Head to head
Alen BreatheSmart 75i Large Room Air Purifier vs Coway Airmega 400
Coway Airmega 400 leads 3 to 1 on the 4 rankable specs and costs $200 less, which makes it the straightforward pick. Most of the 11 attributes tracked here are descriptive rather than numeric.
Catalog as of September 1, 2026
Why, in numbers
Swap
Compare a different air purifier
Levoit Core 300S Smart True HEPA Air Purifier$149Winix 5500-2 Air Purifier$159Levoit Core 400S$219Coway Airmega AP-1512HH Mighty$229Blueair Blue Pure 311i Max$229Honeywell HPA300 HEPA Air Purifier$249Levoit Core 600S Smart True HEPA$299Blueair Blue Pure 211+ Auto$339Coway Airmega 250$399Blueair Protect 7470i$649Dyson Purifier Hot+Cool Formaldehyde HP09$799Swap
Compare a different air purifier
Levoit Core 300S Smart True HEPA Air Purifier$149Winix 5500-2 Air Purifier$159Levoit Core 400S$219Coway Airmega AP-1512HH Mighty$229Blueair Blue Pure 311i Max$229Honeywell HPA300 HEPA Air Purifier$249Levoit Core 600S Smart True HEPA$299Blueair Blue Pure 211+ Auto$339Coway Airmega 250$399Blueair Protect 7470i$649Dyson Purifier Hot+Cool Formaldehyde HP09$799Buying for
Straight answer
Overall: 1 to 3
Buy the Coway Airmega 400.
- Leads 3 of 4 rankable overall specs; Alen BreatheSmart 75i Large Room Air Purifier takes 1.
- Coverage area: 1,560 sq ft vs 1,400 sq ft
- Noise levels: 22 dB vs 25 dB
- It is also $200 cheaper.
At a glance
The handful of numbers that decide most purchases in this category.
CADR≠
Alen
350 CFM across Smoke, Dust, Pollen
Coway
350 CFM (Smoke), 328 CFM (Dust), 400 CFM (Pollen)
Coverage area
Alen
1,400 sq ft (2 air changes/hr) / 700 sq ft (4 air changes/hr)
Coway
1,560 sq ft (2 air changes/hr) / 780 sq ft (4 air changes/hr)
True 3-Year Cost of Ownership (TCO)
Alen BreatheSmart 75i Large Room Air Purifier
Coway Airmega 400
The 90-Day Owner Regret Check
Documented ergonomic quirks, hardware annoyances, and maintenance realities reported by real owners.
Alen: What to watch for
- Maintenance
Requires periodic filter replacements to maintain airflow and odor capture.
Coway: What to watch for
- Maintenance
Requires periodic filter replacements to maintain airflow and odor capture.
Performance
leads 1-0| CADR | 350 CFM across Smoke, Dust, Pollen | 350 CFM (Smoke), 328 CFM (Dust), 400 CFM (Pollen) |
|---|---|---|
| Room size | Large master suites, open living rooms, offices | Large living rooms, open floor plans, offices |
| Coverage area | 1,400 sq ft (2 air changes/hr) / 700 sq ft (4 air changes/hr) | 1,560 sq ft (2 air changes/hr) / 780 sq ft (4 air changes/hr) (wins this row: higher) |
Filters
leads 1-0| Filter types | Medical-grade H13 True HEPA + Antimicrobial layer + Heavy Odor Carbon | Washable Pre-filter + Max2 Filter (True HEPA + Activated Carbon) |
|---|---|---|
| Filter life | 12–15 months extra long filter life (wins this row: higher) | 12 months (Max2 filter) / Washable pre-filters |
Usability & Smart
leads 1-0| Noise levels | 25 dB (WhisperMax) – 49 dB (Turbo speed) | 22 dB (Sleep mode) – 52 dB (Max speed) (wins this row: lower) |
|---|---|---|
| Energy consumption | 45 W (Energy Star certified) | 66 W max power consumption (Energy Star Certified) |
| Smart features | Alen Air App (Wi-Fi), auto modes, color ring status | Smart Auto Mode + Eco Mode (no Wi-Fi app) |
| Air quality sensors | Laser air quality sensor detecting fine particle levels with 5 color rings | Real-time particle sensor with colorful LED ring indicator |
Design & Ownership
leads 1-0| Weight | 27.0 lb (12.2 kg) | 24.7 lb (11.2 kg) (wins this row: lower) |
|---|---|---|
| Warranty | Lifetime warranty (with active filter subscription) | 5 years limited motor / 1 year electronic parts |
Which one should you buy
Pick this one if
Alen BreatheSmart 75i Large Room Air Purifier
Commercial-grade quiet purifier cleaning up to 1,400 sq ft every 30 minutes with a lifetime warranty.
- Industry-exclusive transferable Lifetime Warranty
- Tuned pink noise frequencies promote deeper sleep on WhisperMax mode
- Medical-grade H13 True HEPA filter lasts up to 15 months
What you give up
- High initial investment
- Tall tower profile
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
Best for each use
Bedrooms
For bedrooms, buy the Coway Airmega 400.
Big rooms & allergies
Tied on big rooms & allergies. Coway Airmega 400 is cheaper.
Low running cost
Too close to call on low running cost from the spec sheets. Only filter life is rankable here.
Done deciding?
Open the full standalone spec sheet for either device.
Manufacturer pages: Alen BreatheSmart 75i Large Room Air Purifier ↗ · Coway Airmega 400 ↗
Common questions
Which is cheaper, the Alen BreatheSmart 75i Large Room Air Purifier or the Coway Airmega 400?
Coway Airmega 400 costs $200 less at list price.
What is the biggest catch with the Alen BreatheSmart 75i Large Room Air Purifier or Coway Airmega 400?
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 Alen BreatheSmart 75i Large Room Air Purifier or the Coway Airmega 400?
For bedrooms, buy the Coway Airmega 400. Leads 2 of 2 rankable bedrooms specs. Noise levels: 22 dB vs 25 dB
What cannot be compared from spec sheets?
Of the 11 specs tracked here, 7 are descriptive and cannot be ranked on numbers alone. Spec sheets also cannot measure subjective factors like build quality, real-world performance, or comfort.