Choosing an air purifier can feel overwhelming, but we’re about to make it a lot easier for you. At Alen, we believe the right purifier is the one that aligns with your space, priorities, and lifestyle. With over 20 years of experience in clean-air innovation, serving more than 1 million households, and proven True HEPA filtration across our entire lineup, we’re confident that we have the perfect air purifier for you. Let’s go over sizing, performance, and use cases, so that selecting your new Alen home air purifier is more exciting than overwhelming.
Alen Air Purifier Models Explained
Instead of starting off with the usual comparison chart, let’s look at how each Alen model exactly suits a specific need. By looking at the air purifier’s notable features and quick specs, you’ll easily find your ideal match.
Alen BreatheSmart 25i
Coverage: 400 - 800 sq ft App Controlled: Yes From:
$179.00
BreatheSmart 25i
If you want something light and portable, yet powerful, the Alen BreatheSmart 25i is our most compact purifier. It delivers the same dependable HEPA performance as larger models, all while operating with exceptionally low noise.
Quick Specs
- Coverage: ~400-800 sq ft
- CADR: ~107
- Noise: Whisper-quiet (~20-40 dB)
When your room space is limited, like in a small bedroom or dorm, the 25i brings medical-grade filtration without overwhelming the space. It’s engineered to catch microscopic pollutants while staying unobtrusive and portable.
Best For: small bedrooms, dorm rooms, nurseries.
Customers call it “small but powerful,” praising its ability to clean the air in tight corners where larger purifiers don’t fit.
Choose the BreatheSmart 25i if you want cleaner air in a compact room or nursery.
Alen BreatheSmart 35i
Coverage: 700 - 1,400 sq ft App Controlled: Yes From:
$289.00
BreatheSmart 35i
The 35i is compact yet advanced, built to support restful sleep and healthy air throughout the day. It works well in bedrooms or small home offices where dust, allergens, and sleep quality matter most, providing continuous, quiet filtration without sacrificing performance.
Quick Specs
- Coverage: ~700-1,400 sq ft
- CADR: ~190
- Noise: Whisper-quiet (~23–42 dB)
In bedrooms or small home offices, the 35i runs quietly all night while adjusting to spikes in allergens or dust. It’s powerful enough for most medium-sized spaces yet remains subtle for restful sleep.
Best For: bedrooms, nurseries, small home offices
The 35i holds Quiet Mark certification and is praised for collecting surprising amounts of dust in daily use.
Choose the BreatheSmart 35i for a quiet, professional solution to reliably remove dust and allergens.
“Quiet Mark certification is the unique consumer and trade champion mark of approval and resource platform. It provides reliable and independent information about the sound a product makes and approved noise reduction performance before purchase with the primary focus to improve health and wellbeing.” —Quiet Mark
Alen BreatheSmart 45i
Coverage: 950 - 1,900 sq ft App Controlled: Yes From:
$449.00
BreatheSmart 45i
The 45i is Alen’s all-purpose model, versatile, intelligent, and powerful without being overwhelming. For families, professionals, or anyone who wants one purifier to do it all, the Alen BreatheSmart 45i is built for everyday excellence.
Quick Specs
- Coverage: ~950-1,900 sq ft
- CADR: ~255
- Noise: Whisper-quiet (24–50 dB)
Whether in a master bedroom, shared office, or mid-size living space, the 45i adapts to real-time air quality changes without manual fuss. It maintains air purity while staying quiet during daily life or uninterrupted sleep.
Best For: master bedrooms, shared offices, medium-to-large living spaces
The 45i holds a 4.9-star rating from thousands of users, celebrated for quiet all-day use.
Choose the BreatheSmart 45i if you want one purifier that can handle almost any space.
Alen BreatheSmart 75i
Coverage: 1,400 - 2,800 sq ft App Controlled: Yes From:
$799.00
BreatheSmart 75i
The 75i is Alen’s powerhouse purifier, designed to tackle dust, allergens, or odors spread throughout expansive spaces and open layouts, offering maximum coverage and CADR.
Quick Specs
- Coverage: ~1,400-2,800 sq ft
- CADR: ~375
- Noise: Whisper-quiet (~25–51 dB)
For open floor plans, large living rooms, or whole-home coverage, the 75i maintains clean air across wide zones while being impressively quiet for its size. It’s ideal for homes where allergens tend to circulate throughout the house, or for those who prefer one high-performance device that can take care of everything.
Best For: open floor plans, large living rooms, whole-home coverage
Reviewers call the 75i “the quietest high-capacity purifier” and it earns excellent scores from consumer reports.
Choose the BreatheSmart 75i if you want complete clean air coverage in the largest spaces.
Alen BreatheSmart Models Compared
| Model | Coverage (sq ft) | CADR / Airflow | Noise Level | Best For |
|---|---|---|---|---|
| BreatheSmart 25i | Up to ~800 sq ft | ~107 CFM | ~20-40 dB | Dorms, small rooms, nurseries |
| BreatheSmart 35i | Up to ~1,400 sq ft | ~190 CFM | ~23-42 dB | Bedrooms, small work zones |
| BreatheSmart 45i | Up to ~1,900 sq ft | ~255 CFM | ~24-50dB | Shared rooms, master bedroom, office |
| BreatheSmart 75i | Up to ~2,800 sq ft | ~375 CFM | ~25–51 dB | Open concept, large homes |
Alen BreatheSmart Air Purifiers Compared FAQs
1. Which Alen air purifier is best overall?
The 45i is the sweet spot, combining strong coverage, smart features, and ultra-quiet performance in a way that fits almost any home. It’s Energy Star certified and AAFA certified, giving you proof that it performs as well as it promises. With thousands of units sold every year, it is one of Alen’s most trusted purifiers for real, everyday results.
2. What’s the quietest Alen air purifier?
The 25i is the quietest Alen air purifier, making it the perfect pick if silence is essential (like in bedrooms, nurseries, or study spots).
3. Which Alen air purifier has the highest CADR rating?
The 75i leads with a CADR/airflow around 375 CFM in turbo mode, making it the top pick for highest coverage and performance.
