Protect yourself from poor air quality like smoke pollution, allergies, bacteria, dust, pets and more with our picks for the best air purifier.
Air purifiers might be becoming an essential household product -- especially if you live in an area prone to smoke pollution or poor air quality. The people who live a near the LA wildfires, for example, are experiencing poor quality issues right now. Since climate change and declining air quality is an ongoing problem anywhere on this earth, you might want to consider the benefits of an air purifier. "I would recommend an air purifier to anyone, even if you're just cooking at home,” says Jie Zhao, head of Delos Labs, a human health tech company. Fan Filter Unit
We put dozens of popular air purifier models to the test to see which ones are the best at clearing smoke, dust, mold, allergens and more from your home.
CNET's pick for best overall air purifier goes to the Blueair Blue Pure 311i Max . During lab testing, Blueair outperformed the competition clearing smoke and particles from the air faster and more effectively in our controlled testing chamber. Its versatility, low energy draw and relatively low noise level while running even on the highest setting, combined with its median price, made the Blueair an easy choice for the best overall air purifier.
In terms of smoke, seasonal allergens and dust, an important consideration in buying an air purifier is whether it has an automatic mode. Certainair particles do not remain consistent throughout the year or even throughout the day. “Auto-mode purifiers can automatically ramp up the speed when the pollution is higher,” says Zhao, which ensures they perform efficiently given real-time conditions and don’t waste energy when more power isn’t needed.
Air purifiers such as the BlueAir Blue Pure 311i Max with automatic mode respond to the actual air quality, and adjust the speed accordingly.
In addition to its automatic setting, BlueAir’s Blue Pure 311i Max was the top finisher at both low and high fan settings, bringing the particulate count down to pre-smoke levels in 6.6 and 2 minutes, respectively. On top of that, the Blue Pure 311i Max was the second most energy-efficient unit for its capacity and surprisingly quiet too, reaching only 46.1 decibels when running at its highest fan setting -- a full 9 decibels lower than the loudest model among those we tested.
The Blue Pure 311i Max also has voice controls and comes equipped with a five-color air quality indicator and a pollution-detecting particle sensor. Download the BlueAir App and you’ll be able to track air quality in your home in real time, control the air purifier remotely and even track filter usage so that you can order a new one when the time comes. It’s a simple, well-designed air purifier that performs exceptionally well, both in terms of energy usage and particle removal.
While a HEPA filter is an industry standard for air purification systems, an additional measure, a UV-C light, is specially equipped to handle pathogens such as viruses, bacteria and mold, and stop them from multiplying. “The best way to destroy pathogens is just to expose them to sunlight,” says Shahir Masri, associate specialist in air pollution exposure, assessment and epidemiology at UC Irvine Joe C. Wen School of Population & Public Health. “Air purifiers with a little UV light in there will do one extra task for you,” he said.
“If you're specifically concerned about infectious diseases, that's what that's going to be for,” he adds. “It's a biology killer.”
The Germ Guardian AC4300 had medium air-clearing performance among the air purifiers we tested, clearing 612 square feet in about an hour, with a median CADR (Clean Air Delivery Rate) between 99 and 116 depending on the particulate matter in question. It is suitable primarily for small spaces, with a slightly higher energy draw than those of a similar volume, but a lower running noise level. For those whose primary concern are pathogens such as viruses and bacteria, however, this is an effective model with a relatively small footprint and a modest price tag.
The Coway Airmega 400s is among the largest and most powerful air purifiers on the market, with a hefty price tag to match, but it is an excellent option to consider for larger, open spaces. Its sophisticated four layers of filtering can handle particulate matter as microscopic as .1 micron in size, has among the highest CADR of any available models, between 325 and 400 depending on the particulate matter, and it can clear a whopping 3,100 square feet of space in about an hour.
Its functionality and features are on par with the Blueair Blue Pure 311i Max above, including an automatic mode that aids with particles such as smoke and seasonal allergens without running on high continuously. Its footprint, energy draw and price are all a more serious commitment, but it’s still a good value considering its expansive capabilities. For your money, you’re also getting all the bells and whistles: Wi-Fi capability allowing for voice or app control; smart, sleep, and eco settings; and real-time air quality monitoring.
While different kinds of particulate matter are indistinguishable to the air purifier itself, according to the experts we spoke to, an important consideration for particles such as pet dander is energy draw, since that type of pollutant theoretically remains consistent in your home and necessitates constant use of an air purifier.
