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Coway Airmega 400 HEPA Air Purifier Review

Finding the right dehumidifier is essential for your home, and you need to make sure that you are thinking about your options.

If you are looking for something that will claim to get rid of any smells, dirt, and pollution in the air, you need to make sure you are checking out the reviews.

I reviewed the Coway AirMega 400 HEPAAir Purifier for you today, so you can keep reading to learn more about this product.

Coway Airmega 400 Smart Air Purifier for whole house

Prices pulled from the Amazon Product Advertising API on:



  • Heavy, so not easy to carry or shift around very often
  • Larger in size, which takes up a good amount of space

Coway Airmega 400 Design, Size, and Placement

The Coway AirMega 400 HEPA Air Purifier comes in a few different colors you can pick from, including silver/graphite and white.

This unit is just 23 inches tall and 15 inches in depth and width, which means it will need a bit of space, but it won’t take over the entire area.

It weighs some 25 pounds, which isn’t something you want to carry around, so make sure you have the right space for it.

The Coway Airmega 400 boasts a modern and minimalist design, suitable for various interior settings. Its compact dimensions (insert dimensions if available) ensure it doesn’t take up much space while delivering powerful air purification. The build quality is robust, featuring durable materials that enhance longevity and performance.

How it Works and Sources of Indoor Pollution it Destroys

Coway Airmega 400 has three different automatic operation settings that you can choose from that let it decide what it should do. These include:

  • Automatic speed of fans – The machine regularly monitors the air quality and based on the results; it can change the speed that the fans are running for the conditions in the room.
  • Sleep mode – If the room is dark and there has been no change in the air quality for some 3 minutes, the machine will automatically go into sleep mode.
  • Eco mode – This mode is based on the air quality, and if it stays at a reasonable level for around 10 minutes, the machine will automatically turn itself off. When it notices that the air level changes, it will turn itself back on and automatically start cleaning the air again.

These are just a few main ways this specific air purifier cleans the air. It ensures that the air quality is the best for a certain amount of time before it shuts itself off to save electricity. This one is perfect for removing a few different indoor types of pollution, including:

  • Smoke
  • Dust
  • Smells
  • Chemicals

Coway Airmega 400 is ideal for those with asthma or other allergies as it cleans the air to keep one healthy.

Coway Airmega 400 Smart Air Purifier

Prices pulled from the Amazon Product Advertising API on:

Coway Airmega 400 Key Features

  • Real-time monitoring for the air quality, which is color-coded and easily visible
  • Automatic operation with three settings, such as eco mode, sleep mode, and automatic fan speed
  • Dual-sided filtration system with a pre-filter, combined filtration, and notifications for the life of the filters
  • Touch control panel
  • A timer that can turn the machine off based on hourly increments
  • Handles on both sides of the air cleaner for easier moving
  • Plastic, durable covers to protect the filter from damage
  • Outlet cover to protect the fan
  • Five years (limited) warranty for electric parts and motor

Coway Airmega 400 Noise Level

Coway Airmega 400 is one of the noisier ones on the market, with a sound of 55dB when the fan is on, but not so much otherwise.

However, if you don’t have the fans on, it is around 39 dB, and the lowest level it has is 22dB, which is quieter than any normal fan or even a computer.

The only way you would determine that the system is running is to feel the breeze as it comes from the device itself. 

Coway Airmega 400 Coverage, CADR, and CFM

It has a CFM of 410 and 350 for the CADR levels for dust, smoke, and pollen.

Coway Airmega 400 cleans 624 square feet of large spaces every 12 minutes or 5 times per hour. That’s more than 90% of air purifiers on the market can handle.

In my opinion, there are only a few real competitors – AirDoctor 5000, which handles a massive 868 square feet large area, and AirDog X8, which handles 600 square feet.

You might also check Airpura C600 and IQAir HealthPro Plus Air Purifier, but they lack features, are noisy, consume more energy, and are pricey. 

Coway Airmega 400 Maintenance and Upkeep

Coway Airmega 400 can be an expensive air purifier for maintenance due to the filters that should be replaced yearly.

There are two filters, which will cost you around $200; you need to ensure that they are being replaced to keep their activated carbon and HEPA components working to the best of their ability.

It has a Green-True HEPA filter to contain all the dust and other particles in the air. Within the year that the filters are being used, they can be rinsed off and then placed back in the air cleaner, which is perfect if you don’t want something time-consuming.

Coway Airmega 400 also has lights and notifications that will let you know when the filters’ lifespan goes down, which starts with 100% and goes down by 80%, 60%, 40%, and 20%, so that you can order them promptly.

Filtration System

At the heart of the Airmega 400 is its advanced filtration system, designed to tackle indoor air pollutants effectively. It utilizes a dual filtration process:

  1. True HEPA Filter: This primary filter captures up to 99.97% of particles as small as 0.3 microns, including pollen, dust, pet dander, and other allergens.
  2. Activated Carbon Filter: The activated carbon filter efficiently reduces volatile organic compounds (VOCs), odors, and harmful gases, improving overall air quality and freshness.

Performance and Coverage

The Airmega 400 is engineered to purify air in spaces up to (insert square footage coverage). It features a dual suction system that draws in polluted air from two sides, maximizing efficiency. This ensures rapid air circulation and purification, making it ideal for larger rooms or open-plan areas.

Smart Technology

Equipped with smart features, the Airmega 400 offers convenience and ease of use:

  • Air Quality Monitoring: Built-in sensors continuously monitor indoor air quality, displaying real-time feedback via an intuitive LED indicator.
  • Auto Mode: Automatically adjusts fan speed based on detected air quality, optimizing energy efficiency while maintaining clean air.

User-Friendly Operation

Operating the Coway Airmega 400 is straightforward, thanks to its intuitive control panel and remote control functionality. Users can easily select from multiple fan speeds, set timers, or activate sleep mode for quieter operation during nighttime use.

Maintenance and Filter Replacement

Maintaining the Airmega 400 is hassle-free, with filter replacement reminders ensuring optimal performance. The filters are easily accessible and can be replaced without specialized tools, simplifying upkeep and ensuring consistent air purification.


Coway Airmega 400 Smart Air Purifier

Prices pulled from the Amazon Product Advertising API on:

Finding the right air purifier to clean the air in your home, especially if you have a larger one, can be daunting.

However, you should make sure that you are thinking about what features you will want to have in the device and how much air it moves around.

You need to make sure it does to monitor the air quality in the home and then automatically adjust the fan speed to clean the air.

Coway Airmega 400 is perfect for those sensitive to chemicals or other allergic pollens and dust that might be in the air and want something that will clear it out for them.

Check Coway Airmega 200M and Coway AP-1512HH air purifiers for smaller rooms if you prefer Coway over other brands. 

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