The best air purifiers improve indoor air quality, filter out pollutants, dust, and smoke, and help with asthma or allergies. We tested 30 models.
When you buy through our links, Business Insider may earn an affiliate commission. Learn more
Blueair; Honeywell; Levoit/ Business Insider
Sneeze attacks, a runny nose, itchy eyes, or a cough that doesn't want to go away. These are just some symptoms those of us sensitive to irritants and allergens must put up with when mold, dust, smoke, chemical emissions, and dander are in the air. When thoroughly cleaning your home and keeping your windows don't get the job done, the best air purifiers can help remove allergy triggers and leave you breathing easily.
I interviewed three experts and tested over 30 units to find the best air purifiers that will improve air quality. Our top pick is the Honeywell PowerPlus HEPA Air Purifier; it removed the most pollutants, allergens and VOCs in our tests and operated quietly. For a budget option, consider the Lasko LP300 HEPA Tower Air Purifier. It's well under $100 with low filter replacement costs, though it's best for small rooms.
Learn more about how Insider Reviews tests and researches home products.
Best overall: Honeywell PowerPlus HEPA Air Purifier - See at The Home Depot
Best budget: Lasko LP300 HEPA Tower Air Purifier - See at Amazon
Quietest: Blueair HealthProtect 7470i Smart Air Purifier - See at Amazon
Best for small rooms: Levoit 300S Air Purifier - See at Amazon
Longest-lasting filter: Shark NeverChange Air Purifier Max - See at Amazon
The Honeywell PowerPlus HEPA Air Purifier (model number HPA3300) was the top model when looking at the combined performance in our volatile organic compound (VOC) and particulate matter testing. A little over an hour into our test, it had removed 99% of the particulate matter and the VOC levels were among the lowest at the end of the testing period. While it hasn't specifically been certified by AAFA, these numbers suggest this is an excellent air purifier for allergy sufferers and for people sensitive to other irritants.
Setup was quick and intuitive — I just removed the packaging and plug the unit in. And there's little maintenance. Just wipe the unit down with a dry cloth every three months. When the filter indicator light turns on (approximately once a year) replace the three true HEPA filters, which are widely available and cost $89.95 yearly.
James Brains/Business Insider
The HPA3300 isn't without its negatives. First, it's one of the loudest models we tested. When on low fan speed, it's no louder than the surrounding noise, but on high, it registered 58.9 decibels (dB), which is about as loud as a normal conversation. At over 20 pounds, it isn't as portable, though it does have a handle to help with transport.
That said, it's similar to most models in power use and filter replacement costs, and we think its performance makes it the best air purifier overall, especially for allergy sufferers and for medium-to-large rooms.
Read our full review of the Honeywell PowerPlus Air Purifier.
The Lasko LP300 HEPA Tower Air Purifier is $65 cheaper than any other unit tested, has the lowest filter replacement cost, and, at under 10 pounds, doesn't feel like a heavy-duty appliance.
We found it performed just as well as models that cost three or four times as much. The Lasko air purifier quickly removed airborne dust and debris. With 30 minutes to spare in the testing period, our air quality monitor registered no particulate matter. Though its performance wasn't as impressive with VOCs, it did a good job keeping the levels in a safe range.
James Brains/Business Insider
Setup was straightforward and took about five minutes. The Lasko's light weight makes it easy to move around, so you can take it with you from room to room, which you may need to do since its low CADR makes it better suited for small rooms. If you need more oomph, consider the LP450, which is only $16 more and covers twice as much space.
The Lasko was one of the few units we tested that was louder than ambient sound levels, even when on low. At 45.6 dB on low, it was a little bit louder than a typical library. On high, it was only 51.6 dB.
The biggest negative of this model is that it uses a lot of power. This is likely due to its lack of an auto mode that adjusts with the air quality, which is another negative.
Filters are affordable and widely available, too, with an expected cost of $35.99 yearly.
The Blueair HealthProtect 7470i Smart Air Purifier is the quietest and most high-tech model we tested. On high speed, it's about as loud as a quiet office. On low, the 7470i is no louder than ambient sound.
The Blueair HealthProtect 7470i features a digital color touch screen that allows you to operate the appliance and track the temperature, humidity, and air quality for VOCs and three different particle sizes.
James Brains/Business Insider
The Blueair app (iOS and Android) puts the data and functions at your fingertips wherever you are, including the ability to set a schedule. It's also compatible with Alexa and Google Assistant. I found the app worked well for the most part, though there were times when the data readouts took up to an hour to refresh. Also, connecting to the app upon initial setup took a few tries, which added 10 minutes to the process.
