What an air purifier’s CADR rating means?

CADR: Clean Air Delivery Rate

Always opt for an air purifier that has a CADR label, a metric developed by the Association of Home Appliance Manufacturers (AHAM). This helps you understand how effective the device is at filtering different kinds of particles in a specific room size.

For example, a CADR of 200 for pollen means that the air purifier can reduce the pollen concentration at the equivalent of adding 200 cubic feet of fresh air per minute. 

In general, the higher the number, the more particles the air purifier can remove and the larger the room the device can reasonably be expected to clean. 

If you’re buying an air purifier to clean the air of a person who is sick with COVID-19, Consumer Reports recommends one with a CADR of 240 or above for its recommended room size.

The United States’ Environmental Protection Agency (EPA) offers these guidelines for minimum CADR ratings by room size:

Area (square feet)	100	200	300	400	500	600
Minimum CADR (cubic feet per minute)	60	130	195	260	325	390

Some air purifiers have a single CADR number. Blueair purifiers have a different CADR number for smoke, pollen and dust particles. 

Try to get an air purifier that for a typical room size, will have appropriate CADR ratings so that the purifier can effectively remove large pollutants like dust mites and cockroach-related allergens.

Also, keep in mind that an air purifier’s CADR rating reflects the best-case scenario. These numbers are determined in controlled testing environments. Variables in your home, such as drafts or dampness, may prevent your air purifier from hitting its optimal rating. So keep windows and doors tightly shut when running an air purifier. If you feel there are large gaps under your doors or between your windows, look for a simple foam tubing made specially to stop draft from seeping through the cracks under doors and between windows. You can easily find them in your local hardware store or online e-commerce site.