Coway AIRMEGA 300S Air Purifier: Trusted Review & Specs

The AIRMEGA 300S (AP-1515G) was a huge gamble from Coway, yet one that really paid off six months into our testing. A huge jump from the previous low-range air purifiers, with mid-range to high-range cost, premium design and a bunch of new Smart features. It totally replaced the Coway AP-1511FHE, which is designed to reach the high-end level, but will never achieve it. By far, we finish our AIRMEGA 300S Review to help Breathe Quality’s readers know if they should buy this air purifier or not.

Coway AIRMEGA 300S ranks A+ in our air purifier ranking list

In Breathe Quality, we have reviewed all air purifiers under these sections. Also, we guarantee that:

  • We do give honest reviews (both pros and cons) so anyone will guarantee to have the wisest choices.
  • We do not (and never) exaggerate one product just to let you click the links and buy that product blindly.


airmega 300s review

  • Great air filtration process
  • Premium, strong design
  • Large room coverage
  • Smart App Features

  • Lower performance than expected
  • Price fluctuation

The air purifier giant in Korea – Coway is truly the king of East in the industry of air cleaning. Just like Samsung with Apple, Coway has everything in their hands to head on any other air purifier brands with long history like IQAir, Blueair or Austin Air. They put much efforts in the new AIRMEGA brand, both in technical features and marketing promotion. The AIRMEGA 300S is no longer the flagship of this brand, but it always is the beginning of a stunning concept. Now, you should be ready for our AIRMEGA 300S Review.

Other Coway’s Air Purifier Reviews:

AIRMEGA 300s Price

Coway themselves is calling it the future of the air purifiers, the embodiment of what it’s been trying to achieve for many decades. And they have good reasons to back up the ideas, as AIRMEGA 300S has an undeniable beauty, as well as lots of high-end features that will create an all-new experience for Coway fans.

And the AIRMEGA 300S is exactly the air purifier we’ve been demanding from a well-known brand for years, a world away from the increasingly-tired designs that many others keep repeating. For that change, the AIRMEGA 300S charges us a lot more for the privilege, which we have never seen in any previous Coway devices. However, we all want to know if the AIRMEGA 300S is worth having or not.

The AIRMEGA 300 (the no-app model) starts at $549, while the AIRMEGA 300S will cost you at least $649. The price of the AIRMEGA 300S is exactly the same with the next no-app model AIRMEGA 400. Although it’s expensive for sure, you can use our Amazon deal below for a great discount right now, so the AIRMEGA 300S can go as low as $309. Also, I suggest you to look for the Coway AP-1512HHS as a smaller smart air purifier version, made by Coway.

This price is also the region of the Blueair Classic 405 and Blueair Classic 480i. And don’t forget our champion for the best air purifier – the Rabbit Air MinusA2. All three air purifiers are the best devices you could get for the price, with unmatched performance and Smart features as well. If you demand the best customer service for your air purifier, either the Alen BreatheSmart or Medify MA-112 could be your next purchase.

We also notice the presence of the Dyson Pure Cool Tower and Dyson Pure Cool Link in the same price range. These air purifiers, besides the True HEPA filter, are having an amazing cooling fan power to help you survive the summer time. The Dyson Pure Hot+Cool, with a little bit higher cost, will come with the heating power as well.

Now is our best deal for the AIRMEGA 300S. You should remember that Coway mainly sell their products via Amazon in the U.S, so you don’t want to miss our deal.

Top AIRMEGA 300S deals right now

Coway AIRMEGA The Smarter App Enabled Air Purifier (Covers 1256 sq. ft.), Compatible with Alexa.

The beautiful White edition of the high-end air purifier. Pay as low as $23/month. Free Shipping. 30-day Satisfaction Guarantee.

Related post: Best air purifier 2022.

AIRMEGA 300S Design and Size

As I’ve already mentioned, Coway has taken a fresh approach to design with the AIRMEGA family. An air purifier with unique design that we will definitely realize as a device from AIRMEGA.

We can’t see any familiar old parts in this AIRMEGA 300S, being the iPod-shape of Coway AP-1512HH or the traditional design in AIRMEGA 200M. What you will sense when having an AIRMEGA 300S for the first time is that this is a premium air purifier. It feels more expensive, with a brighter tone color, as well as a intuitive light alert right at the center of AIRMEGA 300S.

If you are looking for the standard version named AIRMEGA 300, you can get it with the below deal. Both versions have the same design and power, only with the difference of Wi-Fi connectivity feature.

