Blueair Blue Pure 211i Max moves more air (CADR) and covers a larger room than FreAire KN-6391RGB.
Which purifier has higher CADR?
Blueair Blue Pure 211i Max has published CADR; FreAire KN-6391RGB does not.
Which purifier is quieter?
Blueair Blue Pure 211i Max lists a minimum of 23 dB; FreAire KN-6391RGB has no published figure.
Which purifier covers a larger room?
Blueair Blue Pure 211i Max is recommended for about 674 sq ft based on CADR.
Which purifier has better smart features?
Blueair Blue Pure 211i Max lists Wi-Fi or app control; FreAire KN-6391RGB does not.
Which purifier has longer filter life?
Filter replacement interval is not published for either model.
Bottom line
Blueair Blue Pure 211i Max moves more air (CADR) and covers a larger room than FreAire KN-6391RGB.
| Metric | Blueair Blue Pure 211i Max | FreAire KN-6391RGB |
|---|---|---|
| CADR (smoke) | 435 CFM | — |
| Recommended room size | 674 sq ft | — |
| Claimed coverage | 3235 sq ft | 1086 sq ft |
| Noise | 23 dB | — |
| Filter type | HEPASilent | — |
| Filter interval | — | — |
| Smart features | None | None |