Air Change Rate (ACH)

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

HVAC

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This calculator requires JavaScript to compute its result. The formula, symbols, and regulatory sources are shown in the Formula section below.

Formula, assumptions, and limits

ACH = \frac{\dot V_\text{supply}}{V_\text{room}}

Symbol	Meaning	Unit
$\dot V_\text{supply}$	Supply air flow	m³/h
$V_\text{room}$	Room volume	m³

Source: ASHRAE 62.1 - Ventilation

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