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 255 CFM for the Alen 45i, a difference of 78%.
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 395 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 True HEPA filtration, Whisper-quiet operation, Smart Sensor, Auto Mode).
Which purifier has better filtration?
Blueair Blue Signature lists HEPASilent; Alen 45i lists HEPA.
Bottom line
Choose Blueair Blue Signature for higher CADR and larger-room coverage.
| Metric | Blueair Blue Signature | Alen 45i | Difference / Winner |
|---|---|---|---|
| Smoke CADR | 455 CFM | 255 CFM | Blueair Blue Signature (+78%) |
| Recommended room size | 705 sq ft | 395 sq ft | Blueair Blue Signature (+78%) |
| Manufacturer claimed coverage | 3385 sq ft | 1900 sq ft | — |
| Minimum noise | 23 dB | 23 dB | — |
| Filter type | HEPASilent | HEPA | — |
| Power | 42 W | — | — |
| Wi-Fi / app | Yes | Yes | — |
| Dimensions | 17.2 × 15.5 × 15.5 in | — | — |
| Weight | 13.2 lb | 14 lb | — |