Best Air Purifier: Tested and Reviewed

Whether you need relief from seasonal allergies, want to eliminate pet odors or worry about , an air purifier is an awesome device that can help you out. We’re about to dive headfirst into the dry summer months, and if you want a home that’s easy to breathe in, snagging your own air purifier is a must.

With so many machines available with various methods of air purification, choosing the best one for you and your family requires some research and expert guidance. First consider how much you can comfortably invest in air purification. Will you need an ionic air purifier or a full home filtration system? Do you want a purifier with an activated carbon filter? I’m here to answer those questions and help you sort through your options.

Why you can trust our reviews on the best air purifiers

I’ve researched the products and interviewed experts in the field of indoor air quality and air purification. I’ve also tested the features of 15 of the most popular models. I considered factors like whether each air purifier has an air quality monitor or clean air delivery rate, along with how frequently you need to replace the filter. I also looked at whether the unit has a washable filter and how much a replacement filter costs.

After careful tests and consideration, these are the top picks for best air purifier options based on our research. Any one of the air purifiers below should improve your indoor air quality, filter out smoke and airborne particles while also providing fresh air.

How do air purifiers work? 

Before you make a purchase, it’s important to understand . To get a handle on these methods, slot I talked to , director of Indoor Air Research at the University of Tulsa.

According to Shaughnessy, who has a doctorate in chemical engineering, most air cleaners run your air through a filter designed to catch indoor air pollutants like dust particles and dust mites you might otherwise inhale. These are usually High Efficiency Particulate Absorbing filters and they’re designed to capture 99.97% of airborne particles sized 0.3 micron or larger. A HEPA filter reliably removes indoor air pollution such as , pollen, spores, dust mites and other particulate matter that pollutes home environments.

Activated carbon offers another type of filter, which captures odors like pet odor, volatile organic compounds and gaseous pollutants that can slip through a HEPA filter. «[A carbon filter is] good … to an extent,» said Shaughnessy, «but they need to have a sufficient amount of carbon. You don’t want breakthrough happening, where the carbon becomes fully saturated and it releases what was captured back into the air.»

According to multiple researchers I talked to, most consumer air purifiers simply don’t have enough activated carbon to be an effective odor filter for more than a short period of time.

Read more:  

Another common type of air cleaning works via ionic filtering. These filters can be effective, according to Shaughnessy, but ionic purifier models have a number of shortcomings: Some don’t actually remove air pollutant particulates from the home, but rather cause them to attach themselves to surfaces around the home. Others must be cleaned consistently, or they might begin to emit ozone — itself a pollutant.

While some ionic purifiers are effective and standards for them  in recent years, the benefits an ionic purifier offers over a HEPA filter are in many cases negligible, particularly given the risk an ionizer occasionally poses.

How we test air purifiers

Outside of a controlled lab environment, air purifiers can’t be tested. That said, certain certifications are standardized, meaning HEPA air purifiers will consistently capture what they claim to capture — as those claims have been tested by a third party. Likewise, you’ll want to keep an eye out for the AHAM Verified Clean Air Delivery Rate, which tells you how much air a purifier can process in a given time frame. Not every company uses this standard, but most do.

I tested each air purifier on this list in my own home over the course of multiple months, checking how each advertised feature worked, testing the volume and monitoring it for any operational problems. As for the actual particle capture and air cycling rate, I relied on the certifications.

Making recommendations gets a little more complicated when companies don’t list a CADR, or when they employ proprietary air filtration methods.

Some major players, like Dyson and Molekule, offer their own standards. That doesn’t necessarily mean that their devices are inferior, but rather that they require extra scrutiny. In these cases, I looked at the explanations presented by the companies themselves and talked to third-party specialists. By and large, such devices — even if they do accomplish what they claim — still end up overpriced compared with competing products with more readily accessible evidence backing up their claims. (I look more closely at both of these brands later in this article.)

It’s also important to note that many of the best air purifier models I tested have been going in and out of stock in recent months, given the demand for such devices during the pandemic and amid wildfires. While that might mean some of the options above are out of stock, we’ve decided to keep our recommendations — and the rationales behind them — posted, so you can use them to find the best product for you. For now, though, our recommendations for the best air purifier options are based on the included prices, and we would recommend avoiding sellers offering the same devices for significantly different price tags. We’ll update this list periodically as we review new products.

For the devices above, I primarily considered the power for the price (that is, the higher the CADR and the lower the price, the better). Secondarily, I looked at additional cleaning modes, the helpfulness of controls, the general design and the noise level. The best air purifier looks sleek enough to fit into most modern decor, can operate as desired with minimal fiddling and can thoroughly and quietly clean your air.

The rest of the field

The above recommended air purifiers are only five of the 15 devices I tested. Other HEPA cleaners, like the $100 , the $78  and the $100  all offer only so-so power for their prices. All five of those models offer a carbon filter or charcoal filters for removing airborne contaminants like odors, pet dander and gaseous pollutants, but the filters in all of them contain only a few ounces of the medium, meaning they won’t last long with regular use. Filter replacement timing will vary. They are not among the best air purifier options.

