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Alen Breathesmart 75i Review

Derek Hales

Written By: Derek Hales

Updated on:

Quiet air purifier with large coverage area

Alen Breathesmart 75i

Alen Breathesmart 75i

The Alen Breathesmart is a medium-sized HEPA air purifier that comes with 3 different filter options. It can cover up to 1,300 sq. ft. with a CADR of 347 CFM and has fantastic purification performance. In our tests, it reduced PM2.5 down to 0.1 and PM10 down to 0.2 after 2 hours. Furthermore, it is simple to use and can run incredibly quiet on the lowest fan speed.


  • Excellent purification performance, reducing PM2.5 down to 0.1
  • Large 1,300 sq. ft. coverage area
  • Quiet air purifier
  • 3 filter options
  • Includes an auto mode


  • Can be a pricey
  • Filters are replaced as a single unit


Excellent performance; Quiet Large Coverage
  • Design - 98%
  • Performance - 97%
  • Quality - 97%
  • Usability - 97%
  • Value - 94%


There are a lot of good things to say about the Alen Breathesmart 75i. It had great purification performance in our tests, lowering PM2.5 down to 0.1 and PM10 down to 0.2 after 2 hours. In addition, it has a simple design that is easy to set up, use, and maintain. Furthermore, it can quietly purify the surrounding air for night time sleeping. Overall, if you need coverage for a large area, the Breathesmart 75i, is a solid choice.

In This Review

Purification | Filters | Wind Speed | Ozone | Noise | Usability | Size | Specs | Summary

Purification Performance

To test purification performance on the Alen Breathesmart 75i, we placed it in a medium sized room (~14’ x 10”) in our office. We then lit incense, letting it smoke for 30 seconds to release smoke and other particulates into the surrounding air. Using a professional air quality detector, we took a measurement of the current air quality.

Air Quality Testing meter
Electronic testing meter we use to measure particulates and air quality

Next, we ran the Breathesmart on the maximum fan speed and let it run for 2 hours. At the 1 hour mark and at the end of the test, we took additional measurements of the air quality in the room.  

Starting Baseline

  • PM2.5: 93.4
  • PM10: 125.4
  • Particles: 11865
  • AQI: 141

After 1 Hour

  • PM2.5: 0.2
  • PM10: 0.4
  • Particles: 44
  • AQI: 1

After 2 Hour

  • PM2.5: 0.1
  • PM10: 0.2
  • Particles: 49
  • AQI: 2

Overall performance results for the Alen Breathesmart 75i were excellent. While it wasn’t able to reduce PM2.5 and PM10 to 0.1 within 1 hour, it still drastically lowered the particulate counts.

Alen Breathesmart 75i
Alen Breathesmart 75i

Below we’ve included information on the testing criteria and what defines good vs. bad air quality. Simply put, the lower the numbers the better. 

air quality index - PM 2.5 particulate matter index

The Filters

The Alen Breathesmart 75i has three different filter options to choose from upon initial purchase:

  • Pure
  • Fresh
  • Pet

We tested the Fresh version which includes 3 different filter types in its singular unit.

  1. Pre-filter
  2. HEPA filter
  3. Activated Carbon filter
  4. Ionizer

The pre-filter acts as the first line of defense, removing larger particles from the air like hair or dust.

Alen Breathesmart 75i Filters Removed
Alen Breathesmart 75i Filters Removed

Next, the HEPA filter does the majority of the work, removing particles as small as 0.1 microns. 

Following the HEPA filter, the carbon filter helps to remove VOCs and smoke making the air smell fresher. 

Alen Breathesmart 75i Carbon Filter
Alen Breathesmart 75i Carbon Filter

Optionally, you can turn on the ionizer with the press of a button. Ionizers charge airborne particulates, causing them to fall to the ground.

Both the Pure and Pet filters forgo the carbon filter in leu of a more robust HEPA filtration system. 

Wind Speed Test

For our wind speed test, we place an anemometer directly on the air vents of the Alen Breathesmart 75i. We run it on the lowest and highest fan speeds measuring the speed of the air coming out of the device. 

Minimum Wind Speed

2.2 mph

Maximum Wind Speed

8.5 mph

The 75i’s maximum fan speed is a little lower than the average across other air purifiers we’ve tested with an anemometer. On average we find maximum wind speeds of 11.7 mph. 

Ozone Test

Ionizers can potentially create unwanted ozone while running, which isn’t a good thing. To test the Alen Breathesmart 75i, we use an electronic ozone meter to measure the ambient ozone levels in a room.

Alen Breathesmart 75i Filters Installed
Alen Breathesmart 75i Filters Installed

Next, we ran the air purifier with the ionizer on and checked after 1 hour to see if any ozone was created. 

Pre-test Ozone

0 ppm

Post-test Ozone

0 ppm

Most air purifiers won’t create any ozone and our readings showed that no harmful levels of ozone were detected. Alen claims their ionizer is ozone-free, which is what our testing equipment also recorded.

