Between the HPA300 and C909, the HPA300 comes out ahead in cadr, while the C909 wins on coverage and min noise. Overall, the HPA300 scores 65 and the C909 scores 66.8 on our Mars Score.
Which should you buy?
These two are nearly even on the Mars Score (65 vs 66.8). The decision isn't about overall quality — both clear the bar — it's about which specific trade-offs fit your use.
Pick the HPA300 if you care most about cadr. The biggest gaps in its favor are cadr.
Pick the C909 if you care most about coverage and min noise. Its strongest claims are coverage, min noise.
Both ship with comparable true hepa h13+, activated carbon, so those specs don't separate the two — focus on the differences below.
Bottom line: there is no wrong answer here — match the spec advantages to how you actually use the product. The Mars Score parity tells you both are well-rounded; the differences are about trade-offs, not quality.
Why Honeywell - HPA300 wins
- ▲CADR — 2.00% more. 510 m³/h vs 500 m³/h.
Why Winix - C909 wins
- ▲Coverage — 13.64% more. 50 m² vs 44 m².
- ▲Min noise — 5.00 dB less. 27 vs 32.
Spec comparison
Performance
| Spec | Honeywell - HPA300 | Winix - C909 |
|---|---|---|
| CADR | 510 m³/hlead | 500 m³/h |
| Coverage | 44 m² | 50 m²lead |
| True HEPA H13+ | true | true |
| Activated carbon | true | true |
Smart & Noise
| Spec | Honeywell - HPA300 | Winix - C909 |
|---|---|---|
| Min noise | 32 dB | 27 dBlead |
| Air quality sensor | false | truelead |
| Smart app | false | truelead |
Frequently asked
Spec-level deep dives
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