Purifies up to 800 sq ft every hour or 400 sq ft every thirty minutes
Dimensions
H 16.8" W 11" D 7.3"
Energy star
i Products/Homes/Buildings that earn the ENERGY STAR prevent greenhouse gas emissions by meeting strict energy efficiency guidelines set by the U.S. Environmental Protection Agency and the U.S. Department of Energy
Automatic speed adjustment and coordinated to 5 color rings/ 4 speeds
Speed settings
4
Warranty
Forever Guarantee | with Product Registration & Active Air Filter Subscription
Weight
8 lbs
We offer standard payment options with credit or debit card, PayPal, GPay, and Apple Pay, in addition to Buy Now, Pay Later options that are available with ShopPay. FSA/HSA payment is available to eligible customers through Flex.
The filter that started it all. Our entry-level filter features medical-grade HEPA filtration that captures 99.9% of airborne dust, viruses, and allergens.
For when you want a little more control. Includes medical-grade high efficiency particulate (HEPA) filtration from the Essential filter, plus a carbon layer providing protection against asthma triggers, chemicals and VOCs, smoke, and other common pollutants..
Your comprehensive clean-air solution. Our top-tier filter features a medical-grade, high efficiency particulate (HEPA) material with a powerful carbon & catalyst layer for broad performance against asthma triggers, chemicals and VOCs, smoke, pollutants, odor, mold, and pet-filled homes.
Essential
(Pure)
The filter that started it all. Our entry-level filter features medical-grade HEPA filtration that captures 99.9% of airborne dust, viruses, and allergens.
Advanced
(Fresh)
For when you want a little more control. Includes medical-grade high efficiency particulate (HEPA) filtration from the Essential filter, plus a carbon layer providing protection against asthma triggers, chemicals and VOCs, smoke, and other common pollutants..
Ultimate
(Odor)
Your comprehensive clean-air solution. Our top-tier filter features a medical-grade, high efficiency particulate (HEPA) material with a powerful carbon & catalyst layer for broad performance against asthma triggers, chemicals and VOCs, smoke, pollutants, odor, mold, and pet-filled homes.
See also
20%
Ranked in the quietest 20% of air purifiers on the market.
Indoor air pollutant levels can be 2 to 5 times higher than outdoor levels.
Asthma & Allergy Friendly
Certified
Achieved Energy Star's 2025 'Most Efficient'
Energy Star
What others are saying
Control your air from anywhere
Alen Air App
Monitor your air quality in real time and control your Alen air purifiers from one intuitive interface. Set alerts, adjust settings, and schedule effortlessly.
airID uses AI-powered optical technology to detect, identify, and measure air particles so you can track pollutants like dander, smoke, pollen, and smog.
Quiet and very efficient. It was shocking to see how much dust it collected.
Jeff
Noticed a big difference in my bedroom the next morning after setting up. My eyes feel better and aren’t red anymore. Room also smells better.
Cindy
I love this machine and the company customer service was awesome ~ best investment !!!
Janice
Picture the perfect spot for your BreatheSmart 25i
Purpose-built for focused work, the 25i purifies up to 800 sq ft every hour or 400 sq ft every 30 minutes, keeping your home office clean and quiet
Proven to supports more restful sleep, the 25i purifies up to 800 sq ft every hour or 400 sq ft every 30 minutes, so your air stays pure all year long.
With quiet-yet-powerful fans perfect for nap time, the 25i purifies up to 800 sq ft every hour or 400 sq ft every 30 minutes, so your baby's space is always allergen-free.
Picture the perfect spot for your
BreatheSmart 25i
Purpose-built for focused work, the 25i purifies up to 800 sq ft every hour or 400 sq ft every 30 minutes, keeping your home office clean and quiet
Proven to supports more restful sleep, the 25i purifies up to 800 sq ft every hour or 400 sq ft every 30 minutes, so your air stays pure all year long.
