Coway Airmega 250 review

With multiple layers of filtration, the Coway Airmega 250 can eliminate particles as small as 0.012 microns. It's best for large spaces or multiple rooms

Coway Airmega 250 air purifier
(Image: © Kasandra Brabaw)

Live Science Verdict

For serious air filtration, the Coway Airmega 250 is an excellent option. Coming with three filters, it combines activated carbon filtration with a certified HEPA (high efficiency particulate air) filter to target dust, pollens and fumes.


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    Activated carbon and HEPA filters

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    Easy-to-clean filters

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    Captures ultra fine particles like viruses, bacteria, fungi, and pollen


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    Loud at highest speed

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In this Coway Airmega 250 review, we’ll explain everything you need to know about this high-end air purifier, including how its three levels of filtration work, how quickly it absorbs particles, its design, and how easy it is to disassemble and clean. Because the Coway Airmega 250 is quite expensive in terms of air purifiers (retailing from around $300-$400), it’s important to know as much as possible before deciding to get one for your home. 

The Coway Airmega 250 is made to purify large spaces up to 930 square feet and can reduce particles as small as 0.01 microns. Using both a certified HEPA filter and an activated carbon filter means that this air purifier can eliminate pollen and other allergens, volatile organic compounds, bacteria, viruses, mold, fumes, odors from cooking or pets, and more. For all these reasons it makes our list of the best air purifiers for allergies right now.

Essential Info:

3 layers of filtration 

Covers 930 square feet 

Both activated carbon and HEPA filters 

Smart mode automatically adjusts fan speed 

LED bar gives up-to-date information on the cleanliness of the air 

Eliminates ultrafine particles 

Rapid mode quickly cleans the air  

Filter indicator lets you know when filter needs to be changed 

Nearly silent at low fan speeds 

Clean design

In terms of aesthetics, the Coway Airmega 250 could easily fit in with most decor. It’s a simple square in a light beige color, with a small grid covering the filters. A thin LED bar on the top of the air purifier indicates the air quality in the room in real time, lighting up blue for good, green for moderate, yellow for unhealthy, and red for very unhealthy. In addition, a smart purifier feature lets the air purifier adapt to its surroundings and clean the air in the most energy-efficient way. 

If you want a serious air purifier and care about how it looks and how much energy it uses, the Coway Airmega 250 is exactly what you need. 

Coway Airmega 250 review: How big is it?

  • Height: 19.7 (in) 
  • Width: 18.5 (in) 
  • Depth: 8.3 (lb) 

In comparison to some other air purifiers, the Coway Airmega 250 is shorter and wider, similar in size to a large box fan and weighs about 20 pounds. The air purifier fits well on the floor in the corner of the room. For optimal performance, the user manual suggests keeping it at least a foot away from the wall. Because it’s rated for spaces up to 930 square feet, the Coway Airmega 250 is best for large open spaces, and likely not best for a bedroom.  

Coway Airmega 250 air purifier

(Image credit: Kasandra Brabaw)

Coway Airmega 250 review: How easy is it to use?

Our tester had a little bit of difficulty using the Coway Airmega 250. While taking it apart to remove plastic wrap around one of the filters, she struggled to get one corner of the front panel loose, but had no problems putting the air purifier back together. She also found the buttons on the air purifier a little confusing. Although the purifier has a power symbol in the left corner, it is not an on/off button. Instead, it indicates when the air purifier is on. To turn the Coway Airmega 250 on, you change either the fan setting or turn it to Smart or Rapid modes. A Sleep function shuts the air purifier down when you don’t need it running. 

Otherwise, the Coway Airmega 250 is an easy air purifier to use. The LED light bar is easy to read, switching between the three different fan speeds and the different modes is done with just a tap, and a simple button allows you to set a timer for one hour, four hours, or eight hours. Once you figure out how to turn the Coway Airmega 250 on, you can set it and forget it.

Coway Airmega 250 review: Performance

To test how quickly the Coway Airmega 250 absorbs particles, we tested it on both its lowest and highest settings, measuring the number of particles in the air with an air quality detector. And to make sure there were plenty of particles for the air purifier to suck up, we did a test after lighting 10 matches and another after burning five incense. 

