Coway AIRMEGA 300S Air Purifier Review

Product: Coway AIRMEGA 300S
Type: Smart Tech and True HEPA
Filtration Stage: 2 Stage Filtration System
Product Warranty: 5 years
Room Coverage: 1256 square feet or 628 square feet

CADR Rating (Smoke, Dust, Pollen): 200 | 220 | 194
ACH Rating:
2X to 4X based on usage
Power Consumption:
57 Watts
Noise Level (db):
43.2 db at highest setting
Annual Filter Costs:
$59.99 per year

  • Reviews by Existing Customers
  • Clean Power
  • Portability
  • Features
  • Power Consumption
  • Price


The Coway AIRMEGA 300S is the best smart air purifier on the market. We RECOMMEND this device if you’re looking for a combination of sleek design, efficiency and performance.



Coway designs high quality air cleaners with their unique Plasmawave Technology and True HEPA filters. Their air cleaners remove 99.97% of particles such as dust, smoke and pollen.

Coway Airmega 300s Air Purifier

Coway AIRMEGA 300S Air Purifier

The Coway AIRMEGA 300S Air Purifier is recommended as the best smart air purifier.

It uses 2 stage filtration system with a washable pre-filter and the Max2 filter consisting of the activated carbon and True HEPA filter.

Coway AIRMEGA 300S Features

2 Stage Filtration System

  1. Washable Fine Mesh Pre-Filter – Designed to catch larger airborne particles found indoors.
  2. Max2 Filter – combined activated carbon and True HEPA filter captures and reduces up to 99. 97% of 0.3 micron particles in the air, including pollen, pollutants and other allergens and reduces volatile organic compounds (VOCs).

Coway AIRMEGA 300S Room Coverage

The Winix HR900 Ultimate is designed for a large room. It can handle between 628 sq. ft to 1256 sq. ft. depending on how many times you want to clean the air per hour.

ACH and CADR Rating

The ACH of this device is 2X to 4X or 2-4 air changes per hour. With its frequent air changes, the device is perfect to improve indoor air quality.

The CADR of Coway AIRMEGA is 260 Smoke | 260 Dust | 260 pollen (cfm).

Coway Airmega 300S Design and Size

The Coway Airmega 300S is one of the best smart air purifiers standing at 21.2 inches in height, 13.6 in width and 21.4 lbs in weight.

Coway Airmega draws contaminated air from two sides and pushes filtered air out the top of the unit, cleaning the air you breathe faster and more efficiently.

The device comes with additional features like the filter indicator, air quality monitor and smart technology which automatically adjusts fan speed based on the room’s air quality.

Noise Level

For a high performing air cleaner, it is relatively quiet. Silent at the lowest setting and 43.2 db at the highest setting (which is still quiet).


The Coway AIRMEGA costs around $474. It is at a good price point for a high end air purifier with smart technology and a sleek design.


+ Complete air purifier control compatible with Alexa and Google Home

+ Large room coverage

+ Indoor and outdoor air quality monitoring


– High cost filter replacement


The Winix HR900 Ultimate Pet Air Purifier is the best for pets. We recommend this device based on the reasoning below:

  • Filtration Quality: The 2 stage filtration system with the washable pre-filter and Max2 Filter combining activated carbon and True HEPA filter. This device filters out 99.97% of particles  including dust, smoke, pollen, pet hair and dander.
  • Smart Technology: The Coway AIRMEGA automatically adjusts fan speeds based on the room’s air quality. That means your unit is energy efficient and high performing.

Where Can I Buy It?

Check the latest price on my number one online trustworthy store, Amazon.


Coway AIRMEGA 300S Air Purifier

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