Ventilation Rate Calculator

Well-mixed enclosure model. Steady-state concentration C8 = leak_rate / (ACH × V / 3600). Time to reach target uses exponential approach. LFL = 4% vol. Target typically =25% LFL (1% vol) per EN 50272.

Enclosure volume (m³)

m³

H2 leak rate (g/s)

g/s

Target concentration limit (% vol)

% vol

Known ACH (reverse mode)

ACH

Ventilation Results

-
Required ACH
air changes/hr

-
Fan Flow Rate
m³/hr

Fan Flow Rate

m³/s

Time to Target Conc.

minutes

Steady-State Conc.

% vol

Max Safe Leak Rate

g/s

H2 Concentration vs Time

Solid line: with ventilation. Dashed line: no ventilation (uncontrolled accumulation). LFL at 4% shown.