Coway Airmega 300 VS 400: Detailed Air Purifier Comparison

  • Author: Irene Batres
  • Date: March 25, 2023
  • Time to read: 7 min.
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When it comes to air purifiers, there are certainly a lot of them on the market today.

While not all air purifiers are alike, the Coway family of air purifiers is second to none.

In this article, we’ll be comparing two of their most popular models – the Airmega 300 Versus the Airmega 400.

If you’ve been considering either one of these and would like to learn more about them first, you’ve come to the right place.

Coway Airmega 300 Versus 400: Quick Side-by-Side Comparison

Coway Airmega 300Coway Airmega 400
Dimensions13.58 x 20.94 x 13.58 inches14.8 x 22.91 x 14.8 inches
Weight21.4 Pounds24.7 Pounds
Energy Star certifiedYesYes
Fan Speeds5 fan modes: Smart, Sleep, Low, Medium and High5 fan modes: Smart, Sleep, Low, Medium and High
Warranty1 year and motor and electronic parts for 5 years1 year and motor and electronic parts for 5 years
Filtration3 Stage, comes with Comes a washable pre-filter, Activated Carbon, and a True HEPA FilterPre-Filter+ Carbon + True HEPA
Nose Level52 dB. At the highest settingLow: 25 dB, medium: 50 dB, high: 60 dB.
Auto ModeYesYes
Timer1, 2, 4, and 8 hoursTimer 1, 4, 8 Hr
Power Consumption57 Watts65 Watts
Sleep ModeYes ManualYes, Automatic
Room Coverage1,256 sq. ft.1,560 sq. ft.
PriceCheck Latest PriceCheck Latest Price

The Airmega 300 and 400 air purifiers are alike in many ways but very different in others.

In some ways, the Airmega 400 is an advanced version of the 300 because the company kept most of the good features and expanded and added to them.


in turn, created a more perfect version of the Airmega 300. Here are some of the main attributes of each of these machines:

  • Square foot coverage: 1,256 (300) versus 1,560 (400) 
  • Sleep mode function: manual (300) versus automatic (400)
  • ong>Power consumption: 57 watts (300) versus 65 watts (400)

Between these two models of air purifiers, the decibel levels, three-stage filtration system, and air intake are all the same.

Simply put, the 300 and 400 models of the Coway Airmega air purifiers have more similarities than differences, but the differences can be significant to some people.

For i

nstance, the 400 covers about 300 square feet more than the 300 model, but 300 square feet is a lot. 

The sleep mode on the 300 is manual and automatic on the 400. That means that the 400 models, can automatically detect when it gets dark and then puts the unit into sleep mode.

Sleep mode reduces the consumption of the machine, so this one feature alone can save you a lot of money on your utility bill.

You s

hould also keep in mind that even though the Airmega 400 is a 66-watt machine, this is because it is a lot more powerful than the Airmega 300 model, which only uses 57 watts. So while the number is bigger, there’s a good reason for it.

Differences Between Coway Airmega 300 Versus 400

One of the biggest differences between the Airmega 300 and Airmega 400 is the square footage they cover, with the 400 covering 1,560 square feet and the 300 covering 1,256 square feet. 

The Airmega 400 also has a better air-purification system, which basically means it purifies the air much faster than the Airmega 300.

The num

bers look like this – these are the clean air delivery rates for each model:

  • For smoke: 285 for Airmega 300 versus 328 for Airmega 400
  • For dust: 306 for Airmega 300 versus 328 for Airmega 400
  • For pollen: 339 for Airmega 300 versus 400 for Airmega 400

This means that the Airmega 400 is more efficient and will purify the air faster than the Airmega 300.

Other differences include the sleep mode function.

Both unit

s have this function, but it is manual on the 300 model and automatic on the 400 model.

Last but not least, the 300 model is 57 watts while the 400 model is 66 watts.

Nevertheless, they are both energy-efficient and powerful, although the Airmega 400 is a bit more powerful than the Airmega 300.

p-block-heading">Similarities Between Coway Airmega 300 Versus 400

As already mentioned, the Coway Airmega 300 and 400 air purifiers have more in common than they do differences. Let’s take a look at some of them.

Air Intake

Both models take in air from both sides of the unit, then push air from an outlet located at the top of the unit. Known as a double air intake, it allows the air to be purified much faster.

