Home » Air Quality » Coway Airmega 150 vs. 250 vs. 300 vs. 400 Air Purifiers

Coway Airmega 150 vs. 250 vs. 300 vs. 400 Air Purifiers

If you sense something in the air that’s not pie fragrance, you know that it’s not good. Thankfully, there’s an appliance that can help rid your home of foul odors in a matter of minutes—an air purifier.

Coway is arguably South Korea’s most famous manufacturer of air purifiers, seeing as how it won first prize in Korea Consumer Electrics Market Share and Brand Awareness. Today, we’re going to examine six of Coway’s air purifiers in depth to see what each model has to offer.

Coway Airmega Air Purifier Comparison

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Coway Airmega 150

The Airmega 150 is one of Coway’s smaller air purifier models. It’s designed to clean the air in rooms of up to 214 square feet, thanks to its moderate motor and fan size. Due to its limited purifying capacity and tiny footprint, it only makes sense that this unit is on the low-cost end of the price spectrum.

Coway Airmega 150
Coway Airmega 150

However, don’t confuse budget-friendliness with inferior quality. It comes with a triple-tier filter setup, consisting of a washable pre-filter, a basic deodorizing filter, and a Green True HEPA Filter, all of which work in conjunction to trap 99.97% of particles as tiny as 0.3 microns in size. Not only does the Airmega 150 get rid of pesky particles like pollen and dust, but it also neutralizes VOCs and kitchen odors.

In terms of technical performance, the Airmega 150 isn’t all that impressive. It has CADR ratings of 150, 161, and 219 CFM for dust, smoke, and pollen, respectively. These figures indicate that the Airmega 150 is best used in smaller spaces like bedrooms, dorms, and home office units, though the max purifying range should have made this clear already.

Perhaps what’s most exciting about the Airmega 150 is that it comes with an Air Quality Indicator, which measures the concentration of pollution in a room. After reaching a certain level, the sensors will kick-start the motor to life to eliminate pesky particles as efficiently as possible. When the air has been thoroughly cleaned, it’ll shut off on its own accord.

Coway Airmega 150 True HEPA Air Purifier with...
  • [Coverage] Designed to clean spaces up to 214 sq. ft. in 12.5 minutes or up to 518 sq. ft....
  • [HyperCaptive Filtration System] Combination of a pre-filter, deodorization filter, and...

Coway Airmega 250 [AP-1720H]

Comparing the Airmega 250 to the 150 is like comparing a watermelon to a cherry, at least in terms of cleaning performance and range. The low-cost Airmega 150 has a limited cleaning range of just around 200 square feet, whereas the Airmega 250 is designed to capture particles in spacious rooms of up to 930 square feet.

Coway AP-1720H
Coway AP-1720H

But how much more effective is the Airmega 250 compared to the little-brother model? Like the 150, this one uses a triple-tier filter system that consists of a washable pre-filter, a HEPA filter, and an activated carbon filter. However, the difference is that the Airmega 250’s HEPA and carbon filter are combined into a single Max2 filter and have a particle-retention rate of up to 99.999% of 0.1-micron particles. The differences are marginal at best, but for allergy sufferers, there’s a noticeable ramp-up in air cleanliness.

In addition, the Airmega 250 comes with six fan speed modes, including an Auto Mode that works together with the smart Air Quality Indicator to measure pollution concentrations before turning the device on and off automatically. There’s also a Rapid Mode, which sends the fans spinning at top speeds to remove more airborne contaminants in much less time and in more spacious rooms.

For its price, we wish that the Airmega 250 came with app and voice support, and even a remote control would’ve been nice, but you can’t have them all.

Coway Airmega 250 Smart Air Purifier, True...
  • [Coverage] Designed to clean spaces up to 930 sq. ft. in 30 minutes.Specification sheet
  • [HyperCaptive Filtration System] Combination of a pre-filter, deodorization filter, and...

Coway Airmega 300

As we move up the Airmega model numbers, we find greater, more powerful air purifiers for larger rooms. The Airmega 300 has a 34% increase in cleaning capacity compared to the 250. This unit can draw in air in rooms as large as 1,256 square feet from the corner while hardly generating a buzz. In fact, this is probably the only benefit it has over the 250 model.

