HouseFresh is reader-supported. When you buy through links on our site, we may earn an affiliate commission. Learn more

Alen BreatheSmart 45i Review

Last updated January 11, 2022

This post may contain affiliate links.


For our latest review, we’ve turned to the Austin-based air purifier manufacturer Alen, to put the BreatheSmart 45i through its paces. Alen are widely regarded as one of the top innovators on the market, creating high-performing purifiers and long-lasting filters. 

The BreatheSmart 45i is the little brother to Alen’s flagship purifier (the 75i), sharing the same great technology but designed for use in spaces up to 800 sq. ft. With impressive facts and figures on the Alen website, we decided to test it for ourselves. 

Alen 45i Air Purifier, Quiet Air Flow for Large Rooms, 800 SqFt, Air Cleaner for Allergens, Dust, Mold, Pet Odors with Long Filter Life (White)
  • B4-PURE FILTER: Recommended for dust, allergens, pollen, fur, pet dander, and odors.
  • SLEEK DESIGN: Fits perfectly in any space from small to large rooms.
  • TRUE HEPA: Includes a Medical Grade H13 True HEPA layer that captures 99.99% bacteria, aerosolized viruses, and airborne particles larger than 0.1 micron. True HEPA filters last 3-5 months longer than standard filters.
  • 5 AIR QUALITY COLORS: A Laser Smart Sensor detects airborne particles and auto-adjusts with air quality changes. Blue = Excellent, Green = Good, Orange = Fair, Red = Poor, Purple = Bad air quality (high levels of particles).
  • SLEEPSCORE VALIDATED: Incredibly quiet and tuned to generate a soothing pink noise for better rest. SleepScore Labs reported participants had improved sleep quality, reduced allergy symptoms, and felt more rested the morning.

Our Verdict

Despite throwing all the dust, pollen, and smoke I could muster, the Alen BreatheSmart 45i performed excellently, noticeably reducing allergy reactions and providing a much fresher feel to my city center apartment.    

Although its price comes in at the higher end of the mid-range market, you’ll struggle to find another purifier for under $450 that boasts 5 air changes per hour in an 800 sq. ft room with a CADR rating of 245, along with the real-world performance to back it up.

Let’s delve a little deeper into what makes this unit a great option for mid-sized rooms and apartments.

Specifications

Air Purifier
Alen 45i Air Purifier, Quiet Air Flow for Large Rooms, 800 SqFt, Air Cleaner for Allergens, Dust, Mold, Pet Odors with Long Filter Life (White)
CADR
245
Technology
H13 True HEPA + Activated Carbon
Room Size
800 sq. ft
Weight
20.1 lbs
Filter Life
12 months
Noise Level
23 dB to 49 dB
Monthly Energy Consumption
Up to $4.40
More information
Price
$428.99
Air Purifier
Alen 45i Air Purifier, Quiet Air Flow for Large Rooms, 800 SqFt, Air Cleaner for Allergens, Dust, Mold, Pet Odors with Long Filter Life (White)
CADR
245
Technology
H13 True HEPA + Activated Carbon
Room Size
800 sq. ft
Weight
20.1 lbs
Filter Life
12 months
Noise Level
23 dB to 49 dB
Monthly Energy Consumption
Up to $4.40
More information
Price
$428.99

The Look

The Alen BreatheSmart 45i has a sleek and modern aesthetic, combining a glossy white facade with gun-metal gray trim for a minimalist and versatile look. 

Despite being a powerful machine, it doesn’t take up too much space and as far as white goods go, sits comfortably in my living space, bedroom or office. Due to its relatively lightweight, it’s easy to maneuver from room to room and can slot nicely into the corner or a cupboard when not in use. 

For those after a more distinctive appearance, the Alen Breathesmart is available in a variety of ‘designer’ faux woodgrain and metallic tones so you can best match the decor of your home.

Operation

To get the purifier up and running is ridiculously simple. Once everything is unwrapped, open the front hatch via the air inlets on the side of the machine and slot in the HEPA filter, with the pre-filter facing towards you. Then once connected to mains, hit the power button and you’re good to go.