“It's more on the consumer experience and user interaction, having it running all of the time, versus the fundamental scientific principle,” says Zhao, when it comes to what makes an air purifier most suitable for pets.
The Blueair Blue Pure 511 air purifier is an effective model in its own right. In our particle-removal test, the Pure 511 cleared our smoke-contaminated test chamber air back to non-hazardous conditions in less than 20 minutes at its lowest fan setting. Every other small-size air purifier we tested took at least 35 minutes to clean the air in that same test. The Pure 511 led the way on the high setting too, clearing the room in a category-leading 7.5 minutes. Its low energy draw is the determining factor here, with among the lowest energy requirements of any air purifier, drawing just 0.0135 kilowatts per hour, even on its highest setting.
Your best bet for larger spaces, regardless of pollutant type, is still either the Blueair Blue Pure 311i Max or Coway Airmega 400s above, but for a space such as a bedroom where your pets stay with you at night, the Blueair Blue Pure 511 is an ideal choice.
Most air purifiers run within a decibel range of 33 and 55, depending on the model and setting. For comparison, that’s the difference between a light rainfall -- easy to sleep through -- and a normal conversation volume -- less easy to sleep through. Noise might be a determining factor, then, if you’re looking to literally rest and breathe easy by running an air purifier in your bedroom. The quietest of the bunch is the Levoit Core Mini, whose tested volume was only 37.2 decibels, even on its highest setting. (Most other models demonstrated 44 decibels and above.)
As a purifier, the Levoit Core Mini isn’t the most powerful, but is suitable for a small bedroom. It can clear 378 square feet in an hour, but only to a particle size of 0.3 microns. This is the industry requirement for HEPA filters, but many other models offer better outcomes. In addition to its extremely quiet running volume, however, it also has the lowest energy draw, at 0.0061 kilowatts per hour, the smallest footprint, and the smallest price tag, making it a reasonable investment if you’re looking to try out an air purifier in your bedroom or other small space.
To help inform our air purifier picks, we gathered 14 of the most popular models at the CNET Labs product testing facility in Louisville, Kentucky, where we put them through a rigorous set of tests. Our goal was to determine which air purifiers offered the best performance in terms of particle removal efficiency, energy consumption and quietness, while also evaluating their respective feature sets and value.
The air we breathe isn't just air. In truth, it's a combination of human-generated and naturally occurring particles. The former is composed mostly of urban, industrial and automotive emissions of hydrocarbons, nitrogen oxides and combustion byproducts, and the latter is mostly represented by smoke from forest fires, sulfates, soot and matter from volcanic activity around the globe.
According to the EPA, some of these microscopic solids and liquid droplets, which can be made up of hundreds of different chemicals, are so tiny that it's almost inevitable to inhale them. PM10 and PM2.5, which are particles of less than 10 and 2.5 micrometers in diameter, respectively, pose the greatest risk to human health since once inhaled. They allocate deep into the lungs and even into the bloodstream, impairing the proper functionality of the lungs and heart.
"That's the size that can go into our body, into our lungs and go into our bloodstream," said Zhao. "That is the number one environmental risk factor globally. It kills about 6 to 7 million people a year," he said, due to cardiovascular or respiratory problems brought on by particulate pollutants.
Our custom air purifier test chamber uses a clear-view front panel made of plexiglass and gloved hand access, which allows us to manipulate the air purifiers, a particle counter holder for our control device, two fans that ensure proper mixing of the air and smoke inside the chamber, vent ports that ensure there is a small amount of fresh air at all times, an ignition port to light up the smoke bombs from outside the rig, and an exhaust port that removes the remaining smoke safely from the chamber and the building after each test.
The chamber is not hermetically sealed, but it's tight enough to ensure that no hazardous amount of smoke escapes to the surroundings. Our mission was to create an environment in which we exposed each air purifier unit to particle-saturated air of roughly the same concentration to assess how quickly and efficiently they get the air back to breathable conditions.
We made custom smoke bombs, which are made of 50% potassium nitrate (KNO3), 40% sucrose (sugar) and 10% sodium bicarbonate (baking soda) and included a safety fuse for igniting it at a distance. The sugar acts as our fuel source, while the potassium nitrate acts as an oxidizing agent and the baking soda ensures that our dry mixture sustains a slow and even burn.
Using the Temtop PMD331 Particle Counter, we were able to verify that 5 grams of our smoke bomb dry mixture produces roughly between 590 million and 610 million particles per meter cubed. The device is able to count particles of different sizes, including PM2.5 and PM10, and it logs this data once every 15 seconds. Although we're able to count particles of different sizes individually, it's the total number of particles we care about, which is the sum of all particles of different sizes.