The HealthProtect 7470i has a HEPA-type filter (see our FAQ for how this differs from a true HEPA filter) that looks like a partially open book and features an RFID chip that tracks the filter life. The filters are comparatively affordable, about $55 annually, and can be ordered in the app or through major retailers, including Amazon. Other than replacing the filter, the only other maintenance is occasionally vacuuming or washing the two prefilters.
In the air-quality tests, the Blueair purifier performed well. After the two-hour testing period, it had one of the lowest VOC readings, and it removed 99% of the particulate matter. The power consumption was about average among the units I tested, which is impressive considering the midrange CADR.
I found the Blueair HealthProtect 7470i is a little too unwieldy to easily move from room to room. At 27.2 pounds and without good handles, this is a purifier you'll want to keep in one spot.
The Levoit 300S Air Purifier is an excellent option for bedrooms and other small rooms because it has three layers of filtration. The pre-filter captures larger debris, including hair and pet dander; the true HEPA filter collects smaller airborne particles; and the carbon filter helps reduce VOCs and odors in the air.
The carbon filter's performance was evident in our testing as the Levoit 300S was among the best at removing VOCs. The purifier also did well with particulate matter, removing virtually all (99.2%) of it from the air during the testing period.
James Brains/Business Insider
The setup was a snap. I had the unit up and running in under 5 minutes and connected to the VeSync app (available for iOS and Android) in another five. The Levoit 300S is the most affordable WiFi-connected air purifier I've tested, and the smart functions work well. I could easily monitor and schedule it from anywhere, and the air quality readings were almost identical to the readings on our testing monitor.
The Levoit 300S is Energy Star-certified and has an auto mode that adjusts the fan speed based on the air quality. It proved to be one of the lowest energy consumers we tested.
Maintenance is minimal: vacuum the pre-filter once or twice a month and replace the filter every 6 to 8 months when the indicator light turns on. Filters are affordable and widely available, costing about $55 a year.
The noise level at high fan speed was average, a little louder than in a quiet office. But at low speed, it was no louder than ambient noise.
While most filters need to be replaced quarterly — and we've seen some filters last up to a year before needing to be changed —Shark takes long-lasting filters to the next level. The Shark NeverChange Air Purifier Max can last up to five years before you need to replace the filter, and when you do, that filter costs $90, which is significant because some filters cost that much just to run annually. The size of the room (up to 1,400 square feet) and the amount of time you run the unit will ultimately determine how much life you get out of the filter, but according to Shark, the five-year number is based on running the air purifier in a 300-square-foot room at the highest speed for 12 hours a day.
From a performance perspective, the Shark took less than 15 minutes to reduce the amount of particles from incense smoke in a 200-square-foot room by 90%. It's also one of the quietest models, just behind the Blueair: an unobtrusive 46 decibels when running on high, and ambient at other levels.
Camryn Rabideau/Business Insider
All controls are handled directly on the unit. The Shark NeverChange Air Purifier Max is not WiFi-equipped, but the LCD screen can show the clean air percentage, the cleanliness level of the pre-filters, or real-time particle count. You can also adjust the fan speed or let it run on Auto. It has one of the lowest energy uses, at about .08 kwh a day.
Despite minimal upkeep costs, it's not completely maintenance-free; two pre-filters, which catch larger particles like pet hair, need to be wiped or vacuumed periodically. The display screen shows a filter-life percentage and will alert you when the filters need cleaning.
Finally, the Shark NeverChange is a larger model, and while you can move it around from room to room, it won't be the most comfortable to do so. Shark also offers a smaller version rated for rooms up to 650 square feet.
Read our full Shark NeverChange Air Purifier Max review.
Over the last year, I've tested 30 air purifiers, and there are several that we almost included in our guide that are still worth considering:
Air purifiers under $250
Instant Air Purifier 300: The makers of the wildly popular Instant Pot have ventured out of the kitchen for the first time with this unit, and it's a great reasonably priced solution. It was one of the top removers of VOCs, didn't use much power, and was easy to clean and maintain. Yet it was one of the worst at removing particulate matter, and it operates loudly.
Coway Airmega AP-1512HH Mighty: We like this purifier because it adjusts the fan speed based on the air quality, which led to low power usage. However, in our tests, it was noisy, did poorly removing VOCs, and was just average at removing particulate matter. The Airmega Mighty has four stages of filtration: pre-filter, deodorization, true HEPA, and "vital ion" ionization. We don't recommend using the ionization function (see why in the FAQ). Fortunately, you can manually turn it off.
