Choose Blueair Blue Signature for higher CADR and larger-room coverage. Choose Blueair Blue Pure 511i Max if you want lower noise.
Which purifier has higher CADR?
The Blueair Blue Signature has a smoke CADR of 455 CFM versus 174 CFM for the Blueair Blue Pure 511i Max, a difference of 161%.
Which purifier is quieter?
Blueair Blue Pure 511i Max is quieter (19 vs 23 dB).
Which purifier covers a larger room?
Blueair Blue Signature fits a larger room (about 705 vs 270 sq ft recommended from CADR).
Which purifier has better smart features?
Both list smart features (7 stages of filtration, 10x more odor removal, Smart VOC sensor, Dynamic display vs Wi-Fi capability, Smart sensor, Auto mode, Night mode).
Which purifier has better filtration?
Both list HEPASilent filtration.
Bottom line
Choose Blueair Blue Signature for higher CADR and larger-room coverage. Choose Blueair Blue Pure 511i Max if you want lower noise.
| Metric | Blueair Blue Signature | Blueair Blue Pure 511i Max | Difference / Winner |
|---|---|---|---|
| Smoke CADR | 455 CFM | 174 CFM | Blueair Blue Signature (+161%) |
| Recommended room size | 705 sq ft | 270 sq ft | Blueair Blue Signature (+161%) |
| Manufacturer claimed coverage | 3385 sq ft | 465 sq ft | — |
| Minimum noise | 23 dB | 19 dB | Blueair Blue Pure 511i Max |
| Filter type | HEPASilent | HEPASilent | — |
| Power | 42 W | 17 W | — |
| Wi-Fi / app | Yes | Yes | — |
| Dimensions | 17.2 × 15.5 × 15.5 in | — | — |
| Weight | 13.2 lb | 4.2 lb | — |