Dyson
Dyson Purifier Hot+Cool Formaldehyde HP09
Air purifiers
$799List price
Explore this product Your shortlist, side by side
Dyson Purifier Hot+Cool Formaldehyde HP09 vs Coway Airmega 250
Find the differences that matter for your next decision.
Coway
Coway Airmega 250
Air purifiers
$399List 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 250.
- Leads 4 of 5 rankable overall specs; Dyson Purifier Hot+Cool Formaldehyde HP09 takes 1.
- CADR: 249 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: 930 sq ft vs 500 sq ft room size with 350° oscillation
It is also $400 cheaper.
The trade-off to know
Coway Airmega 250: No Wi-Fi app connectivity on the standard 250 model (app available on 250S variant)
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 | Dyson Purifier Hot+Cool Formaldehyde HP09 | Coway Airmega 250 |
|---|---|---|
| CADRPerformance | 190 CFM class (Air Multiplier 77 gallons/sec circulation) | 249 CFM (Smoke), 261 CFM (Dust), 230 CFM (Pollen) |
| Room sizePerformance | Medium to large bedrooms, living rooms up to 500 sq ft | Large bedrooms, apartments, living rooms, and open layouts up to 930 sq ft |
| Coverage areaPerformance | 500 sq ft room size with 350° oscillation | 930 sq ft (2 air changes/hr) / 465 sq ft (4 air changes/hr) |
| Filter typesFilters | 360° Glass HEPA H13 + Activated Carbon + Cryptomic Formaldehyde filter | EZ-clean Washable Pre-filter + Max2 Green True HEPA and Activated Carbon filter |
| Filter lifeFilters | 12 months (HEPA/Carbon) / Permanent Formaldehyde catalyst | 12 months (Max2 filter) / Washable slide-out pre-filter |
Showing 5 of 11 specifications. Missing values stay unlisted. About the sources
Both sides of the decision
What you gain. What you give up.
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
Coway Airmega 250
Reasons to choose it
- 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
Worth considering
- No Wi-Fi app connectivity on the standard 250 model (app available on 250S variant)
- Substantial 20.5 lb weight
Beyond the spec sheet
Living with your choice.
Explore the ownership details available for this pair.
What three years could cost
Dyson Purifier Hot+Cool Formaldehyde HP09
3-Year Estimated Total$1,039
Coway Airmega 250
3-Year Estimated Total$564
Room Placement & Bedroom Noise Check
Physical clearance required for airflow, wall placement, and bedroom noise levels.
Wall Clearance Required
Dyson
Cylindrical base: needs 12 in airflow clearance around unit
Coway
Bottom & dual-side intake: sits flush against back wall
Nighttime Sleep Mode Noise
Dyson
28 dB night mode with dimmed LCD
Coway
22 dB sleep mode with auto-dimming LED light sensor
Unit Footprint & Dimensions
Dyson
Bladeless oval loop (30.0 × 8.1 × 8.1 in; 12.6 lb; heats & cools)
Coway
Modern slim tower (19.7 × 18.5 × 8.3 in; 20.5 lb)
Everyday ownership notes
Documented ergonomic quirks, hardware annoyances, and maintenance realities reported by real owners.
Dyson: What to watch for
- Hidden Cost
High replacement filter cost (~$80 each).
Coway: What to watch for
- Maintenance
Requires periodic filter replacements to maintain airflow and odor capture.
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 Dyson Purifier Hot+Cool Formaldehyde HP09 or the Coway Airmega 250?
Coway Airmega 250 costs $400 less at list price.
What is the biggest catch with the Dyson Purifier Hot+Cool Formaldehyde HP09 or Coway Airmega 250?
Dyson Purifier Hot+Cool Formaldehyde HP09 has this deal-breaker: over 55 dB on high. Louder than normal conversation at full speed.
Which is better for bedrooms, the Dyson Purifier Hot+Cool Formaldehyde HP09 or the Coway Airmega 250?
Tied on bedrooms. Coway Airmega 250 is cheaper. The 2 rankable bedrooms specs split 1 to 1. Saves $400 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.