The Dyson Purifier Cool PC1 and the Coway Airmega 400 now cost about the same, which makes this a sharper choice than it used to be. The PC1 replaced Dyson's TP07 at a lower price, and it is the cheaper of the two to own over three years thanks to its $79.99 filter. The Coway is still the one with verified clean-air numbers: 328 CFM of smoke CADR, enough for a room of about 508 sq ft. Buy the Dyson for the fan, the app and the looks; buy the Coway for proven cleaning power in a big room.
Quick answer
| Attribute | Dyson Purifier Cool PC1 | Coway Airmega 400 |
|---|---|---|
| CADR (smoke / dust / pollen) | Not published (Dyson's own testing) | 328 / 328 / 400 |
| Coverage | Not rated | ~508 sq ft @ 4.8 ACH |
| Filtration | Sealed Glass HEPA (H13) + carbon, one filter | Dual True HEPA + carbon |
| Filter cost/yr | $79.99 | ~$129 |
| Rated noise | Not published | 22 to 52 dB |
| Smart features | Auto + sensors + MyDyson app + voice | Auto + sensor, no app |
| Price | $399.99 at Dyson | ~$400 to $450 |
| 3-year cost (purchase + filters) | ~$640 | ~$787 to $837 |
| Best for | Fan + purifier, app control, design | Verified clean air in a large room |
Three-year costs leave out electricity, because Dyson publishes no wattage for the PC1. The Coway draws up to 66 W.
Where Dyson wins
The Dyson Purifier Cool PC1 wins on versatility and running cost. It is a bladeless tower fan with 10 speeds and 350-degree oscillation, so it replaces a summer fan as well as purifying, and its single combined filter is a sealed 360-degree Glass HEPA H13 layer with activated carbon. Dyson seals the whole machine so air can't slip around that filter. Auto mode reacts to its built-in sensors, and the MyDyson app adds schedules, air-quality readings, filter alerts and a report of what it has captured, with Alexa, Google Assistant and Siri support.
The money side has shifted in Dyson's favor. At $399.99 the PC1 costs about the same as the Coway up front, and its $79.99 yearly filter is $49 cheaper than the Coway's set. Over three years that works out to about $640 against roughly $787 to $837. The catch hasn't changed: Dyson publishes no AHAM CADR, noise rating or wattage, so you are buying on Dyson's word and the design rather than a number you can check against your room.
Where Coway wins
The Coway Airmega 400 wins on evidence. Its 328 CFM smoke CADR (400 for pollen) is a published figure, and at the site's 1.55 rule it covers about 508 sq ft at 4.8 air changes an hour, which is an open living room or a large primary bedroom. Two True HEPA and carbon filter sets pull air from both sides, and the sensor-driven auto mode ramps only when it detects something.
It also has a documented quiet floor of 22 dB, which the Dyson can't match on paper simply because Dyson doesn't publish one. What you give up is the app and the fan: there's no phone control on the base model, and it won't cool you. Its filters cost more, so the extra $150 to $200 over three years is what you pay for a verified clean-air rating and a larger rated room.
How to choose
Start with the room. If it's large, around 400 to 500 sq ft or open to other spaces, the Coway Airmega 400 is the one you can size with confidence. If it's a bedroom or office where you'd run a fan anyway, and you like phone control and voice commands, the Dyson Purifier Cool PC1 is now the cheaper machine to own, as long as you accept that its clean-air output is unverified. If neither fits, the Levoit Core 600S posts 391 CFM for about $280 to $320.
If the CADR question is tripping you up, our guide on what CADR and CFM actually mean explains why Dyson's missing figure matters. And to match either machine to your specific room and priorities, run your details through the air-purifier finder.
Frequently asked questions
Why doesn't the Dyson PC1 have a CADR?
Dyson doesn't submit the Purifier Cool PC1 for AHAM CADR certification; it uses its own whole-room testing instead. That makes it hard to compare directly against the Coway Airmega 400, which publishes 328 CFM for smoke and dust and 400 CFM for pollen. The Dyson still filters through a sealed HEPA H13 and carbon filter; you just can't line its cleaning speed up against CADR-rated machines on paper.
Does the Dyson work as both a fan and an air purifier?
Yes, that's the point of it. The Dyson Purifier Cool PC1 is a bladeless tower fan with 10 speeds and 350-degree oscillation wrapped around a purifier, so it cools you in summer while filtering year-round. It cools only; there's no heating. The Coway Airmega 400 is a dedicated purifier and won't blow a cooling breeze at you.
Which gives more clean air per dollar, Dyson or Coway?
On verified numbers, the Coway Airmega 400: 328 CFM of smoke CADR, enough for about 508 sq ft, for roughly $400 to $450. The Dyson PC1 now costs about the same at $399.99 but has no published CADR, so there is no clean-air figure to divide by. If verified cleaning power is what you're paying for, the Coway is the safer buy.
Is the Dyson PC1 quiet enough for a bedroom?
Dyson doesn't publish a decibel rating for the PC1, so there's no spec to check. The Coway Airmega 400 is rated at 22 dB on its lowest speed and 52 dB at the top. If a documented quiet setting matters for sleep, the Coway gives you one; the Dyson's bedroom appeal is doubling as a fan on warm nights.
Are Dyson filters more expensive than Coway's?
No, the Coway's cost more. The Dyson's combined filter is $79.99 a year, while the Airmega 400 takes a two-filter Max2 set at $129 a year. With the PC1 now priced at $399.99, the Dyson comes out roughly $150 to $200 cheaper over three years of purchase plus filters. The Coway's extra cost buys a published CADR and a larger rated room.