Brondell Horizon O2+: For how affordable this Brondell air purifier is, it did an outstanding job, and I'd recommend it if our top budget pick isn't available. It was one of the top removers of particulate matter in our tests and was easy to maintain and clean. The biggest negative is that it doesn't have an auto mode that adjusts the fan speed based on air quality. This would have been nice since it consumes a lot of power.
Air purifiers under $450
Coway Airmega 250: This is the best air purifier I've tested from Coway. The 250 was one of the best removers of particulate matter. It also used minimal electricity in our tests, thanks to the fan that adjusts based on the air quality. However, it didn't beat any of the models in the above categories, and it didn't perform well at removing VOCs from the air.
Mila: Mila is an affordable smart air purifier that has a variety of filter options (only available on the company's website) depending on what air quality issue you want to address. I tested the heavy-duty Overreactor, which is a hospital-grade H14 HEPA filter, and the Basic Breather. The Overreactor was in the middle of the pack in our air purifying tests. The Basic Breather was outstanding at removing particulate matter. But both operated loudly, and there wasn't anything else that made them stand out.
Blueair Blue Pure 211+ Auto: This is the updated version of the Blueair Blue Pure 211+, the top pick in our previous version of this guide. The main addition is an auto mode, which adjusts the filtering speed and intensity based on the air quality. We found it did a good job of filtering the air while using minimal electricity, but it was loud, and filters are expensive and only available on the Blueair website.
Air purifiers over $450
Alen Breathesmart 45i: This Alen air purifier relies on a medical-grade H13 true HEPA filter, which did an outstanding job of removing particulate matter from our test room. This model is also easy to set up, transport, and maintain. However, filter replacement will set you back about $140 per year, and it didn't do well reducing VOCs in the air.
Coway Airmega 400S: Our previous pick for the best smart air purifier, the Coway Airmega 400S is an attractive unit that barely makes any sound and adjusts the fan speed based on the air's pollution level, which lends itself to low energy use. It lost its title due to its average performance in our purifying tests and its smart features aren't as fancy as our smart pick from BlueAir.
RabbitAir MinusA2: If we had a "most visually appealing" category, this model would win. We weren't particularly impressed with how well it did cleaning the air. However, it was easy to set up and maintain. Plus, the filter replacement costs are reasonable.
PhoneSoap AirSoap: The biggest reason the AirSoap isn't in our guide is because it relies on ionization to clean the air, and there is no way to turn it off. In fact, we don't recommend ionizing air purifiers for most people (read why here). The benefits of ionization are questionable, and there's a risk of negative health issues due to the low levels of ozone the AirSoap produces. However, it did well in our air purifying tests, operates quietly, doesn't have filter replacement costs, and is easy to set up and transport.
Aura Air Mini: Like the AirSoap above, the Aura Air Mini relies on ionization to clean the air. It's unique in that it is only three inches deep and wide and 4.5 inches high. It runs for up to six hours on a single charge. It's designed to be used in small spaces, but we're not sure of the use cases. You wouldn't want to use it in public and potentially expose vulnerable individuals to ozone. And in your car, you already have a filtration system.
Dyson HP09: As a space heater, The HP09 does an outstanding job of heating and cooling rooms up to 800 square feet in size. The only problem is that it was one of the worst performers in our air purifying tests.
Honeywell Insight HPA5300B: I like the looks of this air purifier, and it's easy to maintain and has widely-available filters. However, it used a lot of electricity and is loud on high speed. Plus, its performance in the air purifying tests was unimpressive.
IQAir Atem: We were hoping this would be a good compact option, but it performed poorly in the air purifying tests and has high upfront and filter costs.
BetterAir Biotica800: The Biotica800 releases a probiotic mist for 30 seconds every 70 minutes. It runs quietly during those 30 seconds, and its electricity use was too low for our smart plug to register anything. However, if it does anything to clean the air, our air quality monitor didn't notice.
EnviroKlenz Air System Plus: This is the heaviest and least visually appealing purifier we tested. It's designed to take a beating and is used by the US Navy. However, it had the highest VOC reading at the end. It doesn't have an auto mode, used the most electricity, and has the highest filter costs of the bunch.
James Brains/Business Insider
I've been reviewing heating, cooling, and air-quality devices for the past three years. For this guide, I personally tested 30 air purifiers for at least one week each and consulted with Ravi Pandey, MD, an internal medicine specialist on staff at several South Florida hospitals; Junfeng Zhang, PhD, professor of global and environmental health at Duke University; and Bryan Buckley, the brand manager for One Hour Heating & Air Conditioning.
Based on my research and interviews with experts, the most important features to consider when shopping for an air purifier are its ability to remove irritants from the air, long-term costs, and ease of use.
