HomeCalculatorsAir Change Rate (ACH)

Air Change Rate (ACH)

Ventilation rate in air-changes-per-hour from supply-air flow and room volume.

HVAC
Air changes per hour
6.0ACH
Supply flow
333L/s
Formula, assumptions, and limits

Shipboard standards (SOLAS + STCW): cabins 6 ACH, galleys 20–30, machinery spaces 30+, battery rooms ≥ 10 with H₂ dilution spec.

Symbol legend

SymbolMeaningUnitSource
Supply air flowm³/hfan rating
Room volumeGA plan