Purifies up to 1,400 sq ft every hour or 700 sq ft every thirty minutes
Dimensions
H 20.6" (52.32 cm) W 13" (33.02 cm) D 7.6" (19.30 cm)
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
Captures 99.9% of airborne particles as small as 0.1 micron.
Ionizer
No
Noise level
Lowest Speed - 23 dB | Highest Speed - 42 dB
Ozone
0 PPM
Power consumption
0.9 to 35 watts
Power supply
24V, External Power Supply
Sensor
Automatic speed adjustment and coordinated to 5 color rings/ 4 speeds
Sound type
Pink Noise | All speeds
Speed settings
4
Warranty
Forever Guarantee | with Product Registration & Active Air Filter Subscription
Weight
11 lbs (5kg)
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
93%
93% of participants reported improved sleep.
SleepScore Validated
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 35i
Purpose-built for focused work, the 35i purifies up to 1,400 sq ft every hour or 700 sq ft every 30 minutes, keeping your home office clean and quiet.
With big power for big imaginations, the 35i purifies up to 1,400 sq ft every air or 700 sq ft every 30 minutes, ensuring your kid’s air is always clean.
Perfect for multifunctional spaces, the 35i purifies up to 1,400 sq ft every hour or 700 sq ft every 30 minutes, so you flex from dinner time to down time with no lingering odor.
Picture the perfect spot for your
BreatheSmart 35i
Purpose-built for focused work, the 35i purifies up to 1,400 sq ft every hour or 700 sq ft every 30 minutes, keeping your home office clean and quiet.
With big power for big imaginations, the 35i purifies up to 1,400 sq ft every air or 700 sq ft every 30 minutes, ensuring your kid’s air is always clean.
Perfect for multifunctional spaces, the 35i purifies up to 1,400 sq ft every hour or 700 sq ft every 30 minutes, so you flex from dinner time to down time with no lingering odor.
The BreatheSmart 35i comes with four fan speeds, ranging from a whisper-quiet low setting at 23 dB to a higher power setting that still remains under 42 dB, ensuring customizable comfort without disrupting your space.
How does the BreatheSmart 35i smart filter system work?
The 35i uses RFID 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.
Does the BreatheSmart 35i support firmware updates?
Yes, the BreatheSmart 35i supports over-the-air firmware updates via the Alen Air app, ensuring you always have the latest features and improvements without needing to buy a new unit.
What happens if my BreathSmart 35i stops working after the warranty expires?
The BreatheSmart 35i is covered by Alen’s Forever Guarantee as long as you have a filter subscription. Even after years of use, if anything goes wrong, we will repair or replace the unit for free.
How does the BreatheSmart 35i compare to other Alen Air Purifer models?
The BreatheSmart 35i 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 apartments.
What are the benefits of upgrading to the 35i if I already own another air purifier?
The BreatheSmart 35i offers modern upgrades like quieter operation (23-42 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.
Is the BreatheSmart 35i energy efficient?
Yes, the 35i uses only 35 watts at maximum power, making it an energy-efficient option for continuous use, even on higher settings
How often do I need to change the filters for BreatheSmart 35i?
Depending on usage, we recommend changing the filter every 6-9 months. The 35i comes with smart sensors that monitor air quality and will alert you through the app when it’s time to replace the filter.
What is the Alen Forever Guarantee?
The Alen Forever Guarantee means your BreatheSmart 35i is covered for life. As long as you subscribe to regular filter replacements, if any issue arises, we’ll repair or replace it for free. Learn more.
Can I control multiple 35i units via the Alen Air app?
Yes, you can control several 35i units through the Alen Air app, allowing you to manage air quality in multiple rooms, track filter life, and set schedules for each unit from a single interface.
How does the Auto Light Mode work for the BreatheSmart35i?
The 35i features an Auto Light Mode that dims the control panel lights in a dark room, automatically adjusting to the ambient light to provide a distraction-free experience at night.
What is the AQI feature on the BreatheSmart 35i?
The BreatheSmart 35i monitors air quality using a built-in Air Quality Index (AQI) sensor. It provides real-time data on PM2.5 levels and VOCs through the Alen Air app, helping you ensure the air in your home stays clean.
What are the dimensions of the BreatheSmart 35i?
The BreatheSmart 35i is designed to be compact yet powerful, measuring 13 inches in width, 7.6 inches in depth, and 20.3 inches in height. It fits perfectly in small spaces like apartments or bedrooms.
How does the BreatheSmart 35i compare to other Alen models in terms of price and features?
The 35i is the most affordable smart purifier in the lineup. Despite the lower price, it includes key features such as smart sensors, app control, and a quiet motor, making it a great value for smaller rooms.
What makes Alen different from other air purifier brands?
Alen is committed to empowering users with control over their indoor air quality. We offer personalized air solutions through advanced filtration, smart features, and an industry only Forever Guarantee to back our high-quality products.
How does the BreatheSmart 35i handle common indoor pollutants like pet dander, smoke, and VOCs?
The 35i has HEPA-grade filtration that captures 99.9% of particles down to 0.1 microns, including pet dander, smoke, and VOCs. It’s especially effective for pet owners and people living in wildfire-prone areas.
Why should I trust Alen’s products and claims?
Alen is committed to transparency and quality. All our products undergo rigorous testing, and we back them with a Forever Guarantee. We also provide scientifically-backed insights about indoor air quality to guide your decisions.
How do I know if the BreatheSmart 35i is the right purifier for my needs?
The 35i is ideal for small to medium spaces, like bedrooms and offices, up to 1,400 sq. ft. It has advanced smart features like real-time AQI monitoring and app control, making it a great choice for allergy sufferers and those with pets.
How large of a room can the BreatheSmart 35i purify?
The BreatheSmart 35i is perfect for spaces up to 1,400 sq ft with one full air cycle per hour or 700 sq. ft. with two cycles. It’s ideal for small apartments, offices, or bedrooms.
What features does the Alen Air app provide?
The Alen Air app allows you to monitor air quality in real time, control multiple devices, set schedules, and receive air quality alerts for PM2.5, humidity, and more. You can also track your filter’s lifespan.
What does the Auto Light Mode do for the BreatheSmart 35i do?
Auto Light Mode automatically adjusts the brightness of the control panel based on ambient lighting, dimming in dark rooms for an undisturbed night’s sleep.
Can the BreatheSmart 35i help with wildfire smoke and VOCs?
Yes, the 35i includes advanced filtration options that can capture particles from smoke, VOCs, and odors, making it a perfect option for areas affected by wildfires or cooking-related air quality issues.
Is an air purifier worth the ongoing costs of filters and electricity?
The BreatheSmart 35i is energy efficient, using just 35 watts even at its highest setting, and the long-lasting filters only need to be replaced every 6-9 months. Our subscription service helps manage these costs by including 10% off filter replacements, giving you cleaner air without hassle.
Is the BreatheSmart 35i effective for allergies or asthma?
Yes, the BreatheSmart 35i is equipped with HEPA filtration options that can target allergens like dust, pollen, and pet dander, helping to reduce asthma and allergy symptoms. The 35i also captures VOCs for a cleaner home.
How quiet is the 35i during operation?
The BreatheSmart 35i is our quietest purifier, operating between 23 and 42 dB, which is softer than typical conversation or background noise, ensuring peaceful operation even on the highest fan speed.