With the purifier now turned on, I first noticed the power button illuminate. Rather than a mere design feature, the color of this light indicates the quality of air in the room. There are five colors in total, from purple which is poor through to red, orange, green, and finally, blue which signals excellent air quality. 

The capacitive control panel allows you to easily cycle through the settings. Changing between the four fan speeds, adjusting the LED lights from low to high or even off entirely (which comes in handy at bedtime), or set to Auto, which monitors the air quality and adjusts the purifier’s settings for you automatically (we’ll get into that later). 

As well as a handy filter replacement light, which illuminates yellow when the filter is coming to the end of its lifespan and turns red when it is time to replace, you can also lock the control panel to stop any curious kids or boisterous pets from messing with your new pride and joy.

Filtration

When purchasing the Alen Breathsmart 45i you are also given a range of filters to choose from. Each filter offers a slightly different level of protection, mainly in relation to odors and volatile organic compounds (VOCs). I went for the ‘Fresh’ model which contains a medical-grade H13 True HEPA filter plus an activated carbon filter for added protection against VOCs and smoke.


Each of Alen’s True HEPA filters are capable of capturing 99.99% of airborne contaminants down to 0.1 microns, which are certainly impressive figures. However these results reflect controlled lab testing, so I was keen to see how these figures translate in the real world. 

Alen Replacement Air Filter for BreatheSmart 45i or Flex, True HEPA Basic Filter for Allergies, Pollen, Dust, Dander and Fur
Alen Replacement Air Filter for BreatheSmart 45i or Flex, Multi Purpose Filter for Mold, Bacteria, Cooking Odors, Allergies, Pollen, Dust, Dander and Fur
Alen BreatheSmart 45i or Flex Air Purifier, Dust, Mold, Odors + Household Odors, Odors/Pet Dander
Alen FL40-H Air Purifier, Dust, Mold, Pet Odors + Heavy Smoke, White
Technology
Basic model covering: Allergy and Asthma Triggers (dust, dander, pollen) and Pollution
Standard model covering: Chemical toxins (VOCs), Household Odors, Allergens (dust, dander, pollen) Pollution Activated Carbon: Targets indoor and outdoor pollutants (VOCs) & smoke, leaving air smelling fresh.
For homes with pets and kids, covering: Household Odors, Pet Odors, Allergens (Dust, Dander, Pollen) Destroys Odors: Nontoxic technology eliminates bad smells at the molecular level
With the most activated carbon of any filter in its class (2.3 lbs.) covering: Heavy Smoke, Chemical Fumes, Allergies, (Dust, Dander, Pollen) Safety from Smoke: Activated carbon targets dangerous ultrafine particles as small as 0.1 microns and toxins (VOCs)
Price
$69.00
$88.94
$99.00
$119.00
Filter
Alen Replacement Air Filter for BreatheSmart 45i or Flex, True HEPA Basic Filter for Allergies, Pollen, Dust, Dander and Fur
Technology
Basic model covering: Allergy and Asthma Triggers (dust, dander, pollen) and Pollution
More information
Price
$69.00
Alen Replacement Air Filter for BreatheSmart 45i or Flex, Multi Purpose Filter for Mold, Bacteria, Cooking Odors, Allergies, Pollen, Dust, Dander and Fur
Technology
Standard model covering: Chemical toxins (VOCs), Household Odors, Allergens (dust, dander, pollen) Pollution Activated Carbon: Targets indoor and outdoor pollutants (VOCs) & smoke, leaving air smelling fresh.
More information
Price
$88.94
Alen BreatheSmart 45i or Flex Air Purifier, Dust, Mold, Odors + Household Odors, Odors/Pet Dander
Technology
For homes with pets and kids, covering: Household Odors, Pet Odors, Allergens (Dust, Dander, Pollen) Destroys Odors: Nontoxic technology eliminates bad smells at the molecular level
More information
Price
$99.00
Alen FL40-H Air Purifier, Dust, Mold, Pet Odors + Heavy Smoke, White
Technology
With the most activated carbon of any filter in its class (2.3 lbs.) covering: Heavy Smoke, Chemical Fumes, Allergies, (Dust, Dander, Pollen) Safety from Smoke: Activated carbon targets dangerous ultrafine particles as small as 0.1 microns and toxins (VOCs)
More information
Price
$119.00

Testing

Whilst waiting for the purifier to arrive, I thought up some devilish ways to put it through its paces. Pausing all household chores provided a prime layer of dust ready for it to battle. After raiding the local florist, an army of lilies with pollen locked and loaded eagerly awaited its arrival. Even I, like a nervous general going to war, began to smoke like a chimney (well, vape at least).  

