AirDoctor 3000 vs Coway Airmega 400
Quick take: The Coway Airmega 400 costs $170 less; the AirDoctor 3000 moves more air (336 CADR); the Coway Airmega 400 costs about $27 less per year in filters — over five years that often outweighs the sticker gap; the Coway Airmega 400 is the quieter bedroom unit (22 dB on sleep mode); the AirDoctor 3000 includes an ionizer — some buyers avoid these (see its cons for the ozone note).
| Spec | AirDoctor 3000 | Coway Airmega 400 |
|---|---|---|
| Price | ~$519 | ~$349 |
| Rating | — | — |
| Type | Large Room | Large Room |
| CADR (smoke) | 336 CFM | 328 CFM |
| Honest Coverage (AHAM) | ~521 sq ft | ~508 sq ft |
| Claimed Coverage | 1,274 sq ft | 1,560 sq ft |
| Noise (sleep) | 40 dB | 22 dB |
| Noise (max) | 64 dB | 52 dB |
| Filter Cost / Year | $157 | $130 |
| Filter | Pre-filter + Carbon/Gas Trap VOC filter + UltraHEPA (dual-stage) | Washable pre-filters + dual Max2 combined activated carbon + True HEPA |
| Filter Life | 12 mo | 12 mo |
| Max Power | 93W | 66W · Energy Star |
| Auto Mode | Sensor + auto | Sensor + auto |
| Ionizer | Yes | None |
| WiFi Control | None | None |
| Weight | 18 lbs | 24.7 lbs |
| Maintenance | Two clocks run at once: the UltraHEPA lasts 12 months but the Carbon/Gas Trap VOC filter needs changing every 6, putting genuine annual costs at about $157 - generic filters cut that to ~$99 and work fine since there's no chip or DRM. The ionizer is switchable; HouseFresh's testing actually cleaned slightly faster with it on, but it's your call. Watch the pricing games when buying filters (and the unit itself): AirDoctor's site runs a permanent 'sale' against an inflated $629 list price, so never pay sticker for anything. | 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. |
| Warranty | 1 year | 5-year limited (motor and electronics) |
Pros & cons
AirDoctor 3000
- ✓Published CADR figures held up under independent HouseFresh testing
- ✓One of the fastest room-clear times in its class (14-16 minutes)
- ✓Substantial dual-stage carbon filtration handles VOCs better than most rivals
- ✓Responsive air quality sensor and auto mode with a glanceable display
- ✓Switchable ionizer - off means off
- ✓No filter DRM; generic filters cut running costs by a third
- ✗Perpetual fake-discount pricing against an inflated $629 MSRP
- ✗$157/yr genuine filter cost with a 6-month carbon interval
- ✗Loud 64 dB at max and 93 W with no Energy Star certification
- ✗No Wi-Fi/app unless you pay $200 more for the 3000i
- ✗Only a 1-year warranty at a premium price
- ✗No verifiable retailer rating base - sold mostly direct
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