According to the Environmental Protection Agency, the air inside your home may be more polluted than the air outdoors, even if you live in a large city center. One way to improve your air quality indoors is by using an air purifier — they can filter air contaminants like dust, pollen and smoke.
NBC Select staffers have used air purifiers for years to filter dust, pet dander, wildfire smoke and more. That’s why we spoke with filtration experts — to better understand air quality, and learn everything you need to know to buy the best air purifier.
SKIP AHEAD The best air purifiers in 2024 | How to shop for an air purifier
Selected.Our top picks
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We spoke with filtration experts to understand the importance of air quality and purification methods. Using their guidance, we selected top-rated air purifiers with at least a four-star average rating based on the following criteria:
- Filtration: All of our recommendations have high-efficiency particulate air filtration (HEPA) and have a clean air delivery rate (CADR) equivalent of at least two-thirds the recommended room size. (You can learn more about HEPA and CADR in our FAQ section.)
- Independent testing: We only picked air purifiers independently tested by the Association of Home Appliance Manufacturers (AHAM), which certifies the performance of air purifiers through its AHAM Verifide program.
- Adjustability: We only picked air purifiers with at least three adjustable speed levels. Air purifiers can be loud at their highest speed — having a lower speed option is crucial for keeping spaces like bedrooms quiet, in my experience.
Most of our recommendations are either staff favorites or top-rated products from longtime air purifier brands like Blueair and Honeywell.
Below each recommendation we share specifications like recommended room size according to AHAM, decibel levels and clean air delivery rate (CADR).
Editor’s Pick: Blueair Pure 511
What we like
- Small and quiet
- Fabric pre-filter
- Affordable
Something to note
- Nothing to note at this time
NBC Select commerce editor Lindsay Schneider received this air purifier from the brand when it launched in 2023 and promptly bought herself a second one after seeing all the dust it collected inside her 400 square foot NYC apartment. It’s one of the smallest and lightest purifiers on our list — it fits easily into any sized space.
The purifier pulls unfiltered air from all directions into its base and pushes clean air out of the top. It has a machine-washable fabric mesh cover that catches larger clumps of dust, lint and hair — it’s easy to take off and put back on, in my experience.
The Pure 511 strikes a great balance between room size, CADR and price, though it does not have any smart connectivity features. It’s best for small to medium-sized spaces no larger than 180 square feet, according to AHAM.
Recommended room size (AHAM): 180 sq. ft. | Decibels: 24 — 49 dB | CADR (CFM): smoke: 112, dust: 112, pollen: 112 | Connectivity: n/a | Speeds: 3 | Weight: 4.2 lbs | AHAM verified: Yes
For small spaces: Instant AP 100
What we like
- Small and portable
- Smart auto mode
Something to note
- Low CADR
NBC Select associate updates editor Zoe Malin has used this compact air purifier for years. “I love that it’s totally hands-off — it senses the air quality in your room and adjusts settings accordingly,” she says. This feature, called auto mode, is rare in air purifiers at this price.
Another standout feature is the light sensor. When Malin turns off the lights in her apartment, the air purifier automatically dims its display lights and reduces its speed to its quietest setting, which is about as loud as a bedroom fan, says Malin.
This air purifier is best for smaller bedrooms and offices no larger than 126 square feet, according to AHAM.
Recommended room size (AHAM): 126 sq. ft. | Decibels: 24 — 50 dB | CADR (CFM): smoke: 81, dust: 85, pollen: 98 | Connectivity: n/a | Speeds: 3 | Weight: 8 lbs | AHAM verified: Yes
For large spaces: Blueair Pure 311i+ Max
What we like
- Great filtration
- Fabric pre-filter
- Smart connectivity
Something to note
- Nothing to note at this time
I received the Blue Pure 311i+ Max from the brand and have been using it in my large bedroom for years, including during 2023’s Canadian wildfire season. On the day of some of the worst air pollution in NYC, the NBC Select office smelled like a BBQ, but my apartment, which was running this air purifier, smelled completely normal.
Similar to our editor’s pick, it pulls unfiltered air from all directions into its base — I have mine near the corner of my bedroom. During the spring allergy season, I usually wake up with a stuffy nose or I end up sneezing. With this air purifier, I rarely had to deal with either symptom.
I usually keep it on speed 1 or night mode, where it is very quiet — it only adds one or two decibels to the general ambience of my bedroom, increasing noise from 32 dB to 34 dB (according to a decibel reader on my phone).
I also like the 311i+ Max’s fabric pre-filter. It catches large clumps of lint and dander, and is easy to remove, wash and re-install.
You can control it manually or with the Blueair app, where you can see detailed stats like indoor air quality and filter status. I use the app to set a schedule for the purifier — it automatically changes to night mode, the lowest and quietest speed, every evening around 9 PM.
Recommended room size (AHAM): 465 sq. ft. | Decibels: 23 — 50 dB | CADR (CFM): smoke: 300, dust: 300, pollen: 300 | Connectivity: Yes, Blueair app | Speeds: 4 | Weight: 7.9 lbs | AHAM verified: Yes
For powerful performance: Honeywell HPA304
What we like
- High CADR
- Large room size
Something to note
- Large and heavy
This air purifier is a good fit if you need strong filtration for a large space. According to AHAM lab results, it has a very high CADR (especially for its price), meaning it can filter out air contaminants quickly and effectively. It also has a 4.6-star average rating from over 31,000 reviews on Amazon.
