Winix 9800
AHAM verified
- Really cleans
- 513 sq ft47 m² 47 m²513 sq ft
- Box says
- 2,506 sq ft233 m² 4.9× overstated
- New filter
- 3–12 months
Coway · Airmega 350
Coway Airmega 350
Not verified. A verified model that cleans at least as much: Levoit EverestAir-P, 539 sq ft50 m².
Really cleansNot verified
536 sq ft49 m² 49 m²536 sq ft
At 4.8 air changes an hour with a 2.5 m ceiling
- Box says
- Purifies 2,640ft² in 60 minsPurifies 2,640ft² in 60 mins (245 m²) 4.9× overstated
- New filter
- Every 12 months
See it on Amazon: Coway Airmega 350Paid link
A newer square Coway tower with a laser sensor and a choice of filters. Coway's CADR isn't independently verified.
Verdict
Who it's for
Coway's newer large-room tower, with filters for allergens or smoke and laser air quality sensing. It's a large-room unit by Coway's own figure, but the figure is unverified, so we don't make it a pick.
Good
- Laser air quality sensor and auto mode
- Choice of filter types
- No ionizer
Trade-offs
- CADR not independently verified
- Box headline is based on one air change an hour
Spec facts
Coway Airmega 350 · Airmega 350
- Really cleans
- 536 sq ft · 49 m²49 m² · 536 sq ftat 4.8 air changes an hour, 2.5 m ceiling
- Smoke CADR
- 352 CFM · 598 m³/hMaker’s figure, not independently verified
- Maker’s claim: Coway · checked 1 Nov 2026
- Box claim
- Purifies 2,640ft² in 60 minsPurifies 2,640ft² in 60 mins (245 m²)4.9× overstated
- Maker’s claim: Coway · checked 1 Nov 2026
- Filter
- Coway Airmega 350 3-in-1 filter setVacuumable pre-filter + HEPA + activated carbon. Replace every 12 months
- Maker’s claim: Coway · checked 1 Nov 2026
Maker’s claim: the manufacturer’s own figure, not independently checked. Where figures come from
Running it
Filter and upkeep
- Replacement filter
- Coway Airmega 350 3-in-1 filter set
- Type
- Vacuumable pre-filter + HEPA + activated carbon
- Replace every
- 12 months
- Power at top speed
- 62 W
A new filter every 12 months means 1 filter a year. At top speed it draws 62 W: 1.5 kWh if it ran flat out all day. Slower settings use less.
We have no Amazon link for this filter: the maker's page in the sources sells or lists it.
Source: Maker’s claim, Coway, checked 1 Nov 2026
The box vs the maths
The box says 2,640 sq ft245 m². It really cleans 536 sq ft49 m².
To clean 2,640 sq ft245 m² it would only change the air in the room 1 time an hour. We size every purifier at 4.8 air changes an hour, the level AHAM's room-size guideline works out to.
Coway's figure is the room it can change the air of once an hour, and the wording says as much. That's a real number, but at one air change an hour smoke and pollen come back in nearly as fast as the purifier removes them. The CADR behind both numbers is Coway's own; AHAM hasn't certified it.
598 m³/h smoke CADR ÷ (4.8 × 2.5 m ceiling) = 49.8 m² = 536.4 sq ft49.8 m²
Use the calculator for your exact room and ceiling, or read how we pick.
Drawn to scale: the box says “Purifies 2,640ft² in 60 mins”, the purifier really cleans 536 sq ft, 4.9 times less.Drawn to scale: the box says “Purifies 2,640ft² in 60 mins”, the purifier really cleans 49 m², 4.9 times less.
Room sizes
Which rooms it fits
It suits 269 sq ft25 m², 322 sq ft30 m² and 376 sq ft35 m² rooms best: there it has 40–96% more air than the room needs, so it needn't run flat out. At 430 sq ft40 m² it only just keeps up (22% to spare), so it would run near its top speed, usually its loudest (why we don’t list noise). In rooms of 215 sq ft20 m² or less it's more than twice the size needed; a smaller model does the job.
Under a 2.7 m ceiling it covers 496 sq ft, under 3 m 447 sq ftUnder a 2.7 m ceiling it covers 46 m², under 3 m 41 m²: still enough for every size it covers above (why).
For a 538 sq ft room or bigger it's too small, although the box claims 2,640 sq ft: the For a 50 m² room or bigger it's too small, although the box claims 245 m²: the 538 sq ft50 m² page lists models that cover it. In an open-plan space, add up every area without a door between (how).
All of this rests on Coway's own CADR figure. AHAM hasn't certified it, so we never make it a pick; a certified model is the safer buy at the same size.
Alternatives
The Coway Airmega 350 or one of these?
The certified models closest in size, and what is different about each, from the same kinds of source.
Cleans 513 sq ft, 23 sq ft lessCleans 47 m², 2 m² less, on a certified CADR. It has an ionizer you can switch off. It needs filters more often (every 3–12 months). 0.7 kg heavier.
Levoit EverestAir-P
AHAM verified
- Really cleans
- 539 sq ft50 m² 50 m²539 sq ft
- Box says
- 2,635 sq ft245 m² 4.9× overstated
- New filter
- 12–15 months
Cleans 539 sq ft, 3 sq ft moreCleans 50 m², 1 m² more, on a certified CADR. It goes longer between filters (every 12–15 months). 1.6 kg heavier.
Levoit Core 600S-P
AHAM verified
- Really cleans
- 595 sq ft55 m² 55 m²595 sq ft
- Box says
- 2,909 sq ft270 m² 4.9× overstated
- New filter
- 6–12 months
Cleans 595 sq ft, 59 sq ft moreCleans 55 m², 6 m² more, on a certified CADR. It needs filters more often (every 6–12 months) and draws 49 W at top speed. 1.6 kg lighter.
Sources
Where these numbers come from
- Maker’s claim Coway Airmega 350 product page and specifications · Coway
We don't test purifiers ourselves: every figure on this page is copied from these sources and was last checked on 1 Nov 2026. Spotted one that's wrong or out of date? Tell us and we'll fix it and change the date.