Alen BreatheSmart 75i vs Classic air purifier difference & replacement filter cost


Which is good for pet – Alen BreatheSmart 75i vs Classic air purifier? Not only powerful, but one of the quietest air purifiers available. Alen’s True HEPA-Fresh filter captures airborne allergens, dust, pollen, fur, pet dander, airborne allergens, dust, pollen, fur, pet dander, household odors PLUS smoke from cigarettes, cigars, cooking, wildfires, and VOC fumes from chemicals & aerosol sprays.

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The massive size of the filter compartment is what sets it apart from others, with thick layers of HEPA material and a rubber gasket to seal the filter from air leakage; the medical grade H13 True HEPA filter captures 99.99% bacteria, aerosolized viruses, and airborne particles larger than 0.1 micron. In addition, the True HEPA-Fresh filter contains an activated carbon layer that absorbs smoke, cleaning solution fumes, and toxic smells that are all known to cause respiratory issues. 

Pros & Cons – Alen BreatheSmart 75i vs Classic air purifier

Alen BreatheSmart 75i


  • Most energy-efficient air purifier
  • Quietest air purifier with 25-49 noise level internal; perfect for bedrooms
  • True air purification powerhouse; with 350 CADR rating
  • It can cover 1,300 sq ft – that means you can use it to purify the air in more than 1 room
  • Incredibly energy-efficient and quiet operation


  • It’s definitely pricy because you can buy 1 unit to cover several rooms

Alen BreatheSmart Classic air purifier


  • Superb H13 medical-grade HEPA filters
  • Highest CADR rating of the 1st line BreatheSmart air purifiers
  • Perfect for larger rooms, such as a master bedroom or living rooms
  • Lower price compared to its new brother 75i


  • It is powered by 105W; not the best for electricity bill and the environment
  • At turbo level, it produces 56 dB of noise
  • Is surpassed by the BreatheSmart 75i model

Specs – Alen BreatheSmart 75i vs Classic air purifier

Alen BreatheSmart 75i

  • Max. Coverage Area: 1300 sq ft
  • CADR Rating: 350
  • Max. Airflow: 347 CFM
  • Filters: 75i HEPA Pure
  • Filter Lifespan: 12 Months
  • Power Output: 0.8 – 45 Watts
  • Noise Levels: 25-49 dB
  • Dimensions: 27″ x 18.5″ x 11.5″
  • (H x W x D)
  • Weight: 27 lbs

Alen BreatheSmart Classic air purifier

  • Max. Coverage Area: 1100 sq ft
  • CADR Rating: 300
  • Max. Airflow: 290 CFM
  • Filters: True HEPA Pure
  • Filter Lifespan: 12 Months
  • Power Output: 1.6 – 105 Watts
  • Noise Levels: 42-56 dB
  • Dimensions: 26.75″ x 17.75″ x 10″
  • (H x W x D)
  • Weight: 21 lbs

Who is this for

If you have a small to medium size room (i.e. bedroom or living room), any of these models will work; however, for very large spaces (i.e. basement or open floor plan) you’ll likely need the BreatheSmart Classic, FIT50, or 75i since they cover the largest areas.

If you’re buying an air purifier for a bedroom, then the 45i or 75i are the better options since they include the Pink Noise feature.

Compare Alen BreatheSmart 75i vs Classic air purifier

Alen Air Purifier:BreatheSmart 75iBreatheSmart Classic
Max. Coverage Area:1,300 square feet1,100 square feet
CADR Rating:350300
Max. Airflow:347 CFM290 CFM
Power Output:1.8 – 45 Watts1.6 – 105 Watts
Filters:75i True HEPA (H13)True HEPA Pure (H13)
Filter Lifespan:Filter Price:12 Months$$$$12 Months$$$$
Noise Levels:25-49 dB42-56 dB

What is the difference – Alen BreatheSmart 75i vs Classic air purifier?

Alen BreatheSmart Design and Size

The only real difference is the roundness of the front panel corners and the actual size of each machine. But even then, those variations are subtle.

From a quick glance, you’ll see that all of the Alen BreatheSmart air purifiers have the same general design.

  • BreatheSmart Classic = 17.75″ (W) x 26.75″ (H) x 10″ (D)
  • BreatheSmart 75i = 18.5″ (W) x 27″ (H) x 11.5″ (D)

Filter life comparison

BreatheSmart 75iCoverage: 1300 sf.
Air Quality Sensor: Yes
Filter Life: 12-15 mo.
BreatheSmart 45iCoverage: 800 sf.
Air Quality Sensor: Yes
Filter Life: 6-9 mo.
BreatheSmart ClassicCoverage: 1100 sf.
Air Quality Sensor: Yes
Filter Life: 8-9 mo.
BreatheSmart FIT50Coverage: 900 sf.
Air Quality Sensor: Yes
Filter Life: 10-12 mo.
BreatheSmart FLEXCoverage: 700 sf.
Air Quality Sensor: No
Filter Life: 6-9 mo.