Coway Airmega 300
Coway Airmega 300

The Airmega 300 has a sleep mode, like the previous Airmegas, but this one needs to be activated manually, like the 150. This isn’t a deal-breaker by any means, but it does mean that you have to preconfigure the unit’s fan and suction speeds before hitting the hay.

Of course, you could rely on the Air Quality Indicator to shift between speeds for you, but if you want the lowest noise output possible, manually choosing Sleep Mode is your only hope.

Another thing that sets the Airmega 300 apart from the 250 is that it’s missing the Rapid Mode, which isn’t that big of a deal at all. It can reach all four corners of a 1,000-plus-square-foot room on its highest fan setting while delivering over a single air change per hour (ACH).

Again, based on what customers say, we advise sticking to Auto Mode as often as possible for both convenience and efficiency.

So, overall, is the Airmega 300 better than the previous Airmegas? That’s hard to say. While it has a farther reach than the previous two models, compared to the 250, it’s missing some pretty crucial features. Thankfully, it’s not missing anything in the performance department; it comes with Max2 filters to remove up to 99.999% of debris 0.1 microns and larger in size.

Coway Airmega 300 True HEPA Air Purifier with...
  • [Coverage] Designed to clean spaces up to 1,256 sq. ft. in 30 minutes.
  • [HyperCaptive Filtration System] Combination of a pre-filter, deodorization filter, and...

Coway Airmega 300S

Next up, we have the Airmega 300S, which, upon first glance, looks identical to the 300 model in every way. In fact, if you look deeper into the 300S, you’ll learn that it has a maximum reach of 1,256 square feet, just like the 300.


The Airmega 300S comes with manually controlled Sleep and Eco Modes, and it’s even missing Rapid Mode. It features a seemingly identical Max2 filter to the 250 and 300 models, but this unit can “only” get rid of 0.3-micron particles with 99.97% efficiency.

While not terrible, allergy sufferers might notice a difference in air quality when comparing the Airmega 300S to the previous Airmegas.

So, where does the S from 300S come from? It stands for Smart, as the Airmega 300S offers both app and voice control. Using the Coway IoCare smartphone app (iOS and Android), selecting fan speeds, cleaning modes, and programming the scheduler function can be done just by tapping your phone’s screen.

If you have an Alexa speaker at home, you can sync it to the Airmega 300S and send basic voice commands to do everything the app does.

In the end, is the extra cost of the Airmega 300S worth app and voice support? Based on what reviewers say about this air purifier, the convenience of controlling the Airmega 300S from afar is more than worth the trouble, especially since you’d otherwise have to manually change to Sleep and Eco mode on the Airmega 300.

Coway Airmega 300S App-Enabled Smart...
  • [Coverage] Designed to clean spaces up to 1,256 sq. ft. in 30 minutes
  • [HyperCaptive Filtration System] Combination of a pre-filter, deodorization filter, and...

Airmega Comparison Table

CowayAirmega 250Airmega 300Airmega 300SAirmega 400Airmega 400S
Coverage930 sq. ft.1,256 sq. ft.1,256 sq. ft1,560 sq. ft.1,560 sq. ft.
App & Alexa & DRSn/an/aYesn/aYes
Auto ModeYesYesYesYesYes
Eco ModeYesYesYesYesYes
Sleep ModeAutomaticManualManualAutomaticAutomatic
Rapid ModeYesn/an/an/an/a
Filters ConfigurationPre-Filter+ Carbon + True HEPAPre-Filter+ Carbon + True HEPAPre-Filter+ Carbon + True HEPAPre-Filter+ Carbon + True HEPAPre-Filter+ Carbon + True HEPA
Pollution IndicatorYesYesYesYesYes
Filter Life Time IndicatorYesYesYesYesYes
Manual Fan SpeedLow, Medium, HighLow, Medium, HighLow, Medium, HighLow, Medium, HighLow, Medium, High
Timer & SchedulerTimer 1, 4, 8 HrTimer 1, 4, 8 HrTimer 1, 2, 4, 8 Hr, SchedulerTimer 1, 4, 8 HrTimer 1, 2, 4, 8 Hr, Scheduler
Available ColorsBeigeWhiteWhiteWhiteWhite
PriceCheck PriceCheck PriceCheck PriceCheck PriceCheck Price

Coway Airmega 400

Now, let’s take an in-depth look at the Airmega 400, which is supposed to clean rooms of up to 1,560 square feet while delivering at least one ACH. Obviously, you can place the unit in smaller rooms and choose a slower fan speed to cleaner not-as-spacious rooms, which makes it technically more versatile than the previous Airmegas.

