Dreo 338 Air Purifier
#1 in Small roomsFull review
A cheap, certified bedroom purifier with auto mode for rooms under about 180 sq ft.
Amazon $59.98$59.98
The Dreo 338 Air Purifier is the better air purifier overall, rated 3.5 to 3.1. The Dreo 338 Air Purifier leads on value. The KNKA APH2500P wins on warranty. The Dreo 338 Air Purifier costs $30.01 less ($59.98 vs $89.99).
KNKA APH2500P
#8 in Small roomsFull review
A pet-oriented purifier for bedrooms up to about 185 sq ft. Its hair-catching pre-filter is the draw, but plain purifiers deliver more clean air per dollar.
Amazon $89.99$89.99
Prices were last checked October 22, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the Dreo 338 Air Purifier for value ($0.52 per cfm of smoke CADR vs $0.76 per cfm of smoke CADR).
- Choose the KNKA APH2500P for warranty (2-year warranty vs 1-year warranty).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every small rooms air purifier; a clear win is highlighted. How we rank explains each one.
| Factor weight | Dreo 338 Air Purifier | KNKA APH2500P |
|---|---|---|
| Overall rating | 3.5/5 | 3.1/5 |
| Value 25% | 99 $0.52 per cfm of smoke CADR | 83 $0.76 per cfm of smoke CADR |
| Filter cost 20% | 50 filter price or life not published (neutral score used) | 0 $119.96 a year in filters |
| Quiet 20% | 50 noise at top speed not published (neutral score used) | 50 noise at top speed not published (neutral score used) |
| Efficiency 15% | 44 5.5 cfm per watt | 40 5.2 cfm per watt |
| Auto mode 10% | 70 PM2.5 sensor, auto mode | 70 air quality (type not stated) sensor, auto mode |
| Warranty 10% | 0 1-year warranty | 25 2-year warranty |
Specifications
| Dreo 338 Air Purifier | KNKA APH2500P | |
|---|---|---|
| Performance | ||
| Smoke CADR | 115 cfm | 119 cfm |
| Dust CADR | 121 cfm | 123 cfm |
| Pollen CADR | 131 cfm | 147 cfm |
| PM2.5 CADR | 118 cfm | 121 cfm |
| CADR certified by | AHAM Verifide | AHAM Verifide |
| Room size (AHAM) | 178 sq ft | 184 sq ft |
| Coverage (maker) | 856 sq ft | - |
| Efficiency | ||
| Efficiency (IEF) | 5.5 cfm/W | 5.2 cfm/W |
| ENERGY STAR | Yes | No |
| Energy use | 125 kWh/year | 137 kWh/year |
| Filters | ||
| Filter | 3-in-1 filter with carbon layer (HEPA-grade only in sleep mode per Dreo) | HEPA-type |
| Activated carbon | Yes | Yes |
| Replacement | DR-HPA032 | APH2500P filter |
| Replacement cost | $22.98 | $29.99 every 3 months |
| Yearly filter cost | - | $119.96/year |
| Ionizer | No | - |
| CARB certified (ozone) | Yes | Yes |
| Controls and build | ||
| Air-quality sensor | PM2.5 | air quality (type not stated) |
| Auto mode | Yes | Yes |
| Wi-Fi app | No | No |
| Fan speeds | 4 | - |
| Dimensions | 14.21 x 9.21 x 9.21 in | - |
| Weight | 5.6 lb | - |
| Warranty | 1 years | 2 years |
| Released | - | 2026-09 |