Coway AIRMEGA 300S Air Purifier: Trusted Review & Specs

Instead of using a stand, this AIRMEGA 300S has 4 legs, which give us a feeling of stable and solid build. Also, the air purifier is mostly built from metal, and I don’t feel that it could be broken by anything.

Compared with the AIRMEGA 400S, this air purifier is slightly smaller with only 21.2 inches in height and 13.6 inches in both depth and width. However, such slight changes don’t make us more difficult in using AIRMEGA 300S than its brother. In day to day use, I can easily touch the control panel on top.

Talking of the air flow design concept, AIRMEGA 300S uses a 360 Degree air intake grills. However, unlike the previous air grills of Coway, the grills of AIRMEGA 300S consists of small holes to increase the resistance against the large objects. This concept is similar to another Korean brand, with their Winix C535, but this is the only part we can compare between these air purifiers. AIRMEGA 300S is, of course, at a much higher level.

On top of this AIRMEGA 300S, this company has made a bigger air outlet grill that covers almost the whole top. There is only a small on/off button from the right and two reset buttons on the left. Coway truly wants their flagships to be easy to use.

airmega 300s review

Source: Amazon

The AIRMEGA 300S is about 21.4 lbs, which is not the kind of air purifier you can bring anywhere in the world. However, for normal day-to-day using, you can move this air purifier without any trouble.

Related post: Best air purifiers for bedroom.

AIRMEGA 300S Filters

Coway is always proud of their air cleaning system, which consists of at least 4 different air filters. Normally, to decide the performance of one air purifier, we always look at the number of its air filters and the air filter types are used first. But like I said earlier, the AIRMEGA 300S is a huge gamble from this brand. Not only it has a new design concept and a brand new name, it has only an all-in-one air filter.

  1. Pre-filter – First, the AIRMEGA 300S still use a powerful washable pre-filter, which is available to help you capture large objects of contaminants. Remember to dry the pre-filter in the shade before re-installing it.
  2. Max2 filter – A combination of both Activated Carbon Filter and True HEPA filter, this filter can both capture up to 99.97% of airborne particles 0.3 microns. It also reduces more than 99 percent of volatile organic compounds and reduces fumes such as NH3 and CH3CHO.

Actually, the concept of all-in-one air filter is not new. Blueair has used in since their very first beginning, and even the new American brands like Alen and Levoit all favor using the all-in-one air filter.

Now, the flagships of Coway are using the Max2 filter, which remains the same high quality from the previous True HEPA filter of this company, as well as improves the Activated Carbon filter. On to day-to-day use of the AIRMEGA 300S, this air filter stacks up more and more impurities, and I can breathe easier thanks to it.

For a strict test, I choose the Blueair Classic 405 and Alen BreatheSmart to test the AIRMEGA 300S. Because both the non-Wi-Fi AIRMEGA 300 and Wi-Fi-enabled AIRMEGA 300S are using the same internals, I believe that the performance test can be used for both devices.

My testing conditions: A room of 300 square feet, running in one hour.

With a room coverage way much smaller than what Coway advertised, the AIRMEGA 300S scored an efficiency of 99.95% trapping any allergens as small as 0.3 microns, while the Blueair Classic 405 was 99.97%. The Alen BreatheSmart was down to only 98.5%, and if you try the Alen BreatheSmart FIT50 in the same test, its efficiency was only 97%.

airmega 300s review

AIRMEGA 300S uses exactly the same quality air filter as its brother – the AIRMEGA 400S. Maybe this is the top reason why the air filter cost is too high, up to $99. For an air filter that is only good for one year, will you scream in pain? But wait, the Blueair Classic 405‘s filter cost is $59, but needs to be replaced after 6 months. As you can see, $99 is just $0.2 you pay per day for your cleaning air. That’s decent, right?

Related post: Best air purifiers for allergies.

AIRMEGA 300S Room Coverage

AIRMEGA 300S has larger room coverage than any previous air purifiers from this brand, with 1256 square feet to use. That’s quite large, but in a high-range level where all air purifiers are for large room, it makes sense.

Remember that the room coverage is only for 2 air changes per hour. If you use this air purifier in a room of 628 square feet, the ACH rating will double to 4X.

The ACH of AIRMEGA 300s is 2X to 4X. For a high-range air purifier, this ACH is on par with Rabbit Air MinusA2, as the AIRMEGA 300S will clean your room every 15 minutes.

