Alen BreatheSmart 45i Review In 2023: The Cheaper Variant

Think about it as an upgraded version of Flex. Alen BreatheSmart 45i air purifier is the flavor of the month with extended coverage and improved airflow circulation. On top of its trademark lifetime warranty and personalizable front panel, it provides exceptional value for a homeowner with severe allergies. Compared with other BreatheSmart series models, what new features can you expect from Alen BreatheSmart 45i? What are the pros and cons? Should I top up for the 75i instead? Find out in our detailed review below.
online price (US)**
±468.00 $$$$$/ 7

(annual filter cost ±39-118)

** MRSP (Manufacturer's Suggested Retail Price)/ RSP (Retail selling price) is accurate at the time of posting.
^ Annual filter cost is calculated based on filter price and 12 hours of usage. Pricing could vary depending on air quality, usage frequency, and speed.
` The indicated online price guides as follows: $ = under $50, $$ = $50-100, $$$ = $101-200, $$$$ = 201-300, $$$$$ = $301-400, $$$$$$ = 401-500, $$$$$$$ = over $500.

Alen BreatheSmart 45i Specification

ProductAlen BreatheSmart 45i
15 x 25 x 8.5 in
(38.1 x 63.5 x 21.6 cm)
Weight15 lb (6.8 kg)
Coverage (up to)800 sq. ft. (74 m2)
Airflow speed53 - 190 cfm (90 - 323 m3/h)
Dust free (CADR)245 cfm (416 m3/h)
Pollen free (CADR)245 cfm (416 m3/h)
Smoke free (CADR)245 cfm (416 m3/h)
Humidifying(H) speed
- Lifespan
- Replacement cost ($)
Washable Pre-filter (with HEPA filter)
6 - 18 months
HEPA filter
- Lifespan
- Replacement cost ($)
HEPA-Pure Filter FL40
6 - 18 months
+- 59
Carbon filter
- Lifespan
- Replacement cost ($)
Ionizer/ TechnologiesIonizer
UV-light/ PCO
Other filter
All-in-one filter
- Lifespan
- Replacement cost ($)
Optional/ Addon
6 - 18 months+- 79
HEPA-OdorCell Filter FL40-MP
6 - 18 months+- 89
HEPA-Fresh Filter FL40-CARBON
6 - 18 months+- 69
Noise level23-49 dBA
Power usage level50 W
Timer/ Scheduler2, 4, 12 hours
SensorsIntelligent sensor
Auto mode
Air qualityAQ indicator
Filter change indicator
More color options
Wi-Fi/ BTBluetooth
Remote control
Child lock
WarrantyLifetime Limited Warranty
Email/ Phone support

Key Features

  • 3-stage filtration with ionizer
  • Washable pre-filter/ HEPA-Pure filter
  • [Optional] HEPA-Silver filter, HEPA-FreshPlus filter, HEPA-OdorCell filter
  • 4 fan speeds with auto mode/ lights-off mode
  • Smart Filter Light indicator
  • Intelligent sensor technology
  • Personalized front panel design
  • Child-lock control panel and child-safe vent guard
  • 4, 8, 12 hours pre-set timer
  • Lifetime warranty

Design and Usability

With the headline “PREPARE TO CHANGE YOUR AIR”, Alen BreatheSmart 45i air purifier has all the elements of the previous generation model. The updated design is sleeker with the combination of a white facade and premium gun-metal gray trim. As always, the front panel is swappable, where you can replace it with many of the available designs (additional purchase). At a 15 x 25 x 8.5 inches dimension and a 15 pounds weight, it is a mid-range size highly suited for home use. You can effortlessly fit it in most places if it is not cluttered with items. Movability is good thanks to the grippy back-carrying handle that you can grab on when maneuvering it around. Circling the design, You will find air inlets conveniently tucked at the sides and bottom with the air outlet at the top. A conventional bottom to top air circulation setup. There are 3 different types of power cables that can be used in other parts of regions. Overall, the build quality is solid, with no signs of off-gassing. This is an expensive air cleaner, after all.

