Free Air Changes Calculator

Calculate the required ventilation airflow rate from room volume and air changes per hour.

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m
m
ACH

Required Airflow

1,080 m^3/h

Room Volume180.0 m^3
Required Airflow300.0 L/s

Required Airflow vs Room Length

Air Changes per Hour (ACH)

ACH defines how many times the entire room volume of air is replaced per hour.

Formula

Airflow = Room Volume x ACH

Required ACH depends on the room function. Adequate ventilation controls temperature, humidity, odours, and airborne contaminants.

Example Calculation

A 10m x 6m x 3m room requiring 6 air changes per hour.

  1. 01Volume = 10 x 6 x 3 = 180 m^3
  2. 02Airflow = 180 x 6 = 1080 m^3/h
  3. 03Airflow = 1080 / 3.6 = 300 L/s

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