Green product watch: Best air purifiers 3/12
(This article is adapted from the March 2012 Consumer Reports magazine.)
The air inside our homes can be 2 to 5 times more polluted than what we breathe outdoors, according to estimates from exposure studies by the Environmental Protection Agency (EPA). Given the fact that we spend so much time indoors, getting an air purifier may seem like a natural solution, especially if you have young children, or someone in your family suffers from asthma or allergies.
But in fact there's little definitive medical evidence that air purifiers alone will help to relieve respiratory symptoms. And despite product claims, some air purifiers simply fail to clean the air much better than simply opening the windows. Watch video.
First eliminate the sources of indoor air pollution
Before you buy an air purifier, experts recommend that you try some simple, common sense steps to reduce indoor air pollution. Begin by vacuuming often, banning smoking indoors, opening windows whenever possible to ventilate rooms, minimizing use of candles and wood fires, and using outdoor-venting exhaust fans in kitchen, bath, and laundry areas.
These basic steps can be more effective than air purifiers, say the experts, including the American Lung Association. In addition, you can try other inexpensive options such as keeping pets out of bedrooms; removing carpeting, and cleaning other places where there could be dust-mites.
Other important precautions:
• Don't store chemicals, solvents, glues, or pesticides in your house. Best and worst models in tests
• Use greener cleaning products without toxic, harsh chemicals.
• Minimize the risk of deadly carbon monoxide gas by properly maintaining heating equipment, wood stoves, fireplaces, chimneys, and vents--and by installing carbon-monoxide alarms on all levels of your home.
• Don't idle your car, run fuel-burning power equipment, or light a barbecue grill in your garage, basement, or in confined spaces near your home.
• Regularly test your home for radon gas, which can cause lung cancer. Test kits cost about $15-$25.
• Personal care products can be a source of indoor air pollution—especially volatile organic compounds (VOCs), which are emitted by a variety of personal care products. See our personal care products green buying guide, which lists hazardous ingredients.
Among the nearly 40 models tested by Consumer Reports is the LightAir IonFlow 50F at $400, which was also tested in 2010. With no fan to aid airflow, the LightAir was about as effective at removing dust and smoke in the tests as having no purifier at all. It was judged a “Don’t Buy: Performance Problem,” and that recommendation holds true for the current model tested.
Among room type models, the recommended products are the Whirlpool AP51030K at $300 and the Hunter 30547 at $260, which was noisier than the Whirlpool in the tests.
Among whole house models, the Lennox Healthy Climate HC16 at $350 is recommended.
If you need to replace a filter, the do-it-yourself best choice is the Filtrete Elite Allergen 2200 MPR at $25.
Avoid ozone-generating air purifiers
Air-purifier models with an electrostatic precipitator remove pollutant particles by charging them as they pass through and collecting them on an oppositely charged metal plate or filter. In the process, they produce some ozone as a byproduct. According to Consumer Reports, if someone in your home has pulmonary problems or allergy symptoms, this type of purifier is a poor choice – even though it only emits small amounts of ozone. Most of the purifiers that were tested recently use filters that create no ozone, but one—the Brookstone Pure Ion Pro—produces small amounts.
You'll also find dedicated ozone generators, which produce relatively large amounts of this gas by design. While ozone in the upper atmosphere protects us from the sun's ultraviolet rays, ground-level ozone is an irritant that can worsen asthma and compromise your ability to fight respiratory infections. Consumer Reports says that you should avoid dedicated ozone generators entirely, given their high ozone emissions.
Check an air purifier's efficiency rating
The Association of Home Appliance Manufacturers certifies most air purifier room models as part of a voluntary program that includes appropriate room size and maximum clean-air delivery rate (CADR), a measure of cleaning speed. Consumer Reports testers judge a CADR above 350 to be excellent and below 100 to be poor. Although manufacturers recommend air purifiers for rooms of particular sizes, Consumer Reports tests suggest that you should choose a model designed for an area larger than yours for better cleaning at a lower, quieter speed.
For whole-house filters, you should check to see the minimum efficiency reporting value (MERV), developed by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers. The top performers in Consumer Reports’ tests typically had a MERV higher than 10.
Home Sweeter Home: Easy Ways to Reduce Indoor Air Pollution. 2/10
Guide to purifier types and technologies. 8/10
EPA Care for Your Air: A Guide to Indoor Air Quality.
EPA Indoor Air Quality: Air Cleaners.