Our Verdict
Coway 400(G) Wins
Key Differences
The most significant spec differences at a glance
Cadr Smoke
56% moreCoverage Sq Ft
56% moreAdvantages
Where each product wins
Coway
- Cadr Smoke: 56% higher (416.0 vs 266.933)
- Coverage Sq Ft: 56% higher (650.0 vs 417.0833)
Who Should Buy Which?
Find the right product for your needs
Buy Coway if...
COWAY Air Purifiers for
The ideal buyer for the Coway 400(G) is someone prioritizing maximum air purification performance for truly large rooms, up to 650 sq ft. They value superior particle removal (99.999% of 0.01-micron particles), a high CADR of 416, and quiet operation with a minimum noise level of 22 dB. This user is willing to invest in a premium device with a 5-year warranty and accepts the recurring cost of True HEPA filter replacements for top-tier air quality, focusing on allergies, smoke, and pet dander.
Buy Nuwave if...
Nuwave Forever Smart Air
The Nuwave Forever Smart Air Purifier suits buyers who prioritize long-term cost savings and convenience over absolute maximum coverage. They will appreciate the washable, reusable filters, eliminating recurring purchase costs. This user needs effective air purification for medium to large rooms (up to 417 sq ft) and values modern conveniences like Wi-Fi enabled remote control. They are comfortable with a slightly lower CADR (266.933) but appreciate its ozone reduction capabilities, making it ideal for those seeking a "set and forget" system with smart integration.
Spec Comparison
9 specs compared
| Specification | ![]() | ![]() |
|---|---|---|
| Price | $749 | $500 |
| Rating | 4.4(6.5k) | 4.6(497) |
| Cadr Smoke | 416 | 266.93 |
| Coverage Sq Ft | 650 | 417.08 |
| Noise Level db Min | 22 dB | — |
| Weight | 3.05 lbs | — |
| Energy Star | Yes | Yes |
| Filter Type | True HEPA | — |
| Smart Sensor | Yes | Yes |
| WiFi | — | Yes |
| Filter Cost Yearly | — | Free |
Swipe horizontally to see all columns
Pros & Cons
Quick overview of strengths and weaknesses
Coway Air Purifiers
- Removes 99.999% of 0.01-micron particles.
- Covers 780 sq ft with 4 air changes per hour.
- Smart Mode adjusts fan speed based on air quality.
- Eco Mode shuts off fan when air is clean.
- Stated 3,120 sq ft coverage misleading for 4 ACH.
- True HEPA filters require periodic replacement.
- No remote control listed in features.
Nuwave Forever Smart
- Washable filters eliminate recurring purchase costs.
- Captures 100% of particles down to 0.1 microns.
- Lowers ozone levels to 1 ppb.
- CADR smoke rating of 266.933 for effective cleaning.
- Effective coverage (5 ACH) is 417 sq ft, not 2,002 sq ft.
- Ozone removal filters are not washable or reusable.
Frequently Asked Questions
Common questions about this comparison
Which air purifier is better for very large rooms?
The Coway 400(G) is better for larger spaces, covering up to 650 sq ft effectively with a CADR of 416. The Nuwave's effective coverage is 417 sq ft with a CADR of 266.933.
What's the main difference in filter maintenance and cost?
The Nuwave features a "Never Replace Air Filter System" with washable filters, leading to $0 yearly filter cost. The Coway uses True HEPA filters that require periodic replacement, incurring recurring costs for optimal performance.
Is the Coway's higher price justified?
The Coway 400(G) is more expensive but provides superior CADR (416 vs 266.933) and covers a larger area (650 sq ft vs 417 sq ft). It also removes smaller particles (0.01 microns vs 0.1 microns), justifying its premium for higher performance.
Which purifier offers better smart features?
Both have smart sensors. The Nuwave adds Wi-Fi connectivity for remote control and monitoring via an app, which the Coway does not list. The Coway features an Eco Mode to conserve energy when the air is clean.
Explore Other Categories
Popular comparisons across the site
Ask AI
Get instant answers about specs
Get the Deets
Ask our AI assistant
Ask Deets anything!




























