Reviews You Can Rely On

The 5 Best Air Purifiers of 2024

We buy and test models from Winix, Coway, Blueair, Levoit, and more to help you find your ideal air purifier
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Best Air Purifier Review (You should choose an air purifier wisely based on the size of the room in which you plan to use it.)
You should choose an air purifier wisely based on the size of the room in which you plan to use it.
Credit: Natalie Kafader
By Nick Miley, Genaveve Bradshaw, and Buck Yedor  ⋅  Oct 25, 2024

The Best Air Purifiers for 2024


We researched over 100 air purifiers before purchasing the best 11 available today for our in-house, hands-on testing in a controlled space. We built an air quality testing rig and spent hundreds of hours in our test room assessing air cleaning performance, operating costs, ease of use, and the noise produced by the machines.

The Coway Airmega 1512HH is the best for most people because not only is it one of the most effective purifiers, it has a low upfront cost and a low operating cost. If you want the absolute best air cleaning performance or have a bigger space, the Alen BreatheSmart 45i is the one to get (but it's expensive).

We've put a wide range of the best home appliances to the test in a similarly controlled test environment. We test air conditioners and top-rated fans. We also take detailed particulate measurements of vacuum cleaners for people with allergies or who want the cleanest air after cleaning.

Editor's Note: Our air purifier review was updated on October 25th, 2024, with a new test rig and an overhaul of new products with retests of old favorites.

Top 11 Air Purifiers - Test Results

Displaying 1 - 11 (scroll right)
 
Awards Editors' Choice Award
Best High-End Air Purifier
Editors' Choice Award
Best Air Purifier for Most
Best Buy Award
Best Value for a Smart Air Purifier
   Best Buy Award
Best Value for Small Rooms
Top Pick Award
Best for Larger Rooms
   
Price $468 List
$426.18 at Amazon
$230 List
$229.99 at Amazon
$220 List
$219.99 at Amazon
$230 List
$226.75 at Amazon
$230 List
$229.00 at Amazon
$250 List
$155.19 at Amazon
$100 List
Check Price at Amazon
$749 List
$529.00 at Amazon
$90 List
Check Price at Amazon
$100 List
$88.91 at Amazon
$160 List
$73.99 at Amazon
Overall Score Sort Icon
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Pros Cleans air quickly in large rooms, optional app control, comes in many colors, decorativeExcellent air cleaning performance, quiet operation, reasonable lifetime costVeSync smart app, air quality sensor, three-stage filterEffectively cleans air in small spaces, eliminates odors, quiet operationGood purifying performance, nice features, decent operating costSolid air cleaning performance, simple user experienceBudget friendly, small footprint, great performanceExcels in large spaces, powerful purifying, extensive control options, great noise to power ratioQuiet, low operating costs, small footprintSmall footprint, decent cleaning abilityEffective air purification, portable
Cons Expensive operating cost, high overall price tagNoisy on high settings, one filter option, no child lockSome features only accessible with app, expensive replacement filterAbsent carrying handle, somewhat pricey to operateSomewhat loud, only one filter option, no child lockLoud on high setting, large and heavy compared to mostLoud, no carrying handleHigh operating cost, bulky, app required for some features, hefty investmentOnly suitable for small spaces, middling cleaning performanceLimited features, loud, inefficient energy useSomewhat loud, high operating cost
Bottom Line If you want the best it comes at a cost, but you won't be disappointed with this air purifier in terms of its purifying abilityThe small footprint paired with big performance makes this a compelling optionAn easy-to-use, mid-sized air purifier that performs well and offers a variety of programmable features in its companion appThis air purifier proved its worth across many of our testing metrics, and we appreciated the uncomplicated interface and overall designA reliable and highly effective air purifier, only hampered by a lack of filter options and noise levels on the highest settingWhile not exactly the most stand-out option in a crowded market, this air purifier still provides great cleaning performance and straightforward operationA budget-friendly and space-efficient model that gets the job done but is a little underpowered for large spacesA high-performance, high-volume machine that has user-friendly interface options and a wider range of controls than other purifiers of its classThis unit is quiet, well designed, and relatively inexpensive, but is suitable for smaller room sizesDespite a good cleaning performance and reasonable size, this little unit is louder than mostThis zero-frills and comes with a high operating cost, but we valued its effective air purification and convenient carrying handle
Rating Categories Alen BreatheSmart 45i Coway Airmega 1512HH Levoit Core 400S Blueair Blue Pure 3... Coway Airmega 200M Winix 5500-2 Levoit Core 300 Coway Airmega 400S Levoit LV-H132 GermGuardian AC4825E Honeywell PowerPlus...
Air Cleaning Performance (40%)
9.1
8.3
9.4
8.3
8.2
8.3
7.8
9.5
6.0
8.0
7.8
Noise (30%)
7.3
7.6
6.8
7.8
6.6
6.7
7.0
7.1
8.6
3.8
3.7
Ease of Use (20%)
8.9
8.3
7.9
7.6
8.3
8.1
7.4
6.4
6.8
5.4
6.7
Operating Cost (10%)
6.1
8.3
6.7
6.7
8.7
7.4
7.8
2.6
8.2
7.0
2.8
Specs Alen BreatheSmart 45i Coway Airmega 1512HH Levoit Core 400S Blueair Blue Pure 3... Coway Airmega 200M Winix 5500-2 Levoit Core 300 Coway Airmega 400S Levoit LV-H132 GermGuardian AC4825E Honeywell PowerPlus...
Measured Annual Cost $178.96 $110.16 $148.14 $144.30 $96.36 $133.16 $96.81 $271.28 $84.79 $105.27 $219.91
Airborne Particulate Reduction After 1 Hour (%) 99.98% 100.00% 100.00% 99.99% 100.00% 99.98% 99.92% 100.00% 95.30% 99.90% 99.97%
CADR 245 overall
139.9 (Smoke)
207.9 (Dust)
230.4 (Pollen)
234 (Smoke)
248 (Dust)
232 (Pollen)
Sleep: 59
Speed 1: 88
Speed 2: 118
Speed 3: 177
Speed 4: 260

