#10
Product Review · Air Purifiers · #10 Ranked
Coway Airmega 400
Air purifiers — large-room dual-filter HEPA · Reviewed by Katie · amazon.com live, Sept 9 2026
76
Worth It
Rank #10 of 10 · Air Purifiers
$633.67
The verdict
Why it scored a 76
At $633.67 the Coway Airmega 400 is a large-room True HEPA purifier with dual side-intake Max2 filters, long Wirecutter's large-space pick. Quality leads at 90 and Reliability at 90: 328 CFM of smoke CADR covers 1,560 sq ft at 2 ACH, low speed stays near 22 dB, the pre-filters wash, and the 5-year warranty is the longest here after Alen. Value drags at 55 because it usually sells for $350–$450, well below this listing, and Features at 55 since the 2016 design has no app (the 400S adds it), and cannot sit flush against a wall. It is for a big open-plan space, bought on a real discount.
Key specs
What you're getting
- AHAM CADR 328 smoke / 328 dust / 400 pollen CFM, dual side-intake Max2 filters
- 1,560 sq ft at 2 ACH; 3,120 sq ft at 1 ACH
- 22-52 dB(A) across 4 fan speeds; whisper-quiet on low
- Two Max2 HEPA + carbon filters: ~$80-90/yr, 6-12 month life; washable pre-filters
- 66 W max; 24.7 lb; 14.8 x 22.8 x 14.8 in square body, cannot sit flush to a wall
- Particle sensor, AQI LED ring, auto/eco/sleep modes, 1/4/8-hr timer
- No app or Wi-Fi (the 400S adds it); 2016 design
- 5-year warranty, longest here after Alen
ViperScore breakdown
FactorScoreWeightPoints
Value55×25%13.8
Quality90×20%18.0
Features55×15%8.2
Reliability90×15%13.5
Satisfaction92×15%13.8
Warranty88×10%8.8
Weighted total76
At a glance
- AHAM CADR 328 smoke / 328 dust / 400 pollen CFM
- 1,560 sq ft at 2 ACH; 22–52 dB across 4 speeds
- Two Max2 filters ~$80–90/yr; 5-year warranty
- Price$633.67
- TierAir purifiers — large-room dual-filter HEPA
- Category rank#10 of 10
Katie
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