You can determine the Air Changes Per Hour (ACH or ACPH) using these key factors:
- Airflow rate of your air purifier or HVAC system (measured in CFM or m³/h)
- Room size (square footage or length × width)
- Ceiling height
Use the calculator below to find out how many times the air in your space is fully replaced per hour.
Formula:
ACH = (Airflow in CFM x 60) / (Room Area x Ceiling Height)
Find the ideal Clean Air Delivery Rate (CADR) for your room using the CADR Calculator.
If you have two air purifiers what’s the effect on the air changes per hour and time to clean the room.
Thanks
For more than one air purifier, use the cumulative airflow rate (CADR) to calculate the air changes per hour. If you have two air purifiers, the number of Air Changes per Hour (ACH) will be doubled, which means it will take half the time to clean the room.