It was fascinating to see the air quality sensor change in real-time as I began dusting and hoovering my apartment. From what had been strictly good air, once I had disturbed the dust particles the sensor quickly changed to orange then red, and to my surprise even purple, signaling poor air quality! Within an hour, the sensor had changed back to excellent, giving me peace of mind that my floors, surfaces, and now air were all dust-free.  

Under similar real-world tests, the HEPA filter continued to prove its worth. Making light work of vape smoke, odors from my notorious cooking, as well as noticeably reducing allergy symptoms to pollen, when previously having flowers in the house simply wasn’t worth the sneezing attacks. With the purifier set to auto, it was reassuring to see the turbo speed kick into action when needed, especially when I was aware pollutants were in the air.  

After a couple of weeks of running the machine, I was amazed to see the build-up of large dust particles and hair that had collected on the prefilter. To remove the build-up, Alen states simply vacuum the filter with it in place. This worked well for me however this could provide a challenge if you only have an upright vacuum cleaner.  

Filter Replacement 

Even if used continuously, running the purifier as recommended, Alen claims the filter will last for 12 months. This is quite a long lifespan for a HEPA filter, with many other manufactures suggesting replacing the filter after 6 months or a year if used infrequently. However as the replacement filters cost up to $119.00, I hope it proves to be true. It will certainly be interesting to monitor the performance over the year to see how well the filter holds up.

Alen FL40-H Air Purifier, Dust, Mold, Pet Odors + Heavy Smoke, White
  • REPLACEMENT AIR FILTER - For Breathesmart Flex & 45I Air Purifiers Only. Find Your Model Number On The Top Panel Below The Power Button.
  • RECOMMENDED FOR: Dust, Dander, Allergens, Fur, Household Odors, All While Preventing The Growth Of Mold And Bacteria. Plus The Fl40-H Filter Eliminates Smoke With 2 Lbs Of Activated Carbon To Absorb Harmful Airborne Particles Including Smoke (Cooking, Cigarette, Cigar, Wildfire, Fireplace), Household Chemicals, Voc’S, And More.
  • H13 True HEPA: Includes A High Capacity Hepa Layer To Capture 99.99% Of Airborne Particles Down To 0.1 Microns.
  • EXTRA LONG FILTER LIFE: Change Once Every 9-12 Months.
  • PART NUMBER: Fl40-H

Noise

With four fan speeds to choose from, the noise of this purifier can easily be curtailed to suit the user whilst still vastly improving the air quality in your home. 

As I am a light sleeper, I thought utilizing the purifier in the bedroom would be a no-go area. However, I was pleasantly surprised to find, on the lowest setting it is barely noticeable. I also had no issues on the second lowest setting either, which may have even helped send me off to sleep with its gentle ASMR-esq pink noise hum. 

During the day, with the purifier set to auto, it occasionally ramped up the fan speed to higher levels. This does create quite a lot of noise and can be distracting, especially if working or even watching TV or listening to music. Of course, this can easily be adjusted to suit the user and limited to lower speeds when needed. 

Alen states the sound levels of the purifier are 39 dB at speed 1, 42 dB at speed 2, 49 dB at Speed 3, and reaching 55 dB on turbo. To you and me that ranges from a whisper on the lowest level to a box fan on the highest. 

So you can see and hear for yourself, check out our sound guide below:

Cost of Running

Thanks to its Energy Star rated efficiency, running this purifier will cost less than you think. Even if you leave the purifier on auto to work its magic around the clock, as Alen recommends. At full power, the purifier consumes 50 watts of energy, which will set you back approximately $4.40 per month. In reality, the power consumed will be much, much lower as the purifier operates on the lowest setting 99% of the time.

