Best air purifier: Fight allergens, smoke, and germs for cleaner indoor air

The best air purifiers can eliminate indoor pollen, dust, pet dander, and even some germs and airborne chemicals. Here’s what to look for in a good unit.

The air we breathe is filled with tiny particles of every shape and size. Some are invisible to the naked eye, and others can be seen with bright light. But all of the components of these particles—dust, dander, pollen, mold, viruses, and more—can add up to dirtier indoor air. The United States Environmental Protection Agency reports that indoor air can contain anywhere from two to five times more pollutants than air outside, owing to both the enclosed nature of these spaces and to generally poor ventilation. Adding an air purification system to your home can help.

There are a variety of styles and forms of air purifier on the market, and since the primary function of these devices is to enhance the comfort of your home, it’s important to choose a unit that can interface seamlessly with your space and your lifestyle. In this guide, we’ll break down some differences between available models and to help you choose the best air purifier for you.

Things to consider when shopping for the best air purifier

The best air purifier for your indoor space will filter a volume of air appropriate for the size of the room in question and will ideally have the ability to remove a variety of particulate matter in a wide range of sizes down to near-microscopic. Power and volume capability directly affect the noise output of an air purifier, as well as the durability of the filters required for your specific model. Below are a few key considerations to keep in mind when shopping around, plus our recommendations for solid picks. You’ll find that they have some of the best air purifier reviews.

How big is your space?

The square footage of a room, as well as the height of the ceilings, should be taken into account when shopping for an air purifier, as these measurements directly affect the volume of air that needs to be filtered and the required air purifier capacity by extension.

“Air changes per hour” is an effective measurement that can be used to evaluate the rate at which an air purifier can filter all the air in a room before starting over. This number, when paired with the industry-standard Clean Air Delivery Rate (CADR), can paint a clear picture of the air exchange required for a room’s specific square-footage. Two to five air changes per hour is generally recommended, and a CADR of 200 is considered average. In the case of a small room, an air purifier with a lower CADR may still be able to deliver two to five air changes per hour, whereas a higher CADR will provide either many more changes per hour to a small room, or the appropriate two to five per hour for a large room.

The bottom line here is that a higher CADR is always going to provide a quicker rate of filtration, but this measurement can swing widely depending on the size and shape of the space. It’s not necessary to buy a larger, more powerful purifier if your room is small, but if you want to move your purifier between rooms then you may want to consider a large option for more flexibility.

Does anyone in your household smoke?

Air purifiers rely on a variety of internal filters to effectively clear particulates from the air. Certain filters are better at snatching odors or pet dander, others are better at cleaning tobacco smoke from the air. HEPA—short for “high-efficiency particulate air filter”—is the most common style of filtration used in these devices, using a pleated construction that can theoretically purge the air of up to 99.97% of contaminants. These filters are in turn rated on the Minimum Efficiency Reporting Value scale, also known as MERV, which indicates the filter’s effectiveness in capturing particles based on their size in microns. The higher the MERV rating, the smaller the particle that can be captured.

Variants within the HEPA-style of filter exist that can take these normal designs beyond conventional use, which can be especially useful in dealing with specific types of pollutants like smoke and pet dander.

Do you have pets?

Activated carbon or charcoal filters are very effective in dealing with odor absorption when combined with the HEPA filter technology described above, allowing users to pull out smoke or pet odors from the air that might otherwise linger with traditional filters. Over time, odors and their accompanying residues can collect in rugs and on furniture, so looking for activated carbon or charcoal is an important consideration if you’re a smoker or a pet owner.

Do you want smart features?

Most air purifiers have manual controls—turn a dial or press a button to turn it off, on, and switch modes or set timers. Then there are “smart” units that allow you to do all of that via a smartphone app or your favorite voice control system, such as Alexa. But some of the smartest air purifiers do much more. They can report on air quality status, offer up-to-the-minute notifications if certain particulate matter spikes, and even make automatic adjustments to the airflow if needed. Reporting when an air filter is reaching the end of its life adds another dimension of convenience to some smartphone-enabled models, which can prove to be indispensable since it’s not particularly easy to judge the life of a filter simply by looking at it, and because you don’t want to throw it out if it’s still able to do its job.

Are you going to run the air purifier while you sleep?

Air purifiers use onboard fans to pull contaminants through an intake and force it through the filter and out to the other side, a process that can get noisy depending on the settings and size of the fan. While the level of this noise can generally be considered ambient, some can be quite a bit louder than others.

Noise, or sound power, is measured in decibels and is an effective way of gauging the noise introduced by home appliances in relation to other common residential sounds. A refrigerator’s noise runs on average at 50 decibels, while a whispering conversation hovers around 20 decibels. If you are to be using the air purifier in an office or living room where conversations are occurring, a louder setting may not be disruptive at all and may generally go unnoticed. However, placing this same purifier with these settings in a bedroom while trying to sleep may be much too loud. In sleeping situations, a quieter air purifier on a less powerful setting isn’t only recommended, but it may also be all that you need to keep the air clean overnight due to there being limited activity in a small room like a bedroom.