*Per Levoit, their stated CADR ratings for this product are the same for Smoke, Dust, and Pollen but differ for fan speeds
250 (Smoke)
250 (Dust)
250 (Pollen)
233 (Smoke)
246 (Dust)
240 (Pollen)
232 (Smoke)
243 (Dust)
246 (Pollen)
141 (Smoke)
140 (Dust)
145 (Pollen)
328 (Smoke)
328 (Dust)
400 (Pollen)
40 (Smoke)
40 (Dust)
40 (Pollen)
99 (Smoke)
118 (Dust)
125 (Pollen)
129 (Smoke)
145 (Dust)
145 (Pollen)
Measured Dimensions 8.5" x 15.0" x 25.0" 9.6" x 16.8" x 18.3" 10.8" x 10.8" x 20.5" 12.5" x 12.5" x 19.0" 9.6" x 16.8" x 18.3" 15.0" x 8.2" x 23.6" 8.7" x 8.7" x 14.2" 14.8" x 14.8" x 22.8" 7.9" x 7.9" x 12.6" 10.3" x 6.8" x. 22" 14.1" x 9.0" x 15.0"
Measured Weight 15.5 Ibs 13.1 lbs 10.4 Ibs 7.9 Ibs 12.7 lbs 15.8 lbs 7.3 Ibs 24.6 Ibs 5.4 Ibs 8.3 Ibs 9.8
Measured Cord Length 7' 8" 6' 6" 6' 3" 7' 6' 5" 6' 3" 6' 3" 7' 5' 10" 6' 6'
True HEPA (99.97%) Yes Yes No Yes Yes Yes No Yes Yes Yes No
Estimated Lifetime Cost (5 years) $894.81 $550.81 $740.70 $721.50 $481.81 $665.81 $484.03 $1,356.42 $423.93 $526.33 $1,099.57
App Control Yes No Yes Yes No No No Yes No No Yes
Air Quality Sensor Yes Yes Yes Yes Yes Yes No Yes No No No
Measured Decibels 48.3 55.9 51.8 49.2 59.5 53.9 52.3 51.2 46.1 51.2 54.2
Energy Star Certified Yes Yes Yes Yes Not Listed Yes Yes Yes Not Listed Yes Yes
Listed Coverage 1600 sq. ft 1,748 sq. ft 1560 sq. ft 1,800 sq. ft 1,748 sq. ft 1,740 sq. ft 219 sq. ft 3,120 sq. ft 129 sq. ft 743 sq. ft 200 sq. ft


Best Air Purifier for Most


Coway Airmega 1512HH


81
OVERALL
SCORE
  • Air Cleaning Performance 8.3
  • Noise 7.6
  • Ease of Use 8.3
  • Operating Cost 8.3
REASONS TO BUY
Incredible air cleaning performance
Moderately quiet
Intuitive features
Low operating cost
REASONS TO AVOID
Minimal filter options
No child lock
SPECIFICATIONS
Airborne Particulate Reduction After 1 Hour (%) 100.00%
Measured Annual Cost $110.16
CADR 234 (Smoke)
248 (Dust)
232 (Pollen)
Measured Dimensions 9.6" x 16.8" x 18.3"
Measured Weight 13.1 lbs
The Coway Airmega 1512HH is seriously impressive—and you can tell by its high ranking on our list of the best air purifiers. With an exceptional clean air delivery rate of 234 (Smoke), 248 (Dust), and 232 (Pollen), plus decently solid coverage (rated for 1,748 square feet), it really shined in our air cleaning performance test. It cleared 100% of large airborne particles from smoke, which is about as good as it gets.

You might be wondering if a machine this powerful is going to be loud or annoying while it's running. We checked that for you too. At six feet away on the medium setting, where you'll probably keep it most of the time, it's almost silent. But when you crank it up to high, things do change. We noticed a big jump in volume, but it wasn't overly intrusive. One tester said, “It sounds like a fan without that annoying buzz or whine.” So, if you're okay with a bit of white noise (55.9 decibels on high), you should be just fine. The great thing is, you can just keep it on medium or low and barely notice it's even there. If you want a quiet purifier that's still effective, the Levoit LV-H132, but it's only meant to cover 129 square feet.

One thing to keep in mind is the limited filter options, but the current setup does a great job. If you're after something with more specialized filters (maybe for pets or heavy smoke), the Levoit Core 300 offers four different filter choices. Also, if you don't think the 219 square foot coverage will cut it for your space, you might want to check out the Levoit Core 400S, which covers up to 1,560 square feet, or the Alen BreatheSmart 45i which covers 1600 square feet and handles bigger spaces like a pro.

