Blueair - 7770i vs Dyson - Purifier Big+Quiet Formaldehyde
Between the 7770i and Purifier Big+Quiet Formaldehyde, the 7770i comes out ahead in cadr and 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 and min noise. The biggest gaps in its favor are cadr, min noise.
The Purifier Big+Quiet Formaldehyde similarly doesn't 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 don't 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 |
Frequently asked
Spec-level deep dives
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