Question 1

Which is better, Coway Airmega 400 or Dyson Purifier Big Quiet Formaldehyde?

Accepted Answer

Based on our testing, the Coway Airmega 400 scores higher overall at 9/10. The Coway Airmega 400 scored 9/10 and the Dyson Purifier Big Quiet Formaldehyde scored 8.7/10 in our Best Air Purifiers for Large Rooms 2026 evaluation.

Question 2

Is the Coway Airmega 400 worth it over the Dyson Purifier Big Quiet Formaldehyde?

Accepted Answer

The Coway Airmega 400 scores 9/10 while the Dyson Purifier Big Quiet Formaldehyde scores 8.7/10. The Coway Airmega 400 is our "Best Overall" pick in the Best Air Purifiers for Large Rooms 2026 category.

Coway Airmega 400 vs Dyson Purifier Big Quiet Formaldehyde: Which to Buy?