Blueair - 7770i vs Dyson - Purifier Big+Quiet Formaldehyde
Between the 7770i and Purifier Big+Quiet Formaldehyde, the 7770i comes out ahead in cadr / min noise, while the Purifier Big+Quiet Formaldehyde wins on several specs. Overall, the 7770i scores 95 and the Purifier Big+Quiet Formaldehyde scores 89.1 on our Mars Score.
Which should you buy?
The 7770i edges ahead on the Mars Score (95 vs 89.1), but the 5.9-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 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: the 7770i is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Why Blueair - 7770i wins
- ▲CADR — 40.63% more. 900 m³/h vs 640 m³/h.
- ▲Min noise — 2.00 dB less. 22 vs 24.
Why Dyson - Purifier Big+Quiet Formaldehyde wins
- No decisive advantages.
Spec comparison
Performance
| Spec | Blueair - 7770i | Dyson - Purifier Big+Quiet Formaldehyde |
|---|---|---|
| CADR | 900 m³/hlead | 640 m³/h |
| Coverage | 100 m² | 100 m² |
| True HEPA H13+ | true | true |
| Activated carbon | true | true |
Smart & Noise
| Spec | Blueair - 7770i | Dyson - Purifier Big+Quiet Formaldehyde |
|---|---|---|
| Min noise | 22 dBlead | 24 dB |
| Air quality sensor | true | true |
| Smart app | true | true |
Spec-level deep dives
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