Coway Airmega 400 vs Coway Airmega 250
Quick take: The Coway Airmega 400 costs $50 less; the Coway Airmega 400 moves more air (328 CADR, 32% more cleaning power); the Coway Airmega 250 costs about $51 less per year in filters — over five years that often outweighs the sticker gap.
| Spec | Coway Airmega 400 | Coway Airmega 250 |
|---|---|---|
| Price | ~$349 | ~$399 |
| Rating | — | — |
| Type | Large Room | Large Room |
| CADR (smoke) | 328 CFM | 249 CFM |
| Honest Coverage (AHAM) | ~508 sq ft | ~386 sq ft |
| Claimed Coverage | 1,560 sq ft | 930 sq ft |
| Noise (sleep) | 22 dB | 22 dB |
| Noise (max) | 52 dB | 54 dB |
| Filter Cost / Year | $130 | $79 |
| Filter | Washable pre-filters + dual Max2 combined activated carbon + True HEPA | Washable pre-filter + Max2 combined activated carbon + True HEPA |
| Filter Life | 12 mo | 12 mo |
| Max Power | 66W · Energy Star | 64W · Energy Star |
| Auto Mode | Sensor + auto | Sensor + auto |
| Ionizer | None | None |
| WiFi Control | None | None |
| Weight | 24.7 lbs | 20.5 lbs |
| Maintenance | Twin washable pre-filters (one per side) need a rinse every few weeks; the two Max2 carbon+HEPA cartridges are replaced together yearly at about $130 for the set, though the set routinely drops to $75-90 on sale. No DRM or chipped filters, and third-party Max2-compatible sets cost half as much. The dual-intake design means it wants a few inches of clearance on both sides, not a wall corner. The base 400 has no app; the 400S adds Wi-Fi for roughly $100 more. | The washable pre-filter catches hair and dust and should be rinsed every 2-4 weeks; the combined Max2 carbon+HEPA filter is a single $79 cartridge replaced yearly. No chips, no DRM, and Coway's filter-change indicator is usage-based rather than a hard lockout. The 250's wide front panel pops off without tools. Note the plain 250 has no Wi-Fi - if you want app-tracked filter life you need the pricier 250S variant. |
| Warranty | 5-year limited (motor and electronics) | 5-year limited (motor and electronics) |
Pros & cons
Coway Airmega 400
- ✓Excellent noise-to-airflow ratio - 22-52 dB across the range
- ✓Double-barreled carbon filtration handles VOCs and odors better than most HEPA-first rivals
- ✓Proven multi-year reliability and a 5-year motor/electronics warranty
- ✓Effective auto/eco mode that shuts the fan off when air stays clean
- ✓Washable pre-filters on both intakes cut filter spend
- ✓Energy Star certified despite the dual-filter design
- ✗1,560 sq ft claim is 3x its honest 508 sq ft AHAM coverage
- ✗~$130/yr filter sets cost double a Levoit Core 600S
- ✗No Wi-Fi on the base model - the 400S upcharge is steep
- ✗Big 24.7 lb footprint that needs clearance on both sides
Coway Airmega 250
- ✓Coway build quality and a 5-year motor/electronics warranty
- ✓Very quiet across its range (22-54 dB) with a pleasant sound profile
- ✓Simple, cheap upkeep - one $79 Max2 cartridge per year plus a rinseable pre-filter
- ✓Responsive auto mode with a clear air-quality color ring
- ✓Attractive low-profile design that doesn't look like an appliance
- ✓Energy Star certified
- ✗930 sq ft claim is 2.4x its honest 386 sq ft AHAM coverage
- ✗Weak CADR-per-dollar - a $250 Core 600S moves 65% more air
- ✗No Wi-Fi or app on the base 250; the 250S costs more
- ✗At 21.4 lbs it's heavy for its actual coverage class