Read more: Coway Airmega 1512HH review

The Coway Airmega was hard to beat.
Credit: Natalie Kafader

Best High-End Air Purifier


Alen BreatheSmart 45i


82
OVERALL
SCORE
  • Air Cleaning Performance 9.1
  • Noise 7.3
  • Ease of Use 8.9
  • Operating Cost 6.1

REASONS TO BUY
Great cleaning performance
Sleek and available in multiple colors
REASONS TO AVOID
Pricey lifetime cost
Expensive upfront cost
SPECIFICATIONS
Airborne Particulate Reduction After 1 Hour (%) 99.98%
Measured Annual Cost $178.96
CADR 245 overall
139.9 (Smoke)
207.9 (Dust)
230.4 (Pollen)
Measured Dimensions 8.5" x 15.0" x 25.0"
Measured Weight 15.5 Ibs
The standout feature of the Alen BreatheSmart 45i has to be the app. It lets you control the purifier right from your phone, and the app is super intuitive—audible feedback confirms every change you make, so you're never left guessing. It even turns your phone into a remote, so you don't have to mess with the controls on the unit itself. But even if you don't use the app, the purifier's interface is crisp, clean, and really responsive. It's not just about looks either—this model performs as well as it looks, with impressive air cleaning power. While it didn't completely clear out the smell from our smoke test, it did manage to eliminate 99.98% of large particles, putting it right up there with the top performers. If you're interested in a purifier that has the best air cleaning performance of the group, check out the Coway Airmega 400S. It cleaned 100% of particulates in our test room.

Overall, the Alen BreatheSmart 45i is a great choice for most people. With 1600 square feet of coverage, it should be more than enough for the average space. If you need something for an even larger area, you could look at the Coway Airmega 400S, which lists an impressive 3,120 square feet of coverage. Just know that it'll have a lifetime cost of $1,356 factoring in electricity usage, filter replacements, and its high list price.

While the Alen BreatheSmart 45i is energy-efficient and Energy Star certified, the main downside is the $69 filter cost. The initial price for the unit and ongoing filter replacements are on the higher side, which could affect the overall value. If you're budget-conscious, you might want to check out the Blueair 311i Max. It offers similar air purifying performance at a much lower price point. One of our testers mentioned that “Blueair nails the minimalist look.” The model did well in our tests, though the auto mode wasn't always reliable for kicking the fan into high gear when needed. It's also worth noting that Blueair uses a unique design, where the filter is the base of the purifier, covered by a cloth, instead of a bulky plastic frame.

Read more: Alen BreatheSmart 45i review

The Alen BreatheSmart 45i surpassed our expectations and showed why it's one of the best air purifiers on the market.
Credit: Natalie Kafader

Best Value for a Smart Air Purifier


Levoit Core 400S


81
OVERALL
SCORE
  • Air Cleaning Performance 9.4
  • Noise 6.8
  • Ease of Use 7.9
  • Operating Cost 6.7
REASONS TO BUY
App remote control
Includes an air quality sensor
REASONS TO AVOID
Expensive filter replacement
Some functions available only in app
SPECIFICATIONS
Airborne Particulate Reduction After 1 Hour (%) 100.00%
Measured Annual Cost $148.14
CADR Sleep: 59
Speed 1: 88
Speed 2: 118
Speed 3: 177

Speed 4: 260

*Per Levoit, their stated CADR ratings for this product are the same for Smoke, Dust, and Pollen but differ for fan speeds
Measured Dimensions 10.8" x 10.8" x 20.5"
Measured Weight 10.4 Ibs
Towards the end of 2023, Dyson challenged Levoit's “True HEPA” label for their Core series of air purifiers, prompting Levoit to remove this label from their Core products. The Core purifiers we tested provide 3-stage filtration, and our tests still found them to perform quite well.
If you're after an app-controlled air purifier with great performance, low noise, easy setup, and an affordable price tag, the Levoit Core 400S is a fantastic option. With an impressive clean air delivery rate (CADR) of 260 on its highest setting and a built-in air quality sensor, it automatically kicks into gear when the air needs it. Plus, the noise level is super reasonable for its class at 51.8 decibels, so you won't have to choose between clean air and peace and quiet.

Setting up the Core 400S is a breeze. It takes about five minutes from unboxing to turning it on. The app is super handy for remote control and tweaking settings. The Core 400S covers up to 1,560 square feet, which is one of the best in its class. Another option with just as much coverage but even better air cleaning ability is the Coway Airmega 400S. We did have to fiddle a little more with this model during setup due to having to remove the front of the unit in order to access the filter, but it wasn't a deal breaker.

While the upfront cost of the Core 400s is competitive for its size and power, and it doesn't use much electricity. The filter replacements can get pricey at $49.99 a pop, which turns into $100 annually with regular use. So, in the long run, it's not the cheapest to maintain. That said, it's technically not an exorbitantly high price for a unit of this size. But, if you're looking for an even lower-cost alternative, the Winix 5500-2 is a solid choice. It performs well, has a lower initial cost, and often goes on sale—sometimes knocking $100 off the price on Amazon. All told, you're saving money at every turn with this option, and it will still do a great job of cleaning your air.

