Coway Airmega 400(G) Air Purifier, Graphite

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Product guide

Coway Airmega 400(G) Air Purifier, Graphite

Graphite: The Coway Airmega 400(G) is a corded air purifier with washable pre-filter, HEPA and activated-carbon filtration, and automatic modes for large spaces. Its listed coverage is up to 3,120 square feet in 60 minutes, so it is aimed at open areas rather than buyers prioritizing a compact footprint.

At a glance

Manufacturer claims coverage of up to 3,120 square feet in 60 minutes.
The filtration system is described as a washable pre-filter, activated-carbon filter and HEPA filter.
Smart Mode adjusts fan speed based on detected room air quality. Eco Mode can stop the fan after 30 minutes of clean air and restart it when pollution is detected.
Sleep Mode reduces noise and power consumption when the room is dark and the air is clean, according to the listing.
An air-quality display and filter-life indicator provide status information on the unit.

Price

$598.00Save 40%

Reference price: ~~$999.00~~

Price checked: Nov 13, 2026

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Often bought together

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Pros and cons

Pros

The stated large-area coverage suits buyers looking to clean air across an open living space.
Washable pre-filter and filter-life indication offer a clear routine for pre-filter cleaning and filter replacement.
Automatic Smart, Eco and Sleep modes adjust operation to air quality and room conditions.

Cons

At 37.9D x 57.9W x 37.6H centimetres and 11.2 kg, it requires meaningful floor space and is not a lightweight portable purifier.
The listed controls are push buttons, so buyers wanting app-based operation should confirm whether that functionality is available for this model.

Technical specifications

16 specifications

Identity and controls
Brand	Coway
Model	AIRMEGA 400(G)
Controls listed	Push Button

Filtration and coverage
Filter type	HEPA Activated Carbon
Floor area	3120 square_feet
Particle retention size	0.3 micron
Contaminants listed	Allergens, Pollen, Smells, Smoke, Volatile Organic Compounds
Noise level	22 db
Special features	Air Quality Monitor, Filter Life Indicator, Smart Mode

Power and dimensions
Power configuration	Corded Electric
Wattage	66 watts
Dimensions	37.9D x 57.9W x 37.6H centimetres
Weight	11.2 kg

Other listed details
Colour	Graphite
Certifications listed	CARB Certified, ETL Certified, Energy Star Certified
Warranty description	5 year manufacturer's limited warranty

What to know before buying

Listing details to confirm

Coverage is stated as 3,120 square feet in 60 minutes, while manufacturer material also gives 145 m² in 30 minutes and 290 m² in 60 minutes. The listing also mentions a mobile app controller, but the control-method field lists push buttons. Confirm the applicable coverage figures and whether app control is included for the selected model.

What’s in the box

Included

Air purifier
Filter set
User manual

Who is it for?

A good fit for

Buyers seeking an air purifier for a large, open area who want automatic air-quality-based fan adjustment.
Households looking for HEPA and activated-carbon filtration with a washable pre-filter and filter-life indicator.
People who value automatic lower-power or lower-noise operation in Eco and Sleep modes.

Less suited to

Buyers who need a compact or especially lightweight purifier.
Buyers who require confirmed app control rather than the listed push-button controls.

Coway Airmega 400(G) Air Purifier, Graphite · photo 2 — Additional product photo 2

Customer reviews on Amazon

4.5 / 5 · 3,142 ratings

5 stars77%77%
4 stars12%12%
3 stars5%5%
2 stars3%3%
1 star3%3%

Customer feedback is generally favourable about perceived quality, effectiveness, quiet operation, cleaner-feeling air and appearance. That feedback may matter to buyers considering the listed large-area coverage and Sleep Mode, but it does not verify the manufacturer’s performance claims. Opinions are mixed on value and app functionality, which makes the purchase price and the listing’s unclear app-control details worth weighing against your needs.

Positive themes

Customers describe the purifier as effective and quiet, and report satisfaction with perceived air-quality improvement and appearance.

Mixed feedback

Customer opinions vary on value for money and app functionality.

Frequently asked questions

How large an area does the Airmega 400(G) cover?

The title and feature listing claim up to 3,120 square feet in 60 minutes. Other manufacturer material gives different area and timing figures, so confirm which claim applies to the selected model.

What filtration does it use?

The listing describes a washable pre-filter, activated-carbon filter and HEPA filter, and claims reduction of 99.97% of 0.3 micron particles. That is a manufacturer claim, not an independently verified result.

Does it support app control?

A controller field says mobile app, while the listed control method says push button. App control is therefore unconfirmed for this listing.

What comes in the package?

The manufacturer contents list names the air purifier, filter set and user manual.