Alen BreatheSmart 35i

Alen BreatheSmart 35i Air Purifier Review

Brand: Alen
Released: December 8, 2020
Updated: 2 months ago
4.2
Overall review score Expert score: 4.2 Customer score: 4.1
218
Review evidence points
49
Scored features
36
Total reviews
5 expert / 31 customer

Bottom Line

Choose the Alen BreatheSmart 35i for quiet small-room air cleaning, strong sensors, and smart controls. Skip it for large rooms, tight budgets, or if filter costs and rattling risk worry you.

Best for

Best for bedrooms, studios, small living areas, pet homes, and allergy-sensitive users who want quiet operation plus detailed air-quality monitoring.

Not for

Not for buyers expecting large-room performance, low ownership costs, or a heavy-duty build without any risk of rattling complaints.

Verdict

The Alen BreatheSmart 35i earns its strongest praise as a compact, quiet purifier with unusually useful sensing and app features. Expert tests and many customers report better air quality, odor reduction, responsive auto mode, and easy controls, especially in bedrooms, studios, and smaller living spaces. The tradeoff is cost: both upfront price and replacement filters are frequent concerns, and coverage evidence points toward small rooms rather than the largest advertised spaces. Build feedback is also split, with some praise for fit and seal quality but several complaints about plastic feel, rattling, or defects. Overall, it is a polished small-room purifier when quiet operation and monitoring matter more than maximum value.

Feature Scorecards

Summary

49 reviewed features
  • Very positive 4.5-5.0
    26 (53%)
  • Positive 3.5-4.4
    14 (29%)
  • Neutral 2.5-3.4
    7 (14%)
  • Negative 1.5-2.4
    2 (4%)

Pros

  • 5.0
    9 reviews strong consensus
    real-time air quality monitoring: 5.0, 9 reviews, strong consensus
    Real-time monitoring is a major strength, with repeated praise for alerts, app graphs, and color feedback.
  • 5.0
    9 reviews strong consensus
    odor reduction: 5.0, 9 reviews, strong consensus
    Odor reduction is one of the strongest customer-backed benefits, especially for pets, smoke odor, cooking, and basement smells.
  • 4.9
    9 reviews strong consensus
    ease of use: 4.9, 9 reviews, strong consensus
    Setup and controls are repeatedly described as easy, intuitive, or plug-and-use.
  • 5.0
    7 reviews strong consensus
    size and footprint: 5.0, 7 reviews, strong consensus
    Customers and experts like the compact footprint, especially for bedrooms, studios, and unobtrusive placement.
  • 4.6
    11 reviews moderate consensus
    air purification performance: 4.6, 11 reviews, moderate consensus
    Most reviewers say the purifier improves air quality or works well, though one customer reported poor cleaning performance.
  • 5.0
    5 reviews strong consensus
    air quality sensor accuracy: 5.0, 5 reviews, strong consensus
    Experts and customers consistently praise the sensor as responsive, precise, and aligned with external measurements.

Cons

  • 1.5
    2 reviews limited evidence
    durability: 1.5, 2 reviews, limited evidence
    Durability concerns center on rattling after months and flimsier plastic housing.
  • 1.8
    2 reviews limited evidence
    reliability: 1.8, 2 reviews, limited evidence
    Reliability evidence is negative where customers report odd noises, defects, or quitting use.
  • 2.5
    2 reviews limited evidence
    customer support: 2.5, 2 reviews, limited evidence
    Customer support evidence is mixed, with one defective-unit response but another customer calling AI support useless.
  • 2.9
    2 reviews limited evidence
    dust removal: 2.9, 2 reviews, limited evidence
    Dust evidence is mixed: experts measured dust-related removal, while one customer said dust buildup did not improve.
  • 3.0
    8 reviews moderate consensus
    filter replacement cost: 3.0, 8 reviews, moderate consensus
    Filter replacement cost is one of the clearest concerns, though a few customers accept it because replacements are less frequent.
  • 3.0
    3 reviews moderate consensus
    power consumption: 3.0, 3 reviews, moderate consensus
    Power consumption is acceptable in expert testing but one customer complains it raises the bill.

Compared With Category Average

Compared with other Air Purifiers, this product is above average in remote control, smart features, handle design, near average in overall satisfaction, air purification performance, below average in durability, dust removal, reliability.

Comparison summary

49 compared features
  • Above average 0.4+ pts higher
    26 (53%)
  • Same as average within 0.3 pts
    14 (29%)
  • Below average 0.4+ pts lower
    9 (18%)

Largest category differences

Attribute This product Category average Difference
durability 1.5 3.3 -1.8
remote control 4.5 2.7 +1.8
smart features 5.0 3.3 +1.7
handle design 5.0 3.3 +1.7
filter availability 5.0 3.5 +1.5
dust removal 2.9 4.3 -1.4
warranty coverage 5.0 3.6 +1.4
air quality sensor accuracy 5.0 3.7 +1.3

Consider This Instead

If you want better durability

Choose Levoit EverestAir. It scores 4.7 vs 1.5 for durability, with a 4.5 overall score.

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If you want better customer support

Choose Shark HP102. It scores 5.0 vs 2.5 for customer support, with a 4.1 overall score.

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If you want better pollen removal

Choose Levoit Vital 200S. It scores 4.7 vs 3.6 for pollen removal, with a 4.4 overall score.

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Compared in Reviews

Products reviewers directly compared with this model, grouped into quick takeaways.

  • Cheaper: pet-friendly design and price The Levoit Vital 200S is presented as a cheaper pet-friendly alternative.

AirFanta 3Pro

  • Better: small-room cleaning performance The 35i was outperformed by the AirFanta 3Pro in expert particle testing.

FAQ

Is the Alen BreatheSmart 35i good for bedrooms?

Yes. Reviewers repeatedly praise its quiet operation, compact footprint, sleep-friendly lighting, and better nighttime breathing or sleep.

Does it remove odors?

Yes, odor reduction is one of the strongest customer themes, especially for pets, cooking, basement smells, and smoke odor.

Is it good for large rooms?

The evidence points to small-room use. Expert reviewers recommend sizing down from the largest coverage claims if you want stronger air changes.

Are the filters expensive?

Yes. Several reviews mention costly filters, though some customers feel the longer replacement interval makes the cost easier to accept.

How good is the app and smart monitoring?

The app, sensors, schedules, alerts, and real-time monitoring are major strengths, but a few users report app sign-up or registration problems.

Is it quiet?

Most evidence says it is very quiet, including expert testing. A minority of customers report weird sounds or rattling after use.

Sample Expert Reviews We Analyzed

These are a few of the reviews included in our analysis.

Video Reviews

Article Reviews

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