 30.
- 3Locate exhaust intakes low since most flammable vapours are heavier than air.
Worked example
Using the values the calculator loads with:
Inputs
- Storage room area200 sq ft
- Ceiling height9 ft
Results
- Required exhaust200 CFM
- Air changes per hour6.7
- Exhaust pointWithin 12 in of floor (heavier-than-air vapours)
- Fan ratingExplosion-proof / spark-resistant fan required
Frequently asked questions
Does the fan need special construction?
Yes — explosion-proof or spark-resistant construction is required in rooms with flammable vapour potential.
Is makeup air required?
Yes, provide a matched, unobstructed source of replacement air, often from a louvred door or wall vent.
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.