Mold Mitigation Air Changes Formula

What is an air change in a contained room during mold mitigation and how many air changes are required?

Mold Mitigation Containment Air Changes per Hour from AmeriDri 

How many times the air enters and exits a room each hour is how we determine air changes. Mold removal in a contained area requires 4 air changes per hour. At AmeriDri we always try to get at least 6 air changes per hour. Below I will show you how we calculate air changes in a contained work space.


To calculate room air changes, use the CFM from the air scrubber being used in a contained room, and then multiply the CFM (Cubic Feet per Minute) times 60 minutes. Next we measure the room and then divide by the volume of the rooms cubic feet. Here is an example.

Example: 500CFM Air Scrubber X 60 minutes = 30,000.00 Cubic Feet per hour X Room Size in Cubic Feet Length X Width X Height (20 feet length X 25 feet width X 8 feet high to ceiling) = 4,000.00 Cubic Feet Room We are changing cubic foot per minute (500) into cubic foot per hour (30,000.00) X cubic foot of the room, to get our total air changes per hour.

Answer: 30,000.00 divided by 4,000.00 = 7.50 Air Changes per Hour (ACH)



Now that you understand containment air changes, you are much more informed when or if you have mold in your home or business that needs to be mitigated


Thank you,
Joe Crivello, CEO, AmeriDri
30 Buchanan Street, Colorado Springs, CO 80907
Ph. 719-388-8509 Fax: 866-243-0661 Email:



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