Read more: Levoit Core 400S review

The Levoit Core 400S showing what it can do in our testing metrics.
Credit: Natalie Kafader

Best Value for Small Rooms


Levoit Core 300


75
OVERALL
SCORE
  • Air Cleaning Performance 7.8
  • Noise 7.0
  • Ease of Use 7.4
  • Operating Cost 7.8
REASONS TO BUY
Budget-friendly
Compact and light
Good air purifying
REASONS TO AVOID
Loud
No air-quality sensor
SPECIFICATIONS
Airborne Particulate Reduction After 1 Hour (%) 99.92%
Measured Annual Cost $96.81
CADR 141 (Smoke)
140 (Dust)
145 (Pollen)
Measured Dimensions 8.7" x 8.7" x 14.2"
Measured Weight 7.3 Ibs
Not everyone needs massive coverage or tons of power for their space. For some people, the Levoit Core 300 might be more than enough. It covers 219 square feet and has a CADR rating of 141 for smoke, 140 for dust, and 145 for pollen. Those numbers might not sound super impressive compared to units like the Blueair 311i Max or the Alen BreatheSmart 45i, but that raises the question: How much power do you really need? The compact Core 300 weighs just 7.3 pounds, so it's easy to move around and won't take up much space—it can even sit on your nightstand or a side table. And while it's small, it's still highly effective. In our smoke test, it removed 99.92% of large particles from the air in just an hour.

With its low initial price and affordable operating costs, the Levoit Core 300 is a great choice for anyone on a budget. If you need more coverage but don't want to spend a lot, the GermGuardian AC4825E is a solid alternative that handles spaces up to 743 square feet. But, if the room your purifying is only 400 feet or less, you probably don't need all that power.

On the high setting, the Levoit Core 300 can get noisy — we measured the sound level to be 52.3 decibels. Our testers didn't find the sound too obnoxious, but it's definitely there. “It's noticeably louder than the medium setting, with a steady fan noise kind of like a heater,” research analyst Gena Bradshaw said. If noise is an issue for you, there are quieter options out there, like the Levoit LV-H132. But if you're someone who enjoys a bit of white noise, this won't be a problem at all.

Read more: Levoit Core 300 review

The Levoit Core 300 is a favorite among our testers for its great value and air cleaning capabilities.
Credit: Natalie Kafader

Best for Larger Rooms


Coway Airmega 400S


75
OVERALL
SCORE
  • Air Cleaning Performance 9.5
  • Noise 7.1
  • Ease of Use 6.4
  • Operating Cost 2.6
REASONS TO BUY
High clean air delivery rate (CADR)
Air quality sensor
Relatively quiet
REASONS TO AVOID
Expensive
Large dimensions
SPECIFICATIONS
Airborne Particulate Reduction After 1 Hour (%) 100.00%
Measured Annual Cost $271.28
CADR 328 (Smoke)
328 (Dust)
400 (Pollen)
Measured Dimensions 14.8" x 14.8" x 22.8"
Measured Weight 24.6 Ibs
The Coway Airmega 400S is the go-to air purifier if you're looking to tackle lots of particulates in large spaces. It has one of the highest clean air delivery rates (CADR) in its class—328 for smoke, 328 for dust, and a whopping 400 for pollen. In our smoke test, it completely cleared the room of large particles in just 60 minutes, with most of the work done in the first 20 minutes. And despite its powerful performance, the noise level stays impressively low when measured from 6 feet away with a decibel reader. It registered at 51.2 decibels, and one of our team members said, “It just sounds like whirring air. It does not have an annoying buzz or hum.”

Another thing we like about the Airmega 400S is its air quality sensor, which automatically adjusts the purifier to maintain optimal air quality without wasting energy. So, while it's powerful, it's also smart about how it runs, helping to keep power consumption down as much as possible.

Keep in mind that this isn't a small unit. At 14.8" x 14.8" x 22.8" and weighing 24.6 pounds, it's more like a piece of furniture or a large appliance. If you're looking for something more portable, the Honeywell PowerPlus HEPA is a much smaller option. But if you have the space, the Airmega 400S really delivers.

While the Airmega 400S is a beast when it comes to air cleaning, it does have some major downsides. The most notable is the cost. Not only is the upfront price high and hard to justify, but its filter replacements are exorbitantly priced compared to all other purifiers we tested at $129 per filter. Some purifiers in our lineup actually cost less upfront than the Airmega 400S's filter. We measured the estimated lifetime cost of this unit to be $1,356, factoring in the list price, filter costs, and electricity use over five years. That's higher than any other air purifier we tested. That said, no other purifier we tested cleaned the air as thoroughly or quickly as the Airmega 400S. It's an efficient powerhouse. Plus, it's equipped with app support, so you can monitor air quality and program its operation from your phone, which is a huge convenience. So, while it's an investment, if you need a workhorse for large spaces, this is hard to beat.

Read more: Coway Airmega 400S review

The Coway Airmega 400S has a clean air delivery rate of 400 for pollen, which is the highest of the group.
Credit: Natalie Kafader

Compare Products

select up to 5 products to compare
Score Product Price
82
Alen BreatheSmart 45i
Best High-End Air Purifier
$468
Editors' Choice Award
81
Coway Airmega 1512HH
Best Air Purifier for Most
$230
Editors' Choice Award
81
Levoit Core 400S
Best Value for a Smart Air Purifier
$220
Best Buy Award
79
Blueair Blue Pure 311i Max
$230
78
Coway Airmega 200M
$230
77
Winix 5500-2
$250
75
Levoit Core 300
Best Value for Small Rooms
$100
Best Buy Award
75
Coway Airmega 400S
Best for Larger Rooms
$749
Top Pick Award
72
Levoit LV-H132
$90
61
GermGuardian AC4825E
$100
59
Honeywell PowerPlus HEPA
$160

A Note On Ionizers
Many purifiers utilize ionizers that release charged particles into the air that latch onto airborne particulates, making them easier to filter. However, some ionizers can create ozone as a byproduct, which can be a harmful lung irritant. While some ionizers are likely safe, we like to adhere to the precautionary principle in cases like these.

