Our Verdict
Coway 400(G) Wins

It offers a specified CADR of 416.0 and covers 650 sq ft, while Dyson provides no essential performance metrics for air purification. Choose Dyson for formaldehyde destruction and fan-only cooling.
Bottom Line: Coway 400(G) is the better choice. It offers a specified CADR of 416.
Key Differences
The most significant spec differences at a glance
Cadr Smoke
100% moreCoverage Sq Ft
100% moreAdvantages
Where each product wins
Coway
- Cadr Smoke: 100% higher (416.0 vs 0)
- Coverage Sq Ft: 100% higher (650.0 vs 0)
Who Should Buy Which?
Find the right product for your needs
Buy Coway if...
COWAY Air Purifiers for
If you need robust, measurable air purification for a large room and prioritize clean air above all else, the Coway 400(G) is your best choice. Ideal for homeowners concerned with smoke, allergies, pet dander, or general indoor air quality, its 416.0 CADR Smoke and 650 sq ft coverage ensure effective air changes. You appreciate smart features like Auto & Eco Mode for efficiency and value a 5-year warranty, all at a competitive price for its performance.
Buy Dyson if...
Dyson Purifier Cool Formaldehyde
The Dyson Purifier Cool Formaldehyde TP09 is for the buyer who prioritizes advanced air quality detection and targeted removal of specific pollutants like formaldehyde, alongside a cooling fan function. Ideal for those living in newer homes or with specific chemical sensitivities, you appreciate its smart app control and elegant design. While it lacks a stated CADR, its ability to detect and destroy formaldehyde, plus serve as a fan, justifies its premium for a multi-functional device.
Spec Comparison
8 specs compared
| Specification | ![]() | ![]() |
|---|---|---|
| Price | $649 | $500 |
| Rating | 4.4(6.5k) | 4.2(615) |
| Cadr Smoke | 416 | 0 |
| Coverage Sq Ft | 650 | 0 |
| Noise Level db Min | 22 dB | — |
| Weight | 3.05 lbs | — |
| Energy Star | Yes | — |
| Filter Type | True HEPA | HEPA |
| Smart Sensor | Yes | Yes |
| WiFi | — | Yes |
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Pros & Cons
Quick overview of strengths and weaknesses
Coway Air Purifiers
- Removes 99.999% of 0.01-micron particles.
- Covers 780 sq ft with 4 air changes per hour.
- Smart Mode adjusts fan speed based on air quality.
- Eco Mode shuts off fan when air is clean.
- Stated 3,120 sq ft coverage misleading for 4 ACH.
- True HEPA filters require periodic replacement.
- No remote control listed in features.
Dyson Purifier Cool
- Detects and destroys formaldehyde.
- Captures 99.97% of 0.3 micron particles.
- Projects purified air throughout the room.
- Fan mode offers direct cooling or purification only.
- No stated Clean Air Delivery Rate.
- Room coverage area is not specified.
Frequently Asked Questions
Common questions about this comparison
Which is better for general air purification in a large room?
The Coway 400(G) is better for general air purification, covering 650 sq ft with a CADR of 416.0 for smoke. The Dyson TP09 does not specify its CADR or coverage, making its effectiveness in larger rooms uncertain.
What's the main difference in stated air purification capacity?
The main difference is transparency. Coway provides a CADR of 416.0 for smoke and covers 650 sq ft. Dyson does not provide a CADR or specific room coverage, making direct comparison of purification capacity impossible.
Is the Dyson worth it for its specialized features?
The Dyson TP09 detects and destroys formaldehyde and offers a fan mode for cooling, which the Coway lacks. If these specialized features are a priority and you're less concerned about explicit CADR or coverage numbers, it might be worth it.
Which air purifier is quieter?
The Coway 400(G) has a minimum noise level of 22.0 dB, which is very quiet. The Dyson TP09 does not specify its noise level, so a direct comparison is not possible based on available data.
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