Blueair - 7770i vs Dyson - Purifier Big+Quiet Formaldehyde

The 7770i edges ahead on the Mars Score (93.1 vs 89.3), but the 3.8-point gap is small enough that the right pick comes down to which spec advantages matter to you.

Pick the 7770i if you care most about cadr / min noise. The biggest gaps in its favor are cadr, min noise. The single most decisive one: CADR — 40.63% more. 900 m³/h vs 640 m³/h.

The Purifier Big+Quiet Formaldehyde similarly does not carry a headline advantage on the popular specs — look at the full table for category-specific deltas.

Both ship with comparable coverage, true hepa h13+, activated carbon, so those specs do not separate the two — focus on the differences below.

Bottom line: there is no wrong answer here — match the spec advantages to how you actually use the product. The Mars Score parity says both are well-rounded; the differences are about trade-offs, not quality.