Cleans 800 SqFt Every 30 Minutes
Alen’s best-selling air purifier features best in class quietness and is perfectly sized for medium-sized rooms like bedrooms and common spaces in apartments, condos, or lofts. It was the first air purifier to earn validation from SleepScore Labs for helping people achieve better rest.

Don’t wonder if it’s working, know it is.
Alen’s advanced particle sensor technology always lets you know the status of the air quality around you with vivid LED color rings. And when harmful particles are detected, Auto-mode adjusts purifying power to keep your air pure 24/7.

Medical-Grade Protection
Long-lasting True HEPA (H13) filters captures 99.9% of airborne contaminants down to 0.1 microns, including allergens and other harmful airborne particles. Alen’s medical-grade filtration is highly effective thanks to powerful airflow, ensuring pure air for your entire room.

Lifetime Peace of Mind
When you purchase an Alen air purifier, we proudly support it with the industry’s first and only Forever Guarantee*. If anything goes wrong, our in-house experts will help you solve the problem. If they can’t, we’ll happily ship you a free replacement—fast!
*filter subscription required

Discover Better Rest
Proven to improve sleep and reduce allergies, the BreatheSmart 45i helped people fall asleep faster, sleep sounder, and wake feeling more refreshed in a peer-reviewed study by SleepScore Labs. 45i is incredibly quiet and perfectly tuned to generate soothing pink noise—for up to 25% better rest. And at bedtime, display lighting dims or darkens with one touch.

Specs
- CFMiCubic Feet per MinuteSpeed 1: 70 CFM | Speed 2: 135 CFM | Speed 3: 175 CFM | Speed 4: 215 CFM
- CADRiClean Air Delivery Rate.245
- Cord length7ft 8inches (233cm)
- CoverageUp to 800 sq. ft. (74.32 m2) | Cleans all air in room every 30 minutes @ highest setting
- DimensionsH 25" (63.50 cm) x W 15" (38.10 cm) x D 8.5" (21.59 cm)
- Energy stariProducts/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 EnergyYes
- Filter cost$69 | Using "Pure" Filter
- Filter life max12 months | @ Recommended 24hr/day operation
- Filtration rateRemoves 99.9% of particles greater than 0.1 microns
- Noise levelLowest Speed 23 dBa | Highest Speed 49 dBa
- Ozone0 PPM when disengaged, less than 0.001 PPM with optional ionizer engaged
- Power consumption1.1 to 50 watts
- Power supply120 AV, 60HZ (2 Prong Power Cord)
- SensorAutomatic speed adjustment and coordinated to 5 color rings/ 4 speeds
- Sound typePink Noise | All speeds
- Speed settings4
- WarrantyLifetime | with Product Registration & Active Filter Subscription
- Weight15 lbs (6.8 kg)
What's in the box
- BreatheSmart 45i air purifier
- 45i True HEPA filter
- Designer panel (optional)
- Quick start guide
Frequently Asked Questions
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My Room is Bigger than the Listed Coverage Area of the Unit I Want. Will it Still Do Some Good?
The efficacy of an air purifier is typically measured in air exchanges per hour, or how many times within an hour the air in a room is completely replaced. A rate of six exchanges per hour or more is considered very good and would meet our standards. If your square footage exceeds the listed square footage for your air purifier, it can still clean your room, but the rate at which it can do so decreases. When the air exchanges per hour drop to a certain point, you won’t be receiving all of the benefits of allergen-free, breathable air. For optimal performance, a good rule of thumb is to find an air purifier that can cover more than the square footage of your room.
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My apartment is 1500 square feet total, with a living room and a bedroom. Will one air purifier certified for 1500 square feet meet the needs of my entire apartment?
Although your air purifier may still do some good in your entire apartment due to natural air circulation, air purifiers work best in the room they’re placed in. Air purifiers can’t work through walls or doorways, nor can they typically travel up stairs for loft-style apartments. It’s best, then, to get two smaller units and place one in each room. If you can only get one air purifier, place it in the room where you spend the most time, as this is the room that will see the most reliable results. We usually recommend the bedroom, since air quality and allergies can often drastically affect your quality of sleep. Your air purifier is portable and can be moved from room to room as needed, too.
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What Is the Difference Between Your Pre-Configured Air Purifiers and Your Customizable Options?
If you’ve already done your research and you know exactly which purifier and filters are right for you, then our customizable options will allow you to configure the air purifier that meets your exact specifications. If you’re still a bit lost, our pre-configured options are designed to take the guesswork out of compositing your own air filter from scratch. Each pre-configured option is designed with a different set of needs in mind, from allergies to pet odor, and it contains the specific combination of air purifier and filter to fit the job. These options are still customizable from an aesthetic standpoint - you can still choose your own panels - but they are not otherwise customizable.