Here are the main ways we test each model:
Purifying: I burned incense in a 200-square-foot room with the windows and doors closed and used an air-quality monitor to take measurements of the volatile organic compounds (VOCs) and particulate matter in the air every 15 minutes. After the incense burned for 15 minutes, I turned on the air purifier's auto mode, which adjusts the fan speed based on the air quality. If it didn't have an auto mode, I used the highest setting. I looked at both the percentage removed and the amount of VOCs and particulate matter left after two hours. For context, all of the recommended room sizes in our guide are calculated assuming an eight-foot ceiling and four air changes per hour (ACPH).
Setup: I timed how long it took me to set up the air purifier from the moment I opened the box until the unit was running. This includes connecting to an app when applicable. I made note of any unusual or confusing steps. Most models only required removing the packaging and plugging in the unit. This generally took five minutes or less.
Portability: I moved the air purifiers around my house making note of how easy they are to carry. If a model weighed more than 20 pounds or is hard to move in a tangible way, it lost points. Most units were easy to move and featured handles.
Long-term costs: Electricity and filter replacement are the biggest long-term costs. These can often outpace the upfront costs. I looked at how much a year's supply of filters costs and if they're widely available and not just on the manufacturer's website, which can make it hard to price shop. I also used a smart plug to measure the power consumption of each unit over the course of 24 hours under normal circumstances on the same setting I used for the purifying tests.
Noise: An air purifier's operation should not get in the way of hearing the TV, sleeping, or having a conversation. To test this, I used a sound meter to measure the air purifiers on their highest and lowest settings from four feet away. On low, most units were indistinguishable from ambient noise.
Maintenance: I cleaned each air purifier per the manufacturers' recommendations and noted how easy each model was to clean. I also noted whether there were indicators to let me know when to clean or replace the filter.
James Brains/Business Insider
An air purifier does what its name implies, cleaning odors, pollen, pet dander, and more from indoor air. According to the EPA, units with HEPA filters can improve symptoms of COPD and asthma sufferers and effectively remove ash and smoke particles.
The type of filter a purifier has determines what pollutants it can remove. HEPA filters are popular because they can remove smoke, pollen, bacteria, pet dander, dust, mold, and other particulate matter of 0.3 to 10 microns. Activated carbon filters can remove VOCs and other gases.
HEPA is an acronym for "high-efficiency particulate air." The EPA defines a true HEPA filter as a filter that captures at least 99.97% of airborne particles that are 0.3 microns in diameter. This includes bacteria, dust, pollen, and mold.
No, but we give preference to true HEPA filter air purifiers in our picks. The exception is the Blueair 7470i, which has a HEPA-type filter that performed just as well, if not better, than most true HEPA models.
True HEPA filters capture 99.97% of airborne particles that are 0.3 microns in diameter. According to the EPA, true HEPA filters can more easily catch particles larger or smaller than 0.3 microns. There's no standard for HEPA-type filters.
According to the EPA, air cleaners are not enough to protect against coronavirus. Yet, an air purifier can help protect you and your household when used with best practice recommendations from the Centers for Disease Control and Prevention.
Ravi Pandey, MD, a specialist in internal medicine in Florida, said HEPA air purifiers wouldn't eliminate the coronavirus. Still, they help, especially when used with mask-wearing, hand washing, and social distancing.
Bryan Buckley, the brand manager for One Hour Heating & Air Conditioning, suggested always keeping your air purifier running in one spot. He added that you need continuous air purification to clean the air and maintain good air quality levels.
Air purifiers are best in high-traffic areas, such as your kitchen, living room, or bedroom. A purifier is also excellent at removing smoke from cooking. Buckley said you should position the unit to blow clean air where people gather and close your windows during use.
It varies. Manufacturer guidelines range from every 3 to 24 months. We list the replacement schedule for the models in our guide. Follow the schedule in your air purifier's user manual for optimal efficiency and performance.
Probably not. The Journal of Exposure Science & Environmental Epidemiology published a study in 2019 showing that indoor vegetation did not remove air pollutants.
You can clean the air without a purifier by cleaning regularly, ventilating with fans, and storing chemicals outside of your house. Junfeng Zhang, PhD, professor of global and environmental health at Duke University, recommended wearing N95 masks in polluted areas.
If you cannot take steps to improve your indoor air quality by other means or the pollutants still seem to stick around, an air purifier is an intelligent choice. Even the worst air purifiers we tested improved indoor air quality.
Ionizers can generate ozone, a lung irritant. Enesta Jones, an EPA spokesperson, said even low amounts of ozone could cause shortness of breath, chest pain, throat irritation, and coughing. Because of this, we don't recommend any ionizing air purifiers.
