Buyer’s Guide: The Best Air Purifiers

Air purifiers help eliminate dust, dander, pollen, mold, and other airborne contaminants that contribute to respiratory issues. If you're setting out to improve your home's indoor air quality, consider these shopping tips and our top picks among the best air purifiers available today.

Best Air Purifier for Allergies

Nobody wants to breathe in dust, dander, pollen, and mold. Unfortunately, though, the air in our homes is loaded with these pollutants, thanks to poor ventilation and the use of household chemicals, gas-burning appliances, and smoke-producing tobacco products. Once airborne, these irritants often act as allergens.

Air purifiers are designed to improve the situation by catching contaminants and removing them from the air. But before you buy one of these appliances, make sure to weigh the considerations outlined below to be sure that you’re investing in the best air purifier for your home and your needs. You can also start your shopping with our top five picks:

  1. BEST OVERALL: Coway Mighty Air Purifier
  2. BEST VALUE: Winix Air Purifier
  3. BEST UPGRADE: Rabbit Air MinusA2 Ultra Quiet HEPA Air Purifier
  4. BEST FOR BEDROOMS: Alen BreatheSmart FLEX Air Purifier
  5. BEST TECH PICK: Dyson Pure Cool Purifying Fan

How Do Air Purifiers Work?

The best air purifiers draw air through one or more filters. The filtration traps the impurities before recirculating clean air back into the room. In many ways, these machines work in a similar manner to the masks worn by surgeons in the operating room. As the surgeon breathes, airborne particles become trapped on the inside surface of the mask, preventing germs from being transmitted from doctor to patient. Air purifiers similarly allow air to pass through but as they do so, they block the damaging particles. The higher the quality of a filter, the better it can remove dust, animal dander, pollen, mold spores, and other pollutants from the air.

Filtration in the Best Air Purifiers for Allergies

Photo: amazon.com

Key Considerations for Choosing the Right Air Purifier

HEPA: The Best Filter for Allergy Sufferers

Air purifiers with high-efficiency particulate air (HEPA) filters are most effective at catching airborne irritants that plague allergy sufferers. These filters are certified to trap 99.97 percent of all particles of a certain length (0.3 microns or larger). Most pollutants are so microscopic that they can’t be seen by the human eye, so investing in a reliable filter is crucial. The downside of HEPA filters is their replacement cost. Look for a purifier that incorporates additional filters to trap larger particles before they reach the HEPA filter. That can ultimately help your HEPA filter last longer.

Alternative Filtering Options

  • Carbon filters can reduce the amount of some volatile organic compounds (VOCs), which are gaseous particles often found in paint, varnish, cleaning products, carpeting, wood preservatives, and other common household items. These filters can also remove odors. But they, too, must be replaced every few months to maintain effectiveness. For best results, carbon filters should be included as part of the prefiltering system in units that also contain HEPA filters.
  • Ozone-producing air cleaners claim to work by increasing oxygen molecules and activating negative ions to eliminate harmful airborne bacteria. The Environmental Protection Agency has determined, however, that ozone is detrimental to the human respiratory system. For that reason, some health experts discourage the use of ozone-producing air cleaners and their use is often regulated.
  • Ion-exchange technology and electrostatic technology can increase the effectiveness of filter-type air purifiers by attracting particles through static electricity and trapping them. When combined with HEPA filtering, these products can be quite effective. They require frequent cleaning, however, to keep them working well. After conducting extensive tests on air purifiers, Consumer Reports warned that some ion-exchange and electrostatic purifiers can emit ozone as a by-product of purifying the air, so check the purifier’s operating manual (or the information on the box) to ensure that your purchase does not emit ozone.

Capacity

Air purifiers are tested and rated according to the Clean Air Delivery Rate (CADR) scale, which indicates the volume of air that a particular machine can clear of a given size of particle, as measured in cubic feet per minute. The higher the rating, the greater the efficiency:

  • 25 to 450 removes pollen
  • 10 to 450 removes tobacco smoke
  • 10 to 400 removes dust

The purifier’s box and the owner’s manual should also indicate the machine’s air-cleaning capacity according to room size, meaning that it’s been tested and was effective in purifying the air in a room of a given area.

Keep in mind that dirty filters reduce an air purifier’s effectiveness. To increase the useful life of any HEPA filter, take additional steps to keep the air clean, such as vacuuming and dusting daily, banning indoor smoking, and limiting the use of candles.

