Choose Blueair Blue Pure 311i Max for higher CADR and larger-room coverage and lower noise.
Which purifier has higher CADR?
The Blueair Blue Pure 311i Max has a smoke CADR of 365 CFM versus 321 CFM for the Blueair Blue Signature SP3i, a difference of 14%.
Which purifier is quieter?
Blueair Blue Pure 311i Max is quieter (23 vs 54 dB).
Which purifier covers a larger room?
Blueair Blue Pure 311i Max fits a larger room (about 566 vs 498 sq ft recommended from CADR).
Which purifier has better smart features?
Both list smart features (Removes 99.97% of airborne particles down to 0.1 microns, WiFi connectivity and auto-mode, LED air quality indicator, Ultra-quiet performance vs WiFi Smart Control, Auto Mode, Odor & Smoke Removal, AHAM Verified).
Which purifier has better filtration?
Both list HEPASilent filtration.
Bottom line
Choose Blueair Blue Pure 311i Max for higher CADR and larger-room coverage and lower noise.
| Metric | Blueair Blue Pure 311i Max | Blueair Blue Signature SP3i | Difference / Winner |
|---|---|---|---|
| Smoke CADR | 365 CFM | 321 CFM | Blueair Blue Pure 311i Max (+14%) |
| Recommended room size | 566 sq ft | 498 sq ft | Blueair Blue Pure 311i Max (+14%) |
| Manufacturer claimed coverage | 2107 sq ft | 2250 sq ft | — |
| Minimum noise | 23 dB | 54 dB | Blueair Blue Pure 311i Max |
| Filter type | HEPASilent | HEPASilent | — |
| Replacement interval | 9 months | — | — |
| Power | 32 W | 36 W | — |
| Wi-Fi / app | Yes | Yes | — |
| Dimensions | 19 × 12.5 × 12.5 in | — | — |
| Weight | 7.8 lb | 9.5 lb | — |