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Utility 04

Air changes per hour

Check the theoretical room air-change rate from supply or exhaust airflow and room volume. ACH = CFM × 60 ÷ room volume.

CFM
ft
ft
ft
NOMINAL AIR-CHANGE RATE
Room volumeft³
Air changesACH

Confirm whether the applicable criterion uses supply, outdoor, exhaust, or total airflow and whether an effective air-change rate is required.