Air Purifier Information

Whole-house air filters

In addition to portable air purifiers, there are a few solutions for whole-house air cleaning in conjunction with a furnace/central air system. The simplest and cheapest option is a special allergen filter. These slip into your forced-air system to replace your regular filter in the return duct. The 3M Filtrete Ultra Allergen Reduction (*est. $17) and the Precisionaire NaturalAire Micro-Particle (*est. $15) are two options. Both should be replaced at least four times a year. Consumer Reports has good information about these types of filters, which are usually made of a pleated media to trap dust. These filters are enough to cut down on airborne dust and pollen very effectively, but are not good with smoke. We also found some good information and reviews on furnace filters at FurnaceFilterCare.com.

Electronic whole-house air cleaners are more expensive than filters and require professional installation (which will cost at least $200). These models also work in conjunction with forced-air ducts to deliver filtered air to every room. James Dulley (www.dulley.com) discusses these models in his online Update Bulletin No. 950, in which Honeywell and Trion models are highlighted. The Honeywell F52 (*est. $700) and Trion HE1400 (*est. $450) both have washable filters - therefore, these models require regular cleaning. Like room-sized models, whole-house air cleaners such as these are especially effective on smaller particles like smoke.

Personal air purifiers are also marketed. Some of these models are designed to fit on a desk or be worn around the neck. However, there is no evidence that these small personal units are effective, and some are even dangerous. The Fresh Air Buddy (*est. $120) was the cause of a December 2006 fire on an airplane. The owner had used non-rechargeable batteries in conjunction with the unit's battery charger. The batteries overheated and the unit caught fire mid-flight. EcoQuest quickly issued a recall for this model and its charger unit and commissioned safety testing. In February 2007, EcoQuest announced that the Fresh Air Buddy was back on the market and that it was safe to use with brand name non-rechargeable batteries. Sales of the charger were suspended for months but have now resumed. Included are strict instructions to never try to recharge non-rechargeable batteries.

AHAM and clean air delivery rate (CADR)

A concern for some air-purifier manufacturers is the testing method used by Consumer Reports, a method developed and promoted by the Association of Home Appliance Manufacturers (AHAM). You might see the AHAM endorsement sticker on packaging and in advertisements. AHAM initially developed the CADR (clean air delivery rate) standard, a measure that represents the amount of clean air produced by the air purifier per minute. By themselves, these numbers (there are three reported -- one for dust, another for pollen and one for smoke) don't mean much. Since room sizes are seldom exactly the same and window placement, ventilation, etc. are invariably different from home to home, the CADR number can't tell you how well a unit can work in your particular room.

When CADR numbers of various air purifiers are compared, however, they become more useful. You should be able to compare different models of the same capacity to tell which units might be better than others. The higher the CADR number, the better the air cleaner. The problem, however, when we tried to do this, was two-fold. First of all, manufacturers rarely make home air cleaners of the exact same room specifications. Secondly, for brands that do offer comparably sized air cleaners, the CADR numbers show little variety. Most are within a few points of each other and sometimes they are identical.

Lastly, AHAM doesn't test all air purifiers. Manufacturers must pay a hefty fee to have their performance verified by AHAM (between $5,000 and $10,000, according to one manufacturer representative we interviewed). At this time, 30 manufacturers have done so. There are many more companies who make air cleaners, many of them smaller brands that cater to allergy/asthma niche markets. A representative from a small company in Wisconsin explained that they only employ 12 people and can't afford to spend that kind of money for "another sticker." Some manufacturers consider AHAM's methodology to be flawed and don't use AHAM certification for that reason. Another organization, the International Association of Air Cleaner Manufacturers, also has a voluntary certification program for ozone-free air purifiers.

The Association for Home Appliance Manufacturers has now expanded its certification program to allow air filter manufacturers to indicate whether their products comply with American National Standard and Underwriters Laboratories ozone emission standards.

Air purifier alternatives

Houseplants can also help purify your indoor air. James Dulley says foliage cleanses the air, while plant roots and surrounding microorganisms can convert detrimental chemicals into plant food. chrysanthemum, English ivy, aloe vera, Boston fern, philodendron and peace lily are just some of the plants you might consider.

Daily dusting and vacuuming are excellent ways to remove allergens, but experts say the best way to control allergens is at the source, such as keeping pets out of sleeping areas and sending smokers outside.

You should be careful as you search for information about air cleaners on the Internet. Many sources of information that appear to be independently sponsored have hidden agendas. Remember that manufacturer marketing claims are designed to sell products.

Our bottom line lies with what the medical experts say about air purifiers: There's evidence they may work in conjunction with allergen-source control, ventilation and daily HEPA vacuuming, but an air purifier is not a cure-all in itself. The expert consensus is there's no need to buy an ozone-producing device, since there are so many HEPA filters -- the gold standard in air filtration when used correctly -- available on the market.

Air cleaner research

To get past some of the hype regarding air cleaners, read the U.S. Environmental Protection Agency's fact sheet: "Residential Air Cleaning Devices: A Summary of Available Information."

The EPA also has a report on "Ozone Generators that are Sold as Air Cleaners."

This interview with NBCI on air cleaners includes a twelve-point checklist for choosing an air cleaner from AllergyBuyersClub.com.

The American Lung Association has an informative guide to indoor air quality including information on the various types of air purifiers: "Residential Air Cleaners - Types, Effectiveness and Health Impact."

Janet Wilson of the Los Angeles Times reports on The California Air Resources Board's ban on home ozone air purifiers, which becomes final on Oct. 18, 2010.

Reuters.com posts the press release of IQAir's protest against Consumer Reports' review process of air purifiers.

Manufacturer websites are also good sources of information and product specifications:

3M Filtrete

Alen

AllerAir

Austin Air

Blueair

EcoQuest

Friedrich

Hamilton Beach

Honeywell single room portable air cleaners (made by Kaz)

Honeywell whole house air cleaners and replacement filters.

IQAir