The best air purifiers on Amazon

Best air purifier for large spaces: Coway Airmega 400 Smart Air Purifier

Go Big In Your Home

Five fan speeds, LED status indicators, and multiple timer settings round out this unit. Amazon

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The Coway Airmega 400 HEPA air purifier can sweep the air in a 1,560-square-foot area free of pollutants twice in one hour, using a combination of activated carbon and HEPA filtration to reduce accumulations of chemicals and odors. It includes a washable pre-filter to trap larger dust particles before the air hits the HEPA filter.

Best air purifier for small spaces: Bissell MYair

Tiny And Mighty

A set with each perfect for a space up to 100 square feet in size. Amazon

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Bissell’s MYair air purifier is an easy-to-use unit that utilizes three-layered filters that include an activated carbon layer to facilitate the removal of VOCs and odors. It operates in high, low, and sleep fan speed modes, making this a great choice for leaving on overnight in a bedroom.

Best air purifier for smokers: Alen FLEX Air Purifier

Breath Easy

Cleans 800 square feet in 30 minutes, while boasting below-average power consumption. Amazon

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This air purifier from Alen features a “lights-out” mode for sleeping as well as three interchangeable models of proprietary filters. The “Pure” tier of filter is fine-tuned for removing dust, mold, and dander from your air, while the “Fresh” and “Smoke” models of filter employ varying quantities of activated carbon to remove excess smoke and pet odors from the air.

Best air purifier for pet odors: Bissell Smart Purifier with HEPA and Carbon Filters

For A More Pleasant Atmosphere

Three stages of filtration, including an activated carbon filter, allows this unit to clear the air of 99.97% of 0.3-micron particles as well as VOCs and animal odors. Amazon

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Ease of use and flexibility are the hallmarks of this smart purifier from Bissell, which sports a subtle design like a discreet cord wrap and a front-loading mechanism. The CirQulate tech onboard automatically adjusts the fan speed as needed depending on the air quality, filtering rooms up to 800 square feet in an hour.

Best smart air purifier: LEVOIT Smart Wi-Fi Air Purifier

Most Intelligent Controls

Works with Alexa and Google Home over any 2.4-gigahertz WiFi network. Amazon

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This air purifier from Levoit is fully smartphone-controllable and uses a prefilter, carbon honeycomb filter, and HEPA filter in concert to pull allergens and odors from the air with four-speed modes as well as an automatic mode. Air filter and air quality notifications as well as timer and automation settings are all accessible via the app as well.

Best bedroom air purifier: Molekule Air Mini+

For Uninterrupted Slumber

Uses proprietary nanoparticle-coated filters to destroy viruses and bacteria after trapping. Amazon

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The Molekule Air Mini+ runs at a whisper-quiet 30 decibels in silent mode, making it one of the best purifiers for bedrooms. This Molekule air purifier is designed to clean air in spaces up to 250 square feet, and is controllable with a phone app.

Best budget air purifier: RENPHO Air Purifier

Affordable and Effective

This model covers the basics of air filtration without the extra features.

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When the ultimate goal is to breathe clean air free of potentially harmful particles, an air purifier is probably not the best place to skimp. Still, there are a few budget models available that can provide some degree of improvement at the expense of some of the flexibility and user-friendliness of the other models featured here. Quiet modes, which are essential for sleeping, tend to be a little louder on these budget-friendly units, and you generally won’t find smart features or monitoring.

Best air purifier brands to know

The air purifier market is occupied by a variety of companies based in every corner of the world. Some of these brands have their roots in environmental entrepreneurship, and others are dedicated to the whole gamut of home care, but they all share the same goal of ensuring that their customers can maintain their health and breathe the best air they can.

Blueair

The Blueair air purifier brand was founded by Swedish entrepreneur Bengt Rittri in 1996 and achieved sales in over 60 countries before being acquired by consumer goods company Unilever in 2016. Rittri now heads up Bluewater, a water purification products company that uses patented osmosis technology to enable local purification of water with the goal of eliminating the need for plastic and long-distance transport.

Coway

Coway is a Korean appliance company founded in 1989 by former Encyclopedia Britannica salesman Yoon Seok-geum. The company rose to prominence through the rental of water purification systems and has since developed air purifiers, massagers, bidets, and mattresses. Coway currently holds the top spot in the Korean market for air and water purification based on market research data from 2017.

Levoit

Levoit was founded in California in 2017 and is currently headquartered in Anaheim. In addition to air purifiers, the company also sells salt lamps, humidifiers, and yoga products like mats and towels. The company designs their purifiers with a “top-grid” spiral shape which they claim assists in spreading air up to 40% faster than traditional designs.

The last word on the best air purifiers

Just about anyone spending time indoors can benefit from an air purifier’s ability to eliminate the most common indoor pollutants like dust and mold. Taking into account some models’ ability to filter out more harmful and more insidious particles like viruses and VOCs, an air purifier can be one of the easiest and most subtle ways to improve your daily quality of life.