Coway
Coway Airmega 400
Air purifiers
$549List price
Explore this product Your shortlist, side by side
Coway Airmega 400 vs Dyson Purifier Hot+Cool Formaldehyde HP09
Find the differences that matter for your next decision.
Dyson
Dyson Purifier Hot+Cool Formaldehyde HP09
Air purifiers
$799List price
Explore this product What matters most to you?
Start with all rankable specifications, or focus on a particular use.
Your starting point
Buy the Coway Airmega 400.
- Leads 4 of 5 rankable overall specs; Dyson Purifier Hot+Cool Formaldehyde HP09 takes 1.
- CADR: 350 CFM vs 190 CFM class
How we reached this
We compare the published specifications relevant to your priority. Each rankable specification counts once; your selected requirements can rule a product out. This is a guide to the numbers, not a laboratory performance score.
Coverage area: 1,560 sq ft vs 500 sq ft room size with 350° oscillation
It is also $250 cheaper.
The trade-off to know
Check first: the Coway Airmega 400 has no Wi-Fi app. Tick them under deal-breakers if that rules it out.
Look at the differences ↓Refine your requirements
What would rule one out?
Side by side
The differences, in detail.
Start with the key specs, then explore as much as you need.
| What you’re comparing | Coway Airmega 400 | Dyson Purifier Hot+Cool Formaldehyde HP09 |
|---|---|---|
| CADRPerformance | 350 CFM (Smoke), 328 CFM (Dust), 400 CFM (Pollen) | 190 CFM class (Air Multiplier 77 gallons/sec circulation) |
| Room sizePerformance | Large living rooms, open floor plans, offices | Medium to large bedrooms, living rooms up to 500 sq ft |
| Coverage areaPerformance | 1,560 sq ft (2 air changes/hr) / 780 sq ft (4 air changes/hr) | 500 sq ft room size with 350° oscillation |
| Filter typesFilters | Washable Pre-filter + Max2 Filter (True HEPA + Activated Carbon) | 360° Glass HEPA H13 + Activated Carbon + Cryptomic Formaldehyde filter |
| Filter lifeFilters | 12 months (Max2 filter) / Washable pre-filters | 12 months (HEPA/Carbon) / Permanent Formaldehyde catalyst |
Showing 5 of 11 specifications. Missing values stay unlisted. About the sources
Both sides of the decision
What you gain. What you give up.
Coway Airmega 400
Reasons to choose it
- 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
Worth considering
- Cube design has a large floor footprint
- No mobile app connectivity on the non-S model
Dyson Purifier Hot+Cool Formaldehyde HP09
Reasons to choose it
- Combines HEPA H13 purification, fast ceramic heating, and cooling fan in one
- Destroys formaldehyde continuously without filter replacement
- Fully sealed whole-machine HEPA H13 standard prevents bypass
Worth considering
- CADR airflow is lower than dedicated box purifiers
- Expensive upfront purchase price
Beyond the spec sheet
Living with your choice.
Explore the ownership details available for this pair.
What three years could cost
Coway Airmega 400
3-Year Estimated Total$819
Dyson Purifier Hot+Cool Formaldehyde HP09
3-Year Estimated Total$1,039
Room Placement & Bedroom Noise Check
Physical clearance required for airflow, wall placement, and bedroom noise levels.
Wall Clearance Required
Coway
Requires 12 in perimeter airflow space
Dyson
Cylindrical base: needs 12 in airflow clearance around unit
Nighttime Sleep Mode Noise
Coway
Standard sleep speed
Dyson
28 dB night mode with dimmed LCD
Unit Footprint & Dimensions
Coway
Standard room purifier footprint
Dyson
Bladeless oval loop (30.0 × 8.1 × 8.1 in; 12.6 lb; heats & cools)
Everyday ownership notes
Documented ergonomic quirks, hardware annoyances, and maintenance realities reported by real owners.
Coway: What to watch for
- Maintenance
Requires periodic filter replacements to maintain airflow and odor capture.
Dyson: What to watch for
- Hidden Cost
High replacement filter cost (~$80 each).
Know what’s behind the comparison
Published specs. Visible sources.
Clinchmark compares manufacturer specifications and other published information. We have not independently lab-tested these products. Editorial assessments and unknown values are identified in the specification details.
Catalog snapshot: September 1, 2026. Prices, availability, and provider terms can change.
Still weighing it up?
Which is cheaper, the Coway Airmega 400 or the Dyson Purifier Hot+Cool Formaldehyde HP09?
Coway Airmega 400 costs $250 less at list price.
What is the biggest catch with the Coway Airmega 400 or Dyson Purifier Hot+Cool Formaldehyde HP09?
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 Dyson Purifier Hot+Cool Formaldehyde HP09?
Tied on bedrooms. Coway Airmega 400 is cheaper. The 2 rankable bedrooms specs split 1 to 1. Saves $250 at list price.
What cannot be compared from spec sheets?
Of the 11 specs tracked here, 6 are descriptive and cannot be ranked on numbers alone. Spec sheets also cannot measure subjective factors like build quality, real-world performance, or comfort.