Our testing of air purifiers is divided into four rating metrics:
  • Air Cleaning Performance (40% of overall score weighting)
  • Noise (30% weighting)
  • Ease of Use (20% weighting)
  • Operating Costs (10% weighting)

Why Trust GearLab


Authors Buck Yedor, Nick Miley, and Genaveve Bradshaw have spent the last few years researching and testing a variety of health and wellness products, including air purifiers, humidifiers, electric toothbrushes, and fitness trackers. They've also tested many other home and kitchen products, from security cameras and wireless speakers to toaster ovens and pressure cookers. This team is no stranger to diving into the nitty-gritty details and conveying them to consumers clearly and comprehensively. As someone who suffers from asthma and lives in a wildfire-prone area, Bradshaw takes air purifying seriously and runs her air purifier around the clock during fire season. She owns the Levoit Core 300 and finds it to be a great little purifier for her apartment.

Say hello to Chadley, who is responsible for our smoke test.
Say hello to Chadley, who is responsible for our smoke test.
Our tester, Gena Bradshaw, geared up to perform our smoke test.
Our tester, Gena Bradshaw, geared up to perform our smoke test.
It's beneficial to know the exact dimensions of each air purifier in...
It's beneficial to know the exact dimensions of each air purifier in order to determine just how well it'll fit into a specific nook in your home.

Analysis and Test Results


To rate air purifiers, we divided our tests into four different weighted metrics. The results of our air cleaning performance tests factor most heavily into each model's final score. In the following sections, we delve into the details of these metrics so that you can pick the best air-cleaning device for your needs.


What's the Best Value?


In general, paying more for an air purifier will get you a greater clean air delivery rate, a quieter motor, and more customization features — there are exceptions, however. For example, the Winix 5500-2 provides stellar performance and often sells for significantly less than its list price. The Levoit Core 300 also performs well above what its price suggests, offering high-quality air cleaning for less than many competitors. Finally, the Levoit Core 400S is a screaming deal if you want a smart device that provides remote access and monitoring. These devices are great examples of value purchases, as revealed by our exhaustive testing.

air purifier - the levoit core 300 is our testers' favorite value option for...
The Levoit Core 300 is our testers' favorite value option for smaller rooms.
Credit: Natalie Kafader

Air Cleaning Performance


Air cleaning performance is the heaviest-weighted metric in our review. It analyzes the thoroughness in removing particulate matter, the rate of particulate filtering, and the ability of each purifier to remove odors while cleaning the air. We sealed a 150-square-foot room in our testing facility and filled it with smoke by burning paper. Once we got the room to the desired level of airborne particulate pollution, we ran each purifier for an hour, all the while monitoring the air cleaning progress with a Dylos air quality meter and an additional air quality data logger for good measure. We also used an AQI Reader as another point of reference. Our tests focused on eliminating airborne particles measuring 2.5 microns and larger because this range includes most airborne allergens affecting humans, such as pet dander, pollen, and mold. We chose to focus on allergens because our research indicates that most people looking to purchase an air purifier are doing so for allergy relief.

We burned incense and paper in a controlled room, and then used an air quality monitor to measure how well each purifier could clear large particulates and odors from the air.
Credit: Genaveve Bradshaw

Clean air delivery rate (CADR) is an industry standard used to rate air purifiers. As the name implies, CADR describes how much air these devices can process. As a general rule, the CADR should be about ⅔ of the square footage of the area, assuming 8-foot ceilings. Understanding this rating will clarify the results of our tests because most models tested in our 150 square foot smoke-filled room have CADRs that are more than adequate for such a space. Thus, almost every model in our test successfully removed 99% or more particulate matter in the allotted time. Those models that performed below this standard either lacked a CADR rating or their CADR was below 100.


The Coway Airmega 400S (along with some other models) breaks up its CADR ratings into different types of particulate matter: 328 for smoke, 328 for dust, and 400 for pollen. It also cleared out 100% of the large particles in our smoke test which is very impressive. It's capable of covering large spaces up to 3,120 square feet. The Levoit Core 400S doesn't quite match it regarding its CADR rating, but the air cleaning ability was still top notch. Not to be overshadowed, the Alen BreatheSmart 45i is also a powerful and capable machine. These models did exceptionally well at clearing out the odor left behind by the smoke. The Blueair 311i Max was one of the top performers when it comes to odor elimination, but fell a tiny bit short in terms of coverage. For the sake of consistency, we used the filter that came with each air purifier, though some models allow for specialty filters that can more effectively eliminate things like odors or smoke. This is worth keeping in mind if you plan to use your model of choice for a specific application.

air purifier - we tracked the performance of all the products in our lineup as they...
We tracked the performance of all the products in our lineup as they cleaned filthy air in a sealed testing room for a one hour trial.
Credit: Genaveve Bradshaw


As you can see in the chart above, those air purifiers with the highest clean air delivery rates fared the best in our smoke testing which was logged over the course of an hour.

