Measuring performance of air purifiers: A controversial process
The Internet is crawling with phony air purifier reviews -- actually marketing propaganda in disguise -- and it can be hard to figure out which reviews to trust, when you're shopping for the best air cleaner. We checked up on dozens of sources to find the most honest experts -- and most accurate user reviews -- in our quest to pinpoint the best air purifiers.
ConsumerReports.org doesn't accept money, advertising or freebies from the air-purifier industry -- so its ratings are free from that kind of bias. As usual, it conducts the most impartial, scientific tests we found. Testers place dozens of air purifiers, one at a time, in a sealed room filled with measured amounts of dust, pollen and cigarette smoke. They then use instruments to judge how well each one clears the pollution from the air, and how noisy it is, before rating the models from best to worst and recommending which ones to buy. ConsumerReports.org's ratings are up-to-date and cover a lot of air purifiers and furnace filters, including popular brands like 3M Filtrete, Honeywell, Kenmore and Whirlpool. However, they don't include some little-advertised brands, such as IQAir and Austin Air, that other experts say make the best air purifiers on the market.
An industry group, the Association of Home Appliance Manufacturers (AHAM), also objectively tests air cleaners. Companies can pay AHAM to test how quickly their air purifiers remove dust, pollen and tobacco smoke from the air; they can then carry the AHAM-Certified seal. However, several manufacturers (including IQAir and Austin Air) don't bother with AHAM. One expert -- Ed Sherbenou at Air-Purifier-Power.com -- says AHAM puts too much emphasis on speed, while high-end air cleaners (which filter out chemical gases) may work more slowly but be more effective.
Sherbenou's own reviews reveal a deep knowledge of air purifiers and the science behind them; he started reviewing air cleaners because of his own multiple chemical sensitivities. Another reliable review source is AllergyBuyersClub.com. It's a retail website, but it also publishes expert reviews that are test-based and don't hesitate to criticize the air cleaners it sells. These sources form the backbone of our report, but we also take into account less extensive reviews by sources like The Washington Post and Newsweek. To get a feel for how air purifiers work in real life, we checked owner reviews at Amazon.com and Epinions.com.
Air purifier reviews unearth plenty of duds. A leading consumer-review publication warns consumers not to buy two of the air cleaners it tests. The LightAir IonFlow 50F Surface (*Est. $330) lacks a fan to draw air through the unit: It's "about as effective at removing dust and smoke in our tests as having no purifier at all." The Web Plus Adjustable Electrostatic (*Est. $25) is a filter that you place in your forced-air heating/cooling system, and tests found it does little to trap dust or pollen.
One air filter, the Andrea (*Est. $175), simply fans air across a potted plant to "purify" it: It doesn't work, one reviewer says. Meanwhile, some tested air purifiers emit ozone -- a lung irritant that can worsen asthma and cause other health problems -- while others make questionable claims that they can kill germs with ultraviolet (UV) light. See our sections on Air-Purifier Alternatives, Air Purifiers and Ozone and UV Air Purifiers to see why experts say these are a waste of money -- or worse, harmful to your health.