If a Purifier Has a 99.99% Efficiency HEPA Filter, Shouldn’t Its CADR Be Equal to the Airflow?

The CADR rating of an air purifier takes into account inefficiencies with the air purifier due to cleaning air that had recently already been cleaned.

Think about it this way: an air purifier designed in a loop that directs all clean air coming out of the air purifier back into the air purifier would not do a great job at cleaning a room, even though the HEPA filter is 99.99% effective.

Learn more about: The difference between CADR and airflow »



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