Room Air Changes Calculator
Calculate nominal air changes per hour from a room volume and entered airflow.
Your result
EVERYDAYEnter your values and select calculate.
On this page How it works & practical examples
How to use the Room Air Changes Calculator
Use actual airflow for the operating condition, with all room dimensions in meters. The output counts nominal volume exchanges rather than tracking the age of every parcel of air.
The calculation
Worked example
A 5×4×3 m room has 60 m³ volume; an entered 300 m³/h flow gives five nominal air changes per hour.
Assumptions and limits
Does not recommend ventilation rates or certify indoor air quality. Mixing, short-circuit flow, filtration and pollutant sources are excluded; filtered recirculation is not necessarily outdoor ventilation.
Common questions
Which inputs should I use?
Use actual airflow for the operating condition, with all room dimensions in meters. The output counts nominal volume exchanges rather than tracking the age of every parcel of air.
What does the result exclude?
Does not recommend ventilation rates or certify indoor air quality. Mixing, short-circuit flow, filtration and pollutant sources are excluded; filtered recirculation is not necessarily outdoor ventilation.