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Best independently tested and certified air purifiers

Finding the right air purifier for your square footage can help clear your air of contaminants.
Check out these AHAM-approved air purifiers, along with expert tips on choosing one of your own.
Check out these AHAM-approved air purifiers, along with expert tips on choosing one of your own.Amazon ; Dyson

If you live in wildfire territory, or a smoggy city, you might feel that the air inside your house is cleaner, or safer than the air outside. However, the truth might surprise you: According to the Environmental Protection Agency, the air inside your home can be more polluted than the air outside. Air purifiers, which filter particles from the air, can help reduce indoor air contaminants that arise from everyday life.

SKIP AHEAD Best air purifiers | What is a HEPA filter? | What is CADR?

Air purifiers are designed to remove indoor air pollution from cooking, car emissions, or dust from wildfires, among other contaminants. These airborne particles enter your lungs, causing irritation or triggering allergic reactions, explained Kenneth Mendez, president of the nonprofit Asthma and Allergy Foundation of America. To help guide your search for an air purifier that best suits your needs and budget, we consulted health and filtration experts to learn more about air purifiers and what you need to know before buying one.

How to find the best air purifier for you

Experts agree that filtration is key when choosing an air purifier. There are two standards and testing procedures, HEPA and CADR, that help show how efficiently air purifiers clear the air in a room.

  1. High-efficiency particulate air (HEPA) filters: Every expert we spoke to agreed that HEPA is crucial for filtration, but HEPA isn’t a centrally regulated standard, so shopping for these filters can be complicated. That’s why experts recommend you shop for HEPA-level filtration and note each air purifier’s clean air delivery rate (CADR) which gives you more information about how well an air purifier will clear a given space of contaminants (including tobacco smoke, dust and pollen), its primary purpose. You can learn more about HEPA filters here.
  2. Clean air delivery rating, or CADR: The Association of Home Appliance Manufacturers (AHAM) works with independent laboratories to certify air purifiers that meet its standards. CADR tells you how much air (in cubic feet per minute) an air purifier can process within one minute. According to AHAM, your air purifier should have a CADR rating equivalent to about two-thirds the area of your space (in square feet). For more on HEPA and CADR, see our primer on HEPA and CADR filtration testing.

Best air purifiers

Since we don’t test air purifiers ourselves, we rely on expert guidance to recommend the best air purifiers. Aligning with that guidance, the air purifiers below are AHAM-approved and/or recommended by Consumer Reports. For each purifier, we list its capacity and efficiency rates, according to AHAM testing. We ordered them by their capacity in square feet.

Blueair Classic 605

In Consumer Reports testing, this air purifier was one of only four models tested that scored an “Excellent” for removing particles at both the highest and lowest speeds. The purifier uses the brand’s HEPASilent technology, which Blueair says can filter 99.97 percent of particles down to 0.1 microns. You can also control settings from the companion Blueair app or from an Alexa device with voice control.

  • Tobacco Smoke CADR: >450
  • Dust CADR: >400
  • Pollen CADR: >450
  • Capacity: 698 square feet

Blueair Blue Pure 211+

Like the Blueair Classic 605, this purifier is one of just four Consumer Reports-tested air purifiers to earn an “Excellent” rating on both the highest and lowest speed settings. Like the other Blueair purifiers, this model uses the brand’s HEPASilent technology, which the company says can filter 99.97 percent of particles down to 0.1 microns.

  • Tobacco Smoke CADR: 350
  • Dust CADR: 350
  • Pollen CADR: 350
  • Capacity: 540 square feet

Honeywell HPA300 Air Purifier

Honeywell says this HEPA purifier filters and circulates air up to five times an hour. It is relatively affordable given its size and comes with features like a timer setting and filter change indicator. It has two filters: a pre-filter to capture large particles like pet hair and lint, and a HEPA filter for smaller particles. AHAM provided the following ratings for the air purifier:

  • Tobacco Smoke CADR: 300
  • Dust CADR: 320
  • Pollen CADR: 300
  • Capacity: 465 square feet

Blueair Protect 7470i

This purifier scored an “Excellent” rating on the highest setting and a “Very Good” rating on the lowest setting in Consumer Reports testing. The purifier also uses the brand’s HEPASilent technology, which Blueair says can filter 99.97 percent of particles down to 0.1 microns. You can also connect to the companion Blueair app to track your air quality.

  • Tobacco Smoke CADR: 270
  • Dust CADR: 275
  • Pollen CADR: 280
  • Capacity: 418 square feet

Instant AP300 Air Purifier

The Instant Air Purifier employs a HEPA-13 filter and a carbon filter, as well as an antimicrobial coating on said filters to prevent bacterial growth. Notably, the brand says it can remove 99.7 percent of dust, pollen, smoke, or mold from the air and the purifier has sensors that monitor air quality.

  • Tobacco Smoke CADR: 251
  • Dust CADR: 259
  • Pollen CADR: 289
  • Capacity: 388 square feet

Bissell air320 Max Smart WiFi Air Purifier

Bissell’s air purifier is Wi-Fi equipped, allowing you to control it through the brand’s app or check its air quality monitor when you’re not home. Its three-part filtration system includes a pre-filter, an activated carbon filter and a HEPA filter. The air purifier has an Automated CirQulate System that independently monitors air quality and adjusts accordingly to the appropriate fan speed.

  • Tobacco Smoke CADR: 234
  • Dust CADR: 247
  • Pollen CADR: 264
  • Capacity: 363 square feet

Germ Guardian AC4825 Air Purifier

The GermGuardian AC4825 is a 3-in-1 air purifier that includes a HEPA filter, charcoal and PCO filter. It is equipped with three speed settings and comes with a filter replacement indicator.