Yes. Zhang recommended air purifiers with HEPA filters to improve indoor air quality in areas affected by wildfires. Air purifiers will be most effective if you keep windows and doors closed. Also, have purifiers in each room rather than moving one from room to room.
In this guide, we throw around a lot of terms you may not be familiar with. Here are a few definitions of terms and acronyms that are commonly used when talking about air purifiers:
CADR: Clean air delivery rate. Typically measured in cubic feet per minute or cubic meters per hour, the CADR tells you how much air an air purifier can clean.
cfm: Cubic feet per minute. This is the most common unit of measurement used to express how much air an air purifier can clean.
HEPA: High-efficiency particulate air. True HEPA or HEPA-type filters are generally considered to be the gold standard in the industry. For more details, see our FAQ section.
VOCs: Volatile organic compounds. These compounds have low water solubility and high vapor pressure. They are commonly produced in the manufacturing of refrigerants, pharmaceuticals, and paints and are often found in paints, craft materials, adhesives, markers, furniture, pesticides, cleaning supplies, and more.
James Brains/Business Insider
The Honeywell PowerPlus HEPA Air Purifier (model number HPA3300) was the top model when looking at the combined performance in our volatile organic compound (VOC) and particulate matter testing. A little over an hour into our test, it had removed 99% of the particulate matter and the VOC levels were among the lowest at the end of the testing period. While it hasn't specifically been certified by AAFA, these numbers suggest this is an excellent air purifier for allergy sufferers and for people sensitive to other irritants.
Setup was quick and intuitive — I just removed the packaging and plug the unit in. And there's little maintenance. Just wipe the unit down with a dry cloth every three months. When the filter indicator light turns on (approximately once a year) replace the three true HEPA filters, which are widely available and cost $89.95 yearly.
The HPA3300 isn't without its negatives. First, it's one of the loudest models we tested. When on low fan speed, it's no louder than the surrounding noise, but on high, it registered 58.9 decibels (dB), which is about as loud as a normal conversation. At over 20 pounds, it isn't as portable, though it does have a handle to help with transport.
That said, it's similar to most models in power use and filter replacement costs, and we think its performance makes it the best air purifier overall, especially for allergy sufferers and for medium-to-large rooms.
Read our full review of the Honeywell PowerPlus Air Purifier.
James Brains/Business Insider
The Lasko LP300 HEPA Tower Air Purifier is $65 cheaper than any other unit tested, has the lowest filter replacement cost, and, at under 10 pounds, doesn't feel like a heavy-duty appliance.
We found it performed just as well as models that cost three or four times as much. The Lasko air purifier quickly removed airborne dust and debris. With 30 minutes to spare in the testing period, our air quality monitor registered no particulate matter. Though its performance wasn't as impressive with VOCs, it did a good job keeping the levels in a safe range.
Setup was straightforward and took about five minutes. The Lasko's light weight makes it easy to move around, so you can take it with you from room to room, which you may need to do since its low CADR makes it better suited for small rooms. If you need more oomph, consider the LP450, which is only $16 more and covers twice as much space.
The Lasko was one of the few units we tested that was louder than ambient sound levels, even when on low. At 45.6 dB on low, it was a little bit louder than a typical library. On high, it was only 51.6 dB.
The biggest negative of this model is that it uses a lot of power. This is likely due to its lack of an auto mode that adjusts with the air quality, which is another negative.
Filters are affordable and widely available, too, with an expected cost of $35.99 yearly.
James Brains/Business Insider
The Blueair HealthProtect 7470i Smart Air Purifier is the quietest and most high-tech model we tested. On high speed, it's about as loud as a quiet office. On low, the 7470i is no louder than ambient sound.
The Blueair HealthProtect 7470i features a digital color touch screen that allows you to operate the appliance and track the temperature, humidity, and air quality for VOCs and three different particle sizes.
The Blueair app (iOS and Android) puts the data and functions at your fingertips wherever you are, including the ability to set a schedule. It's also compatible with Alexa and Google Assistant. I found the app worked well for the most part, though there were times when the data readouts took up to an hour to refresh. Also, connecting to the app upon initial setup took a few tries, which added 10 minutes to the process.
The HealthProtect 7470i has a HEPA-type filter (see our FAQ for how this differs from a true HEPA filter) that looks like a partially open book and features an RFID chip that tracks the filter life. The filters are comparatively affordable, about $55 annually, and can be ordered in the app or through major retailers, including Amazon. Other than replacing the filter, the only other maintenance is occasionally vacuuming or washing the two prefilters.
