Cold weather means closed windows so it’s the time of year when allergy sufferers worry more about indoor air than outdoor air. And the season they start shopping for air purifiers. To help, Consumer Reports is preparing to test almost 20 portable and whole-house air purifiers that we’ve just purchased.
Portable models can be taken from room to room, while whole-house models replace a forced-air furnace's filter. Besides the new portable models from Kenmore, Sharp, and Whirlpool, one that seems to target allergy sufferers head-on is the $200 Allergy Pro AP350. This room model uses a replaceable HEPA filter and an ionizer to remove smoke, pollen, dust, animal dander, and dust mites from the air. Of course, as we’ve found in our air purifier tests, these machines are only effective against airborne pollutants, not what's settled on surfaces. The model has four fan settings, and there’s a 12-hour timer.
For every portable air purifier we test, we measure whether the unit (such as its ionizer) creates any ozone as a byproduct. Ground-level ozone is an irritant that can aggravate asthma and affect lung function. The State of California has even banned air purifiers that produce ozone levels greater than 50 parts per billion from being marketed or sold in the state for personal use in occupied spaces such as homes, businesses, and schools. We believe that models that emit even small amounts of ozone (less than 50 ppb) are not your best choice.
Primarily, however, we test air purifiers for how well they remove dust (similar in size to pollen) and smoke, along with how noisy they are at both their lowest fan speed and their highest, most effective setting. We also calculate the annual cost using the national-average cost for electricity as well as filter replacement. Models with washable filters should cost less to run.
Consumer Reports agrees with the U.S. Environmental Protection Agency about the many free or low-cost ways to improve your home’s air quality before you spring for an air purifier. But if you feel you still need one, you’ll find more information about selecting the right model in our air purifier buying guide, worth a read before you visit our Ratings of more than 30 portable and whole-house models.