Alen BreatheSmart 45i Review: The Slightly 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. Compare with other BreatheSmart series models, what new features can you expect from Alen BreatheSmart 45i? Find out in our detailed review below.
± 468.00 p
     Annual filter ^    
± 39 - 118 p
 Online price*
** 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.

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

Alen BreatheSmart 45i dimension
15 x 25 x 8.5 in
(38.1 x 63.5 x 21.6 cm)
Alen BreatheSmart 45i weight
15 lb (6.8 kg)

Alen BreatheSmart 45i air purifier has all the elements of the previous generation model. 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 at a mid-range size that is highly suited for home use. You can fit it in most places as long as it is not over cluttered with items. Movability is good thanks to the grippy back carrying handle. Circling the design, You will find air inlets conveniently tucked at the sides and bottom with the air outlet at the top. In general, the build quality is solid with no signs of off-gassing.

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. You can turn on or off the ionizer or auto mode that automatically adjusts the fan speed based on the room air quality. Last but not least, the room air quality color rings will illuminate blue when the air is clean and purple when the air is dirty.

Rounding up the specification, Alen BreatheSmart 45i comes with a child lock feature that is very useful if you have children at home. Another passive feature is a child-safe vent guard that shuts down the air purifier when the front panel is not properly closed. Alen BreatheSmart 45i is also UL listed and CARB approved ozone-safe which produces less than 0.001 PPM. It comes with a lifetime warranty but with a catch where Alen BreatheSmart 45i has to be registered with an active filter subscription.

Airflow, Coverage, And CADR

Alen BreatheSmart 45i coverage
Purifying coverage
800 sq. ft. (74 m2)
Alen BreatheSmart 45i fanspeed
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, lofts, apartments, and residential use in the kitchen, basement, garage, bedroom, and living hall.
Alen BreatheSmart 45i dust CADR
245 cfm (416 m3/h)
Alen BreatheSmart 45i pollen CADR
Pollen CADR
245 cfm (416 m3/h)
Alen BreatheSmart 45i smoke CADR
Smoke CADR
245 cfm (416 m3/h)
Alen BreatheSmart 45i clean air delivery rate (CADR) is measured at 245 cfm for dust, pollen, and smoke. While the 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

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, and bacteria. For additional smoke, cooking odors, and VOCs, you can opt for the HEPA fresh filter for an extra 15 dollars. The filter comes with antimicrobial treatment that prevents captured mold and other microorganisms' growth. To neutralize odors from pets and diapers, opt for the HEPA OdorCell filter. Finally, the additional 30 dollars Heavy smoke HEPA filter comes equipped with 2+ lbs of activated carbon that absorb smoke, VOCs, and chemicals aerosol sprays on top of allergens. 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 is a safe technology that does not generate harmful ozone during the process.

Noise And Energy Usage

Alen BreatheSmart 45i noise level
Noise level
23-49 dBA
Alen BreatheSmart 45i power consumption
Power consumption
50 W
For such a powerful air purifier, Alen BreatheSmart 45i is considerably silent with a noise level of just 23 dBA at the lowest speed and 49 dBA at the highest speed. It is ideal for a person that enjoys sleeping with pink noise running in the background. As an Energy Star Rated model, power usage is around 45-50 watts per hour, similar to its higher variant model. Expect an electric cost of $0.08 a day, $2.43 a month, or $29.16 annually with 12 hours of run time. For those that intend to run it 24x7, multiply the cost by 2 so the daily rate would be $0.16, or $4.86 a month, or $58.3 a year.

Pricing And Maintainence Cost

Alen BreatheSmart 45i MRSP/ RSP
+- 468.00
Alen BreatheSmart 45i annual filter replacement cost
Annual Filter Cost
+- 39 - 118
^ Replacement filters/ estimated cost
Alen BreatheSmart 45i is listed at 468 dollars before applying any discount or sales. A fair deal especially when you compared with the higher variant 75i it is around 300 cheaper but at a cost of inferior specification. 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.
Last we checked, Alen BreatheSmart 45i is available at Amazon with 40-50 discounts on its listed price. You'll get free shipping, hassle-free purchase, installment plan options (T&C applied), and a standard 30-days return policy. Alen official web store is also another good place to go with seasonal discounts and 25% off for service members. You can also try your luck with giant retailers like Walmart, Costco but do give their customer service a call before you head over.

Alen BreatheSmart 45i VS The Challengers

Rabbit Air MinusA2 SPA-780A

Rabbit Air MinusA2 SPA-780A

Go with this if you prefer a wall-mountable air purifier with a comprehensive 6-stage filtration yet don't mind the weaker airflow.
Airmega 300

Airmega 300

The mirror model with identical airflow output, CADR, and filtration setup. Go with this if you mind giving up on the ionizer.


  • As always, there is no shortage of front panel designs to choose from.
  • Wide purifying coverage with superior airflow distribution.
  • Customizable filter with up to 3 optional H13 HEPA filter upgrades.
  • Useful ionizer that can be turned off when not needed.
  • Uses the same long-lasting filter set as BreatheSmart Flex.
  • Newer intelligent sensor to support the air purifier auto/ lights-off mode.
  • Like most Alen newer air purifiers, you can easily lock 45i controls from child's fiddling.
  • Guaranteed for life from any manufacturer's defect (with product registration & active filter subscription).


  • Lacks chemical and odor filtration on the standard HEPA-Pure filter.
  • While the all-in-one filter setup is easy to replace, it lacks the filtration depth to compliment the H13 HEPA filter.
Alen BreatheSmart 45i

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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