Is the Alen 25i good for a bedroom?

Yes. It runs at 20 dB on low, emits pink noise tuned for sleep, and its compact size suits bedrooms. One owner did find it noisy in a small bedroom, so placement matters.

What size room does the 25i handle?

Alen rates it for up to 400 sq ft cleaned every 30 minutes, or 800 sq ft every hour. Its CADR is 107, so it suits small rooms better than open living spaces.

How often do I replace the filter?

The Essential filter lasts 9-12 months; the Advanced and Ultimate filters last 6-8 months. The purifier ships with a HEPA filter included.

Does the 25i produce ozone?

No. It has no ionizer and is rated at 0 PPM ozone.

What comes in the box?

The purifier, a long-lasting HEPA filter, power adapter, quick start guide and user manual.

Is $179 a good price for the 25i?

It is the best new price among the 5 stores listing it, at $179.00 at Alen as of November 7, 2026. Check the price history to see how it compares with past lows.

Where is the 25i HEPA Air Purifier cheapest?

At Alen, for $179.00, as of our latest check.

What do buyers say about the 25i HEPA Air Purifier?

Rated 4.8 out of 5 from 25 ratings. Buyers like: Runs very quietly; Compact size, good for bedrooms and small rooms; Colored rings show air quality. Common complaints: One reviewer found it noisy in a small bedroom and said it did not clean dust and odors well; App registration described as a nightmare.

Where can I buy the 25i HEPA Air Purifier?

6 stores we checked sell it, including Alen, Walmart, Ace Air Purifiers, Amazon, Cleanova.

Alen

25i HEPA Air Purifier

Best price now

$179.00at AlenObserved at 10:42 PM

Compared across 5 stores. Prices are checked against each store and labelled with when.

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What reviewers say

4.8 / 525 ratings

Rated 4.8 out of 5 from 25 ratings, the 25i is mostly praised for quiet operation, compact size and the color-ring air quality display. Owners report less dust, smell and congestion. A few complaints center on the app and one report of noise and weak cleaning.

What people mention

NoiseMixedMost owners call it very quiet, but one found it noisy in a small bedroom.
Air quality displayPraisedOwners like the color rings that show current air quality at a glance.
AppCriticisedRegistration and software updates were reported as difficult.
Dust and odor removalMixedMany report less dust and smell, while one reviewer saw little effect.
SizePraisedThe small footprint and 8 lb weight fit bedrooms and small rooms well.

About the 25i HEPA Air Purifier

• BUILT FOR EXCELLENCE: Alen air purifiers offer superior performance through the combination of a powerful fan, quiet motor, and advanced filtration technology to deliver and maximize airflow while minimizing noise. Our H13 filters capture particles as small as 0.1 micron, removing even the tiniest pollutants including odor, dust and viruses. Alen air purifiers are energy efficient and designed to run 24/7, generating a total energy cost of only $0.12 per day

• INCLUDES H13 HEPA ADVANCED FILTER: Eliminates 99.9% of particles as small as 0.1 micron so you can breathe easy. Perfect for bedrooms, living rooms and home offices

• POWERFUL ROOM COVERAGE: Ideal for up to 400 sq. ft., the BreatheSmart 25i quietly and efficiently circulates air every hour, making it an impressive room air purifier. Our filters will last you for up to a year while operating 24/7

• SMART AIR PURIFICATION: Elevate your home with Alen BreatheSmart 25i. Our SmartSensor adjusts fan speed based on air quality, with color-coded feedback. Blue rings indicate excellent air quality levels while purple rings indicate high particle presence.

• DESIGNED FOR BETTER SLEEP: The BreatheSmart 25i, a HEPA air purifier, is proven by SleepScore Labs to enhance sleep according to a peer study. Its ultra-quiet operation emits pink noise, optimizing lower octave frequencies, and ensuring a restful night. An excellent addition to air purifiers for bedroom for undisturbed, quality sleep, so you wake up feeling rested

The Alen BreatheSmart 25i is ideal for bedrooms and other rooms up to 400 sq. ft. Proven to improve sleep by an independent SleepScore Labs study, the BreatheSmart 25i emits a soothing pink noise that boosts frequencies in the lower octaves, so you wake up feeling rested. Alen air purifiers offer superior performance through the combination of a powerful fan, quiet motor, and advanced filtration technology to deliver and maximize airflow while minimizing noise. Our H13 filters capture particles as small as 0.1 micron, removing even the tiniest pollutants including dust, pollen, pet dander, and more. Laser sensor technology detects when particles are present and auto-adjusts fan speed, so you don’t have to. The 5 color-coded rings show your indoor air quality at a glance and let you see how Alen is working to clean the air quickly and efficiently. Get real-time air quality insights, view historical trends, or control your purifier remotely using the Alen Air app.

What buyers say

Buyers like

Runs very quietly
Compact size, good for bedrooms and small rooms
Colored rings show air quality
Less dust and smell; helps with allergies and congestion
Easy filter subscription
Good for sleep

Buyers complain about

One reviewer found it noisy in a small bedroom and said it did not clean dust and odors well
App registration described as a nightmare
App software update would not finish downloading
Wishes the 25i were included in bundles
Wants more color options