  • Tobacco Smoke CADR: 99
  • Dust CADR: 118
  • Pollen CADR: 125
  • Capacity: 153 square feet

Other highly rated air purifiers to consider

While the following air purifiers are not rated by AHAM, they’re highly-rated, have HEPA filters, and are made by notable brands.

Levoit LV-H132 Air Purifier

The Levoit LV-H132 removes particles from the air with its three-stage filtration system that includes a pre-filter, a HEPA filter and an activated carbon filter. It has a cleaning capacity of 129 square feet and circulates the air in the room over four times in an hour. It has a night light and built-in smart filter replacement that reminds you when it’s time for a new one. I personally own this purifier and have noticed considerably less dust in my apartment since I started using it. The purifier has a 4.6-star average rating from over 46,000 reviews on Amazon.

Cuisinart Purxium Freestanding Air Purifier

In addition to its HEPA filter, Cuisinart’s air purifier offers washable, reusable metal filters and active carbon filters, all of which work together to capture 99.9 percent of airborne particles 0.1 microns or larger. It has a timer, an automatic shutoff option and four fan speeds. The air purifier comes in two sizes: Freestanding, which has a cleaning capacity of 1,000 square feet, and Countertop, which has a cleaning capacity of 500 square feet, according to the brand. It has a 4.9-star average rating from over 60 reviews on Wayfair.

Dyson Purifier Cool Formaldehyde TP09 Purifying Pan

This air purifier-fan from Dyson has a HEPA filter that can remove 99.97% of particles 0.3 microns in size, the brand says. The purifier-fan also can remove formaldehyde from the air, according to Dyson. Its fan oscillates up to 350 degrees, so it can spread the clear, purified air in nearly all directions. It has a 4-star average rating from over 60 reviews on Dyson.

What is a HEPA filter?

HEPA filters should meet a Department of Energy standard of clearing out at least 99.97 percent of particulates that are 0.3 microns in size, the particle size that most easily evades filtration, according to the EPA. Particles larger than 0.3 microns have a difficult time fitting through the filter, and smaller particles move too haphazardly to pass through. Having a HEPA filter, by definition, should ensure efficient filtration.

But HEPA isn’t a centrally regulated standard, explained Michael Corbat, vice president of engineering for Rensa Filtration, so it’s up to companies and sometimes third-party laboratories to test filters. Tests like these are based on standards created by organizations like the Institute of Environmental Sciences and Technology (IEST). To determine whether you can trust HEPA features you see on an air purifier you’re considering, Corbat says to look for “compliance” with an “accepted test method” like IEST RP-CC-001. But the lack of oversight is still a concern — you’re relying on manufacturers to perform and report on these tests correctly.

Corbat also said that since HEPA testing methods involve a single pass-through, and air purifiers use multiple pass-throughs when processing air, HEPA tests aren’t as suitable for these devices. The tests also don’t give much information on how fast a purifier can process air or how much air one can clear in a certain time period. Rather than rely on decentralized HEPA testing and manufacturer claims, Corbat recommended finding air purifiers tested and certified by AHAM that are given a CADR by the organization.

What is CADR?

CADR measures the “volume of filtered air an air cleaner delivers, with separate scores for tobacco smoke, pollen and dust,” according to AHAM, often measured in cubic feet per minute (sometimes in cubic meters per hour).

These tests are helpful because they quantify both how fast and how effectively a purifier clears a room of contaminants — the test better fits the real-world application of air purifiers than HEPA tests do. For example:

  1. A tobacco smoke CADR rating of 234 means the air purifier can remove smoke and deliver 234 cubic feet of clean air per minute

  2. A dust CADR of 320 means that the air purifier can remove dust and deliver 320 cubic feet of clean air per minute

  3. A pollen CADR of 125 means that the air purifier can remove pollen and deliver 125 cubic feet of clean air per minute

The two-thirds rule we went over above means an air purifier that has a CADR rating of 300 would be suitable for a 500-square-foot room. However, it’s important to note that CADR tests assume an 8-foot ceiling, so if you have a higher ceiling, you’ll need an air purifier that can process air more quickly.

All air purifiers certified by AHAM have been tested in an independent laboratory and across the same metrics and given a CADR, AHAM says. You can find the CADR ratings of any AHAM-certified air purifier on the AHAM Verifide website — a centralized resource that makes it simple to compare one purifier to another and find one that helps best suit your needs.

AHAM also tests air purifiers for whether they meet ozone limits — Mendez explained that ozone can be a byproduct of some air purifiers. Ozone is very reactive and is effective for removing odors and killing mold. But it can also "can cause health problems at high concentrations," according to the EPA.

In short, if an air purifier has AHAM testing data, you’ll have a fairly complete picture of how the purifier is likely to perform in real-life circumstances and whether the purifier will fit your needs.

Consumer Reports Filtration Testing

Other groups have their own standards for testing. Consumer Reports, for example, tests air purifiers by injecting 0.1- to 1-micron particles into a sealed chamber, then measuring the particle concentration after running an air purifier for 15 minutes (at both highest and lowest speeds) — for more on their conclusions, you can check out their picks for the best and worst air purifiers.

Tips for maintaining good air quality

Outside of buying an air purifier, there are some good home habits that you can adopt to help reduce the amount of air pollution in your space. The CDC offers a range of guidance for how to improve ventilation in buildings, including:

  1. If you can, open your windows and doors as safety allows.

  2. Place fans to increase fresh airflow from open windows.

  3. Make sure your exhaust fans are operational.

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