In the air-quality tests, the Blueair purifier performed well. After the two-hour testing period, it had one of the lowest VOC readings, and it removed 99% of the particulate matter. The power consumption was about average among the units I tested, which is impressive considering the midrange CADR.
I found the Blueair HealthProtect 7470i is a little too unwieldy to easily move from room to room. At 27.2 pounds and without good handles, this is a purifier you'll want to keep in one spot.
James Brains/Business Insider
The Levoit 300S Air Purifier is an excellent option for bedrooms and other small rooms because it has three layers of filtration. The pre-filter captures larger debris, including hair and pet dander; the true HEPA filter collects smaller airborne particles; and the carbon filter helps reduce VOCs and odors in the air.
The carbon filter's performance was evident in our testing as the Levoit 300S was among the best at removing VOCs. The purifier also did well with particulate matter, removing virtually all (99.2%) of it from the air during the testing period.
The setup was a snap. I had the unit up and running in under 5 minutes and connected to the VeSync app (available for iOS and Android) in another five. The Levoit 300S is the most affordable WiFi-connected air purifier I've tested, and the smart functions work well. I could easily monitor and schedule it from anywhere, and the air quality readings were almost identical to the readings on our testing monitor.
The Levoit 300S is Energy Star-certified and has an auto mode that adjusts the fan speed based on the air quality. It proved to be one of the lowest energy consumers we tested.
Maintenance is minimal: vacuum the pre-filter once or twice a month and replace the filter every 6 to 8 months when the indicator light turns on. Filters are affordable and widely available, costing about $55 a year.
The noise level at high fan speed was average, a little louder than in a quiet office. But at low speed, it was no louder than ambient noise.
Camryn Rabideau/Business Insider
While most filters need to be replaced quarterly — and we've seen some filters last up to a year before needing to be changed —Shark takes long-lasting filters to the next level. The Shark NeverChange Air Purifier Max can last up to five years before you need to replace the filter, and when you do, that filter costs $90, which is significant because some filters cost that much just to run annually. The size of the room (up to 1,400 square feet) and the amount of time you run the unit will ultimately determine how much life you get out of the filter, but according to Shark, the five-year number is based on running the air purifier in a 300-square-foot room at the highest speed for 12 hours a day.
From a performance perspective, the Shark took less than 15 minutes to reduce the amount of particles from incense smoke in a 200-square-foot room by 90%. It's also one of the quietest models, just behind the Blueair: an unobtrusive 46 decibels when running on high, and ambient at other levels.
All controls are handled directly on the unit. The Shark NeverChange Air Purifier Max is not WiFi-equipped, but the LCD screen can show the clean air percentage, the cleanliness level of the pre-filters, or real-time particle count. You can also adjust the fan speed or let it run on Auto. It has one of the lowest energy uses, at about .08 kwh a day.
Despite minimal upkeep costs, it's not completely maintenance-free; two pre-filters, which catch larger particles like pet hair, need to be wiped or vacuumed periodically. The display screen shows a filter-life percentage and will alert you when the filters need cleaning.
Finally, the Shark NeverChange is a larger model, and while you can move it around from room to room, it won't be the most comfortable to do so. Shark also offers a smaller version rated for rooms up to 650 square feet.
Read our full Shark NeverChange Air Purifier Max review.
James Brains/Business Insider
Over the last year, I've tested 30 air purifiers, and there are several that we almost included in our guide that are still worth considering:
Air purifiers under $250
Instant Air Purifier 300: The makers of the wildly popular Instant Pot have ventured out of the kitchen for the first time with this unit, and it's a great reasonably priced solution. It was one of the top removers of VOCs, didn't use much power, and was easy to clean and maintain. Yet it was one of the worst at removing particulate matter, and it operates loudly.
Coway Airmega AP-1512HH Mighty: We like this purifier because it adjusts the fan speed based on the air quality, which led to low power usage. However, in our tests, it was noisy, did poorly removing VOCs, and was just average at removing particulate matter. The Airmega Mighty has four stages of filtration: pre-filter, deodorization, true HEPA, and "vital ion" ionization. We don't recommend using the ionization function (see why in the FAQ). Fortunately, you can manually turn it off.
Brondell Horizon O2+: For how affordable this Brondell air purifier is, it did an outstanding job, and I'd recommend it if our top budget pick isn't available. It was one of the top removers of particulate matter in our tests and was easy to maintain and clean. The biggest negative is that it doesn't have an auto mode that adjusts the fan speed based on air quality. This would have been nice since it consumes a lot of power.
