Name: Alen Air Purifier BreatheSmart 45i HEPA with Odor Filter for Large Rooms up to 1900 Sq. Ft. - Perfect for Bedrooms & Home Offices - Captures Dust -...
Brand: Alen
SKU: B0FPCVBMLJ
Price: 479 USD
Availability: InStock
Rating: 4.7 (754 reviews)

Our Verdict

Coway 400(G) Wins

COWAY Air Purifiers for Home Large Room Up to 3,120ft², 2 Sets of Washable Pre-Filters and True HEPA Filters for Smoke, Allergies, Pet Dander, Odor, AQI, Auto & Sleep Mode, Timer, 5yr Warranty, 400(G) 400 GRAPHITE - High-End Air Purifiers

It offers significantly higher CADR (416.0 vs 253.33) and larger coverage (650 sq ft vs 395.83 sq ft). Choose Alen if strong odor neutralization and ultra-quiet operation are top priorities for a smaller space.

$649Buy on Amazon

Bottom Line: Coway 400(G) is the better choice. It offers significantly higher CADR (416.

Key Differences

The most significant spec differences at a glance

253.33

Cadr Smoke

39% less

416

395.83

Coverage Sq Ft

39% less

650

Advantages

Where each product wins

Coway

Cadr Smoke: 39% higher (253.33 vs 416.0)
Coverage Sq Ft: 39% higher (395.83 vs 650.0)

Who Should Buy Which?

Find the right product for your needs

Buy Alen if...

Alen Air Purifier BreatheSmart

Ideal for those prioritizing a quiet, clean sleeping or working environment. If you frequently deal with strong household odors in a bedroom or home office up to about 400 sq ft, the Alen 45i's HEPA Odor Filter and ultra-quiet operation are perfect. Its SmartSensor auto-adjusts, maintaining air quality without disturbance. Buyers who value a peaceful atmosphere and medical-grade filtration for smaller large rooms will find its $479 price point a great investment for restful sleep and fresh air.

Buy Coway if...

COWAY Air Purifiers for

The Coway 400(G) is for individuals seeking robust air purification for larger spaces, particularly those with severe allergies, heavy pet dander, or smoke concerns. If you need to cover up to 650 sq ft efficiently with a high CADR of 416.0, this is your choice. Its ability to remove 99.999% of 0.01-micron particles provides superior air quality. The higher $649.0 price is justified by its powerful performance, energy efficiency, and a solid 5-year warranty for lasting peace of mind.

Spec Comparison

7 specs compared

Specification	Alen Air Purifier BreatheSmart	Coway Air Purifiers for
Price	$479	$649
Rating	4.7(754)	4.4(6.5k)
Cadr Smoke	253.33	416
Coverage Sq Ft	395.83	650
Noise Level db Min	—	22 dB
Filter Type	HEPA Odor Filter	True HEPA
Smart Sensor	Yes	Yes
Weight	—	3.05 lbs
Energy Star	—	Yes

Swipe horizontally to see all columns

Pros & Cons

Quick overview of strengths and weaknesses

Alen Air Purifier

Pros

Neutralizes strong household odors
Medical-grade filter captures 0.1 micron particles
SmartSensor auto-adjusts fan speed
High CADR smoke rating (253.33)

Cons

Effective coverage (395 sq ft) less than advertised
Pink noise feature may not be preferred by all users
Requires periodic filter replacement

Coway Air Purifiers

Pros

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.

Cons

Stated 3,120 sq ft coverage misleading for 4 ACH.
True HEPA filters require periodic replacement.
No remote control listed in features.

Frequently Asked Questions

Common questions about this comparison

Which is better for large rooms?

Coway 400(G) is better, covering 650 sq ft with a CADR of 416.0 for smoke. The Alen 45i covers 395.83 sq ft with a CADR of 253.33. Coway offers greater capacity for larger spaces.

What's the main difference in filtration?

Alen uses a HEPA Odor Filter capturing 0.1 micron particles and neutralizing strong odors. Coway uses a True HEPA filter, removing 99.999% of 0.01-micron particles, offering superior fine particle removal.

Is the price difference worth it?

The Coway 400(G) costs $649.0 compared to Alen's $479.0. If you need higher CADR (416.0) and greater room coverage (650 sq ft), especially for more severe air quality issues, the Coway's higher price offers better performance value for larger areas.

Which offers quieter operation?

Alen BreatheSmart 45i is noted for ultra-quiet operation, aiding sleep, though a specific dB isn't given. Coway 400(G) has a minimum noise level of 22.0 dB, which is also very quiet. Alen emphasizes quietness more.