Can air purifiers help you breathe easier?
While some experts, including the EPA, question whether or not air purifiers can significantly improve health, there's no question that many are effective in their primary role of removing particles and allergens from the air, and in some cases reducing odors as well. The best guidance suggests that taking steps to eliminate sources of irritants in the first place rather than cleaning the air afterwards is more effective still, but air purifiers can be a reasonable alternative if that's not possible or desirable. Even so, air filters should be used in conjunction with other allergen-control strategies such as ventilation and daily HEPA vacuuming for the best results.
Air purifiers do their work using different technologies, and some use multiple technologies, to deal with airborne pollutants. HEPA air purifiers use pleated high-efficiency particulate arresting (HEPA) filters to mechanically trap particles, along with a fan to pull air through the filter. By a wide margin, reviewers say this type of air purifier is the most effective. These models don't produce any ozone. Because they use fans, they can be noisy, but some are quieter than others. Be on the lookout, however, as not every air purifier that relies on mechanical filtration uses true HEPA filters.
Some air purifiers use electronic technology in place of or in addition to a mechanical filter. Electronic ionizers work by reversing the charge of particles in the air. The charged particles are then passed back out to the room where they are attracted to objects such as clothing, walls, floors and furniture. In effect, particles are removed from the air and deposited on your furnishings and clothing. You need to dust and vacuum to actually remove allergens from the room and prevent them from being reintroduced into the air. Some air purifiers have an electrostatic precipitator that works by putting a charge on particles and then collecting those using oppositely charged metal plates.
While both types of electronic air purifiers are effective for collecting particles as small as .1 microns, they can also produce a small amount of ozone, a lung irritant, though typically at levels below the standard set as safe by Underwriters Laboratory and by government agencies. Some electronic air cleaners put a small charge on a mechanical filter to help it collect particles more effectively. With that type of air cleaner, the charge is low enough that measurable amounts of ozone are not produced.
While ionic and electrostatic air purifiers emit small amounts of ozone as a byproduct, ozone generators sold as air purifiers emit high levels intentionally to neutralize chemical irritants and odors. Research has shown that while this can be effective, it's also fairly dangerous. The best advice we found is to avoid ozone generators altogether. For more information, see our discussion of air purifiers and ozone elsewhere in this report.
Another alternative is to consider a whole-house furnace filter. These aren't air purifiers; they simply replace your regular furnace filter. Filters such as the Filtrete Healthy Living 1900 (Est. $20 each and up) do an outstanding job trapping dust and pollen in one leading test, and they do a good job with smoke. Filters need to be replaced every three months otherwise their airflow, which is excellent in testing when clean, could be reduced.
It's important to note that, with the exception of ozone generators, none of the mechanical or electronic air purifying techniques above are particularly effective against chemical gases and odors. Some air purifiers add some type of chemical filtration -- typically activated carbon -- to deal with those irritants. The most effective of those sell for a premium price compared to the majority of air cleaners, but if you suffer from chemical sensitivities, they could be worth every penny.
Finding the best air purifiers
To find the top performing air purifiers, we consult professional reviews, such as those from ConsumerReports.org and The SweetHome.com. We also consider whether or not an air purifier has been submitted for testing and has had its ratings certified by the Association of Home Appliance Manufacturers (AHAM). Blogs created by allergy sufferers such as such as Ed Sherbenou of Air-Purifier-Power.com provide additional and often helpful guidance as well. Rounding things out, we analyze the hundreds and sometimes thousands of user reviews some air purifiers have garnered at sites like Amazon.com, HomeDepot.com, AllergyBuyersClub.com and elsewhere. Armed with that information, we consider factors such as performance, ease of use, noise and how costly an air purifier is to both buy and run to find the top choices and the best values.
Best Air Purifiers
Air purifiers from Blue Air and IQAir emerge as top choices
Because portable air cleaners can remove only airborne pollutants, they are not very effective against dust mites and their droppings (those are too heavy to be airborne for long), which are a significant allergen for many people. Most air cleaners also don't remove most viruses, or gases like carbon monoxide and radon. That's because even HEPA filters are most effective on particles larger than 0.3 microns, such as molds, pollen, dust, plant spores, pet dander and the larger particles in cigarette smoke.
Some air purifiers do a better job with smaller particles however. Among those, we see consistently good feedback for the Blueair 503 (Est. $660). It's a fast worker that is rated to remove particles down to 0.1 microns. It's Recommended in one large independent review. TheSweetHome.com also gives it top grades for performance. Value is a concern as it's pricier and more costly to operate than other air purifiers that are also judged to be effective, but that's offset by the ability to filter particles out of the air faster than other tested machines. It's number two on Ed Sherbenou's list of top air purifiers at Air-Purifier-Power.com. He calls it ideal for clearing allergens from a room quickly.
