Choose Blueair Blue Signature for higher CADR and larger-room coverage.
Which purifier has higher CADR?
The Blueair Blue Signature has a smoke CADR of 455 CFM versus 365 CFM for the Blueair Blue Pure 311i Max, a difference of 25%.
Which purifier is quieter?
Both list a minimum of 23 dB.
Which purifier covers a larger room?
Blueair Blue Signature fits a larger room (about 705 vs 566 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 Removes 99.97% of airborne particles down to 0.1 microns, WiFi connectivity and auto-mode, LED air quality indicator, Ultra-quiet performance).
Which purifier has better filtration?
Both list HEPASilent filtration.
Bottom line
Choose Blueair Blue Signature for higher CADR and larger-room coverage.
| Metric | Blueair Blue Signature | Blueair Blue Pure 311i Max | Difference / Winner |
|---|---|---|---|
| Smoke CADR | 455 CFM | 365 CFM | Blueair Blue Signature (+25%) |
| Recommended room size | 705 sq ft | 566 sq ft | Blueair Blue Signature (+25%) |
| Manufacturer claimed coverage | 3385 sq ft | 2107 sq ft | — |
| Minimum noise | 23 dB | 23 dB | — |
| Filter type | HEPASilent | HEPASilent | — |
| Replacement interval | — | 9 months | — |
| Power | 42 W | 32 W | — |
| Wi-Fi / app | Yes | Yes | — |
| Dimensions | 17.2 × 15.5 × 15.5 in | 19 × 12.5 × 12.5 in | — |
| Weight | 13.2 lb | 7.8 lb | — |