Head to head
Coway Airmega 400 vs Coway Airmega 250
Coway Airmega 400 leads 2 to 1 on the 3 rankable specs, but Coway Airmega 250 costs $150 less. Most of the 11 attributes tracked here are descriptive rather than numeric.
Catalog as of September 1, 2026
Why, in numbers
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Coway sibling models compared across generations.
Our recommendation: Compare the spec differences below to see if the price premium justifies the newer model's additions.
Buying for
Straight answer
Overall: 2 to 1
Buy the Coway Airmega 400.
- Leads 2 of 3 rankable overall specs; Coway Airmega 250 takes 1.
- CADR: 350 CFM vs 249 CFM
- Coverage area: 1,560 sq ft vs 930 sq ft
- Coway Airmega 250 is $150 cheaper. Pay the difference only if cadr matters to you.
At a glance
The handful of numbers that decide most purchases in this category.
CADR
Airmega 400
350 CFM (Smoke), 328 CFM (Dust), 400 CFM (Pollen)
Airmega 250
249 CFM (Smoke), 261 CFM (Dust), 230 CFM (Pollen)
Coverage area
Airmega 400
1,560 sq ft (2 air changes/hr) / 780 sq ft (4 air changes/hr)
Airmega 250
930 sq ft (2 air changes/hr) / 465 sq ft (4 air changes/hr)
True 3-Year Cost of Ownership (TCO)
Coway Airmega 400
Coway Airmega 250
Room Placement & Bedroom Noise Check
Physical clearance required for airflow, wall placement, and bedroom noise levels.
Wall Clearance Required
Requires 12 in perimeter airflow space
Bottom & dual-side intake: sits flush against back wall
Nighttime Sleep Mode Noise
Standard sleep speed
22 dB sleep mode with auto-dimming LED light sensor
Unit Footprint & Dimensions
Standard room purifier footprint
Modern slim tower (19.7 × 18.5 × 8.3 in; 20.5 lb)
The 90-Day Owner Regret Check
Documented ergonomic quirks, hardware annoyances, and maintenance realities reported by real owners.
Airmega 400: What to watch for
- Maintenance
Requires periodic filter replacements to maintain airflow and odor capture.
Airmega 250: What to watch for
- Maintenance
Requires periodic filter replacements to maintain airflow and odor capture.
Performance
leads 2-0| CADR | 350 CFM (Smoke), 328 CFM (Dust), 400 CFM (Pollen) (wins this row: higher) | 249 CFM (Smoke), 261 CFM (Dust), 230 CFM (Pollen) |
|---|---|---|
| Room size | Large living rooms, open floor plans, offices | Large bedrooms, apartments, living rooms, and open layouts up to 930 sq ft |
| Coverage area | 1,560 sq ft (2 air changes/hr) / 780 sq ft (4 air changes/hr) (wins this row: higher) | 930 sq ft (2 air changes/hr) / 465 sq ft (4 air changes/hr) |
Filters
2 differences| Filter types | Washable Pre-filter + Max2 Filter (True HEPA + Activated Carbon) | EZ-clean Washable Pre-filter + Max2 Green True HEPA and Activated Carbon filter |
|---|---|---|
| Filter life | 12 months (Max2 filter) / Washable pre-filters | 12 months (Max2 filter) / Washable slide-out pre-filter |
Usability & Smart
4 differences| Noise levels | 22 dB (Sleep mode) – 52 dB (Max speed) | 22 dB (Sleep mode) – 54 dB (Max speed) |
|---|---|---|
| Energy consumption | 66 W max power consumption (Energy Star Certified) | 60 W max power consumption (Energy Star Certified) |
| Smart features | Smart Auto Mode + Eco Mode (no Wi-Fi app) | Smart Auto Mode, Rapid Mode, Eco Mode, and Sleep Mode |
| Air quality sensors | Real-time particle sensor with colorful LED ring indicator | Real-time particle sensor with colorful LED air quality indicator |
Design & Ownership
leads 1-0| Weight | 24.7 lb (11.2 kg) | 20.5 lb (9.3 kg) (wins this row: lower) |
|---|---|---|
| Warranty | 5 years limited motor / 1 year electronic parts | 5 years limited warranty on motor / 1 year electronic parts |
Which one should you buy
Pick this one if
Coway Airmega 400
Dual-suction large room air purifier with Max2 HEPA and activated carbon filtration covering 1,560 sq ft.
- Massive CADR cleans up to 1,560 sq ft twice per hour
- Dual-sided air intake with combined True HEPA and carbon filters
- Smart Eco mode turns off fan when air remains clean for 30 minutes
What you give up
- Cube design has a large floor footprint
- No mobile app connectivity on the non-S model
Pick this one if
Coway Airmega 250
Modern slim aesthetic air purifier with Green True HEPA Max2 filtration, covering up to 930 sq ft, Smart Auto mode, and easy-clean washable pre-filter.
- Green True HEPA filter captures 99.999% of 0.01-micron ultrafine particles and neutralizes odors
- Easy-to-clean EZ-pull front pre-filter slides out from the top without opening the machine
- Covers up to 930 sq ft with Smart Auto Mode and real-time PM2.5 particle sensor LED ring
What you give up
- No Wi-Fi app connectivity on the standard 250 model (app available on 250S variant)
- Substantial 20.5 lb weight
Best for each use
Bedrooms
Too close to call on bedrooms from the spec sheets. Only weight is rankable here.
Big rooms & allergies
For big rooms & allergies, buy the Coway Airmega 400.
Low running cost
Too close to call on low running cost from the spec sheets.
Done deciding?
Open the full standalone spec sheet for either device.
Manufacturer pages: Coway Airmega 400 ↗ · Coway Airmega 250 ↗
Common questions
Which is cheaper, the Coway Airmega 400 or the Coway Airmega 250?
Coway Airmega 250 costs $150 less at list price.
What is the biggest catch with the Coway Airmega 400 or Coway Airmega 250?
Coway Airmega 400 has this deal-breaker: no Wi-Fi app. No schedules or remote control from your phone.
Which is better for bedrooms, the Coway Airmega 400 or the Coway Airmega 250?
Too close to call on bedrooms from the spec sheets. Only weight is rankable here. Noise levels: 22 dB vs 22 dB Smart features: Smart Auto Mode + Eco Mode vs Smart Auto Mode, Rapid Mode, Eco Mode, and…
What cannot be compared from spec sheets?
Of the 11 specs tracked here, 8 are descriptive and cannot be ranked on numbers alone. Spec sheets also cannot measure subjective factors like build quality, real-world performance, or comfort.