If you want better condition on arrival
Choose Alen BreatheSmart Flex. It scores 4.8 vs 1.0 for condition on arrival, with a 4.3 overall score.
Alen BreatheSmart 45i Air Purifier Review
Bottom Line
Choose the Alen BreatheSmart 45i for quiet, efficient medium-room cleaning with strong filters and simple controls. Skip it if you need the lowest price, very large-room coverage, or guaranteed app-first control.
Best for
Best for medium-room owners who want strong particle cleaning, quiet lower speeds, straightforward onboard controls, and long-term filter support. It especially fits people who care about dust, allergens, and a smoother fan sound.
Not for
Not ideal for shoppers chasing the lowest CADR-per-dollar, very large spaces, or app-first smart control. Buyers focused on odors, smoke, or VOCs should avoid the base Pure filter and budget for upgraded carbon filters.
Verdict
The Alen BreatheSmart 45i earns broad approval for air-cleaning performance, low-speed quietness, energy efficiency, and approachable controls. Lab-style reviews show strong particle reduction and reassuring ozone results, while customer reviews often praise fresher air, less dust, and allergy relief. Its best case is a medium room where smooth fan sound, filter choice, and build quality matter. The tradeoff is value: several reviewers say cheaper competitors offer more raw CADR, and app/Wi-Fi support is inconsistent or modest. Odor, VOC, and smoke performance also depends on buying upgraded carbon filters rather than the base Pure filter.
Feature Scorecards
Summary
48 reviewed features-
Very positive 4.5-5.023 (48%)
-
Positive 3.5-4.422 (46%)
-
Neutral 2.5-3.41 (2%)
-
Negative 1.5-2.41 (2%)
-
Very negative below 1.51 (2%)
Pros
-
Noise is a major strength at low and quiet speeds, although higher settings are more audible.
-
Setup, controls, and filter access are repeatedly described as easy and intuitive.
-
Real-time monitoring is repeatedly praised for clear feedback and quick detection.
-
Auto mode is consistently described as responsive, handy, and useful for hands-off operation.
-
Upgraded carbon options are repeatedly praised for odors, VOCs, and smoke, but the base Pure filter lacks carbon.
-
Reviewers like the discreet, customizable design and swappable front panels.
Cons
-
The only condition evidence is a strongly negative customer report of receiving a used, scuffed unit.
-
Remote control is mixed because the base model lacks it, while app-enabled units can be controlled remotely.
-
Pre-filter evidence is mixed: it catches larger particles but can be harder to clean than a separate pre-filter.
Compared With Category Average
Compared with other Air Purifiers, this product is above average in filter availability, handle design, air quality sensor accuracy, near average in air purification performance, overall satisfaction, below average in condition on arrival, odor reduction, pre-filter quality.
Comparison summary
48 compared features-
Above average 0.4+ pts higher25 (52%)
-
Same as average within 0.3 pts18 (38%)
-
Below average 0.4+ pts lower5 (10%)
Largest category differences
| Attribute | This product | Category average | Difference |
|---|---|---|---|
| condition on arrival | 1.0 | 2.8 | -1.8 |
| filter availability | 4.8 | 3.5 | +1.3 |
| handle design | 4.5 | 3.3 | +1.2 |
| air quality sensor accuracy | 4.9 | 3.7 | +1.2 |
| reliability | 4.2 | 3.0 | +1.2 |
| durability | 4.5 | 3.3 | +1.2 |
| smart features | 4.4 | 3.3 | +1.1 |
| real-time air quality monitoring | 4.9 | 3.9 | +1.0 |
Consider This Instead
If you want better size and footprint
Choose Shark HP102. It scores 4.9 vs 3.5 for size and footprint, with a 4.1 overall score.
If you want better CADR rating
Choose Coway Airmega 250. It scores 5.0 vs 4.1 for CADR rating, with a 4.2 overall score.
If you want better pre-filter quality
Choose AirDoctor AD3500. It scores 4.8 vs 3.4 for pre-filter quality, with a 4.6 overall score.
Compared in Reviews
Products reviewers directly compared with this model, grouped into quick takeaways.
AirDoctor 3000
- Alternative: purification performance AirDoctor 3000 is named as a performance-focused alternative if Wi-Fi is not important.
Alen Breathesmart 75i
- Older model: room coverage The 75i is presented as the larger model in the same series for bigger coverage needs.
Breeze smart 75i
- Upgrade: size and coverage The 45i is described as the smaller, lighter version of the BreezeSmart 75i.
FAQ
Is the Alen BreatheSmart 45i good for medium rooms?
Yes. Reviews repeatedly place it in the medium-room range, with strong results around 300 to 400 square feet and some claims up to 800 square feet.
Is it quiet?
Mostly yes, especially at low and quiet fan speeds. Higher settings are audible, but reviewers often describe the sound as smooth or less intrusive.
Does it reduce dust and allergies?
Most evidence is positive, with customers reporting less dust and allergy relief. One customer in a desert home with pets said it did not reduce dust.
Does the base filter remove odors and VOCs?
Only partly. Reviewers say the base Pure filter is weak for odors, smoke, and VOCs, while upgraded carbon filters are the better choice for those problems.
Does it have app support?
Some versions support the Alen app, but reviews are mixed. One reviewer found app support hidden, another could not connect their unit, and Modern Castle tested a non-Wi-Fi base model.
Is the warranty good?
The lifetime warranty is viewed as valuable, but reviewers stress that it depends on registration and using OEM filters or a filter subscription.
Sample Expert Reviews We Analyzed
These are a few of the reviews included in our analysis.
Video Reviews
YouTube - Essential Home and Garden
- Review score
- 4.3
YouTube - Spending & Saving
- Review score
- 4.3
YouTube - HouseFresh
- Review score
- 4.4
Article Reviews
moderncastle.com
- Review score
- 4.3
Top Air Purifiers to Consider
Choose the H7124 if you want a quiet smart purifier for odors, dust, pets, and app control. Skip it if you need foolproof Wi-Fi, wall-facing intake, UV light, or strong...
Pros: particle removal effectiveness, pollen removal
Cons: UV-C light effectiveness, air dryness
Best for quiet, simple cleaning in bedrooms or apartments. Skip it if you need verified large-room CADR value, app control, or guaranteed neighbor-smoke removal.
Pros: particle removal effectiveness, dust removal
Cons: CADR rating, air changes per hour
Best for strong room cleaning, allergy relief, odor control, and simple operation. Skip it if high filter costs, a larger footprint, or possible nighttime fan noise would bother you.
Pros: particle removal effectiveness, HEPA filtration
Cons: customer support, warranty coverage
Choose this if you want strong odor, dust, smoke, and pet-air cleanup with washable filters. Skip it if turbo noise, Wi-Fi setup, or a high upfront price will bother you.
Pros: filter replacement cost, allergen reduction
Cons: Wi-Fi reliability