Choose Blueair Blue Pure 211i Max 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 Pure 211i Max has a smoke CADR of 435 CFM versus 174 CFM for the Blueair Blue Pure 511i Max, a difference of 150%.
Which purifier is quieter?
Blueair Blue Pure 511i Max is quieter (19 vs 23 dB).
Which purifier covers a larger room?
Blueair Blue Pure 211i Max fits a larger room (about 674 vs 270 sq ft recommended from CADR).
Which purifier has better smart features?
Both list smart features (Captures 99.97% of particles as small as 0.1 microns, RealTrack technology for filter lifetime tracking, WiFi connectivity with smart features vs Wi-Fi capability, Smart sensor, Auto mode, Night mode).
Which purifier has better filtration?
Both list HEPASilent filtration.
Bottom line
Choose Blueair Blue Pure 211i Max for higher CADR and larger-room coverage. Choose Blueair Blue Pure 511i Max if you want lower noise.
| Metric | Blueair Blue Pure 211i Max | Blueair Blue Pure 511i Max | Difference / Winner |
|---|---|---|---|
| Smoke CADR | 435 CFM | 174 CFM | Blueair Blue Pure 211i Max (+150%) |
| Recommended room size | 674 sq ft | 270 sq ft | Blueair Blue Pure 211i Max (+150%) |
| Manufacturer claimed coverage | 3235 sq ft | 465 sq ft | — |
| Minimum noise | 23 dB | 19 dB | Blueair Blue Pure 511i Max |
| Filter type | HEPASilent | HEPASilent | — |
| Power | 46 W | 17 W | — |
| Wi-Fi / app | Yes | Yes | — |
| Dimensions | 22.7 × 14.4 × 14.4 in | — | — |
| Weight | 16.2 lb | 4.2 lb | — |