Alen BreatheSmart 45i Air Purifier control panel

For usability, Alen BreatheSmart 45i is very easy to operate, with dedicated buttons on each function. You can cycle between the 4 fan speeds (Low, Medium, High, Turbo), reset the real-time filter replacement indicator, or use the 2, 4, 12 hours timer to shut down the air purifier after an interval. There is also an option to turn on or off the ionizer. Auto mode automatically adjusts the fan speed based on the room air quality.

Alen BreatheSmart 45i is WiFi-enabled for remote access, but there is limited support for it at the time of this review. With the help of the particle sensor, the room air quality color rings will illuminate blue when the air is clean and purple when the air is dirty. Perfect to monitor room air quality and manage energy efficiency.

Rounding up the specification, Alen BreatheSmart 45i comes with a child lock feature that is very useful if you have children at home. It prevents them from altering the setting on the air purifier. Another passive feature is a child-safe vent guard that shuts down the air purifier when the front panel is not closed correctly. Alen BreatheSmart 45i is also UL listed, and CARB approved ozone-safe, producing less than 0.001 PPM. It comes with a lifetime warranty that only a few brands manage to replicate. The company will stand by its policy and repair/ replace any malfunctioned parts for free. However, that is a catch. For the warranty to be active, you have to register the product with Alen and have an active filter replacement subscription.

Airflow, Coverage, And CADR

Despite the lower variant, Alen BreatheSmart 45i is well suited for large room size up to 800 square footage every 30 minutes or 2 air changes per hour. At 5 adjustable fan speeds, it outputs 70 cfm (speed 1); 135 cfm (speed 2); 175 cfm (speed 3); 215 cfm (speed 4). Ideal for seasonal use e.g. wildfire, summer, forest burning, and common areas e.g. kitchen, basement, garage, bedroom, home office, playroom, living hall. When placed in an ideal location, Alen BreatheSmart 45i can also be a whole-house air purifier in a small loft, apartment, studio, or dorm.

BrandPurifying CoverageFan Speed
Blue Pure Fan200 sq. ft.3
Medify Air MA-501,100 sq. ft.4
Winix AM90230 sq. ft.4
Winix AM80230 sq. ft.4
Coway Airmega AP-1216L330 sq. ft.3
Blueair Classic 205280 sq. ft.3
Continue with the impressive airflow distribution, Alen BreatheSmart 45i clean air delivery rate (CADR) is measured at 245 cfm for dust, pollen, and smoke. It passes our 200 CADR benchmark, and Consumer Reports recommended 240 CADR. All test is done in a controlled environment under AHAM supervision, Alen also independently lab tests its model to ensure 45i efficiency against airborne allergens and viruses.

Recommended Read

Filters And Performance

Only the best medical-grade HEPA protection for your home. Alen BreatheSmart 45i air uses an H13 True HEPA filter capturing 99.99% of airborne allergens down to 0.1 microns, such as dust, dust mites, mold, pollen, pet dander, germs, bacteria, and virus. All Alen's air purifier filters come attached with a pre-filter for an extra layer for protected and proprietary antibacterial treatment that halts microorganisms from growth. The default HEPA-pure filter does not come with any smoke filtration; you will need to upgrade to the following:

  • HEPA Pure filter - The default and cheapest option.
  • HEPA Fresh filter - For an extra $15, you'll get an antibacterial agent effective against mold, bacteria, and other pathogens. You also get a carbon filter to remove musty smells, gaseous particles, and cooking odors.
  • HEPA OdorCell filter - Best used for pet owners. For an additional $30, it effectively neutralizes odors from pets and diapers. Standard allergens removal and antibacterial properties are also included.
  • Heavy Smoke filter - For an additional $30, the HEPA filter comes with 2+ lbs of activated carbon that absorb smoke, VOCs, and chemicals aerosol sprays on top of microscopic particles removal. Best suited for a heavily polluted home.

Under the long list, you also have an optional ionizer that diffuses negative ions to merge and pull down pollutants for the filter to capture. It pairs well with the HEPA filter in targeting microscopic particles in the air. The ionizer is also a safe technology that will generate insignificant ozone byproducts under 0.001 PPM (parts per million). Way below EPA's health standard 0.08 PPM ozone inhalation guideline. For those with sensitive lungs, you can switch it off at any point of the purification.