It has four speed modes: low, medium, high and turbo. If you plan to put this in a bedroom, use the dimmer button to turn off the panel lights on top of the purifier. It also has a timer button for intervals of two, four and eight hours.
Unlike the Blueair Pure 311+ Max, this purifier does not have an auto mode, a companion app or a night mode.
Recommended room size (AHAM): 465 sq. ft. | Decibels: Undisclosed | CADR (CFM): smoke: 300, dust: 320, pollen: 300 | Connectivity: n/a | Speeds: 4 | Weight: 17 lbs | AHAM verified: Yes
For a stylish design: Bissell Air320
What we like
- Elevated design
- Rear cord wrap
Something to note
- Nothing to note at this time
The Bissell Air320 has a sleek design that looks more like a modern piece of furniture than an air purifier. It stands elevated off the ground on four wooden legs, making it easier for you (or a robot vacuum) to clean underneath it. In the same vein, the power cord can also be tucked out of the way using the wrap-around slot on the back.
Instead of touch buttons, the Air320 has a single dial that controls speed and indicates filter status. Like our editor’s pick, this purifier has a fabric cover that captures larger particles of dust and hair, according to the brand.
Recommended room size (AHAM): 363 sq. ft. | Decibels: Undisclosed | CADR (CFM): smoke: 234, dust: 247, pollen: 264 | Connectivity: No | Speeds: 5 | Weight: 19.2 lbs | AHAM verified: Yes
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Air purifiers are designed to remove indoor air pollution caused by fuel-burning appliances, cleaning products, heating and cooling systems, car pollution, wildfire smoke and everything in between. These indoor contaminants can enter your lungs and cause irritation or trigger allergic reactions, says Kenneth Mendez, president of the nonprofit Asthma and Allergy Foundation of America.
Filtration is key when choosing an air purifier. Our experts highlight two factors in getting effective filtration: HEPA filters and an appropriate CADR.
Frequently asked questions
HEPA (high-efficiency particulate air) filters are made of pleated fibers and can remove at least 99.97% of airborne particles (like dust or pollen) that are 0.3 microns in size, according to the EPA. The EPA specifically measures this size of micron because it is the hardest to catch — other sized particulars are filtered at an even higher rate.
But HEPA isn’t a centrally regulated standard, says Michael Corbat, vice president of engineering for Rensa Filtration and former president of the National Air Filtration Association. It’s up to brands and third-party laboratories to test and disclose accurate filter data, he says.
Shoppers are reliant on manufacturers to perform and report on these filter tests accurately, according to our experts. Rather than rely on decentralized testing and manufacturer claims, our experts recommend checking each air purifier’s CADR.
CADR (clean air delivery rating) is an indicator of how well an air purifier will clear a given space of contaminants (measured in cubic feet per minute). Brands will indicate CADR for contaminants like tobacco smoke, dust or pollen. For example, a pollen CADR of 125 means that the air purifier can deliver 125 cubic feet of pollen-free air per minute.
According to AHAM, your air purifier should have a CADR rating equal to about two-thirds of the cubic feet of your space. CADR tests assume an eight-foot ceiling, so if you have a higher ceiling, you’ll need an air purifier with an even higher CADR.
Corbat recommends air purifiers with tested and certified CADRs from AHAM, otherwise, you are relying on the manufacturer’s self-reporting. That’s why all of our picks are AHAM certified, and we include AHAM’s recorded CADR scores in each product recommendation.
A decibel (dB) is a measurement of sound — a ticking watch is around 20 dB, a soft whisper 30 dB and a motorcycle 95 dB. According to the Center for Disease Control (CDC), prolonged exposure to sound above 70 dB can bother you, while sound above 90 dB can damage your hearing, depending on how long it lasts.
It is largely up to the manufacturers and third-party laboratories to test and disclose accurate sound data around air purifiers. In our guide to the best quiet air purifiers, we recommend cross-checking advertised air purifier decibel levels with data from consumer groups like Quiet Mark, a UK-based independent global certification program that identifies the quietest products.
A smart or Wi-Fi-compatible air purifier can typically connect to a smartphone app where you can control the machine remotely. You can control the Blue Pure 311i+ Max with the Blueair app, for example, and adjust speeds, brightness or set a schedule.
I find smart connected air purifiers convenient — I can use my phone from the comfort of my couch or bed to adjust the purifier or check my indoor air quality.
At NBC Select, we work with experts who have specialized knowledge and authority based on relevant training and/or experience. We also take steps to ensure all expert advice and recommendations are made independently and without undisclosed financial conflicts of interest.
- Kenneth Mendez is the president of the nonprofit Asthma and Allergy Foundation of America.
- Michael Corbat is the vice president of engineering for Rensa Filtration and former president of the National Air Filtration Association.
Harry Rabinowitz is a reporter at NBC Select who covers technology including guides to smartwatches, portable air conditioners, and over-ear headphones. For this piece, he spoke with filtration experts to better understand air purifiers and how they function. He leveraged his and NBC Select staff experience using air purifiers to recommend the best ones certified by AHAM.
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