User reviews, while not abundant, are highly positive. At Amazon.com it earns a 4.5 star-rating following 60 reviews. At HomeDepot.com, many of the nearly 50 reviews are drawn from Blueair's web site. Nonetheless, it earns a 4.8-star rating.
The Blueair 503 is rated for rooms up to 580 square feet, though Sherbenou recommends it for smaller spaces -- up to 400 square feet. Experts note that while the standard filters (Est. $80 per set) do a great job with particles, they aren't effective against odors or gases. If that's a concern, you can use Blueair's optional SmokeStop filters (Est. $150 per set) instead, and those are judged to do a great job of getting rid of odors. However, the SmokeStop filters cut back on the 503's filtration rate and add a bit to the unit's annual operating cost.
Noise gets mixed feedback. One review says that noise at low speeds is minimal, but a little excessive at high speed. Sherbenou agrees that the top speed is loud, but adds that the most typical operating speeds "look very good from a noise-to-performance standpoint." The five years warranty is good at (with free registration), but users need to make sure they stay current with the machine's required maintenance to keep it in force, including changing the filters every six months (regardless of type) with official Blueair filters.
One concern: the Blueair 503 does use low-voltage ionization -- and ionizing air purifiers have, in the past, been linked to high ozone levels. However, Sherbenou notes that the "Blueair 503's low voltage negative ionization brushes do not create ozone."
Among other premium air purifiers, we've seen some widely differing feedback on the IQAir New Edition HealthPro Plus (Est. $940). It earns the top rating in Sherbenou's list of top air purifiers at Air-Purifier-Power.com, and his "highest commendation." At AllergyBuyingClub.com it is named a Category Winner among air purifiers, and users agree -- giving it a 4.8-star rating after more than 70 reviews. Amazon.com users largely fall in line, and the HealthPro Plus gets 4.5-stars at Amazon.com.
There are a couple of dissenting voices, however. IQAir does not submit its air purifiers for voluntary testing by The Association of Home Appliance Manufacturers (AHAM). TheSweetHome.com tests the New Edition HealthPro Plus and comes away a bit unimpressed. In that review the HealthPro Plus edges out the Blueair 503 with the StopSmoke filters when it comes to removing odors, but it is in turn edged out when it comes to particle removal. What tilts the scale toward the Blueair 503 is operating costs. The HealthPro Plus "had the highest power consumption over five years of $1,236, more than double that of any other unit," says John Holecek at TheSweetHome.com. "Budget a whopping $2,276 over the first five years for operating costs alone," he adds.
Part of that cost is the sophisticated series of filters used by the HealthPro Plus. The filter complement includes a PreMax large-capacity prefilter (Est. $70), IQAir's HyperHEPA filter (Est. $200) and a V5-Cell filter (Est. $100) that includes two types of media for gas and odor elimination. If coarse dust is a problem, the PF40 coarse dust pads (Est. $55) can be added as well. The PreMax filters are designed to last up to 18 months, while the HyperHEPA filter lasts up to four years. The V5-Cell filter should be replaced approximately every two years, and the coarse dust filter pads last three to six months.
Whether or not the HealthPro Plus can fully live up to its claim of being able to remove particles down to 0.003 microns in size -- about 10 times smaller than a virus and 100 times smaller than standard air-filtration technology -- it's undoubtedly effective. Its performance is in the top rank at TheSweetHome.com, with Holecek calling it the "gold standard" among air purifiers.
Elsewhere in this report:
Air Purifiers and Ozone: Some air purifiers emit large amounts of ozone to neutralize odors and chemicals in the air. They work, but don't buy one anyway. Here's why.
Cheap Air Purifiers: These air cleaners won't do much to remove odors, but the best are every bit as effective against allergens and other particle pollution as the very best -- and priciest -- models.
Best Small Air Purifiers: If you just need an air purifier for a small bedroom or similar space, these low cost models are surprisingly effective.
Furnace Filters and UV Air Purifiers: Looking for an alternative to a room-sized air cleaner? Here's one thing to try, one thing to avoid, and a few hints that might help make for easier breathing no matter what you opt for.
Buying Guide: Not sure where to start in your hunt for an air purifier? These helpful hints can put you on the right path.
Our Sources: These are the expert and user reviews we consulted to find the top air purifiers in all prices and capacities. They are ranked in the order of their helpfulness and expertise.