Air Quality research
Coway Airmega 400: Large-Room CADR, Noise, and Filter Cost
Coway Airmega 400 review: compare 328 CFM smoke/dust and 400 CFM pollen CADR, 1,560 sq ft coverage, 22–52 dB noise, 66 W power draw, and dual Max2 filter cost.
Written by BenchPicked Editorial Team · Sources checked May 16, 2026
Executive Summary
Bottom line
Coway Airmega 400 serves as a dual-intake large-space purifier with Max2 carbon + Green HEPA with published smoke CADR of 328 CFM, stated coverage of 1,560 sq ft (~508 sq ft at 4.8 ACH under AHAM sizing), and pre-filter plus Max2 activated carbon and Green True HEPA filter. Compare its verified airflow, 22-52 dB noise profile, and annual filter replacement cost before checkout.
- Best Suited For
- people choosing a room air cleaner for a defined room and operating routine
- Core Buying Check
- Evaluate Coway Airmega 400 across air quality sensor, auto mode, and total checkout cost before ordering
- Key Evaluation Context
- matching cleaned-air delivery, noise, filter upkeep and room conditions
Decision matrix
Compare each documented specification against your room, routine, or operating requirements before checking live prices.
| Evaluation Factor | Documented Spec / Status | Buyer Takeaway |
|---|---|---|
| Air Quality Sensor | Pollution sensor | Cross-check Air Quality Sensor (Pollution sensor) on the active checkout listing for Coway Airmega 400 before ordering. |
| Auto Mode | Yes | Compare Auto Mode (Yes) directly against mainstream retail alternatives in the same price tier. |
| Brand | Coway | Verify that the checkout page and warranty card list Coway as the fulfilling manufacturer. |
| CADR (Dust) | 328 CFM | Compare the 328 CFM dust CADR against room floor area where carpet lint and household particulates accumulate. |
| CADR (Pollen) | 400 CFM | Use the 400 CFM pollen CADR to gauge seasonal allergen clearance speed when windows are closed. |
| CADR (Smoke) | 328 CFM | Multiply the 328 CFM smoke CADR by 1.55 to calculate maximum room square footage at 4.8 air changes per hour. |
Claim and evidence record
All 15 structured specification claims on this page are cross-referenced against the primary records listed below. Before checkout, confirm live unit pricing, included accessories, warranty coverage, and return windows.
When another option is the better fit
A higher-CADR purifier
Choose this when your room square footage demands A higher-CADR purifier's higher cubic-feet-per-minute airflow rather than Coway Airmega 400's compact footprint.
A quieter compact purifier
Choose this when low-decibel bedside operation with A quieter compact purifier matters more to your bedroom setup than Coway Airmega 400's maximum high-speed airflow.
Source control or ventilation
Choose this when addressing indoor pollutant sources or ventilation directly with Source control or ventilation is more effective than running Coway Airmega 400 continuously.
Current buying option
Check live price, stock, and seller terms before ordering
Use the evidence and limitations above to decide whether this product fits. Static research cannot verify today's inventory, bundle discounts, shipping fees, or return windows on the seller page.
Research details
Coway Airmega 400 Room Coverage & CADR Reality Check
The Coway Airmega 400 uses a dual-intake pull-through cabinet to achieve published Clean Air Delivery Rates of 328 CFM for smoke, 328 CFM for dust, and 400 CFM for pollen. While Coway lists a headline coverage rating of 1,560 square feet (calculated at roughly 1.5 to 2 air changes per hour), applying the strict 4.8 ACH standard to its 328 CFM smoke CADR yields a rapid-scrubbing footprint of 508 square feet—and 620 square feet for pollen. It effortlessly handles large open living/dining rooms, high-ceiling lofts, and basement rec rooms.
Filtration Architecture & Pollutant Capture Scope
Air enters through both the left and right side grilles, passing through two washable mesh pre-filters and two Max2 combo cartridges that fuse granular activated carbon with Green True HEPA media. Because it draws air through two full-height filter walls simultaneously, the Airmega 400 maintains high CFM throughput at lower fan RPMs and offers significantly more activated carbon surface area than the smaller AP-1512HH.
Acoustics, Power Draw & Bedroom Placement
Despite its heavy-duty 14.8 x 14.8 x 22.8 inch, 24.7 lb chassis, the Airmega 400 runs across a quiet 22 to 52 dB acoustic range while consuming 66 W at peak speed (ENERGY STAR certified). Its Smart mode integrates three intelligent routines—Auto particle sensing, Sleep fan-down when the room darkens, and Eco motor standby when air stays clean—accompanied by a real-time LED air quality ring.