While the Alen Breathesmart 45i proves to be highly efficient in energy use, the average running costs are increased considerably by the filter replacement costs. Ranging from $69.00 for a basic filter to $119.00 for the premium option, this is a notable expense to be paid out and is something to be seriously considered before purchasing. 

Pros

  • Its minimalist design helps it blend nicely into my home.
  • It is surprisingly lightweight, making it easy to move from room to room.
  • It’s quite enough to run through the night, allowing me to sleep soundly.
  • The ionizing feature is optional so can be switched off if you have respiratory issues. 
  • It comes with a lifetime warranty

Cons

  • The replacement filters are expensive
  • The cheapest filter option doesn’t have an activated carbon filter.
  • Being provided with 3 different power cables for various regions is unnecessary and wasteful.

Bottom Line

Upon opening the box to the purifier you’re met with a simple one-sheet instruction manual, with the header “PREPARE TO CHANGE YOUR AIR” written across the top in large letters. Having researched plenty of air purifiers in the past, I was well aware of Alen’s stellar reputation and knew that their range of products was some of the best in the business. This all contributed to some rather lofty expectations on my part and I wondered, could this purifier really transform the quality of air in my city center apartment?

By putting it through its paces in a variety of real-world tests, it proceeded to tick all the boxes. Working well at eliminating odors from cooking and nearby breweries as well as noticeably reducing allergies to pollen and dust. All while being extremely simple to operate and maneuver around the home.   

Of course, this performance comes at a cost, (both with the initial purchase and with steep filter replacement costs) but its performance backs up its price tag and is helped by being very energy efficient. I’m pleased to say it has lived up to the expectations of an Alen product. 

For those looking for a versatile and powerful purifier for under $450.00, you would be well served with the Alen Breathesmart 45i. If you are based in the United States I would recommend that you check out the unit at Alen.com as you get automatic registration for their lifetime guarantee, you also get more options to choose your initial filters and they often have the best price.

Alen 45i Air Purifier, Quiet Air Flow for Large Rooms, 800 SqFt, Air Cleaner for Allergens, Dust, Mold, Pet Odors with Long Filter Life (White)
Alen FIT50 Air Purifier, Quiet Air Flow for Large Rooms, 900 SqFt, Air Cleaner for Allergens, Dust, Mold, Pet Dander, Heavy Odors with Long Filter Life
Alen 75i Air Purifier, Quiet Air Flow for Extra-Large Rooms, 1300 SqFt, Air Cleaner for Allergens, Dust, Mold, Pet Odors, Smoke with Long Filter Life
Technology
H13 True HEPA + Activated Carbon
H13 True HEPA + Activated Carbon
H13 True HEPA + Activated Carbon
CADR
245
220
347
Room Size
800 sq. ft
900 sq. ft
1300 sq. ft
Filter Life
12 months
12 Months
15 Months
Price
$428.99
$579.00
$759.00
Air Purifier
Alen 45i Air Purifier, Quiet Air Flow for Large Rooms, 800 SqFt, Air Cleaner for Allergens, Dust, Mold, Pet Odors with Long Filter Life (White)
Technology
H13 True HEPA + Activated Carbon
CADR
245
Room Size
800 sq. ft
Filter Life
12 months
More information
Price
$428.99
Air Purifier
Alen FIT50 Air Purifier, Quiet Air Flow for Large Rooms, 900 SqFt, Air Cleaner for Allergens, Dust, Mold, Pet Dander, Heavy Odors with Long Filter Life
Technology
H13 True HEPA + Activated Carbon
CADR
220
Room Size
900 sq. ft
Filter Life
12 Months
More information
Price
$579.00
Air Purifier
Alen 75i Air Purifier, Quiet Air Flow for Extra-Large Rooms, 1300 SqFt, Air Cleaner for Allergens, Dust, Mold, Pet Odors, Smoke with Long Filter Life
Technology
H13 True HEPA + Activated Carbon
CADR
347
Room Size
1300 sq. ft
Filter Life
15 Months
More information
Price
$759.00

Last update on 2022-01-17 / Affiliate links / Images from Amazon Product Advertising API