Three-stage Filtration System

The system includes a pre-filter, a true HEPA filter, and a carbon filter. What makes the system special is that the carbon and HEPA filters are combined into one filter, known as the Max2 filter. This one feature makes maintenance a whole lot easier. In both models, the pre-filter is made to catch large particles in the air, and it is also washable.

block-heading">Air Filter Indicator

Both units have two air filter indicators: a pre-filter indicator and a Max2 filter indicator. If the pre-filter becomes too dirty, the indicator will let you know this. When the Max2 filter is clogged and needs to be replaced, the indicator will let you know this as well.

Air Quality Monitoring

Found in both models, this feature monitors the quality of the air in real-time and even displays it using an LED ring located at the front face of the unit. It changes color to inform you about the air quality so that at any given moment, you know exactly what it is.

Timer Mode

This feature allows you to set how long you want the air purifier to run, and you can schedule it to run for 1, 4, or 8 hours at a time.

block-heading">Smart Auto Mode

The way these feature works is simple. If the unit detects that the air quality is bad, it will automatically increase the fan speed. If it’s good, the unit will choose the best fan speed for that scenario. 

Smart Eco Mode

This feature essentially helps you conserve energy by automatically turning the fan off when the air quality is clean for 10 minutes. This goes a long way in helping you conserve energy in both models.

Product Overview Of Coway Airmega 300

Product Overview
Coway Airmega 300
  • Designed to accommodate room sizes up to 1,256 square feet
  • Easy and fast to
    set up
  • LED indicators display air quality in real-time
  • Energy Star certified
  • Warranty- 1 year
    and motor and electronic parts for 5 years

The Coway Airmega 300 has numerous pros and a few cons, including the following:



Product Overview of Coway Airmega 400

Product Overview
Coway Airmega 400
  • Designed to accommodate room sizes up to 1,560 sq. ft. 
  • Easy and fast to set up
  • 5 fan modes: Smart
    , Sleep, Low, Medium, and High
  • Has an indicator to let you know to wash the pre-filter
  • Energy Star certified
  • Runs Very Quiet!
  • Warranty- 1 year and motor and electronic parts for 5 years

Here is a list of the pros and cons for the Airmega 400:



Coway Airmega 300 Versus 400: Feature Comparison

In case you’d like to see some of the main features of the Coway Airmega 300 and 400 models, here is a side-by-side comparison that provides a lot of details about each unit.

Other Things To Keep In Mind

The Coway Airmega 300 is perfect for large rooms and smaller apartments, whereas the Airmega 400 is best for very large spaces. Keep in mind that neither of these air purifiers is small.

They will not sit daintily on a countertop or table. They are made to go on the floor and can sometimes be almost as large as a nightstand.

To demonstrate, t

ake a look at the dimensions of each of these models:

In other words, both mo

dels are on the large side, but of course, they are also very powerful air purifiers so most people consider that feature to be insignificant.

Just make sure you’re positive where you want it placed before you move it to a particular location. Relocating it to another spot might prove cumbersome.

The prices, however, only vary slightly. As of this writing, you can get the Airmega 300 for roughly $400, while the Airmega 400 sells for about $520. Both of these prices come from Amazon.

You also have to take into cons

ideration the prices for the Max2 filters, which cost roughly $120 per year for the 400 and around $80 per year for the 300 models.

Bottom Line: What Is A Better Air Purifier – Coway Airmega 300 Or 400?

If you want to learn which of these units is best, just know that the answer depends on what your preferences are. That being said, the Airmega 400 is obviously a more powerful unit than the Airmega 300.

Both are energy-efficient but the 400 offers more room coverage, a convenient automatic sleep mode, better performance, and a better clean air delivery rate.

The 400 does consume a little mor

e power, but its performance and efficiency make it worth it in the long run.

The good news is, both models are getting rave reviews from most of their real-life customers.

This means you can count on them to work the way they’re supposed to work and last for many years to come.

ooking For Air Purifier Guides?

If you’re looking for more air purifier resources, consider checking out our other post on air purifiers.

irene mills author of freshairdevices


Irene Batres is eager to help others create an indoor allergen-free home. She has years of experience testing out air purifiers, dehumidifiers, and other products designed to help with indoor air quality. Learn more about me.

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