Even though our tester has two cats and lives in New York City, the air quality in her apartment was already good when she first ran the air purifier. Still, the Coway Airmega 250 reduced particles of 0.3 microns by 10% within 15 minutes on low and by 24% during the same time period on high. The number of particles of each of the three sizes the air quality monitor measured significantly increased after burning the matches, which let us better see how quickly and efficiently the air purifier cleared the air. 

Coway Airmega 250 air purifier

(Image credit: Kasandra Brabaw)

In 15 minutes on low, the Coway Airmega 250 cleared 44% of the smallest particles the matches released, and cleared 66% on high. Incense reduced the air quality even more, so much so that the air quality monitor could no longer measure how many of the smallest particles were in the room. However, after 15 minutes on low, the air purifier cleared 83% percent of particles of 2.5 microns and cleared 74% of the 0.3 micron particles in 15 minutes on high. 

These numbers might be slightly exaggerated compared to how the air purifier would work in a 930 square foot room, as our tester’s largest space was 619 square feet. 

Coway Airmega 250 air purifier

(Image credit: Kasandra Brabaw)

Coway Airmega 250 review: What’s good about it?

The Coway Airmega 250 is an excellent air purifier that effectively and quickly reduces particles and odors. We like the ability to set the air purifier on a Smart mode that adjusts the fan speed based on the quality of the air in the room, ultimately saving energy and time. If you’re happy with Smart mode, you could put the air purifier in the corner of your room, turn it on once, and forget about it until you need to change the filter. 

Rapid mode is a unique feature of the Coway Airmega 250, which we like because it helps to quickly clear the air in cases when your air quality turns bad — for our tester, that often happens when she’s searing a steak. Rapid mode circulates the air at maximum power until the air is clean. 

We also like that the Coway Airmega 250 has both a HEPA filter and an activated carbon filter, meaning it’s able to remove odors as well as volatile compounds.  

Coway Airmega 250 review: What’s not so good about it?

There’s a lot to like about the Coway Airmega 250 — a high-powered, smart air purifier. But one thing you might not love is the price. This air purifier is expensive at $300-$400. If you have serious air purity needs, like concerns about chemicals in the air or allergies to pollen or dust, then the price may be worth it. But if you’re not too concerned about your air quality, there are many air purifiers that can take care of your needs at a fraction of the cost. 

Coway Airmega 250 review: User reviews

The Coway Airmega 250 is extremely well-rated, with 4.5 stars on Amazon and five stars on the company’s website. Reviewers like the sleek design, but are most impressed with the quality of the air purifier. One Amazon reviewer wrote: “I’ve been coughing a lot less and my nose and eyes are clearer in the mornings.”

There are very few negative reviews, but a couple of people complained about the fan wobbling and causing the machine to vibrate. 

Coway airmega 250 air purifier

(Image credit: Kasandra Brabaw)

Should you buy the Coway Airmega 250?

In our opinion, the choice to buy or not buy the Coway Airmega 250 comes down to how worried you are about the quality of your air. If you’re someone who would greatly benefit from such a powerful and effective air purifier, because of dust or pollen allergies, it can be worth the cost. If you’re looking for a more affordable model, or one that goes well in your bedroom, you might be better off with another model. 

Coway Airmega 250 review: If this product isn’t for you

As we mentioned, there are many other, cheaper air purifiers you can choose from. In fact, our tester has and loves the Levoit Core 400S, which is on our list of the best air purifiers. The Levoit is also a smart air purifier that uses the same color code to show you the quality of the air and has an auto mode that adjusts the fan speed based on the air quality at the time. It’s a great option, and cheaper at about $200. 

If you want to go a little more bare bones, we’d recommend a different Coway air purifier — the Coway AP 1512 HH. You can get this air purifier for under $200. This one is best for smaller spaces, as it’s rated for 361 square feet. 

Finally, we’d suggest one of the most affordable options — the KOIOS EPI810. You’ll get this air purifier for about $50. It’s a small, compact purifier that covers 269 square feet and doubles as a night light. 

Kasandra Brabaw
Live Science Contributor

Kasandra Brabaw is a freelance science writer who covers space, health and psychology. She has a bachelor's degree in science and a bachelor's degree of arts from the University of Syracuse; she completed her master's of arts degree in journalism at Syracuse University in 2014. In addition to writing for Live Science and our sister site, Kasandra has written for Prevention, Women's Health, SELF and other health publications. She has also worked with academics to edit books written for popular audiences.