The Best Air Purifier for 2021 | Reviews
A great air purifier can really improve your life. But to qualify as great, it needs to be powerful enough to clean the air in a large living room or playroom, quiet and dark enough for you to sleep near it in a bedroom, and inexpensive enough that it’s reasonable to have several spread throughout your home. Few machines meet that standard, but after seven years of testing 42 different air purifiers, we believe the exceptional Coway AP-1512HH Mighty is the best among them—as we have since 2015.
Winix 5500-2 Exceptional performance, brutalist design
- The Winix 5500-2 is an exceptional performer on particulates, capturing 99.9% of the smoke in our test room in just 30 minutes on high, and 97.2% on its medium-high setting, where it emits an easy-to-live-with 40 decibels.
- In both cases, that’s a bit better than the Coway AP-1512HH, though in practice the differences are moot: Both machines, when used continuously as they are in most homes, will drop particulates to near zero in under an hour—and keep them there.
- We still prefer the Coway for its lower energy consumption, smaller footprint, display-shutoff feature, and more attractive look, but it’s a close race.
Winix AM90 Exceptional performance, modern style
- Another Winix, the AM90, uses the same HEPA filter as the 5500-2 and delivered virtually identical performance in our testing.
- It has a more contemporary design that many will find more attractive (if you prefer white—the only color option).
- It adds Wi-Fi capability and a rudimentary app, and it costs a few dollars more than the 5500-2. The almost identical Winix AM80 lacks the AM90’s Wi-Fi capability and only comes in gray, but as of October 2020 is only available direct from Winix, where it costs $250. We expect that price to drop when it hits broader retail.
- Again, though, the Coway AP-1512HH still wins out versus both the AM90 and AM80, based on its more compact form, display shutoff, and greater energy efficiency.
Levoit Core 300 Small, effective, and attractive
- If you need to clean the air in a space of around 200 square feet, the Levoit Core 300 is a solid and inexpensive purifier. It was impressive in our tests, reducing particulates by more than 97% on its high setting in 30 minutes in a 135-square-foot New York City office. On medium, it reduced them by more than 92%.
- It’s attractive and compact, measuring just 14½ inches tall and 8½ inches in diameter, and its display-shutoff feature means it won’t interrupt sleep with bright lights. At around $100 to purchase, it’s also the cheapest up front of all our picks.
- But it’s not terribly energy efficient: Running it 24/7 on medium will consume about $300 of electricity over five years, and seven new filters in that period will cost $180, making it slightly more expensive than the Coway Mighty over the long term. And it doesn’t keep pace with the Coway or the Blue Pure 211+ in larger rooms.
Winix 5500-2 Air Purifier with True HEPA, PlasmaWave and Odor Reducing Washable AOC Carbon Filter
- True HEPA filter captures 99.97% of airborne pollutants; dust mites, pet dander, pollen and other allergens as small as 0.3 microns
- Washable AOC Carbon Filter, made from activated carbon granulars for removal of household odors. Decibels 27.8 dB
- PlasmaWave acts as a permanent filter to safely break down odor, allergens, chemical vapors and other pollutants with no harmful ozone
- Smart Sensors gauge the air and our Auto Mode adjusts the fan to filter the air as needed; with a sleep mode for silent night time operation
- CADR rated for 360 square feet room size. Suitable for medium and large rooms; kids bedrooms, family rooms and kitchens
- Product has no extra filters
How to set up, use, and maintain your air purifier
To get the most out of an air purifier, you need to set it up properly, operate it properly, and perform very occasional maintenance. Here’s a list of what to do:
Remove the wrappers. Most air purifiers arrive with the filters installed—but also sealed in plastic wrappers. And we know of at least one Wirecutter reader and one Wirecutter staffer who didn’t realize they needed to remove the plastic before turning their purifier on, which rendered their purifiers useless. So open up your machine and, if the filters are indeed wrapped, unwrap and reinstall them. The HEPA filters should have an arrow or other marking indicating the correct orientation.
Place them correctly. Install your purifier at least 18 inches from a wall and any furniture, ideally near the midpoint of the room you’re using it in.
One purifier per room is best. Purifiers work best in a contiguous space; if you want to clean the air in both the living room and a bedroom, for example, it’s best to get a purifier for each room or to move a single purifier around with you. However, that’s not always practical, which is why we gave points to lightweight purifiers with handles that made moving them from room to room easy.
Oversized is better than undersized. It’s better to have “too much purifier” than not enough. Manufacturers typically base their room-size recommendations on tests with the machines set on high—no doubt for marketing purposes, but also because CADR ratings are usually based on this setting. But high is usually too loud to watch TV or sleep with. Purifiers rated for spaces larger than the one you plan to use them in can operate on lower, quieter speeds.
Keep your purifier running. Under typical conditions, we recommend running air purifiers 24/7 on their highest “quiet” setting—which we define as 50 decibels (dBA) or less. That generally means the medium setting on three-speed purifiers, or the high-medium setting on four-speed machines. Specifically, that means avoiding the “automatic” setting that some purifiers come with. We recommend avoiding this feature for two reasons. First, there’s no way of telling whether the sensor these machines use to determine their automatic on/off cycles is working properly. Second, depending on what a manufacturer determines as “poor enough” air quality, an automatic setting may let the air in your home get quite laden with particulates before kicking the purifier on.
Under known bad-air conditions, such as during a nearby wildfire, we recommend running purifiers on high for an hour and thereafter on quiet/medium. In 2018, we specifically tested this advice, and our results bear it out.
Keep doors and windows closed. You should keep the doors and windows closed when using an air purifier. A draft or an open door can draw unfiltered air into a room faster than the purifier can deal with it. Normal in-and-out foot traffic isn’t an issue; just close the door behind you.
Clean the prefilter monthly. For optimal performance, vacuum, wipe down, or rinse off the prefilter (it looks like a window screen or plastic netting) every month or so. The prefilter catches larger particles, such as pet hair, and keeping it clean helps the HEPA filter work unimpeded on fine particles.
Schedule filter replacement. It’s easy to forget the occasional obligation of replacing your purifier’s filters—set a calendar reminder. Purifier manufacturers typically recommend annual replacement, but check the manual to be certain; some call for less-frequent or more-frequent replacement. We think it’s wisest to follow the manufacturer’s recommendation, but we have also found that HEPA filters continue to perform almost like new even after a year of continuous use—so if you blow past the deadline, it’s likely not a crisis.