Exhaust Air and Ventilation Exchange Calculator

Compute required ventilation exhaust volumes (CFM) based on target Air Changes per Hour (ACH).

Air Exchange Rate Formula:

$ \text{CFM}_{\text{vent}} = \frac{V_{\text{room}} \times \text{ACH}}{60} $

Room & ACH Targets

Space Volume ($V_{\text{room}}$ in cu ft)

Target Air Changes per Hour (ACH)

Required Ventilation Exhaust 4,000 CFM

Air Exchange Frequency Every 2.0 Minutes