Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Honeywell - HPA300 | Winix - C909 |
|---|---|---|
| Coverage | 44 m² | 50 m² |
| Min noise | 32 dB | 27 dB |
| CADR | 510 m³/h | 500 m³/h |
Between the HPA300 and C909, the HPA300 comes out ahead in cadr, while the C909 wins on coverage / min noise. Overall, the HPA300 scores 74.4 and the C909 scores 77.7 on our Mars Score.
Which should you buy?
The C909 edges ahead on the Mars Score (74.4 vs 77.7), but the 3.3-point gap is small enough that the right pick comes down to which spec advantages matter to you.
Pick the HPA300 if you care most about cadr. The biggest gaps in its favor are cadr. The single most decisive one: CADR — 2.00% more. 510 m³/h vs 500 m³/h.
Pick the C909 if you care most about coverage / min noise. Its strongest claims are coverage, min noise. The single most decisive one: Coverage — 13.64% more. 50 m² vs 44 m².
Both ship with comparable true hepa h13+, activated carbon, so those specs do not 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 says both are well-rounded; the differences are about trade-offs, not quality.
Which should you buy: Honeywell - HPA300 or Winix - C909?
Winix - C909 leads the current Mars Score by 3.3 points.The more useful decision is the trade-off behind that result: compare cadr, coverage, min noise against the way you will actually use the product.
Choose Honeywell - HPA300 if…
Honeywell - HPA300 has the measurable edge on cadr m3h.
Choose Winix - C909 if…
Winix - C909 has the measurable edge on coverage m2, noise db min.
This is a structured comparison of the published catalog values. It is not a claim of identical real-world performance across every workload; use the linked spec drill-downs and methodology page to inspect the inputs.
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 |