What is an Air Purifier Clean Air Delivery Rate?

Every quarter, the Association of Home Appliance Manufacturers (AHAM) publishes its directory of Certified Room Air Cleaners to the public. As a U.S. based trade association of the home appliance manufacturing industry, the AHAM closely monitors energy, environment, safety, trade, and other issues regarding home appliance products, as well as developing and maintaining technical standards for these products in an attempt to provide uniform and repeatable procedures for measuring specific product characteristics and performance features.

As such, the AHAM also administers certification programs for products such as room air conditioners, dehumidifiers, and air purifiers through independent, third party laboratory tests. Specifically regarding air purifiers, appliances certified by the AHAM helps assure consumers that rated products are accurate, and this information has been proven to be useful to consumers, retailers, and government regulatory agencies alike.

When testing air cleaners, the AHAM measures the performance of an air purifier using a standard performance metric called the Clean Air Deliver Rate (CADR), a system that is recognized as accurate and impartial by the EPA and the American Lung Association. The CADR is a measure of the air purifier's ability to reduce smoke, dust, and pollen particles in the 0.10 to 11 micron size range from the air in one minute. For consumers, the CADR can prove to be a very useful tool in comparing the overall performance of different air purifiers on the market. CADR test results are expressed in what is known as CFM, or cubic feet per minute, and reflect the size of the particle, the percentage of particles removed, and the volume of air moving through the air purifier. Some air purifier manufacturers may measure the effectiveness of their products through air exchange rates as opposed to CADR numbers, but it is important to understand that these two systems of measurement are not equivalent.

While some air purifier manufacturers choose not to submit their products to the AHAM for testing, many air purifier companies such as BlueAir use their CADR ratings as a way to inform consumers of the efficacy of their products. Although the CADR rating may not be the only criteria one should look at when purchasing an air purifier, CADR ratings can provide consumers with important information about an air cleaner's ability to remove harmful airborne pollutants.