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For sufferers of seasonal allergies like me, an air purifier that filters airborne pollutants from the air inside your home can be life changing. Air purifiers are also one of the best ways to remove virus particles, eliminate pet odors and minimize the negative effects of wildfire smoke and air pollution indoors.

With a multitude of air purifier machines on the market touting various methods of purification -- you could invest in an ionic air purifier, a purifier with an activated carbon filter or even a full home filtration system -- it can be challenging to find the best one for your needs on your own, but I'm here to help you sort through the best air purifier options.

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I've researched the products, interviewed experts in the field of indoor air quality and air purification, and tested the features of 15 of the most popular models, taking into consideration 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 and how much a replacement filter costs and more. The result is a definitive list of the best air purifier options around. Keep reading to learn how to improve your indoor air quality and freshen up your home.

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A dozen of the most popular home air purifiers on the market.

David Priest/CNET

Before the recommendations…

Before getting into the details of which is the best air purifier and why, it's important to understand the basic mechanisms that these products use to clean your air. To get a handle on these methods, I talked to Richard Shaughnessy, 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 and airborne particles such as 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 smoke (including cigarette smoke and smoke from wildfires), pollen, spores, dust mites and other particulate matter that pollutes home environments.

Activated carbon offers another type of filter, which captures odors, 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 moreWill air purifiers protect you from COVID-19, wildfire smoke and pollen? 

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 have risen significantly 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.

An important standard to keep an eye out for is 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.

Recommendations get a little more complicated when companies don't list a CADR, or when they employ proprietary air filtration methods.

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Dyson's $550 air purifier doesn't offer a CADR rating at all.

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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, though, if you're interested).

It's also important to note that many of the home 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 below 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 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 below, 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 perfect air cleaner looks sleek enough to fit into most modern decor, can operate as desired with minimal fiddling and can thoroughly and quietly clean your air.

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Blueair's excellent large-room air cleaner looks great, runs fairly quietly and -- most importantly -- cleans large rooms efficiently. The Blue Pure 211 Plus weighs 13 pounds and has a simple interface: The touch-sensitive button on the front of the device lets you set it to low, medium, high or off. That's it.

While it would be nice if it had a few more smarts, like an automatic setting that responds to air quality, Blueair has invested where it matters: the cleaning technology. The True HEPA filter is certified to clean the air in spaces up to 560 square feet, and the activated carbon filter helps remove odors, too. That much power for $300 is pretty impressive.

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Honeywell's air purifier is a little more expensive than other HEPA models, but it can cover a larger space than almost any other purifier I tested: 465 square feet. Despite its clunky design (this thing weighs a hefty 21 pounds), the Honeywell Home is actually one of the quieter models around.

The Honeywell Home's aesthetic isn't my favorite, but you get good control for setting timers and checking whether the prefilter or filter needs replacing. If you're looking for great basic performance for a reasonable price, you can't beat this Honeywell HPA300.

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After months of use in my own home, Coway's HEPA air purifier cemented itself as my favorite available HEPA air cleaner. Prices for these devices have fluctuated over the past year, but $250 is solid for the 361-square-foot coverage it offers. In addition to its coverage, the Coway's ion filtration technology that removes pet dander, dust and other allergen particles sets it apart from many other purifiers in the price range. The Coway's striking, retro design was also one of my favorites among the devices I tested.

Personally, while using this air purifier brand, I've experienced fewer allergy symptoms during typically difficult seasons for me. A colleague's mother also recently bought a Coway for smoke in her home during the West Coast wildfires, and she noticed an immediate improvement in the air quality.

While the ionic filtration technology isn't a huge plus, it also won't produce significant ozone, as tested by the California EPA. If you want an air purifier for a midsize room, Coway's HEPA air purifier is one of the best air purification options around with one of the most adventurous looks.

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The Blueair Blue Pure 411 is a simple, straightforward purifier with smart design and solid bang for your buck. You get particle and carbon filtration (the activated carbon filter removes odors, pet dander, airborne allergens and gaseous airborne pollutants) that will work well in a 160-square-foot room, all for $120. Some devices, like Sharp's Air Purifier, don't even offer that much cleaning power at nearly twice the price.

The Blue Pure has different colored prefilter sleeves for the outside of the device, so it will fit into almost any color palette, and its single-button interface is as intuitive as it gets. The device is also light, with middle-of-the-road noise production. Besides the noise, the only real downside of the Blue Pure is the lack of extra goodies, like timer buttons.

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OK, if you've got the money and want a super powerful air purifier -- or if you'd rather get one purifier to cover your whole house than get one for each room -- Coway's Airmega 400 might be for you. This thing costs a pretty penny at $519, but you get air cleaning coverage of 1,560 square feet.

The Airmega comes with a lot of perks: You get a real-time air quality indicator, a variety of fan speed settings (the highest of which is surprisingly quiet), smart settings that adjust fan speed according to air quality and a range of timers. Of course, it's also larger than many competitors, weighing nearly 25 pounds.

Most homes are going to be better served with one or two smaller Coway or Honeywell air purifiers, but if you have a specific need for a lot of coverage, the Airmega might be the right call for you.

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 Levoit Core 300, the $160 Winix 5500-2, the $176 Winix AM90, the $89 Bissell and the $100 GermGuardian 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.

The IQAir HealthPro Plus wasn't among the devices I tested, in part because I was looking at more affordable options. But IQAir's $900 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.

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The Holmes air purifier is a cheap option for your desktop.

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Two devices I tested featured an ionic filter: the $250 Coway AP-1512HH I mentioned above and the $200 Sharp FPK50UW. 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 Partu ($65) and Holmes ($50) 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 grabbed headlines for its attractive design and proprietary filtration technology back in 2017 -- and is even, strangely enough, sold at the Museum of Modern Art 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 its highly critical 2019 review).

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Molekule was recently forced by the National Advertising Board of Review to retract misleading claims it made in its advertisements.

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On the other hand, the Lawrence Berkeley National Laboratory, one of the premiere indoor air research centers in the country, last year released a government-funded study showing that the PECO effectively filters out volatile organic compounds -- that is, compounds that can easily become gaseous pollutants in the air, which a HEPA filter does not capture. Reviewers at Consumer Reports and the New York Times' Wirecutter, which called the Molekule's larger model "the worst air purifier we've ever tested" 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 force a retraction 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 Class II medical device.

Dyson's devices offer a similar but slightly different problem. Some of its air purifiers, such as the Dyson Pure Cool TP04, 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 really liked these features of the TP04. 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 Wirecutter's, 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. 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. Purifiers may help businesses and restaurants trying to improve the air in their indoor spaces.

According to microbiologist and vice president of Scientific Communications at the American Council on Science and Health Alex Berezow, "Unless you have some sort of medical condition (asthma, allergies), I just don't think an air purifier is worth the money."

Human lungs, Berezow pointed out in a 2019 blog post, filter the air we breathe sufficiently -- especially in places like most parts of the United States, where air is fairly consistently clean.

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On the other hand, for households with an asthmatic or otherwise immunocompromised child, air purifiers have significant benefits, according to Berezow and Dr. Elizabeth Matsui, 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 air purifier FAQ for more info.

Correction, July 13, 2020: 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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