Noise Test

To test noise levels of the Breathesmart 75i, we first measured the ambient noise levels of the room, for a baseline comparison. Next, we ran the Alen on the lowest and highest fan speed, measuring how much noise was generated in each mode. 

Here are the results:


39.6 dB


39.6 dB


50.3 dB

Noise levels for the Alen were quieter than what we see on average across other air purifiers we’ve tested. At the maximum fan speed, air purifiers make an average 60.8 dB of noise, which is 10.5 dB higher than the 75i. 

Alen Breathesmart 75i Fan
Alen Breathesmart 75i Fan

What is equally as impressive, is on the lowest fan speed the Alen created no detectable noise above the ambient noise levels of the room. Alen states it can create at a minimum 25 dB of noise, so, if your ambient noise levels are lower than ours it may be more noticeable. Regardless, that is still an incredibly quiet performance from Alen. 

Common noise levels:

  • 20 dB – rustling leaves
  • 30 dB – whisper
  • 40 dB – quiet library, babbling brook
  • 50 dB – refrigerator, moderate rainfall
  • 60 dB – normal conversation, dishwashers
  • 70 dB – traffic, showers
  • 80 dB – alarm clock, telephone dial tone

Usability Tests

Overall usability for the Alen Breathesmart 75i is excellent. It takes little setup and includes many features that enhance the user experience. 


Setup is incredibly simple thanks to virtually no included accessories in the box.

Alen Breathesmart 75i Unboxed
Alen Breathesmart 75i Unboxed

Here is what comes with the Alen Breathesmart:

  • BreatheSmart 75i
  • Filter (pre-installed)
  • Power cord
  • Protective grate
  • Manuals

You will need to remove all the packaging and plug in the power cord before the device is ready to go. That whole process takes a singular person just a few minutes. 

Controls & Display

On top of the Breathesmart 75i is a touchscreen display to interact with the air purifier. The display is clear and offers information regarding the device, as well as the current air quality it is detecting. 

Alen Breathesmart 75i Display
Alen Breathesmart 75i Display

There are 7 buttons that you can interact with that allow you to:

  • Toggle ionizer
  • Check filter life
  • Set a preset timer (2, 4, 12 hours)
  • Toggle power
  • Adjust fan speed
  • Toggle auto mode
  • Child lock the screen

All these buttons are intuitive and reactive with the touch of a finger. 


For wireless control of the Breathesmart you can connect the device to the Alen Air app. The app offers more detailed reports of the air quality in the area surrounding the device as well as all the controls you have physically, but from your phone. 


Maintenance is also quite simple for the Alen Breathesmart 75i. You will need to replace the filter, which can be done every 12-15 months according to Alen.

Alen Breathesmart 75i Removing Filter
Alen Breathesmart 75i Removing Filter

Generally, HEPA filters last 8-12 months depending on usage and environment, so 12-15 months is a welcome addition. 

Size & Dimensions

The Breathesmart 75i is a medium-large air purifier that comes on wheels for ease of movement. 

Alen Breathesmart 75i Bottom
Alen Breathesmart 75i Bottom

Here are the exact dimensions of the Alen Breathesmart 75i:

  • Width: 18.5”
  • Depth: 11.5”
  • Height – 27.0”
  • Weight – 27 lbs.

It can cover up to 1,300 sq. ft. with a CADR of 347 CFM, which is great for large rooms or even some small apartments.


ModelBreathesmart 75i
Weight27 lbs.
FiltersHEPA, carbon
Wifi CompatibleYes
Max. Wind Speed8.5 mph
Room Coverage1,300 sq. ft.
CADR347 cfm
ReturnsVaries by retailer
PriceCheck Price

Should you buy the Alen Breathesmart 75i?

I would recommend the Alen Breathesmart 75i if you’re looking for the following features:

  • Excellent purification performance: Across our 2 hour purification test, the Alen Breathesmart 75i was able to reduce PM2.5 down to 0.1 and PM10 down to 0.2. Even within 1 hour the air quality was well within what is considered safe to breathe.
  • Quiet with large coverage area: At the maximum fan speed the Alen can cover up to 1,300 sq. ft., but even then it is a fairly quiet air purifier. If you need something even more quiet, the lower fan speeds will create even less noise.
  • Simple usability: Whether setting up, using, or maintaining the device, the Alen Breathesmart 75i is simple. Thanks to the inclusion of an auto mode, you can spend even less time tinkering the device

For more information or to buy the Alen Breathesmart 75i, click here.

About Derek Hales

Derek HalesDerek Hales is the Founder and Editor-in-Chief of He has been featured in Fast Company, Reader's Digest, Business Insider,, She Knows, and other major publications. Derek has a Bachelor's Degree in Business Administration from Kansas State University. Hales has been testing and reviewing products for the home since 2014.