Hydrogen Room Ventilation Calculator
Dilution ventilation for a hydrogen storage or battery charging room.
Enter your values
ⓘ Live results
Results
- Required continuous exhaust
- 150 CFM
- Air changes per hour
- 6
- Exhaust location
- High point / ceiling (H2 rises quickly)
- Monitoring
- Hydrogen gas detector interlocked to alarm and boost ventilation
Quick answer
Hydrogen rooms are commonly ventilated at 1 CFM per square foot continuous, taken from high points since hydrogen is much lighter than air, keeping concentration far below the 4% LFL.
CFM = area x 1 (minimum), exhaust from ceiling level
How to use the Hydrogen Room Ventilation Calculator
- 1Enter the room area and ceiling height.
- 2Use at least 1 CFM per sq ft continuously, with exhaust points near the ceiling.
- 3Add a hydrogen gas detector to trigger alarms and increased ventilation if concentration rises.
Worked example
Using the values the calculator loads with:
Inputs
- Room area150 sq ft
- Ceiling height10 ft
- Battery cells / cylinders20
Results
- Required continuous exhaust150 CFM
- Air changes per hour6
- Exhaust locationHigh point / ceiling (H2 rises quickly)
- MonitoringHydrogen gas detector interlocked to alarm and boost ventilation
Frequently asked questions
Why exhaust near the ceiling?
Hydrogen is far lighter than air and rises immediately, accumulating at high points and in roof pockets.
What triggers extra ventilation?
A gas detector set well below the 4% lower flammability limit, commonly at 25% of LFL (1%), should trigger alarms and boosted airflow.
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.