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AIRMEGA 300 vs 300S vs 400 vs 400S: Air Purifier Comparison

Air purifiers are the latest trend in home hygiene products. Quality air purifiers are easy to come by, but the ones made for large spaces aren’t always the most attractive appliances. If you need a large-room air purifier that looks as great as it performs, get the Airmega 300, 300S, 400 or 400S by Coway.

Coway Airmega Comparison
Airmega 400S

Each one contains all the filters required for comprehensive air cleaning, and the pre-filter is reusable. An air quality indicator lets you know the current state of the surrounding air’s health. Plus, they all allow you to customize the fan speed and runtime. If you’re a tech fanatic, the 300S and 400S offer Wi-Fi connectivity. From the mobile app, you can set a schedule, receive alerts and more.


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Multi-Speed Fan and Coverage Area

All four of the Airmega air purifiers feature a three-speed fan that you can manually control. Whether they’re set to the 52-decibel high level or the 22-decibel low level, these air purifiers provide quiet performance as they collect dirty air from both sides of the unit and release clean air from the top.

There is even a smart mode that automatically adjusts the fan speed per the air quality. If you want to conserve electricity, eco mode stops and starts the fan to maintain a good air quality without wasting energy.

Airmega Air Purifiers
Airmega 400

Airmega 300 and Airmega 400
At 57 watts, the Airmega 300 and 400 are low-energy users. Both air purifier models can cover as much as 1,256 square feet while circulating the room’s air twice in 1 hour. In rooms up to 628 square feet, the air charge rate increases to four times per hour.

Airmega 300S and Airmega 400S
Although their 66 wattage is higher than that of the 300 and 400, the difference is minuscule. These S models are designed for extra-large rooms in mind, covering 1,560 square feet of space at an air charge rate of two times per hour. When in 780 square feet rooms, the ACH rate doubles.

Filters and Air Quality Indicators

Inside of the air purifiers, there are four filters. If you take off both side panels on any of the Airmega models, you’ll see a washable pre-filter that captures coarse particles like hair. Behind the pre-filter, there is a Max2 filter. The odor-reducing Max2 is a true-HEPA filter, which means it traps 99.97 percent of particles as small as 0.3 microns.

AIRMEGA 300 vs 300S vs 400 vs 400S
AIRMEGA 300

Airmega 300 and Airmega 400
On the front panel of the Airmega 300 and Airmega 400 air purifiers, there is a double-ring indicator that displays the current indoor air quality. Blue rings indicate a good air quality. Moderately polluted air causes the rings to turn purple.

Pink means the air is unhealthy, and red indicates the air is very unhealthy. There is also a separate indicator that illuminates when either filter needs attention.

Airmega 300S and Airmega 400S
The two-ring air-quality indicator on the Airmega 300S and Airmega 400S are two-toned. Blue and green mean the air is good while pink and red indicate the air is very unhealthy. In between the two extremes, there is moderately polluted, which turns the rings green and yellow, and unhealthy, which changes the indicator to yellow and pink. The 300S and 400S also have a filter indicator; however, the filter life is displayed in 20-percent increments.

Coway Airmega 300
AIRMEGA 300 vs AIRMEGA 300S

Controls and Wi-Fi

Coway’s Airmega air purifiers are equipped with manual controls and backlit indicators, which are located on the top panel of each unit. To make it easier to find them in low lighting, Coway used concave buttons. From the control panel, you can change the fan speed, turn off the air-quality indicator and set a timer. When you power on any of the air purifiers, you’ll hear a pleasant chime sound.

Airmega 300 and Airmega 400
If you aren’t into smart appliances, you’ll be more than pleased with the 300 or the 400 model. Despite the lack of Wi-Fi connectivity, these air purifiers still have plenty to offer. The controls are clearly labeled and logically illustrated, and you can enjoy automation in terms of the fan speed and 8-hour timer.

Airmega 300S and Airmega 400S
Put your iPhone or Android to work with the Airmega 300S or 400S. These two Wi-Fi-equipped models are a breeze to set up – just download the Coway IoCare app, pair your phone to the purifier and launch the home screen.

With the mobile app, you can flesh out an operation schedule, receive indoor and outdoor air quality reports and adjust smart mode’s sensitivity. The 300S and 400S are even compatible with Alexa for voice control and the Amazon Dash Button for filter orders.

AIRMEGA 300
AIRMEGA 300

Sleep Mode and Size

If light or noise bothers you when you’re asleep, you don’t have to toss and turn to enjoy clean air. The Airmega air purifiers will go into sleep mode if the purifiers are set to the smart option. When the room is dark for 3 minutes and the air quality is good, sleep mode engages, turning off the indicator light and lowering the fan speed.

Airmega 300 and Airmega 300S
With their pure white housing atop four tapered peg legs, the Airmega 300 and 300S give off a strong mid-century modern vibe. In their entirety, the air purifiers measure 13.6 by 13.6 inches in width and depth and 20.1 inches in height. Two recessed handles give you a firm grip on the 21.4-pound purifiers when carrying them.

Airmega 400 and Airmega 400S
Coway chose to keep the same clean, modern style for the 400 and 400S as it did for the 300 and 300S, and we don’t blame them! At 24.7 pounds, the 400 models are slightly heavier than the 300s, but they are still manageable to move, especially when holding them by the side handles. They are also larger, measuring 1.2 inches more in width and depth and 2.7 inches in height.

Airmega 300S Air Purifier
Corway Airmega 300s

A Purifier for Everyone

Get all the functions you expect from a top-of-the-line air purifier and even some premium features at a price point that won’t empty your bank account. The air purifiers monitor the air quality, offer three fan speeds, look fantastic in almost any space and contain a pre-filter and a carbon-lined HEPA filter. Want to add to your smart home appliance collection, there are Airmega air purifiers with Wi-Fi too.

If you’re having a tough time deciding which Airmega air purifier to buy, here’s a simple breakdown. The Airmega 300 is perfect for large, enclosed rooms, and the Airmega 400 works great in open-living areas. If you want a Wi-Fi enabled air purifier, choose the 300S for big spaces and the Airmega 400S for extra-spacious rooms. No matter which Airmega model you buy, you’ll get a stylish, efficient and well-designed air purifier.

Airmega 400S Air Purifier
Airmega 400S

Air Recommended Air Purifiers

Our Pick Perfect for bedrooms, playrooms, and living rooms, the Coway Airmega AP-1512HH is one of the best-performing, most durable, and most economical purifiers we’ve tested.

Most Popular The Levoit Core 300 air purifier has some strong suits, but in our opinion it falls short of carving out a meaningful niche for itself. Its ideal use would be in a small bedroom occupied by someone who is sensitive to noise.

Also Great With high end air cleaning performance and a whisper quiet fan, the Winix 5500-2 is the perfect combination of power and finesse. It cleared airborne particulates out of our smokey testing room faster than any other model.

Best of the Best If you have a large space you want to remove irritants from, We recommend the Airmega 400S. All of Coway air purifiers do an excellent job of attacking indoor pollutants, and we highly recommend any of them. The 400S is designed to accommodate large room sizes.

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About the author

Hi I’m Alex, founder of HouseholdMe.com and I’d like to say thank you for dropping by. Like most of you, the first thing I look at before buying something online is reviews or buying guides. By reading what other people say will help me gauge whether or not a product is good or not.  I am trying to help people find answers, solve problems, and get inspired.

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