Model comparison
Coway Airmega 350 vs 450: room rate, footprint and display
The Coway Airmega 350 and Airmega 450 share a tall cylindrical form, local Auto operation, color feedback, and a replaceable 3-in-1 filter, but they serve different room-size and information needs. The 350 offers White and Beige finishes and color-category feedback; the reviewed non-S 450 has White and Beige offers, numeric particle readouts, and documented wheels. Neither reviewed configuration has an app plan. Compare rate-specific area and the feature you actually require rather than treating the largest square-foot headline as a repeated-cleaning rating.
Compare room capacity at the same rate
| Manufacturer figure | Airmega 350 | Airmega 450 |
|---|---|---|
| Area at 1 ACH | 2,640 sq ft | 3,285 sq ft |
| Area at 2 ACH | 1,320 sq ft | 1,643 sq ft |
| 4.8-ACH comparison | 550 sq ft, calculated | 685 sq ft, calculated |
| Manual's 15-minute figure | 660 sq ft | 821 sq ft |
Coway directly lists the one- and two-change figures for both models; each linked manual also gives the 15-minute figure on an eight-foot ceiling basis. The 4.8-ACH values are calculations from the two-change ratings (area × 2 ÷ 4.8), not manufacturer claims at 4.8 ACH. The 350 is adequate for the comparison's medium tier but falls below its 606-square-foot large-room threshold. The 450's calculated 685 square feet clears that tier, though open layouts, high ceilings, placement, and actual fan settings can reduce practical coverage.
Particle feedback and controls
The 350's manual describes a four-color indicator and sensor-based Auto mode. Coway says its sensor detects particles as small as PM10, but the reviewed panel does not show a numeric PM value. The non-S 450 shows numeric PM1.0, PM2.5, and PM10 readings as well as a color category. If numeric readings on the appliance matter, that distinction favors the 450; if a color cue is enough, the 350 can meet that simpler need. Neither particle display establishes a separate VOC or general gas readout.
Both reviewed plans use physical controls. The 350 has Auto, Sleep, Turbo, Eco, and manual airflow levels; the 450 has corresponding local modes and manual levels. Coway's app-compatible list does not include the 350, and app/Wi-Fi directions in the 450/450S manual belong to the separate 450S rather than the reviewed 450 offer. If a phone app is essential, do not treat either as a connected choice.
Filter routine and recurring ownership
Each uses one 3-in-1 filter with a vacuumable pre-filter, Green True HEPA, and activated carbon. Both have separate model-specific Airmega replacement pages offering Fresh Starter+, Allergen+, and Intense Smoke+ styles. The purifier offers are finish choices, not a confirmed selection of which custom profile ships in the box. Do not assume that the 350 and 450 filter cartridges interchange simply because the product names and option labels look alike.
The manuals call for pre-filter vacuuming or dry wiping every two to four weeks, sensor cleaning about every two months, and annual replacement of the full 3-in-1 filter under an eight-hours-per-day Turbo example; actual life depends on use and environment. Neither filter assembly should be washed. Both save space versus a large paired-filter cabinet, but the owner's maintenance is not automatic—neither reviewed model documents a debris-scraping tray routine.
Fit, moving, and the CADR tradeoff
The 350 is listed at 12 × 12 × 23 inches on the product page and 12 × 12 × 23.2 inches in its manual. Its 17.19-pound weight is consistent across the available sources. The 450's body dimensions conflict more materially: the product page says 13 × 13 × 29 inches and the manual says 13.4 × 13.4 × 29.6. Do not use either as a settled tight-fit measurement. Coway documents wheels on the 450 but warns that they may not roll well across carpet or uneven flooring. The 350 manual shows a handle but no wheel plan; do not count it as a wheeled unit. Both require clear intake and outlet paths.
CADR also differs by pollutant rather than one generic number. The 350 is listed at 352 CFM smoke, 376 dust, and 450 pollen; the 450 is 439 smoke, 445 dust, and 450 pollen. The 450's gains are larger for smoke and dust, while the pollen figure is equal. These are manufacturer specifications, not independent lab measurements. A minimum generic CADR cannot be verified by substituting the most favorable of the three pollutant-specific values.
Which one fits your answers?
Choose the Airmega 350 when a 1,320-square-foot two-ACH ceiling is adequate, a 12-inch body width is useful, and color feedback plus local Auto meet your needs. It is lighter and uses less rated power, but its height and wheel status should not be treated as fully verified. Choose the Airmega 450 when you need the larger two-ACH rating, on-unit numeric PM readings, or documented wheels; expect a heavier body and preserve the product-page/manual dimension conflict for tight placements.
If you need the 450's display but prefer the Airmega 400's lower two-ACH area, that model is another local-control comparison with color feedback and two side-by-side Max2 filters. If app control or a pet-specific option is essential, none of these three should be forced into the match: use a model with a confirmed app or included pet-filter plan. Read the Airmega 350 review and Airmega 450 review for their separate operating limits and maintenance instructions.