air purifier - this chart features our award-winning products and top performers...
This chart features our award-winning products and top performers that we recommend for those whose primary concern is air cleaning performance. We tracked the percentage of large particles removed over the course of an hour in a sealed (and intensely smoky) testing room, logging the air quality for each minute.
Credit: Genaveve Bradshaw

air purifier - this chart features the products in our line-up that didn't win...
This chart features the products in our line-up that didn't win awards but still performed adequately during our rigorous smoke test.
Credit: Genaveve Bradshaw

Clean Air Delivery Rate


There are two main takeaways from the air cleaning performance metric. One is that it's vital to match the CADR to the room size — meaning that if you have a rather large room, you'll want an air purifier that can cover that amount of space. The other takeaway is that air purifiers are poor at removing odors. That said, the Coway Airmega 400S, Blueair 311i Max, and Levoit Core 400S did pretty well in this difficult task. These air purifiers use multi-layered filter systems, including a prefilter and activated carbon filter. The Coway Airmega 400S and Blueair have a True HEPA filter, while the Levoit Core does not. All told, the Alen BreatheSmart 45i, Coway Airmega 400S, and Levoit 400S are some of the best choices for overall air cleaning performance.

CADR Ratings
ProductSmokeDustPollen
Coway Airmega 400S328.0328400
Levoit Core 400S260.0260260
Blueair 311i Max250.0250250
Winix 5500-2232.0243246
Coway Airmega 200M233.0246240
Coway Airmega 1512HH234.0248232
Alen BreatheSmart 45i139.9207.9230.4
Levoit Core 300141.0140145
Honeywell PowerPlus HEPA129.0145145
GermGuardian AC4825E99.0118125
Levoit LV-H13240.04040

As part of our air performance rating, we take into account the CADR ratings of each unit, which makes up 15% of each units air performance score. The units with the highest CADR ratings are unsurprisingly some of the best performers in our smoke test, namely the Coway Airmega 400S, Levoit Core 400S and the Blueair 311i Max.


The air purifiers with some of the highest listed coverage also performed the best in our smoke test.

The Dylos Air Quality Meter was crucial for the air purifications tests.
Credit: Genaveve Bradshaw

Overall Air Cleaning Performance


The final air cleaning performance score combines results from the smoke/odor test, the listed coverage area, CADR (clean air delivery rate) specs, and how many specialty filters each purifier can use. The top-scoring devices simply cleaned the air more efficiently and effectively.


Noise


Since most people will be in the same room as the air purifier, any odd noises the device produces could have a significant negative impact on your relationship with it. The good news is that most of the tested models are not particularly loud — none registered more than 60 decibels on our sound meter, which is roughly the sound of a chatty office or restaurant. Still, even relatively quiet noises can be annoying if they're at the wrong pitch. Thus, we spent a night with each in our bedrooms and hours working on our computers right next to each model as they ran.

air purifier - many of the air purifiers we tested registered the lowest sound...
Many of the air purifiers we tested registered the lowest sound possible on the lower settings, signified by “LO” displaying on our decibel reader.
Credit: Genaveve Bradshaw

The Levoit LV-H132 is nearly silent when set on low and audible but not offensive when set on high and measured in at only 46.1 decibels. When considering the noise and power of a purifier, very few models come close to the Alen BreatheSmart 45i. We were quite impressed at how quiet this machine is (just 48.3 decibels on high), as much smaller units produce significantly more noise.

Outside of exceptions like the GermGuardian AC4825E and Honeywell PowerPlus HEPA, which were still pretty loud on low, every other air purifier we tested was nearly silent on their lowest setting. If you plan to run your air purifier on high most of the time, you can't beat the Alen BreatheSmart 45i or Levoit LV-H132.

Measured decibels on the highest setting of each unit.

Overall Noise


This overall noise score combines the results from our tests on the loudness, tone, and pitch of each air purifier at all power settings. Higher-scoring devices either had low sound levels, as measured by a decibel reader, or their tone and pitch were pleasant enough to fade into the background. Those with lower scores were either registering pretty loud (50+ decibels) or the noise that was emitted was considered grating or annoying by testers.

Noise
ProductHighMediumLow
Levoit Core Mini10.01010.0
Levoit LV-H1328.17.610.0
Blueair 311i Max6.57.010.0
Shark Clean Sense HEPA HP1026.76.510.0
Coway AP-1512HH2.91010.0
Alen BreatheSmart 45i6.94.910.0
Coway Airmega 400S5.45.810.0
Levoit Core 3004.86.210.0
Levoit Core 400S5.15.310.0
Winix 5500-24.06.110.0
Coway Airmega 200M1.0910.0
GermGuardian AC4825E5.41.05
Honeywell PowerPlus HEPA3.82.35

Ease of Use


Outside of periodically replacing the filter, air purifiers are generally simple and require no maintenance. However, certain features can make day-to-day use more enjoyable. Variable fan modes let you dial down the noise while watching TV, and remote controls let you do that without leaving the couch. Handles and wheels make it easy to transport the purifier if you want to move it from the living room to the bedroom. If you're likely to forget to turn the purifier off when you leave the house, timers can help, too. We evaluated all user/device interaction aspects to determine how easy they are to operate and incorporate into your daily routine.

air purifier - functions such as timers or auto modes can help add quality of life...
Functions such as timers or auto modes can help add quality of life so you don't have to micromanage your air purifier. It also won't be running unless you need it to.
Credit: Genaveve Bradshaw

Nearly all the air purifiers we tested required very little setup, and we didn't struggle much with replacing the filters either. Models like the Alen BreatheSmart 45i took a little longer to set up due to the app integration and inserting the filter, but it was one of the easiest to change the filter on once the original was depleted, so it balanced out. In contrast, the GermGuardian AC4825E comes with the filter already installed, so you simply have to plug it in and go.