Coway Airmega 400
Coway Airmega 400

Surprisingly, the Airmega 400 doesn’t feature a more efficient filtration system than the 300 and 300S. It relies on the same Max2 filter that has a 99.97% retention rate or 0.3-micron particles and larger.

Again, it’s technically a “less efficient’ unit as opposed to the 250 model with its Green True HEPA, but the difference is marginal at best. Based on reviews by allergy sufferers, this unit works exceptionally well at removing dander and dust from the air.

What’s not so surprising is that the Airmega 400 comes with the same Air Quality Indicator sensors to measure pollution concentrations before automatically starting and stopping the internal motor. It can even switch to Sleep Mode on its own accord if there isn’t very much pollution to clean. Sadly, it doesn’t have a Rapid Mode.

Overall, the Airmega 400 is another fantastic air purifier for large rooms. There’s really nothing about it that makes it stand out from the rest, even among other Airmega models, but it definitely does the job in extraordinary fashion. You should seriously consider getting the Airmega 400 if you can live without app and voice support.

Coway Airmega 400 True HEPA Air Purifier with...
  • [Coverage] Designed to clean spaces up to 1,560 sq. ft. in 30 minutes.Noise Level : 22-52...
  • [HyperCaptive Filtration System] Dynamic combination of a washable pre-filter, activated...

Related Coway Air Purifier Articles

Buying Guides
 • Best Coway Air Purifiers

Single Reviews
 • Coway AP-1512HH
 • Coway Airmega 150
 • Coway Airmega 250
 • Coway AP-1216L

Comparison Articles
 • Coway Airmega Comparison
 • Coway Airmega 300S vs 400S

Coway Airmega 400S

But if you can’t, then allow us to introduce you to the Airmega 400S. Similar to comparing the Airmega 300 and 300S models, the only thing that separates the Airmega 400S.from the 400 is the addition of app and voice support.


This unit syncs seamlessly to your smartphone, so you can manually shift between fan speeds and set up purifying schedules from the convenience of your smartphone. If you have an Alexa device at home, simply connect the two together, and you can send basic commands from a distance.

In every other regard—purifying range (1,526 square feet), purifying performance (Max2 filters with a HEPA filter), and design—the two are one and the same. What’s good is that the Airmega 400S does its job incredibly well while also using less electricity to power up.

Plus, you can rely on Auto Mode to do the thinking for you, which is definitely something homeowners are looking for in an air purifier. Overall, the Airmega 400S is a great long-range air purifier that comes with all the convenience-adding bells and whistles anyone could ask for.

Coway Airmega 400S App-Enabled Smart...
  • [Coverage] Designed to clean spaces up to 1,560 sq. ft. in 30 minutes
  • [HyperCaptive Filtration System] Combination of a pre-filter, deodorization filter, and...

Air Recommended Air Purifiers

Our Pick Perfect for bedrooms, playrooms, and living rooms, the Coway Airmega AP-1512HH is one of the best-performing, most durable, and most economical purifiers we’ve tested.

Most Popular The Levoit Core 300 air purifier has some strong suits, but in our opinion it falls short of carving out a meaningful niche for itself. Its ideal use would be in a small bedroom occupied by someone who is sensitive to noise.

Also Great With high end air cleaning performance and a whisper quiet fan, the Winix 5500-2 is the perfect combination of power and finesse. It cleared airborne particulates out of our smokey testing room faster than any other model.

Best of the Best If you have a large space you want to remove irritants from, We recommend the Airmega 400S. All of Coway air purifiers do an excellent job of attacking indoor pollutants, and we highly recommend any of them. The 400S is designed to accommodate large room sizes.

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Last Update: 2024-02-25 | Affiliate links/Images from Amazon Product Advertising API

About the author

Hi I’m Alex, founder of HouseholdMe.com and I’d like to say thank you for dropping by. Like most of you, the first thing I look at before buying something online is reviews or buying guides. By reading what other people say will help me gauge whether or not a product is good or not.  I am trying to help people find answers, solve problems, and get inspired.

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