The wasn’t among the devices I tested, in part because I was looking at more affordable options. But IQAir’s $800 air cleaner is one of the few devices on the market to contain multiple kilograms of activated carbon, which will filter out odors and gaseous pollutants much more effectively than most consumer air cleaners under $1,000, according to specialists I talked to.

Two devices I tested featured an ionic filter: the  I mentioned above and the $178 . The Sharp’s CADR rating is only 259 square feet, which is significantly lower than the Coway’s and not great for the price.

The ($50) and ($55) air purifiers were the most affordable devices I tested and they both provide a true HEPA filter option for small rooms. If you are looking for a portable air purifier, I could see them being used on a desk in an office, for instance, to great effect. But both felt a little cheap and neither gave an official CADR, so I would recommend saving up for something a little more reliable if air purification is a high priority.

What about Molekule and Dyson?

You may have heard of another air purifier called Molekule, made by a company of the same name, which   for its attractive design and proprietary filtration technology back in 2017 — and was even, strangely enough,  in New York. What about that?

The Molekule presents a complicated problem: Its maker claims its proprietary PECO air filter destroys airborne particles much smaller than 0.03 micrometer, but it filters air at such a slow rate that, even if the company’s claims are accurate, it cleans the air very inefficiently compared with HEPA air purification models (as Consumer Reports rightly pointed out in ).

On the other hand, the Lawrence Berkeley National Laboratory, one of the premier indoor air research centers in the country, released  showing that the PECO effectively filters out volatile organic compounds — that is, compounds that can easily become gaseous pollutants in the air — that a HEPA filter does not capture. Reviewers at Consumer Reports and the New York Times’ Wirecutter, which called the Molekule’s larger model «» and the Air Mini «the second-worst,» didn’t appear to test VOC reduction.

We can’t recommend the Molekule Air Mini Plus, which I tested, as a result of these problems coupled with a 2020 decision by the National Advertising Review Board to  of many of Molekule’s misleading advertising claims. That said, the air purifier does appear to address a problem that most HEPA filtration cleaners simply don’t: the presence of gaseous pollutants in the home. Such pollutants have plenty of sources, whether from paint, furniture, cleaning solutions or even some composite boards. For that reason alone, Molekule’s eye-catching brand is worth keeping tabs on — especially as its latest air cleaner was approved by the FDA as a .

Dyson’s devices offer a similar but slightly different problem. Some of its air purifiers, such as the , which I tested, use a HEPA filter, but provide no CADR. A Dyson spokesperson told me, «CADR as measured by some current methods is not an accurate representation of a real home,» and thus the company has developed its own testing procedures «to replicate a more realistic setting.» That includes a testing room that has over double the footprint of AHAM’s testing rooms, along with nine sensors placed around the space (versus AHAM’s single sensor). The Dyson TP04, perhaps unsurprisingly, performs well according to Dyson’s own metrics.

In addition, the Dyson TP04 air purifier features a handful of extra goodies, including an oscillating fan to help circulate clean air around larger rooms, an app with home air quality data and a small but nifty display. Our tower fan reviewer . But is all that worth the price bump from, say, Coway’s purifier?

For most people, the answer is likely no — especially considering that Dyson’s devices haven’t stacked up especially well against the competition in third-party testing, such as , where the TP04’s performance was in line with the far more affordable Blueair 411.

Do you even need an air purifier?

Given COVID-19, wildfires and pollution, we may be more aware of air quality today than ever before. But air purifiers aren’t necessarily a panacea for these problems. As mentioned before, in home settings, virus transmission usually occurs through close contact, which means an air purifier probably won’t protect you if a roommate or family member in the same house gets sick. That said, purifiers may help businesses and restaurants trying to improve the air in their indoor spaces.

For households with an asthmatic or otherwise immunocompromised child, air purifiers have significant benefits, according to , a professor of population health and pediatrics at the University of Texas, Austin’s Dell Medical School.

Matsui has extensively researched the effects of air purifiers on children with asthma and says the devices can make a big difference — though they’re no substitute for well-ventilated and smoke-free homes or proper medical care. Furthermore, there is no evidence to suggest that air purifiers diminish the chance of children developing asthma.

In short, air purifiers are popular for a reason: They mostly do what they say, cleaning the air inside your home. And depending on your health needs, or if you live in a home with many sources of air pollution, cleaner air and better air flow might really make a big difference for you or your children. If you think the benefits of an air purifier might help someone in your own home, it’s always worth talking to an allergist. If you’d rather just grab an air cleaner and call it a day, you can’t go wrong with the recommendations above.

Still have more questions about air purifiers and whether you’re ready to buy one? Check out our  for more info.

Air purifier FAQs

Here are the answers to more common questions about air purifiers. If you have any others, feel free to reach out on Twitter () or you can email me from  (click the little orange envelope).

Correction: A previous version of this article incorrectly described the Blueair 411’s features. The Blueair 411 has a «change filter» indicator and is AHAM-certified for a 161-square-foot room.

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