Some of the air purifiers we tested came with a robust app, which enhances ease of use by offering features such as remote control and the ability to create a cleaning schedule. Here is the robust app for the Coway Airmega 400S.
Credit: Natalie Kafader

Out of all the models we've tested, the Alen BreatheSmart 45i and Coway Airmega 200M offer the most convenient user experiences overall. The BreatheSmart was a pleasure to use from top to bottom, with everything from unboxing to changing filters and navigating the interface being spot on. You won't encounter any issues operating this model. It's also relatively portable at 15.5 pounds, thanks to its slim design, making it easy to place in your home without much intrusion. The Airmega 200M performed similarly, though filter replacement wasn't quite as quick—though still not a burden by any means. The Winix 5500-2 also provided a pleasant user experience, with easy-to-read interface and responsive controls. The Winix 5500-2 control panel is straightforward, allowing you to easily access its shutoff timers, fan speeds, and auto setting, which adjusts the air output based on the ambient air quality, as measured by its internal air quality sensor. Thanks to a well-designed carrying handle, it is quite easy to move this unit around despite its 15.4 pounds.

The Levoit Core 400S comes with an intuitive app that allows you to remotely control the device.
Credit: Natalie Kafader

Many air purifiers come with an app to control advanced functions or simply operate the device. The main attraction of the Levoit Core 400S is its VeSync app, which turns your smartphone into a remote control. Not only is the app convenient for setting, monitoring, and operating the air purifier from across the room or even from anywhere in the world, but it also hosts several features unavailable on the user interface of most air purifiers in its class. For example, the app displays the current air quality around the Core 400S, the remaining filter life, and offers scheduling and timer options. Additionally, the app tracks data related to air quality—a pretty cool feature if you want to see how the device impacts your home environment over time.


Like the Levoit Core 400S, the Coway Airmega 400S uses an app to control it remotely via WiFi connection, though it has fewer features. Yet, its interface is also among the best, with a light bar displaying fan speeds controlled by touch. The unit has smart and night modes as well. The app has a timer, too, and accepts voice commands. While the app is useful, we acknowledge that some people may not want another app on their phone. Moreover, as some features on these two models are only available on the app, this can be seen as a mark against them.

air purifier - a larger air purifier like the coway airmega 400s might be...
A larger air purifier like the Coway Airmega 400S might be inconvenient if you don't have ample space, but the cleaning performance speaks for itself.
Credit: Natalie Kafader

The *Honeywell PowerPlus HEPA and Levoit Core 300 deserve special mention for their portability. The Levoit Core 300 is also relatively small at 7.3 pounds, with both models easily fitting on a nightstand. Although the Honeywell is slightly larger at 9.8 pounds and has a square form factor, it can still be placed just about anywhere in the home.

Keep in mind that while models like the Coway Airmega 400S, Levoit Core 400S, and Winix 5500-2 don't have the smallest footprint, they are designed for larger spaces. In other words, they are too large to be placed on a nightstand or small table. You'll want to choose a model based on your specific use case. Some users may need to move the air purifier frequently, while others may prefer to keep it stationary in their office, bedroom, or living room.

air purifier - the weight of an air purifier is important if portability is a...
The weight of an air purifier is important if portability is a priority. The Coway Airmega 400S, however, isn't the lightest option available.
Credit: Natalie Kafader


Overall Ease of Use


The overall ease of use score considers several factors like setup, filter replacement, smart integration through an app, interface, customization, portability, and storage footprint. Air purifiers that scored higher on this list tend to offer more convenience through smart design or are compact and easy to move around.


Operating Cost


It's easy to forget that you'll have to pay for replacement filters and electricity costs throughout the lifetime of using your air purifier. To estimate how much each unit will cost buyers in the long run, we've measured every purifier's energy consumption and price-checked the replacement filters. Our lifetime cost calculations assume the national average of $0.13 per kilowatt-hour and average usage of 12 hours a day on the medium setting, as well as replacing your filters according to the manufacturers' recommendations. We also include the cost of the device itself and split it up over five years in our calculations.


air purifier - many air purifiers available such as the honeywell powerplus utilize...
Many air purifiers available such as the Honeywell PowerPlus utilize highly effective HEPA filters which tend to cost more on average.
Credit: Genaveve Bradshaw

The discerning reader might guess that the most efficient units have low clean air delivery rates (CADR), which means they have low power consumption and smaller filters. For the most part, that's correct, as most purifiers that performed well in this metric have CADR ratings of 120 or less. However, the Coway Airmega 200M is an exception, with a CADR of 233-246.


air purifier - functions such as auto mode, night mode, or timers can help reduce...
Functions such as auto mode, night mode, or timers can help reduce costs. The Levoit Core 300 has it all.
Credit: Natalie Kafader

Amazingly, the 200M also uses a HEPA filter — the highest standard non-industrial filter and often the most expensive. However, with this specific unit, you'll only need to change the filter out once a year. The interesting thing about the 200M is that we couldn't determine if it was Energy Star certified, as it was not listed anywhere we could find.

