Buying guide for Best air purifiers
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Between wildfires, pollen and air pollution, air quality ranks high among our everyday health concerns. With all the sources of bad air, opening a window could make the situation worse. A reliable air purifier can help solve your indoor air concerns.
An air purifier is basically a fan and a series of filters in one tightly sealed unit. As the fan draws air in, the filters remove particulate matter (PM) such as dust, smoke, pollen, dander, mold spores, and more. The cleaned air is then expelled back into the room. Although the U.S. Environmental Protection Agency (EPA) neither recommends nor cautions against using an air purifier in the home, it agrees air purifiers can improve indoor air quality.
Air purifiers can remove particles smaller than 2.5 microns (PM2.5) that are of the greatest concern. Activated carbon filters also extract volatile organic compounds (VOC), including fumes and odors. High-efficiency particulate air (HEPA) filters trap many but not all airborne microorganisms, including the H1N1 influenza virus and SARS-CoV-2 virus that causes COVID-19, although they shouldn’t be relied upon to protect against the diseases. Air purifiers do not help with carbon monoxide (CO) or radon (Rn). Air purifier filters need to be replaced regularly to remain effective.
When shopping for an air purifier, look for the clean air delivery rate (CADR) in cubic feet per minute (CFM). This is the volume of air cleaned per minute. The higher the CADR, the larger the space an air purifier can clean effectively. There are CADRs for smoke, dust and pollen, but since smoke particles are the smallest, the smoke CADR number is a quick way to rate an air purifier’s overall effectiveness.
We’ve researched and tested air purifiers, and we think the Blueair Bedroom Air Purifier is the best device for most people, while the Levoit Air Purifier for Home provides excellent performance for the price.
Expert tip
Take care to place your purifier in a room with adequate space all around it for the best air exchange.
BestReviews Home Improvement and DIY Expert
Best air purifiers
The Blueair air purifier has a stylish fabric prefilter that comes in a choice of subtle colors and an intuitive single-button control. Beneath its simple chassis is a powerful air purifier with a smoke CADR of 250 CFM, which can fully exchange the air in a 388-square-foot room every 12.5 minutes, or 4.8 changes per hour (a standard measure for air purifiers).
The soft fabric prefilter captures pollen and dander, while the HEPA and activated carbon filters remove 99.97% of PM2.5 and absorb VOCs and cooking odors. It boasts three speeds and a sensor-based automatic mode, while an LED indicator light changes color when it detects bad, medium or good air quality. Sleep mode turns off all the device’s lights and reduces the noise level to a low 23 decibels (dB). Replacement filters cost around $25 for every six months of 24/7 use.
This Levoit air purifier offers the best bang for your buck in our opinion. It has a CADR rating of 141 CFM that changes the air in a small 219-square-foot room like a bedroom or bathroom five times per hour. The air purifier has a washable prefilter for dander and larger particles, an H13 HEPA filter for particulates, and an activated carbon filter for VOCs and odors. Designed for small spaces, it’s 14.2 inches tall and 8.7 inches wide, and it works well on a nightstand or table.
We evaluated this device in our Testing Lab and found it to be an effective performer in multiple situations. Levoit sells four different filters for this model, including ones designed for wildfire smoke and pet allergens. Filters cost about $30 every six to eight months if used 24/7.
The Medify, available singly or in a two-pack, is another great air purifier that can clean the air in a 500-square-foot room twice in an hour. Slightly smaller than the Levoit, it can live on a tabletop or side table, but its dual filters give it the power and coverage of the Blueair with a similar CADR of 250.
Each of its two filters has a prefilter, HEPA H13 filter and activated carbon filter, and the three-speed fan can run as low as 25 dB, so it won’t disturb your sleep. The Medify has a sleek touch panel control and display and looks good in your home. The filters cost $50 for two and should be replaced every three to four months of continuous use.
