The Clean Air Delivery Rate also known as CADR indicates the volume of filtered air delivered by an air purifier. It is a numerical value assigned to an air purifier based on tests performed by AHAM (Association of Home Appliance Manufacturers. The AHAM lists three CADR ratings ─ one for smoke, one for pollen and one for dust. The CADR is meant to be impartial and is advertised as the the best way to compare air purifiers.
In order to establish some sort of standard for all air purifiers, AHAM came up with the CADR ratings. AHAM provides a uniform and commercially practical verification of manufacturers’ Clean Air Delivery Rates for tobacco smoke, dust and pollen. The Program provides verification of operating and standby energy usage under the requirements of the
Environmental Protection Agency (EPA) for models that are part of the ENERGY STAR program. Also, one thing which needs to be pointed out is that CADR ratings are never given out for whole-house air purifiers because they’re measured differently to portable units. Government Agencies have specified the number of tests required to obtain a certified value that is representative of a model’s energy use. The intent of this industry program is to verify that each portable electric room air cleaner represented by a manufacturer or brand name owner is consistent within the Program.
How is CADR Determined?
Many factors affect the ability of an air purifier to remove particles from the air. The size of a particle, or a microorganism, is an extremely important factor, but not the only one that need to be considered. 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 20 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.