The differences between these machines, however, are much more subtle.

To save you countless hours of research, we’ve included an in-depth look at those differences in this Alen BreatheSmart review:

Ionizer Function (This boosts the air cleaning power by electrostatically charging air molecules.)BreatheSmart FLEX is the only model without this feature.

Timer Function (Automatically turns the unit off after a specified time.)BreatheSmart Classic offers 4, 8 and 12-hour timers.All other models offer 2, 4 and 12-hour timers.

Child Lock (Locks the control panel so the settings can’t be changed.)BreatheSmart Classic is the only model without this feature.


The 75i is approximately 1.5 inches bigger all round and 6lbs heavier than the classic, but it also can handle 1,300 square feet against the Classic’s 1,100 square feet.

Power consumption

The 75i is even more energy efficient using only 45 watts at the highest speed versus 105 watts for the Classic. The 75i cleans 99.7% of particles over 0.3 microns whereas the Classic is a close runner up with 99% cleaning of the same.


Both run quietly, especially in the lowest operating mode at 41 decibels up to only 49 dB for the 751 and 56 dB for the Classic at the turbo speed mode. With the “lights-off” mode, their quiet operation means they can run in your bedroom whilst you are sleeping.

CADR Rating (From 220 To 350)

The CADR rating is probably the single most important air purifier specification. You will find other specs such as coverage area, airflow, wattage, noise levels in air conditioner, dehumidifier, even furnace specification sheets.

It stands for Clean Air Delivery Rate; basically, the amount of clean air an air purifier can deliver. The more, the better, right?

All Alen air purifiers have exceptionally high CADR ratings. The BreatheSmart FLEX, FIT50, and Classic have 225, 220, and 300 CADR rating, respectively.

A higher CADR rating also means that you can put such an air purifier – like BreatheSmart Classic with a 300 CADR rating – in bigger rooms.

Max. Airflow (187 CFM To 347 CFM)

Maximal airflow is an air purifier specification that is secondary to CADR rating. In all our reviews – including this Alen SmartBreathe review – we stress the following:

150 CADR rating is a safe bet that an air purifier is actually a good purifier, not a mere air blower. The filter has to actually pick all those dust, smoke, mold, dander, and other particulates out of the air and deliver clean air back into the room.

Here is how big an airflow BreatheSmart FLEX, FIT50, Classic, 45i, and 75i create, respectively: 187 CFM, 231 CFM, 290 CFM, 215 CFM, 347 CFM.

Similarities – Alen BreatheSmart 75i vs Classic air purifier

Both machines have a carrying handle so they can be moved from room to room.

The easy to read displays show you immediately how bad the pollution is in your air. Blue shows you a low level, yellow a higher level, and red suggests potentially dangerous air quality levels.

Alen meets the most important air purifying needs in each machine.

Regardless of the air purifier you choose, you’ll enjoy these benefits:

  • Customizable HEPA Filter (Traps 99.97% of pollutants down to 0.3 microns in size.)
    • HEPA-Pure – This is the basic version of the filter that removes indoor allergen particles, such as dust, pollen, pet dander, and mold spores.
    • HEPA-Silver – This version includes an antimicrobial compound on the HEPA material that protects it from bacteria and microbe growth. An additional layer of Activated Carbon also reduces light odors and chemical compounds in the air.
    • HEPA-OdorCell – This version features hundreds of cells filled with Alen’s patented Molecular Conversion Powder in addition to the HEPA material. Odors from pets, babies, and cooking are destroyed at a molecular level to leave the air smelling fresh.
    • HEPA-FreshPlus – This version includes 3 lbs. of Activated Carbon in addition to the HEPA material. It provides maximum performance against household odors and chemical vapors from cleaning products, smoke, cooking, pets, etc.
  • Smart Sensors – These sensors monitor the air quality and automatically adjust the device’s fan speed to filter out pollutants. Consider it intuitive intelligence that works on your behalf.
  • Numerous Color Options – More than 14 different colors and designs available so you can match your personal style and taste. Also includes unique options such as brushed bronze, marble, rosewood, and more.
  • Timer – This allows you to set up a time in the future for the device to shut off. The timer function ranges between 2 to 12 hours. (See the differences section below for specifics on each BreatheSmart machine).

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