The GermGuardian is a tall, slender tower air purifier with a smoke CADR of 108. It hits the desired five air changes an hour in a small room of around 167 square feet. This device features a HEPA filter and activated carbon filter, but it also bathes the air that passes through it in germicidal UVC light. UVC is a form of ultraviolet light that’s used in industrial air duct systems to kill most viruses, bacteria and other microorganisms. Notably, UVC is able to destroy the outer coating of the SARS-CoV-2 coronavirus.
Filters for the GermGuardian cost $35, and if the device runs continuously, they need to be replaced every six to eight months.
AirDoctor’s classic model has a CADR of 336 and can achieve four air exchanges an hour in a spacious 630-square-foot area like a combined living/dining room. AirDoctor promotes its proprietary “UltraHEPA” filter, which claims to trap particles down to 0.003 microns, a hundred times smaller than PM2.5. AirDoctor also promotes its carbon/gas trap combo filter that captures odors and VOCs including formaldehyde.
AirDoctor has four models to choose from for small to large spaces. Depending on which model you choose, the special filters cost $45 to $125. The combo carbon/gas/VOC filter needs changing every six months of continuous use, and the UltraHEPA filter should be swapped once a year.
Coway’s Airmega has a smoke CADR of 233 and makes 4.8 air exchanges an hour in a room of 388 square feet, or two per 847 square feet. The glossy, rounded cabinet looks both futuristic and retro, and it contains a HEPA filter and carbon filter for particulates, odors and VOCs. You can set a timer to turn the Airmega off automatically in one, four or seven hours, and the filter indicator lights let you know when it’s time to change the filters or wash the prefilter. Coway recommends changing the carbon filter every six months of 24/7 use and the HEPA filter once a year. It sells a combo pack of one HEPA and two carbon filters for $60.
Like the Coway Airmega, this tried-and-true Honeywell model has been around for a while thanks to its dependable performance. It is Energy Star certified to be efficient to run. With a smoke CADR of 300, it can achieve 4.8 air exchanges per hour in 465 square feet, or a whole house of 2,250 square feet once an hour. Its turbo mode makes quick work of a smoky space.
Featuring an automatic shut-off timer you can set for two, four or eight hours, the Honeywell air purifier has a combined prefilter and carbon filter for odors and VOCs and a HEPA filter for particulates and (nonliving) allergens. Genuine Honeywell filters cost around $25 each and usually come in a $75 three-pack, but they only need changing annually if the device is run continuously.
If you’ve got an Echo speaker or other Amazon device, the Winix Wi-Fi Air Purifier may be the model for you. Wi-Fi capable, this tall air purifier responds to Alexa voice control when connected to an Amazon hub. It’s got a solid 230 smoke CADR for 4.8 air exchanges per hour in a room of 360 square feet. The device includes a fine mesh prefilter, activated carbon filter and HEPA particle filter.
This device also has what Winix calls “PlasmaWave Air Cleaning Technology” that uses ionization to help clean the air. Though ionization creates ozone, this model is on the CARB-certified safe list. Aside from Alexa, you can also control it using the Winix smartphone app. A set of four carbon filters and one HEPA filter, which will last a year, costs $80.
Compared to other Blueair models, this device is the big sibling designed for large spaces. It has a smoke CADR of 353 and achieves 4.8 air exchanges per hour in a roomy 550 square feet. This Blueair has a 360-degree air intake for impressive airflow. Like on the smaller models from this company, the fabric prefilter is washable.
Aside from particulates and VOCs, the Blueair claims to capture 99.99% of SARS-CoV-2 viruses in the air. It is Energy Star certified and won’t exceed 38 watts even at high power. The replacement filters cost $70 and should be changed every six to 12 months.
Expert tip
Mark your calendar for a weekly washing of pre-filters. Doing so adds to the longevity of HEPA and carbon-activated filters.
BestReviews Home Improvement and DIY Expert
How we tested
The BestReviews Testing Lab reviews products in real-world usage. For this buying guide, we bought the Levoit Air Purifier for Home and examined it based on the following criteria.
First impressions
- Setup: We noted the setup process from opening the packaging to the first use. We graded it on difficulty, number of steps, technical knowledge required and whether it would be simple for the average person.