air purifier - determining the kilowatt rating of the winix 5500-2.
Determining the kilowatt rating of the Winix 5500-2.
Credit: Natalie Kafader

As expected, with CADR ratings greater than 240, the cost of operation increases. Models in this group include the Coway Airmega 1512HH, Winix 5500-2, Alen Breathesmart 45i, and the Coway Airmega 400S. The annual cost of operating these large-area air cleaning machines ranges from $112 to $271, with the Coway Airmega 1512HH on the low end and the Coway Airmega 400S on the high end. The 400S comes with two pairs of filter sets (HEPA filter and carbon filter), as this purifier has a filter on either side of the body. All of the units in this group utilize HEPA filters.

air purifier - this chart compares each purifier's expected 1 year cost against the...
This chart compares each purifier's expected 1 year cost against the cost of running for 5 years. For this metric, top scores = low prices.
Credit: Genaveve Bradshaw

All told, operating costs are largely based on the amount of air you want to clean — the larger the space you want to clean, the more you'll have to spend. To put it more plainly, the higher the CADR, the larger and more expensive the filter, the more electricity the unit will draw, and, in general, the higher the cost of the purifier itself. The takeaway here is that you want to make sure you are matching the room where the purifier will be used to the purifier's CADR.

Overall Operating Cost


The overall operating cost score factors in electricity usage, filter costs, long-term ownership expenses, and the current MSRP. Higher-scoring models were either super efficient with electricity, had lower upfront costs, cheaper filters, or needed fewer filter changes—or some combination of those. Interestingly, some of the top-performing air purifiers might rank lower on this list because they use more electricity or rely on true HEPA filters, which can be significantly more expensive.



air purifier - consider the cost of filters with your chosen air purifier, because...
Consider the cost of filters with your chosen air purifier, because some are more expensive than others.
Credit: Natalie Kafader

How to Choose The Best Air Purifier


We have provided four important considerations to help guide your next air purifier purchase based on size, pollutants, noise, and energy efficiency.

Choosing the right air purifier can be a challenging task, but we’re here to help you find the perfect one.
Credit: Natalie Kafader

How Big is Your Desired Area?


Air purifiers come in a variety of different sizes, ranging from small portable applications to large-scale purifiers capable of covering multiple rooms. When looking at air purifiers it's important to consider your desired coverage area and the amount of space you're willing to dedicate to an air purifier.

air purifier - the coway airmega 400s is powerful enough for large spaces.
The Coway Airmega 400S is powerful enough for large spaces.
Credit: Natalie Kafader

What Pollutants Are You Targeting?


The filter type in your air purifier plays an essential role in the type of pollutants captured and the effectiveness of each type. True HEPA filters are rated to capture 99.7% of particles as small as 0.3 microns. While some filters will be labeled as HEPA-like or HEPA-type they have not been fully certified up to HEPA standard but can still provide adequate air purification. It's also worth considering the cost of true HEPA filters since they can be quite pricey. Carbon filters are another filter type often used in conjunction with HEPA filters to capture odors and chemicals but do not capture particles well. When identifying the filter type, it's important to consider replacement intervals and the costs associated with doing so.

air purifier - some air purifiers, such as the coway airmega 400s, offer multiple...
Some air purifiers, such as the Coway Airmega 400S, offer multiple filters designed for specific pollutants.
Credit: Natalie Kafader

How Important is Noise Level?


Since air purifiers are often used in home spaces such as offices or bedrooms, it is important to consider the amount of noise you're comfortable with. To start, identifying the decibel rating is an easy way to identify the level of noise. Placement of your purifier can also change the noise level such as in the corner of a room vs in the middle. Lastly, air purifiers often come with multiple operating speeds and can vary in noise depending on the setting.

air purifier - most air purifiers we tested fell within an acceptable noise range...
Most air purifiers we tested fell within an acceptable noise range, however, some were more noticeable than others due to the frequency.
Credit: Natalie Kafader

How Often Will it Run?


If you plan on running your air purifier for extended periods, it's important to consider the energy efficiency and costs associated with running it. Attributes such as being Energy Star certified by the Environmental Protection Agency are one way to ensure your purifier has met efficiency requirement standards. We have also provided lifetime costs associated with each purifier to give you an idea of the cost of running your machine and replacing filters regularly over a five-year lifespan.

air purifier - the coway airmega 200m is an efficient machine.
The Coway Airmega 200M is an efficient machine.
Credit: Natalie Kafader

Air Purifiers and COVID-19 (Coronavirus)
Credible research studies such as NASA's test results suggest that HEPA filter air purifiers can filter more than 99.9% of airborne virus particles that enter the air purifier. However, they cannot stop virus particles from contaminating surfaces or passing directly between people. Therefore, purifiers likely offer only marginal, if any, protective benefits from the virus itself and definitely should not be used as a replacement for any of the best practices put forth by the CDC or local healthcare and governmental organizations.

Related: Are HEPA Air Purifiers Effective Against COVID-19 Coronavirus?

Conclusion


Whether you live in the wildland urban interface, city, or somewhere in between, air purifiers will improve the air in the room where they are operating. These machines are easy to use, fairly inexpensive to operate, and have real and immediate benefits to respiratory health and peace of mind. The above review looks at all aspects of these machines and rates their performance so that you can pick a device quickly and accurately. With the information provided above, you can breathe easy knowing that you have selected the right machine for your home or office needs and budget.

Nick Miley, Genaveve Bradshaw, and Buck Yedor