With quiet-yet-powerful fans perfect for nap time, the 25i purifies up to 800 sq ft every hour or 400 sq ft every 30 minutes, so your baby's space is always allergen-free.
"We bought the bundle of 3 25i for our three bedrooms and they are exactly what we needed. The constant soothing hum of the purifier allows us to sleep, compared to other brands that are loud when then kick on and off. We will be purchasing a larger one for our open living room/kitchen space"
— Hailee (5/5)
"Bought a larger model for open area in living room, dining area and kitchen. Works great. Very quiet. Absorbs cooking odors very well since we do not have a vent over the stove. Couldn’t be happier with THAT one. THIS one is in a small bedroom and its really NOISY and does clean it as well dust and odors. Maybe I shouid have ordered the added charcoal layer filter. And try to register these machines are a nightmare so not happy with the app. DO BETTER ALEN."
— Elizabeth (1/5)
"So far so good"
— Bryan (5/5)
"Alen makes great air purifiers. Their one filter a year subscription is easy and less costly than other air filters that require more filters to be changed more often."
— Katie (5/5)
We love our Breathesmart!
"We are a pet loving home (3 dogs and 3 kitties) and I have had asthma and allergies since babyhood. Despite this, I love animals and take allergy and asthma meds. However, one of our kitties developed asthma and we decided to get this for the room the pets like most (the litter box is also there). It has helped us all, dramatically! Even better, we decided to get the Ultimate filter - not only is the air quality and feel excellent, but a friend came over and couldn’t believe how great the room smelled (well, at least they were shocked there was a litter box in the room and at least 4 pets hanging out in that favorite room at literally all times - they can go wherever they want in the house of course, but their fave furniture and rest areas are there). I can’t say enough about it, other than wishing I purchased it sooner."
— Becksstein (5/5)
Bye bye Allergies
"Let me tell you have ive tried all kinds of purifiers and even with meds they would go away. My flex stays on the my side of the room and she is everything I wanted her to be and more. I wont ever use another brand. The different function filters really stand out and its nice to be able to interchange the look of your machine."
— Lian R. (5/5)
"I love it!! The air quality sensors are very informative. And it's so quiet! I forget it's there!"
— Michael C. (5/5)
"Great purchase. Definitely purifying the air."
— Michael (5/5)
"The app has great information, easy to access. The color ring on top of the machine relieves my anxieties about air quality at home. I like the compact clean look to the unit."
— Carolyn A. (5/5)
"Here in one day."
— John (5/5)
Q&A
tried to update software and it wont finish downloading it just keeps going until it says it cant finish and try later
For app support, click the chat button on the bottom left of the website screen and connect with customer service. You can also search your topic in the help center. If you are still not able to get an answer, please call customer service at 1-800-630-2396
FAQs
How often do I need to change the filters for BreatheSmart 25i?
Depending on usage, we recommend changing the filter every 6-12 months. The 25i comes with smart sensors that monitor air quality and will alert you through the app when it’s time to replace the filter.
What are the benefits of upgrading to the 25i if I already own another air purifier?
The BreatheSmart 25i offers modern upgrades like quieter operation (20-40 dB), better smart features (AQI monitoring), and the ability to control multiple units through the app. With an active filter subscription, it is also covered by a Forever Guarantee, so it’s a long-term investment.
How many fan speeds does the 25i have?
The BreatheSmart 25i comes with four fan speeds, ranging from a whisper-quiet low setting at 20 dB to a higher power setting that still remains under 40 dB, ensuring customizable comfort without disrupting your space.
How does the BreatheSmart 25i smart filter system work?
The 25i uses smart filters that communicate with the purifier, tracking filter life and letting you know when it’s time for a replacement. The app also allows you to monitor filter status.
How does the BreatheSmart 25i compare to other Alen Air Purifer models?
The BreatheSmart 25i is the most compact and affordable model in the smart purifier lineup. It offers advanced filtration with a quiet motor, smart sensors, and app control—making it perfect for smaller spaces like bedrooms.
