Photo of AIRMEGA 300

Are you thinking about buying the Coway AIRMEGA 300 or 300S air purifier, but not sure if these are the right products for you?

Do these models really deliver outstanding airflow as they claim?

Or is it all just hype?

If you’re looking for a comprehensive Coway AIRMEGA 300 review, then you’ve come to the right place.

In this post, we’ll go over the most important aspects of this machine so you can find out if this is the best home air purifier choice or not.

Overall, the 300 series are high-quality devices that offer a lot of value for the price and are great for anyone who needs a large amount of air cleaning coverage.

Now, let’s find out more about what makes these air purifiers stand out.

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Coway AIRMEGA 300 Review

When you’re shopping for the Coway AIRMEGA 300 air purifier, you’ll find that it comes in two versions:

The only difference between these two models is that the 300S version is smart-enabled.

Everything else about the two air purifiers works the same.

So consider this a combined AIRMEGA 300 and AIRMEGA 300S review.

With the AIRMEGA 300S you get the added benefit of Coway’s mobile application that provides:

  • Complete air purifier control with a smartphone or tablet
  • Indoor and outdoor air quality monitoring
  • Filter change notifications
  • Flexible scheduling
  • Alexa voice control

If smart controls are important to you, then the 300S will be the better buy. If not, the AIRMEGA 300 can save you about $100.

AIRMEGA 300 Air Filter Types

The AIRMEGA 300 series includes two powerful air filters:

  • Pre-filter — This is the first line of defense against airborne pollutants. It captures the largest particles, like dust, hair, and dirt, in a fine micromesh material. It also extends the life of the Max2 filter.
  • Max2 Filter — This is a high volume filter that combines two filters in one:
    • True HEPA Filter: Captures 99.97% of ultrafine particles down to 0.3 microns in size, such as allergens, mold spores, bacteria, and particulate matter (PM2.5).
    • Activated Carbon Filter: Reduces 99% of Volatile Organic Compounds (VOCs) and fumes such as NH3 and CH3CHO which are toxic substances commonly found in indoor air.

The pre-filter is washable and permanent and never needs replacement.

The all-in-one Max2 Filter is not washable and therefore needs to be replaced every 12 months. If your air is less polluted than usual, then it could last longer.

The average cost for replacing the Max2 Filter is $80 which is about the same as other competing large room air purifiers.

See the Filters on

AIRMEGA 300 Room Size Coverage

The real power behind the AIRMEGA 300 air purifier is the room size coverage.

It handles a massive amount of space at 1,256 square feet (sq. ft.)

In fact, not many other air purifiers are rated to cover rooms as large as this machine.

The AIRMEGA 300 air purifier is perfect for areas such as:

  • Open floor plans (a combination of living/dining/kitchen rooms)
  • Finished or unfinished basements
  • Garages and workshops
  • Office spaces

ACH Rating

Air Changes Per Hour (or ACH Rating) indicates how many times per hour an air purifier can exchange the full volume of air inside a room.

The higher the number, the better it is.

To cover such a large amount of space (1,256 sq. ft.), the AIRMEGA 300 has to lower its ACH to 2X per hour.

For people without any serious sensitivities, a 2X ACH rating is usually fine; however, if you suffer from severe asthma or allergies, then you really want an air purifier that has a 4X or higher ACH rating.

If you like the AIRMEGA 300 though, you can effectively double the ACH rating to 4x though by using it in a room that’s half the size it’s been recommended for.

For example, the AIRMEGA 300 can achieve a 4X ACH rating in a room that’s up to 628 sq. ft. (1,256 sq.ft. ÷ 2 = 628 sq. ft.)

CADR Rating

Some air purifier manufacturers conduct an independent test on their products by the Association of Home Appliance Manufacturers (AHAM) to get a verified Clean Air Delivery Rate (or CADR).

The CADR provides a separate score for filtering out tobacco smoke, pollen, and dust particles. This helps boost consumer trust in the product.

This air purifier doesn’t have that verification, so we can’t give you those numbers in our Coway AIRMEGA 300 Review.

Not having a CADR rating doesn’t necessarily make this a bad air purifier. Some manufacturers simply don’t choose to pay for a third-party test.

AIRMEGA 300 Review Photo 2

AIRMEGA 300 Top Features

Below, are the most standout features of the AIRMEGA 300 series:

  • Instant Air Quality Indicator — Displayed as a ring of color lights on the front of the unit.
    • Blue= Good
    • Purple = Moderate
    • Pink = Unhealthy
    • Red = Very Unhealthy
  • Dual Suction — Air is drawn in from two sides of the unit which cleans it faster and more efficiently than air purifiers with a single intake system.
  • Eco Mode — The unit automatically turns off if air quality is good for 10 minutes or more. When air quality lowers, the unit will automatically turn back on again. This maximizes energy savings and extends filter life.
  • Remote, Touch Panel, and App Controls — The 300 model includes a remote control in addition to the modern touch panel buttons. The 300S gives you another level of control with a mobile application.
  • Quiet — Noise levels range between 22~52 dB which is very quiet. Only the highest speed is considered loud.

See More Features on

AIRMEGA 300 Design and Size

Coway took a fresh approach with this air purifier.

In many ways, it’s one of the most unique and modern looking air purifiers you’ll find today.

The sleek exterior is built in a box shape with four legs to make it blend in and look more like a piece of furniture than an air purifier machine. People often mistake it for an audio speaker or a side table.

As for exact dimensions and weight, these include:

  • 21.2″ (H) x 13.6″ (W) x 13.6″ (D)
  • 21.4 pounds

White is the only color option for the AIRMEGA 300.

If you upgrade to the 400 series, you can get the additional variant of graphite. You can view our Coway AIRMEGA 400 Review here.

Who is the AIRMEGA 300 Air Purifier for?

The people who would benefit most from this air purifier include:

  • Allergy sufferers
  • Anyone with multiple chemical sensitivities
  • Those who like to cook and want to reduce odors
  • People exposed to high levels of outdoor PM2.5 air pollution (i.e. city living)
  • Light smokers
  • Anyone with large rooms to cover (this model is featured on our best large room air purifier page)

AIRMEGA 300 Warranty Information

Coway offers an exceptionally long 5-year limited warranty on the motor and electric parts.

That’s much better than the standard one to two-year warranty that other brands provide.

What Others Have to Say About the AIRMEGA 300 Series

Still not sure if this is the right air purifier for you?

Check out more Coway AIRMEGA 300 reviews and AIRMEGA 300S reviews on Amazon to see what other people have to say about it.

See Reviews

We hope those comments and this review are beneficial in helping you make a final decision.