Choosing an Air Purifier

Because we live on a tight budget, my roommate and I endured years of chronic scratchy throats and swollen sinuses before we considered buying an air-purifying machine. We had identified the culprits: feathers and dander from our four free-flying pet birds; the fine city soot that blew in the windows; and musty cigarette smoke, followed by clouds of sickly sweet perfume, that seeped up through our floorboards from the apartment downstairs. We imagined that our lungs had taken on the charred tint of a smoker's, especially after September 11, when the acrid fumes from the burning World Trade Center periodically filled our apartment.

Although air purifiers don't generally absorb gases, such as perfume and cigarette odors, good ones will remove tiny airborne particles of dust, dander, tobacco smoke, soot, mold and pollen. For guidance, we turned to a February 2002 rating by Consumer Reports.

Whole-House Air Filters

For retrofitting homes with central air, CR advises that homeowners first try replacing the existing filter with a pleated electorstatic one, inexpensive and easy to install yourself. If that doesn't help, CR recommends the electronic precipitator models, which collect particles on electrically charged plates.

Portable Room Air Cleaners

A fan draws air through, and particles are trapped in either a HEPA filter or on collector plates. These three can filter an area about 500 sq. ft.

Because our apartment has no central air, we chose a portable room air cleaner, the Friedrich C-90A, which CR rated most effective. Although it was also more expensive than models with high-efficiency particulate air (HEPA) filters, its washable filter would offset the waste and cost of replacement filters (up to $170 a year). And because it was designed to cover an area much larger than our 154-sq.-ft. room, it could clean on its lowest setting, which is the quietest and uses the least electricity. The machine circulates the air so quickly it creates a draft, which helps blow perfume and smoke out the windows, left open a crack.

In the course of our research, we learned to steer clear of ozone-generating air purifiers. While manufacturers claim that they cleanse the air of pollutants and bacteria, these machines actually may elevate indoor ozone to levels above federal health limits. "Avoid using air purifiers that produce ozone, which has consistently been shown to trigger asthma," advises Luz Claudio, Ph.D., associate professor of environmental medicine at the Mount Sinai School of Medicine, in New York City.

Are we breathing easier? So far, so good. When we checked the filter after its first day of use, it contained a thick, grimy layer of dust and feathers-a reassuring sight.