- Product quality: We evaluated the product’s look and feel, aesthetic appeal and quality of its materials and construction.
Operation
- Air quality: This is the most important feature. We set up the unit in different rooms and ran it 24 hours a day, seven days a week, to see if it made a perceptible difference in air quality.
- Room size: We used the unit in rooms of different sizes to see how well it performed at its rated square footage and higher.
- Fan speed: We operated the unit at all the fan speeds it offers and noted its performance at each level.
- Noise level: We noted how loud the unit was at various fan speeds and whether or not it would interrupt sleep or conversation.
- Ease of use: We observed how easy the controls were to understand and use, including any smart apps or assistants, as well as timers and automatic on/off.
Maintenance
- Filters: We checked the price of replacement filters and how simple or difficult it was to change them.
Tips for using an air purifier
- Run the air purifier at top speed for an hour. For best results, run your air purifier at its maximum speed for 60 minutes to make a real difference in a room. Afterward, you can switch it to a lower fan speed, but keep it running continuously for the best air quality.
- Keep the space clear around the air purifier. For the best performance, place the air purifier as close to the center of the room as possible. Some devices work well on the floor, while others work better on a table. Give the air intake enough clearance to draw in air, avoiding curtains, pillows and other items that may block in the airflow.
- Clean the prefilter. The prefilter catches the pet hair, dust bunnies and other large particles before they reach the other filters. Regularly vacuuming or washing the prefilter extends the life of the other filters and keeps the air purifier running efficiently.
- Avoid filters labeled “HEPA-type.” Some brands use the term “HEPA-type” to refer to filters that act like HEPA filters but don’t actually meet the HEPA specification of the U.S. Department of Energy. Those that do meet the official HEPA spec are marketed as “True HEPA” filters, although that isn’t an official term.
Expert tip
Consider ordering filters in bulk if possible to save money.
BestReviews Home Improvement and DIY Expert
FAQ
Q. How much do air purifiers cost?
A. Home air purifiers cost anywhere from $50 to $1,000. However, air purifiers that cost less than $100 are either too small or can be of poor quality from less reputable manufacturers. Good air purifiers from reputable brands, with solid CADR numbers and realistic square foot coverage, cost $100 to $400. The range of $200 to $250 is the sweet spot for size and performance. It’s a good idea to find out how much the replacement filters cost, and how often they need to be changed. Manufacturer recommendations are typically based on running an air purifier continuously 24 hours a day, seven days a week.
Q. Do air purifiers really work?
A. Air purifiers really work for what they’re designed to do. According to the EPA, “research shows that filtration can be an effective supplement to source control and ventilation,” and that a “portable air cleaner with a high CADR and an activated carbon filter can filter both particles and gasses.” However, the EPA also emphasizes that “no air cleaner or filter will eliminate all of the air pollutants in your home.” Ventilating with fresh outdoor air and removing sources of pollution are always recommended first, whenever practical.
Q. Is it worth getting an air purifier?
A. If you live in an area that frequently enjoys fresh outdoor air and your home is well ventilated, you may not need an air purifier or need to run one continuously. However, if you live in an area vulnerable to air pollution, including cities, near major roads or airports or in areas downwind of wildfire, you probably need an air purifier, especially when the outdoor air quality index (AQI) is poor. Pet owners also will benefit from using a pet vacuum in addition to an air purifier. If you have health concerns related to breathing or lung disease, an air purifier may help.
Q. Can I use an air ionizer instead of an air purifier?
A. An air ionizer can help reduce the number of particulates in the air and may help with some airborne germs. However, it won’t actually remove the particulates unless it has some sort of air purifier components, like a fan and filter. Some air purifiers do have an ionization function.
Q. Can I use an ozone generator instead of an air purifier?
A. No! Ozone (O3) is helpful in the stratosphere to block ultraviolet rays, but at ground level, it’s a harmful pollutant. Ozone generators are sometimes used by professionals, for example, to remedy smoke damage from a fire, but ozone by itself does nothing about particulate matter or other pollutants. According to the EPA, you should never stay in the same room as an ozone generator.
