Choose Winix 5500-2 for higher CADR and larger-room coverage. Choose Knka APH4000 if you want lower noise.
Which purifier has higher CADR?
The Winix 5500-2 has a smoke CADR of 243 CFM versus 226 CFM for the Knka APH4000, a difference of 8%.
Which purifier is quieter?
Knka APH4000 is quieter (22 vs 27 dB).
Which purifier covers a larger room?
Winix 5500-2 fits a larger room (about 377 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?
Winix 5500-2 lists True HEPA + PlasmaWave; Knka APH4000 lists HEPA.
Bottom line
Choose Winix 5500-2 for higher CADR and larger-room coverage. Choose Knka APH4000 if you want lower noise.
| Metric | Winix 5500-2 | Knka APH4000 | Difference / Winner |
|---|---|---|---|
| Smoke CADR | 243 CFM | 226 CFM | Winix 5500-2 (+8%) |
| Recommended room size | 377 sq ft | 350 sq ft | Winix 5500-2 (+8%) |
| Manufacturer claimed coverage | — | 1695 sq ft | — |
| Minimum noise | 27 dB | 22 dB | Knka APH4000 |
| Filter type | True HEPA + PlasmaWave | HEPA | — |
| Power | — | 45 W | — |
| Wi-Fi / app | No | No | — |
| Weight | — | 9.7 lb | — |