Choose Blueair 2-in-1 Pro Purify + Humidify for lower noise.
Which purifier has higher CADR?
The Blueair 2-in-1 Pro Purify + Humidify has a smoke CADR of 235 CFM versus 226 CFM for the Knka APH4000, a difference of 4%.
Which purifier is quieter?
Blueair 2-in-1 Pro Purify + Humidify is quieter (20 vs 22 dB).
Which purifier covers a larger room?
Blueair 2-in-1 Pro Purify + Humidify fits a larger room (about 364 vs 350 sq ft recommended from CADR).
Which purifier has better smart features?
Neither lists Wi-Fi or app control in our sources.
Which purifier has better filtration?
Blueair 2-in-1 Pro Purify + Humidify lists HEPASilent; Knka APH4000 lists HEPA.
Bottom line
Choose Blueair 2-in-1 Pro Purify + Humidify for lower noise.
| Metric | Blueair 2-in-1 Pro Purify + Humidify | Knka APH4000 | Difference / Winner |
|---|---|---|---|
| Smoke CADR | 235 CFM | 226 CFM | Blueair 2-in-1 Pro Purify + Humidify (+4%) |
| Recommended room size | 364 sq ft | 350 sq ft | Blueair 2-in-1 Pro Purify + Humidify (+4%) |
| Manufacturer claimed coverage | 391 sq ft | 1695 sq ft | — |
| Minimum noise | 20 dB | 22 dB | Blueair 2-in-1 Pro Purify + Humidify |
| Filter type | HEPASilent | HEPA | — |
| Power | Up to 60 W | 45 W | — |
| Wi-Fi / app | No | No | — |
| Dimensions | 24.6 × 12.5 × 12.5 in | — | — |
| Weight | 18.5 lb | 9.7 lb | — |