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Home / Home & kitchen / Air Purifiers / Coway Airmega 400
7.6 Tested Aug 21, 2026 by Team RankingRight

Coway Airmega 400 (Non-smart) review 2026

Two large filters and 1,560 sq ft of rated coverage — the purifier for a whole floor, priced and sized accordingly

PriceFrom $449.99 · checked Sep 11, 2026
90% clear, high8 min
Noise on low22 dB

Is the Coway Airmega 400 Worth It?

Best for whole-floor coverage. If one purifier has to cover a whole open floor, the Airmega 400 does it faster and more quietly than anything we tested. For a normal room it is more machine than you need.

Coway Airmega 400 Pros & Cons

Pros
  • Cleared our room in 8 minutes — the fastest here
  • Quietest low setting at 22 dB for a unit this size
  • Dual filters last a year
  • Rated for open-plan homes
Cons
  • $450 and $130 a year in filters
  • Heavy and boxy
  • 66 W on medium

Coway Airmega 400 at a Glance

7.6 Editor Score
Particle removalMinutes to cut PM2.5 by 90% in our 400 sq ft room on high, and on the highest setting under 50 dB; AHAM CADR where published.
34/35
NoiseMeasured dB at 1 m on low, medium and high; sleep-mode usability.
12/15
Energy & filter costWatts on medium, replacement filter price and interval — five-year running cost.
12/20
FeaturesAir-quality sensor and auto mode, app, filter indicator, carbon layer for odours and VOCs, build.
8/10
ValuePrice per square foot of rated coverage, plus five-year running cost.
10/20
Reader ratingNo reader ratings yet — not part of the score
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Own one? Rate it:

Rubric v1: Particle removal 35 · Noise 15 · Energy & filter cost 20 · Features 10 · Value 20. Score = Σ ÷ 10, locked Sep 11, 2026. How we rank.

Where to buy — prices checked Sep 11, 2026

Amazon — $449.99

Best priceSee Price

Coway — $449.99

Also sold atSee Price

Coway Airmega 400 specifications

Rated coverage1560 sq ft
CADR (smoke/dust/pollen)350 / 400 / 400
True HEPAYes
Carbon filterYes, two combined filters
Replacement filter130 USD
Filter life12 months
Power on medium66 W
Noise on low22 dB
Auto mode / appAuto mode with sensor (app on 400S)

Why it scored 7.6

If one purifier has to cover a whole open floor, the Airmega 400 does it faster and more quietly than anything we tested. For a normal room it is more machine than you need.

Where it loses

Value; running cost.

Still the right pick for

Open-plan homes and serious allergy sufferers.

Coway Airmega 4007.6 · $449.99
See Price