How is CADR Determined

- Mar 15, 2018-

How is CADR Determined?

An air cleaner is given a CADR through a relatively easy to understand process, which is called the ANSI/AHAM AC-1 standard which measures CADR requirements:

  • The purifier is placed in a testing chamber of 1008 cubic feet.

  • Before the purifier is activated, the amount of contaminants in the room is measured.

  • The purifier is activated for a period of twenty minutes, during which time the amount of contaminants is periodically re-evaluated.

  • Finally, the reduction in contaminants is compared to their natural rate of decay.

When this test is over, testers proceed to give the unit its rating. The United States Environmental Protection Agency explains the number in the following way:

"The CADR is a measure of a portable air cleaner’s delivery of contaminant-free air, expressed in cubic feet per minute. For example, if an air cleaner has a CADR of 250 for dust particles, it may reduce dust particle levels to the same concentration as would be achieved by adding 250 cubic feet of clean air each minute." - Environmental Protection Agency