Multi-Year Filter & Energy Ownership Cost
Sitting in the $$$ bracket, the most important ownership factor for the Airmega 400 is its dual-pack Max2 filter replacement cost: because the unit requires two Max2 cartridges per swap (approximately once a year), annual consumable spend is roughly double that of single-cartridge purifiers. Clean the two slide-out pre-filters every two weeks to maximize the lifespan of the expensive Max2 cores.
How It Compares Against Category Benchmarks
Compare the Coway Airmega 400 directly with the Blueair Blue 211i Max (435 CFM smoke CADR, 46 W, single folding filter) and the Honeywell HPA300 (300 CFM smoke CADR, 3 HEPA R cores, manual controls). Choose the Coway Airmega 400 if you want dual-sided mechanical True HEPA + granular carbon filtration and Smart Eco shutoff in a refined cube cabinet; choose the Blue 211i Max for higher smoke CADR and lower annual filter replacement cost.
Full source-attributed specification record (16 fields)
Published specs
| Field | Value | Source basis |
|---|---|---|
| Air Quality Sensor | Pollution sensor | Source Attributed (view source) |
| Auto Mode | Yes | Source Attributed (view source) |
| Brand | Coway | Source Attributed (view source) |
| Cadr Dust | 328 CFM | Source Attributed (view source) |
| Cadr Pollen | 400 CFM | Source Attributed (view source) |
| Cadr Smoke | 328 CFM | Source Attributed (view source) |
| Category | Air purifier | Source Attributed (view source) |
| Coverage Area Sqft | 1560 sq ft | Source Attributed (view source) |
| Dimensions | 14.8 x 14.8 x 22.8 in | Source Attributed (view source) |
| Energy Star | Yes | Source Attributed (view source) |
| Filter Type | Pre-filter plus Max2 activated carbon and Green True HEPA filter | Source Attributed (view source) |
| Model | Airmega 400 | Source Attributed (view source) |
| Noise Level Db | 22-52 dB | Source Attributed (view source) |
| Power Consumption W | 66 W | Source Attributed (view source) |
| Price Range | $$$ | Source Attributed |
| Weight | 24.7 lb | Source Attributed (view source) |
Buying options
| Store | Price | Confirm on seller page | Action |
|---|---|---|---|
| Amazon | Check current price on Amazon | Live unit price, genuine replacement filter stock & return window | Check price on Amazon* |
| * Affiliate links - prices may vary. Last checked: Sep 26, 2026. | |||
Source notes
- Coway Official Airmega 400 Specifications · Manufacturer · Checked May 16, 2026
- AHAM Verifide Room Air Cleaner Directory · Industry Standard · Checked May 16, 2026
Questions
What room size can Coway Airmega 400 realistically clean at 4.8 air changes per hour?
With Coway Airmega 400 rated at smoke CADR 328 CFM, dust CADR 328 CFM, and pollen CADR 400 CFM, realistic high-turnover sizing for Coway Airmega 400 reaches ~508 sq ft at 4.8 ACH (1,560 sq ft manufacturer rating is based on ~1.5–2 ACH) rather than the headline 1560 sq ft figure.
How loud is Coway Airmega 400 for overnight bedroom use and how much power does it draw?
Coway Airmega 400 lists an acoustic span of 22-52 dB and 66 W electrical draw across multiple speeds inside a 14.8 x 14.8 x 22.8 in (24.7 lb) enclosure. Overnight sleepers using Coway Airmega 400 can rely on onboard controls after a high-speed room purge.
What filter stages does Coway Airmega 400 use and how often do they need maintenance?
Coway Airmega 400 relies on pre-filter plus Max2 activated carbon and Green True HEPA filter with a rated service interval of 6 to 12 months and published safety certifications. Maintaining Coway Airmega 400 under manufacturer coverage terms means cleaning any outer pre-filter monthly and swapping core cartridges on schedule.
How do the controls and warranty on Coway Airmega 400 fit long-term household deployment?
Coway Airmega 400 combines multiple speeds and onboard controls with manufacturer coverage and published safety certifications for dual-intake large-space purifier with Max2 carbon + Green HEPA duties. Match Coway Airmega 400's 14.8 x 14.8 x 22.8 in footprint and 6 to 12 months consumable cycle against your room layout before ordering.
Before you buy
Recheck fit and current terms
Confirm Coway Airmega 400's model, included items, delivery, return policy, and any recurring costs before checkout.
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