Air purifiers under $450
Coway Airmega 250: This is the best air purifier I've tested from Coway. The 250 was one of the best removers of particulate matter. It also used minimal electricity in our tests, thanks to the fan that adjusts based on the air quality. However, it didn't beat any of the models in the above categories, and it didn't perform well at removing VOCs from the air.
Mila: Mila is an affordable smart air purifier that has a variety of filter options (only available on the company's website) depending on what air quality issue you want to address. I tested the heavy-duty Overreactor, which is a hospital-grade H14 HEPA filter, and the Basic Breather. The Overreactor was in the middle of the pack in our air purifying tests. The Basic Breather was outstanding at removing particulate matter. But both operated loudly, and there wasn't anything else that made them stand out.
Blueair Blue Pure 211+ Auto: This is the updated version of the Blueair Blue Pure 211+, the top pick in our previous version of this guide. The main addition is an auto mode, which adjusts the filtering speed and intensity based on the air quality. We found it did a good job of filtering the air while using minimal electricity, but it was loud, and filters are expensive and only available on the Blueair website.
Air purifiers over $450
Alen Breathesmart 45i: This Alen air purifier relies on a medical-grade H13 true HEPA filter, which did an outstanding job of removing particulate matter from our test room. This model is also easy to set up, transport, and maintain. However, filter replacement will set you back about $140 per year, and it didn't do well reducing VOCs in the air.
Coway Airmega 400S: Our previous pick for the best smart air purifier, the Coway Airmega 400S is an attractive unit that barely makes any sound and adjusts the fan speed based on the air's pollution level, which lends itself to low energy use. It lost its title due to its average performance in our purifying tests and its smart features aren't as fancy as our smart pick from BlueAir.
RabbitAir MinusA2: If we had a "most visually appealing" category, this model would win. We weren't particularly impressed with how well it did cleaning the air. However, it was easy to set up and maintain. Plus, the filter replacement costs are reasonable.
PhoneSoap AirSoap: The biggest reason the AirSoap isn't in our guide is because it relies on ionization to clean the air, and there is no way to turn it off. In fact, we don't recommend ionizing air purifiers for most people (read why here). The benefits of ionization are questionable, and there's a risk of negative health issues due to the low levels of ozone the AirSoap produces. However, it did well in our air purifying tests, operates quietly, doesn't have filter replacement costs, and is easy to set up and transport.
Aura Air Mini: Like the AirSoap above, the Aura Air Mini relies on ionization to clean the air. It's unique in that it is only three inches deep and wide and 4.5 inches high. It runs for up to six hours on a single charge. It's designed to be used in small spaces, but we're not sure of the use cases. You wouldn't want to use it in public and potentially expose vulnerable individuals to ozone. And in your car, you already have a filtration system.
Dyson HP09: As a space heater, The HP09 does an outstanding job of heating and cooling rooms up to 800 square feet in size. The only problem is that it was one of the worst performers in our air purifying tests.
Honeywell Insight HPA5300B: I like the looks of this air purifier, and it's easy to maintain and has widely-available filters. However, it used a lot of electricity and is loud on high speed. Plus, its performance in the air purifying tests was unimpressive.
IQAir Atem: We were hoping this would be a good compact option, but it performed poorly in the air purifying tests and has high upfront and filter costs.
BetterAir Biotica800: The Biotica800 releases a probiotic mist for 30 seconds every 70 minutes. It runs quietly during those 30 seconds, and its electricity use was too low for our smart plug to register anything. However, if it does anything to clean the air, our air quality monitor didn't notice.
EnviroKlenz Air System Plus: This is the heaviest and least visually appealing purifier we tested. It's designed to take a beating and is used by the US Navy. However, it had the highest VOC reading at the end. It doesn't have an auto mode, used the most electricity, and has the highest filter costs of the bunch.
James Brains/Business Insider
I've been reviewing heating, cooling, and air-quality devices for the past three years. For this guide, I personally tested 30 air purifiers for at least one week each and consulted with Ravi Pandey, MD, an internal medicine specialist on staff at several South Florida hospitals; Junfeng Zhang, PhD, professor of global and environmental health at Duke University; and Bryan Buckley, the brand manager for One Hour Heating & Air Conditioning.
Based on my research and interviews with experts, the most important features to consider when shopping for an air purifier are its ability to remove irritants from the air, long-term costs, and ease of use.