Total Cost

When shopping for a purifier, consider the filter replacement cost as well as the machine’s initial price. An inexpensive unit that requires expensive replacement filters may not be a bargain. Air purifiers with HEPA filters range from the small and low-priced all the way up to high-capacity models with multiple filtering systems that treat large areas.

Other Bells and Whistles

First-time air purifier shoppers may be surprised at the technology incorporated in even the less expensive models. Multiple speed settings, programmable day and night cycles, sealed systems for noise reduction, and remote controls are common features for many brands. Not all air purifiers perform at the same level, though. Choose wisely!

Top Picks for Air Purifiers

Best Air Purifier for Allergies - Coway Purifier

Photo: amazon.com

1. BEST OVERALL: Coway Mighty Air Purifier

High performance, high design, and low filter replacement costs make the Coway Mighty Air Purifier a strong customer favorite. This purifier’s four-stage filtration system works wonderfully well in removing not only dust and pollen and smoke, but also unpleasant household odors. Its CADR ratings are in the 230-250 range, and these ratings hold up in spaces up to 360 square feet—meaning, the Mighty Air best suits small- to medium-size rooms. Its filter replacement kit, sold separately, includes two carbon prefilters that should last six months apiece, as well as a single HEPA filter that should last a year.



The Best Air Purifier for Allergies: Winix

Photo: amazon.com

2. BEST VALUE: Winix Air Purifier

Though it’s the least expensive of our picks, the Winix doesn’t skimp on features or effectiveness. Of course, it removes dust, pollen, and smoke, delivering competitive CADR numbers for each. But it also goes further than many air purifiers. For one thing, its Winix PlasmaWave technology filters out disagreeable odors and chemical vapors. For another, its Smart Sensor reads the air and automatically modulates the air purifier’s fan speed up or down as needed. Filter replacement costs are lower than that of many competitors; only note that replacement may be necessary as often as four times per year.



The Best Air Purifier for Allergies: Rabbit Air

Photo: Amazon.com

3. BEST UPGRADE: Rabbit Air MinusA2 Ultra Quiet HEPA Air Purifier

Entertaining at home is nothing to sneeze at. Ensure easy breathing in a large great room or family room by purifying up to 700 feet of living space with the Rabbit Air MinusA2 Ultra Quiet HEPA Air Purifier. Thanks to its combination of a high-efficiency HEPA filter, two pre-filters, and an activated carbon filter, the Rabbit Air achieves impressive CADR numbers: 200 for pollen, 193 for dust, and 180 for smoke. In all, there are five daytime and operating speeds in addition to a night mode. The filter lasts a relatively long time, too, and typically only needs replacement once per year.



The Best Air Purifier for Allergies: Alen BreatheSmart

Photo: amazon.com

4. BEST FOR BEDROOMS: Alen BreatheSmart FLEX Air Purifier

For relief overnight, you need an ultra-quiet air purifier like this one, featuring WhisperMax technology that limits noise to a soft, almost pleasant hum. Alen, the manufacturer of BreatheSmart, does not perform CADR testing but emphasizes the unit’s high-capacity HEPA-Pure filter, designed to trap airborne particles as small as 0.3 microns. Treating rooms up to 700 square feet in area, the BreatheSmart operates in four modes, including sleep mode, all while its sleek design (available in 14 designer colors) allows the unit to look at home in your space. Purchase replacement filters separately and change out once every six to nine months.



The Best Air Purifier for Allergies: Dyson Pure Cool

Photo: amazon.com

5. BEST TECH PICK: Dyson Pure Cool Purifying Fan

It sure looks cool, but another cool thing about the Dyson is that it pulls double duty. That is, you can use it remove allergens from indoor air all year round, and you can also use it to cool off with a breeze on warm days. The unit treats up to 400 square feet and boasts a whopping ten speed settings, including a nighttime sleep mode. It’s the Dyson’s “smart” capabilities that make it really stand out, though. After downloading the Dyson mobile app, you can turn the air purifier on and off from your smartphone, program an operational schedule, and view real-time air quality reports. Dyson does not provide CADR numbers for its air purifier, but because it features a True-HEPA filter, we know it is capable of removing up to 99.97% of airborne allergens as small as 0.3 microns. Replacement filters, sold separately, should be used for six to eight months.