Alen BreatheSmart 45i filter

Noise And Energy Usage

Enjoy uninterrupted sleep with purified air. For such a powerful air purifier, Alen BreatheSmart 45i is considerably silent, with a soothing noise level of just 23 dBA at the lowest speed and 49 dBA at the highest speed (turbo). The quiet operation is validated by SleepScore Labs, a company that focuses on sleep quality. It is still livable even at max speed, considering the airflow rate BreatheSmart 45i is outputting. Ideal for a person that enjoys sleeping with a methodical, consistent frequency of pink noise running in the background.

Noise TypeDecibels
Alen BreatheSmart 45i23-49 dBA
Breathing10 dB
Rustling leaves20 dB
Whispering/ Quiet library30 dB
Light rainfall40-50 dB
Conversation50-60 dB
Vacuum cleaner/ Hair dryer/ Washing machine65-80 dB
City traffic80-90 dB

Pricing And Maintainence Cost

Powerful performance and versatility come at a cost. Alen BreatheSmart 45i is listed at $468 before applying any discount. It's a fair deal, especially when you compare it with the higher variant 75i. You lose some specifications but save up to $300 in the purchasing price. Unless you have the dollars to go with the absolute best, Alen BreatheSmart 45i performance will be decent enough for the majority of the people.

The annual filter cost varies depending on home air quality and which filter you choose. Alen BreatheSmart 45i original filter sets range from $69 to $119 for the premium HEPA odor filter that can last 12-18 months. Expect the maintenance cost to go as low as $39 to $118 under adverse conditions. the filters come in a convenient bundled set that has to be replaced all at one go. There is no individual pack like Honeywell. In any case, never go cheap and settle with a third-party filter to avoid voiding the warranty.

Last we checked, Alen BreatheSmart 45i is available on Amazon with 40-50 discounts at its listed price. On top of that, you'll get free shipping, hassle-free purchase, installment plan options (T&C applied), and a standard return policy. If for some reason, you do not fancy purchasing on Amazon, Alen's official web store is another good place to go with seasonal discounts, automatic registration for the lifetime warranty, 60 Day Love It, or Return It promise policy, and 25% off for service members. You can also try your luck with giant retailers like Walmart and Costco, but give their customer service a call before heading over to avoid disappointment.

Alen BreatheSmart 45i Air Purifier

Final Thoughts On Alen BreatheSmart 45i

One of the best brands in the air cleaning world. Alen BreatheSmart 45i True HEPA air purifier lived up to the expectations of Alen's fantastic product lineup. It is energy-efficient, easy to operate, and runs silently at most speeds. Alen BreatheSmart 45i also works great in removing smoke and odors, providing you opt for the filter upgrade. You will be rewarded with clean air free from smoke and odors within 30 minutes of runtime. When the indoor air quality improves, you will notice a change in your health and breathing pattern with reducing symptoms like cough, sinus, itchiness, inflammation. Ignoring its few obvious flaws, look no further if you need a solid air purifier that can remove a wide range of airborne allergens in medium to large-sized rooms.


  • Minimalist and lightweight design with no shortage of front panel designs.
  • Comprehensive purifying coverage with superior airflow distribution.
  • Customizable filter with up to 3 optional H13 HEPA filter upgrades.
  • Uses the same long-lasting filter set as BreatheSmart Flex.
  • Newer intelligent sensor to support the air purifier auto/ lights-off mode. Runs quiet enough that it will not disrupt your sleep.
  • Like most of Alen's newer air purifiers, you can easily lock 45i controls.
  • A guaranteed lifetime warranty protects from any manufacturer's defect (with product registration & active filter subscription).


  • Lacks chemical and odor filtration on the standard HEPA-Pure filter. Upgradable with additional cost.
  • While the all-in-one filter setup is easy to replace, you cannot change them individually.

Verdicts And Ratings

Build Quality



Particle Filtration

Smoke Filtration


Filter Cost



Alen BreatheSmart 45i Air Purifier Review

Max Fernandez

A loving father and a dedicated reviewer for airfuji.com with more than 1000 air purifiers under his belt. Max Fernandez is also one of the million patients currently suffering from asthma. Feel free to nudge him if you have any questions.

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