Air Purifiers: Expert and User Reviews

Our AssessmentConsumerReports.org conducts the most unbiased, scientific tests of air purifiers. Editors test 22 portable room-sized purifiers, two professionally installed whole-house filter systems and six furnace-type filters, then rank them from best to worst and point out which models to buy. Testers rate each model for dust, pollen and smoke removal (testing room filters on both low and high speed). Filters that attach to your heating/cooling system are rated for airflow, and room air purifiers are rated for noise on low and high speed. Editors also calculate the annual energy and filter costs for each purifier. ConsumerReports.org points out a few models to avoid, and editors provide helpful information on the health dangers of ozone generators, whether you should pay attention to UV and virus-removal claims, and whether you really need an air purifier at all.

Our AssessmentRetailer AllergyBuyersClub.com also reviews furnace filters. The top ratings go to pricey washable furnace filters; they cost hundreds of dollars initially, but save money in the long term by eliminating the need for disposable filters. Disposable 3M Filtrete filters -- which get the highest ratings elsewhere -- are merely rated "good" or "very good."

Our AssessmentThe Association of Home Appliance Manufacturers (AHAM) uses an outside lab to verify clean air delivery rates (CADR) quoted by manufacturers for given air cleaners. Products are rated only for effectiveness on dust, pollen and smoke. Manufacturers have to pay several thousand dollars to have their product certified; at the time of this writing, 31 have done so. The charts posted on the AHAM site are helpful for comparing products, and we find that most air cleaners of the same size perform similarly. This site does not cover the controversy surrounding air purifiers that produce ozone. It merely indicates whether or not a unit meets the current U.S. Food and Drug Administration limit of 50 parts per billion for medical products. Three current air cleaners -- all from Blueair -- are certified to meet the ozone standard and deliver good performance (above 350 CADR) in removing dust, pollen and tobacco smoke.

Our AssessmentConsumerGuide.com publishes air-purifier reviews, a buying guide and a section on how air purifiers work. However, there are 341 air purifiers listed. Twenty of these are reviewed and nine receive a Best Buy designation. These ratings are based on value, performance, ease of use and features, but performance doesn't appear to have been tested at all. Whirlpool, Honeywell, IQAir, Austin Air and Blueair air purifiers receive Best Buy designations.

Our AssessmentAmazon.com lists furnace filters separately from standalone air purifiers. 3M Filtrete models get the highest ratings from consumers here.

Our AssessmentFurnace filters are designed to keep the furnace system clean -- not clean the air in your home, says Glenn Fellman, executive director of the Indoor Air Quality Association and Indoor Environmental Standards Organization. He tells The Washington Post that HEPA filter-based air cleaners are the best option if your home's air is dirty. The article notes that IQAir's HealthPro Plus earns top marks in reviews.

Our AssessmentPrevention magazine editors, interviewed on NBC's "Today" show, say ionic and other ozone-generating air purifiers can be harmful to health -- and desktop air purifiers of any type are too small to make much difference. Prevention advises switching to a large, true HEPA-filter model, specifically recommending the Honeywell HEPAClean 3-in-1 for its UV light and odor neutralizer.

Our AssessmentThis is another retail site dedicated to products in the allergy-relief category. Like most other sites, they do not recommend air cleaners that emit ozone such as the Ionic Breeze, EcoQuest or Oreck XL. Their list of the top five air cleaners for allergies, "the most popular among our allergy customers," includes two blanket endorsements of brands (Honeywell and Blueair) and three specific models: Austin Air The Bedroom Machine, Austin Air Allergy Machine and IQAir Health Pro Plus. Editors do test some of the units, although not as scientifically as ConsumerReports.org does; for example, the site's reviewer says the IQAir Health Pro Plus caused "a dramatic decrease in my usual seasonal allergy symptoms."