Buyers Guide for Room Air Purifiers

Before You Buy

• Try to clean up your indoor air yourself before you buy an air purifier. Increase the number of times you vacuum. Install exhaust fans in the kitchen and bathroom, and ban smoking indoors, if you haven't already.

No Ozone

• An air purifier that produces ozone sounds like a great idea at first glance, but it's not. Ground-level ozone can actually act as an irritant, especially for individuals with asthma, allergies or pulmonary disorders, and can make it difficult to fight respiratory problems.

Efficiency

• On any air purifier you buy, you want to check the clean-air delivery rate. The CADR, as it's often called, is the air purifier's certified efficiency rating from the Association of Home Appliance Manufacturers. According the Consumer Reports, a CADR rating of 350 or above is excellent, and a rating below 100 is poor.

  If you buy a whole-house air-purifying system, look for the MERV, or minimum efficiency reporting value. The MERV was developed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, and whole-home air purifiers that had a MERV of at least 10, scored better in the tests performed by Consumer Reports.

Go Bigger

• Buy a model intended for a larger room than the room where you're going to put it. Your air purifier will run quieter and more efficiently.