The CADR of AIRMEGA 300S is again not told in the manual. But through many tests, I recorded a reliable CADR of 300 Dust/ 310 Smoke/ 340 Pollen. For a room coverage of 1256 square feet, this CADR rating is quite insufficient, and the AIRMEGA 300S will need more time to clean the room.

Related post: Best large room air purifiers.

AIRMEGA 300S Sound

Coway has a good tradition at keeping their air purifiers operate in silence. To achieve that, this company always uses smaller fan, and sacrifice the fan power for the low noise level.

On the lowest fan speed, AIRMEGA 300S has a very low noise level of 22 decibels, which is exactly the noise level of rustling leaves. This is even better than the ultra silent operation of the Rabbit Air MinusA2.

Even if you are running on the highest speed, the noise level is only 52 decibels (db), and because the AIRMEGA 300S produces white noise, you can easily sleep while running this air purifier.

Related post: Best air purifiers for baby.

AIRMEGA 300S Power Consumption

One of our most FAQs is “Do air purifiers use a lot of energy?” The fact is you need to use air purifier for a long time to be efficient. It is especially important for the large room air purifiers, as they always have big fan and need more energy to operate.

The power consumption of our AIRMEGA 300S is only 57 watts, which is quite reasonable to use. Actually, in this price range, others like Blueair Classic 405 and Alen BreatheSmart consume nearly the same energy as the AIRMEGA 300S.

The AIRMEGA 300S is also an air purifier with Energy Star rating for being energy efficient. This is the government-backed symbol to ensure you to get the most efficient air purifier.

So to say, if you run the AIRMEGA 300S 8 hours per day, it would cost you $21 each year.

Related post: Best air purifiers for pets.

AIRMEGA 300S Additional Features

The keyword for any modern high-end air purifiers is “Smart”. AIRMEGA 300S is not an exception, as it is one of the most progressive air purifiers at the moment. And we will see if this air purifier is truly what Coway should be applauded for or not.

First is the real-time air quality monitor of this AIRMEGA 300S, which is indeed the Smart Sensor, and will detect the indoor air quality every minute. Below is all the statuses of the LED ring that Coway show you how clean or dirty your indoor air is.

airmega 300s review

Moreover, AIRMEGA 300S will switch to the Auto Mode, and automatically adjust the fan speed according to the room’s current air quality. For example, if your room’s air quality is very unhealthy, AIRMEGA 300S will run on highest fan speed to clean the room faster. Otherwise, it will keep on the lowest speed for the good air quality.

Coway also the only brand features the Eco Mode, a signature name for all Coway products. When the air quality in the room remains purified for 10 minutes or more in Eco Mode, AIRMEGA 300S will completely turn the fan off to conserve energy. This is a very smart concept, and only for the brand with a very accurate air sensor like Coway to utilize. Therefore, we can think of the Eco Mode as the unique selling point of all Coway products.

Just like any high-end devices, the Smart Wi-Fi connectivity function is another plus for this air purifier. With the IOCare app, you will get the real-time air quality notifications, set the unit timer and even activate the air purifier remotely when connected to Wi-Fi. Notice that the AIRMEGA 300 edition won’t have this feature.

Finally, you have a manual Sleep Mode, which is in fact running the AIRMEGA 300S in the lowest fan speed. The indicator for filter replacement works great, too.

Related posts:

1, Best air purifiers for smoke.

2, Best air purifiers for dust.

3, Best air purifiers for mold.

AIRMEGA 300S Customer Service

As one of the top electronic brands in Korea, Coway is somehow as huge as Samsung. This brand not only carries out clean innovations for the customers, Coway also delivers their direction as Coway Trust. That’s why Coway always strongly focus on their customers and community. With global subsidiaries and regional dealerships that serves over 60 countries, you should believe in the 3-year warranty for every product from Coway brand.

Moreover, you can contact them via phone at 800-285-0982, or via email at Normally, they will try to contact you back within 24 hours.

Top AIRMEGA 300S deals right now

Coway AIRMEGA The Smarter App Enabled Air Purifier (Covers 1256 sq. ft.), Compatible with Alexa.

The beautiful White edition of the high-end air purifier. Pay as low as $23/month. Free Shipping. 30-day Satisfaction Guarantee.

Our verdict

The design of Coway AIRMEGA 300S is sleek, and the features are so, so good. This air purifier is exactly the first step Coway take into the high-range market, and that is the new standard they have set.

  • Performance
  • Features
  • Annual Cost
  • Design
  • Price


If you are happy to spend for this AIRMEGA 300S, then you won’t be disappointed.