Air Changes per Hour
Compare ventilation flow with room volume.
Your numbers
Air changes per hour
Perfect mixing is not assumed to guarantee contaminant removal. No ventilation safety or infection-risk assessment is made.
Scenario comparison
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Formula
Use ACH = Q/V. Q is measured airflow in m³/h and V is room volume in m³. ACH is air changes per hour; it is a flow-to-volume ratio, not a contaminant-removal guarantee.
Compare ventilation flow with room volume.
Worked example
- Room volume (m³)
- 60
- Measured airflow (m³/h)
- 300
- Air changes per hour
- 5 1/h
- Ideal single-volume replacement time
- 12 minutes
Scope and limitations
Perfect mixing is not assumed to guarantee contaminant removal. No ventilation safety or infection-risk assessment is made.
Inputs are checked for missing values and allowed ranges. A result outside the finite numeric range is not displayed. Rounding affects display, while the calculation uses the model’s numeric precision.
Check your units and assumptions before relying on a result. Changing a label does not convert a currency or physical unit.
Formula version: 2207f972d708 · Example checked: