Consumer Reports finds filter-based air purifiers are better

Posted Monday, December 3, 2007

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Whirlpool Whispure is CR’s top-rated, portable filter purifier; Two ozone generators deemed Not Acceptable

 

While ozone in the upper atmosphere protects people from the sun’s ultraviolet rays, ground-level ozone is an irritant that can aggravate asthma and lessen lung function. Studies also suggest that ozone creates other irritants as it reacts with household products such as scented cleaners and air fresheners. Among these irritants are formaldehyde, a carcinogen; and acrolein, a toxic irritant found in cigarette smoke.

Consumer Reports tested portable air purifiers, furnace filters, and professionally-installed whole-house purifiers, as well as two portable ozone generators for a report in the December issue, which goes on sale at newsstands November 6.

Whirlpool’s Whispure AP45030S, at $230, is Consumer Reports’ top choice among the 27 portable filter purifiers that were tested and rated followed by the Kenmore Progressive 83202, at $270. The highest rated models did a better job of cleaning at their lowest, quietest speeds than many others did at their higher, noisier settings.

Among whole-house air purifiers that don’t produce ozone, the Lennox Healthy Climate HC16 was CR’s top choice among professionally-installed filter systems; it was also a CR Best Buy at $350. The Healthy Climate system uses non-HEPA filtration and emits no ozone.

Two do-it-yourself furnace filters—3M Filtrete 1700, at $20, and 3M Filtrete Ultra Allergen Reduction 1250, at $16—did nearly as good a job at removing dust and are a simple, inexpensive upgrade from a standard furnace filter. But they aren’t the best at removing smoke—an issue if there are people living in the house who smoke.

“There is little definitive medical evidence that using an air cleaner will help people’s allergies and asthma,” said Celia Kuperszmid Lehrman, deputy home editor for Consumer Reports. “If you don’t have asthma or aren’t allergic to pet allergens and dust, and keep your house reasonably clean, you probably don’t need an air purifier.”

Lehrman also pointed out that many of the germ-cleaning claims of air purifiers—which are supposed to rid your home of airborne bacteria in addition to dust, pollen and smoke—are oversold: While CR’s tests of five portable air purifiers that made those claims confirmed that they reduce germs in the air, so should any purifier that effectively removes dust and smoke.

Full tests and ratings of air purifiers appear in the December issue of Consumer Reports, on sale now. The complete report is also available to subscribers at www.ConsumerReports.org.
 

Ozone generators, another type of purifier, are a growing part of the market. They create large amounts of ozone by design and claim to use it to purify the air.

Consumer Reports rated two such models — the $850 EcoQuest Fresh Air and the $230 EdenPure Area—Not Acceptable because even at the generators’ low everyday settings, their ozone production quickly exceeded the 50 parts per billion limit (ppb) set by the U.S. Food and Drug Administration for medical devices. Purifiers aren’t considered medical devices by the FDA. Ozone concentrations in CR’s test room measured about 650 to 990 ppb for the EdenPure, depending on the setting. The EcoQuest produced about 110 to 350 ppb at its normal and high settings, and up to 4,300 ppb at its “away” settings, which the company says to use only when you and your pets aren’t home.

California recently banned the sale of ozone generators for most non-industrial uses, effective 2010, because of concerns about the health impacts of ozone.

Another type of air purifier that creates some ozone as a by-product—electrostatic precipitators—are the most heavily promoted purifiers, accounting for about half of the models sold. These purifiers are designed to trap particles by applying an electrical charge to them as they pass through the unit and depositing them on plates or filters. However, that process creates some ozone as a by-product.

CR experts now believe that air purifiers that emit even small amounts of ozone (less than 50 parts per billion) are not consumers’ best choice. CR strongly advises using whole-house and portable air purifiers that rely on filters and produce no ozone. This is all the more true for those who have respiratory diseases because they’re especially sensitive to ozone.

No standard exists for acceptable indoor ozone levels generated by a non-medical device. Consumers Union, the nonprofit publisher of Consumer Reports, urges the Consumer Product Safety Commission to set indoor ozone limits for all air purifiers and mandate performance tests and labels disclosing the results.

Consumer Reports’ story, titled “Air Purifiers, Filtering the Claims,” states that taking some basic steps such as keeping pets out of bedrooms, using outdoor-venting fans in the bathroom and kitchen, and removing carpeting can be more effective in improving indoor air quality. (This is consistent with advice given by other organizations including the U.S. Environmental Protection Agency and the American Lung Association.) And, even though CR found that some air purifiers work very well, the report reminds people that no air purifier alone will clean the air.

More simple ideas to improve the air quality in your home are available at: www.ConsumerReports.org/aircleaning.

For shoppers set on buying an air purifier, CR recommends keeping these tips in mind:

• Purchase a filter-based model. These do the best job of removing dust and smoke from the air without producing any ozone.
• Consider whole-house models. Forced-air heating/cooling systems circulate so much air that they can overwhelm portable purifiers. Whole-house purifiers are a better option. Buy a whole-house model with a filter rather than an electrostatic precipitator, which produces some ozone.
• Portables: Bigger is better. Portable air purifiers work best at high speeds but are quietest on low. Run the unit on the higher, louder setting when you’re not in the room, and turn it down to low when you’re nearby.

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