We prepared a 5-gram smoke bomb, which is ignited via the ignition port after installing the air purifier and ensuring proper sealing. Once the air in the chamber becomes particle-saturated (greater than 580 million particles/m3) we turn on the air purifier in question. The data extracted from the Temtop allows us to accurately track the impact that the air purifier has on the particle count in real time.
Using a decibel meter, we measured how loud the air purifiers are at their low, medium and high fan settings. This is particularly important if you plan on having your air purifier on in your bedroom overnight and you don't want it to disrupt your sleep. We performed this test in our sound-enhancing studio to make sure that the decibel meter picked up only soundwave stimuli from the air purifiers, excluding other possible sources.
To answer this question, we used a device called Kill-a-Watt and measured how much power each air purifier consumed at different fan settings. Knowing the energy draw for your air purifier could make a difference to your energy bill.
Kenmore Smart 2300E : This is a high-functioning, consistent, fast-acting option with a reasonable price tag for its size and operation, if you're specifically in the market for a large-room or whole-home air purifier with a moderate price tag. We preferred the Coway Airmega 400s, above, merely for its stated capacity to manage particles down to 0.1 micron in size.
Levoit Core 400s : It's the most expensive medium-sized air purifier we tested but it offers great performance in all test categories. Features include Wi-Fi connectivity, voice control and the VeSync app, which allows you to monitor air quality and control the unit remotely. It's also compatible with Google Assistant and Alexa.
Medify MA-25 : The performance didn't justify the price of this unit. It struggled in our particle removal test and was the loudest of the small-sized air purifiers we tested.
Kenmore 850e : This unit offers decent particle removal efficiency thanks to its three-stage filtration system and sports a touchscreen display and dimmable night light. It wasn't quite as strong a performer as the Blueair Blue Pure 511, but is equally budget friendly.
Coway Airmega AP-1512 : Above-average performance overall. Sports a color-coded air quality indicator, eco-mode and filter alerts. It has an ionizer option that may enhance bacteria and virus removal, but is a feature that also has the potential for harmful by-products.
CleanForce CP-Rainbow : I was impressed by the performance of this unit. It was the fastest air purifier at removing particles at the high fan setting, removing all smoke particles in just 1 minute and 45 seconds. It comes with app control and voice command, an HD LED display for air quality monitoring and color-coded indicators. It offers just a hair fewer features than other large air purifiers.
EnviroKlenz Mobile UV : The highlight of this unit is that it comes with two UV-C bulbs to eliminate airborne bacteria and viruses. Other than that, it's quite large and heavy, sitting at 40 pounds. It took the longest to purify the air in our particle removal test, and it's quite expensive both to buy and operate.
Veva 8000 : Not a lot to highlight about this unit other than the low cost and the super quiet design. It was a bottom-of-the-pack performer in our particle removal test and in terms of energy efficiency as well.
Dyson’s air purifiers are a bit different from the products on this best list in the sense that most of them are bladeless, while most air purifiers we tested have a conventional fan system. Dyson’s TP04 air purifier, for example, includes an oscillating fan to help circulate clean air around larger rooms, an app with home air quality data and a small but nifty display.
Dyson uses a HEPA filter, but provides no CADR in its specifications. "CADR as measured by some current methods is not an accurate representation of a real home," a Dyson spokesperson told us, 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.
We are in the process of reaching out to Dyson to test its latest air purifier models and we aim to see how it stands up against the others we’ve tested. If there's one thing we know for sure, Dyson products are usually on the pricier end, so if its air purifiers score well on our testing, the question will be: Is it worth the cost? More to come on that.
Climate change has caused wildfire activity and air pollution to increase, with smoke infiltrating areas that are typically not subject to wildfires. Although most people who suffer from severe allergies have always been aware of air quality, we are now all becoming more aware of it due to these changes. Persistent allergy symptoms, visible smoke or pet hair and lingering odors can all be indicators that you may want to consider an air purifier. Air purifiers are useful even for minor pollutants such as cooking smoke, car exhaust, occasional dust and burning candles.
Depending on your living conditions, if there are numerous pollutants affecting the air in your home, the cleaner air and increased air flow that air purifiers provide can potentially make a big difference for the quality of life (and breath) for those in your household.
If you're thinking of getting an air purifier and want additional reassurance, it may also be worth speaking to your doctor or allergist.
Electronic Air Cleaner Read more: Do Air Purifiers Protect Against COVID-19? What About Wildfire Smoke?