Here are the main ways we test each model:
Purifying: I burned incense in a 200-square-foot room with the windows and doors closed and used an air-quality monitor to take measurements of the volatile organic compounds (VOCs) and particulate matter in the air every 15 minutes. After the incense burned for 15 minutes, I turned on the air purifier's auto mode, which adjusts the fan speed based on the air quality. If it didn't have an auto mode, I used the highest setting. I looked at both the percentage removed and the amount of VOCs and particulate matter left after two hours. For context, all of the recommended room sizes in our guide are calculated assuming an eight-foot ceiling and four air changes per hour (ACPH).
Setup: I timed how long it took me to set up the air purifier from the moment I opened the box until the unit was running. This includes connecting to an app when applicable. I made note of any unusual or confusing steps. Most models only required removing the packaging and plugging in the unit. This generally took five minutes or less.
Portability: I moved the air purifiers around my house making note of how easy they are to carry. If a model weighed more than 20 pounds or is hard to move in a tangible way, it lost points. Most units were easy to move and featured handles.
Long-term costs: Electricity and filter replacement are the biggest long-term costs. These can often outpace the upfront costs. I looked at how much a year's supply of filters costs and if they're widely available and not just on the manufacturer's website, which can make it hard to price shop. I also used a smart plug to measure the power consumption of each unit over the course of 24 hours under normal circumstances on the same setting I used for the purifying tests.
Noise: An air purifier's operation should not get in the way of hearing the TV, sleeping, or having a conversation. To test this, I used a sound meter to measure the air purifiers on their highest and lowest settings from four feet away. On low, most units were indistinguishable from ambient noise.
Maintenance: I cleaned each air purifier per the manufacturers' recommendations and noted how easy each model was to clean. I also noted whether there were indicators to let me know when to clean or replace the filter.
James Brains/Insider
An air purifier does what its name implies, cleaning odors, pollen, pet dander, and more from indoor air. According to the EPA, units with HEPA filters can improve symptoms of COPD and asthma sufferers and effectively remove ash and smoke particles.
The type of filter a purifier has determines what pollutants it can remove. HEPA filters are popular because they can remove smoke, pollen, bacteria, pet dander, dust, mold, and other particulate matter of 0.3 to 10 microns. Activated carbon filters can remove VOCs and other gases.
HEPA is an acronym for "high-efficiency particulate air." The EPA defines a true HEPA filter as a filter that captures at least 99.97% of airborne particles that are 0.3 microns in diameter. This includes bacteria, dust, pollen, and mold.
No, but we give preference to true HEPA filter air purifiers in our picks. The exception is the Blueair 7470i, which has a HEPA-type filter that performed just as well, if not better, than most true HEPA models.
True HEPA filters capture 99.97% of airborne particles that are 0.3 microns in diameter. According to the EPA, true HEPA filters can more easily catch particles larger or smaller than 0.3 microns. There's no standard for HEPA-type filters.
According to the EPA, air cleaners are not enough to protect against coronavirus. Yet, an air purifier can help protect you and your household when used with best practice recommendations from the Centers for Disease Control and Prevention.
Ravi Pandey, MD, a specialist in internal medicine in Florida, said HEPA air purifiers wouldn't eliminate the coronavirus. Still, they help, especially when used with mask-wearing, hand washing, and social distancing.
Bryan Buckley, the brand manager for One Hour Heating & Air Conditioning, suggested always keeping your air purifier running in one spot. He added that you need continuous air purification to clean the air and maintain good air quality levels.
Air purifiers are best in high-traffic areas, such as your kitchen, living room, or bedroom. A purifier is also excellent at removing smoke from cooking. Buckley said you should position the unit to blow clean air where people gather and close your windows during use.
It varies. Manufacturer guidelines range from every 3 to 24 months. We list the replacement schedule for the models in our guide. Follow the schedule in your air purifier's user manual for optimal efficiency and performance.
Probably not. The Journal of Exposure Science & Environmental Epidemiology published a study in 2019 showing that indoor vegetation did not remove air pollutants.
You can clean the air without a purifier by cleaning regularly, ventilating with fans, and storing chemicals outside of your house. Junfeng Zhang, PhD, professor of global and environmental health at Duke University, recommended wearing N95 masks in polluted areas.
If you cannot take steps to improve your indoor air quality by other means or the pollutants still seem to stick around, an air purifier is an intelligent choice. Even the worst air purifiers we tested improved indoor air quality.
Ionizers can generate ozone, a lung irritant. Enesta Jones, an EPA spokesperson, said even low amounts of ozone could cause shortness of breath, chest pain, throat irritation, and coughing. Because of this, we don't recommend any ionizing air purifiers.
Yes. Zhang recommended air purifiers with HEPA filters to improve indoor air quality in areas affected by wildfires. Air purifiers will be most effective if you keep windows and doors closed. Also, have purifiers in each room rather than moving one from room to room.
