The ‘Classic’ model is one of the 3 original air purifiers in the sleep-friendly Alen BreatheSmart series. It is commonly referred to as Alen BreatheSmart Classic large room air purifier for one simple reason:
It’s the biggest of the 3 original Alen BreatheSmart models, most appropriate for large rooms.
In this review of the Alen BreatheSmart Classic, we’ll look at the specifications that make the Classic one of the best air purifiers for large rooms. In short, it removes indoor air pollutants like dust, pollen, and smoke down to 0.1-microns exceptionally well (99.99% efficiency).

Before we answer if the Alen BreatheSmart Classic large room air purifier is any good, we need to address the elephant in the room: the new Alen BreatheSmart series models, 45i and 75i.
Smaller original Alen BreatheSmart series models – FLEX and FIT50 – are outmatched by the new Alen BreatheSmart 45i model (with 245 CADR rating).
Similarly, the superb Alen BreatheSmart Classic model has been outranked by the new Alen BreatheSmart 75i air purifier. The 75i model is not only better than the Classic; it’s literally the best air purifier in the world.
75i model does solve all the misgivings the Alen BreatheSmart Classic model had: high noise levels at Speed 1, high energy consumption, and not-all-that-great CADR rating for a large room air purifier.
With this in mind, we can start the in-depth Alen BreatheSmart review.
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Alen BreatheSmart Classic Review At-A-Glance: One of the best large room air purifiers. Compared to Coway, Blueair, and Levoit air purifiers, Alen BreatheSmart Classic has a better filtration system (H13 HEPA filters), higher CADR rating, and more optimum noise profile at high fan speed settings. 3-stage Smart Sensor real-time air quality is a nice addition, and the overall look is quite appealing.
Overall rating:
Alen BreatheSmart Classic Specifications

Max. Coverage Area: | 1,100 sq ft (2 ACH) 440 sq ft (5 ACH) |
CADR Rating: | 300 |
Max. Airflow: | 150 CFM (Speed 1), 185 CFM (Speed 2), 225 CFM (Speed 3), 290 CFM (Turbo Speed) |
Filters: | True HEPA Pure (H13) |
Filter Lifespan: | 12 Months |
Power Output: | 1.6 – 105 Watts |
Noise Levels: | From 42 dB to 56 dB |
Dimensions: | 26.75″ x 17.75″ x 10″ (H x W x D) |
Weight: | 21 lbs |
Price: | $$$$ |
Average Rating: | ![]() |
Alen BreatheSmart Classic Filters
Alen has always been known for their top-of-the-line filtration systems. That’s actually the most important part of any air purifier; filters are the very thing that capture airborne pollutants and eliminate them from the air circulation.
Alen BreatheSmart Classic has Alen’s signature H13 HEPA filters. While ordinary HEPA filters are designed to capture 99.97% of air pollutants that are 0.3 microns in size, the H13 HEPA filters Alen BreatheSmart Classic uses remove 99.99% of air pollutants that are 0.1 microns in diameter. In short, they are brilliant even at removing the smallest air particulates such as small dust particles, smoke particles, pollen, mold, mold spores, certain bacteria, and so on.
Before the main filter, Alen BreatheSmart Classic has a large pre-filter that blocks hair and large dust particles from hitting and overwhelming the delicate main filter.
As for the main filter, Alen BreatheSmart Classic has 4 options:
- Pure filter BF35. The most basic Alen filter for removing allergens and dust.
- Silver filter BF35-Silver-Carbon. Anti-microbial filter that removes mold and bacteria, in addition to other allergens and dust.
- FreshPlus filter BF35-VOC. Also known as ‘the chemical filter’. It has an additional layer of activated carbon that helps the Alen BreatheSmart Classic model adsorb cooking odors, smells (cigarette smoke), and volatile organic chemicals (VOCs).
- OdorCell BF35-MP. The big odor-adsorbing filter completely adsorbs even the most awful smells, including diaper odor (useful if you have kids or pets).
All these Alen BreatheSmart Classic filters have a prolonged lifespan of 12-15 months, even if you use the Classic model continuously 24/7 365 days per year.
The cost of the Classic model filter ranges from $79 for the Pure filter to $119 for the OdorCell filter. The beauty of this is that you only have to replace filters once per year; with other air purifiers, having to replace filters 3-5x per year is the standard.
In short, the Classic model has great filters that are available at a low long-term cost because you only need one per year, instead of five per year.
Let’s look at exactly how well the Alen BreatheSmart Classic filters perform:
Alen BreatheSmart Classic CADR Rating And Maximum Airflow
The CADR rating is the principal metric for all air purifiers, including the Alen BreatheSmart Classic model. It measures how well the combo of filters and the airflow in the Classic model performs as far as removal of 3 specific air pollutants – dust, pollen, and smoke particles – is concerned.
Alen BreatheSmart Classic has a CADR rating of 300. CADR scale goes from 0 to 450, with an approximated 200 average for a standard air purifier. In this regard, we can say that Alen BreatheSmart Classic does the an-above-average job at removing dust, pollen, and smoke particles from the 1,008 sq ft test chamber AHAM uses to measure CADR rating.

What is fantastic is that the Classic model achieves a 300 CADR rating at a low 290 CFM airflow. As far as the airflow, it has 4-speed settings with designated airflow output:
- Speed 1 = 150 CFM.
- Speed 2 = 185 CFM.
- Speed 3 = 225 CFM.
- Turbo Speed = 290 CFM. At this top speed, the Classic Alen BreatheSmart achieves a 300 CADR rating.
Based on the above-average CADR rating, we can calculate the recommended coverage area:
Alen BreatheSmart Classic Square Footage (For Large Rooms)
As previously stated, the Classic model is the largest air purifier from the original line of Alen BreatheSmart units.
Due to the 300 CADR rating, it can cover up to a maximum of 1,100 sq ft. If you put the Alen BreatheSmart Classic in a 1,100 sq ft large room, it will be capable of changing air (and filtering out air pollutants) 2 times per hour. That is also known as 2 ACH – air changes per hour – and is a key metric for air purifiers.
It is recommended that for the best air purification, the ACH should be 5. That reduces the Classic model’s recommended square footage to 440 sq ft.
Example: If you put it in a 440 sq ft large room, it will change all the air in that room every 12 minutes. Such high ACH is recommended for allergy-prone individuals.
Due to larger coverage, Alen BreatheSmart is considered a large room air purifier.
Alen BreatheSmart Classic Power Consumption (Wattage)
The one problem that the Classic model successor – the Alen BreatheSmart 75i – solved is the energy-efficiency.
Truth be told, Alen BreatheSmart Classic drain quite a lot of energy given its CADR rated output. It’s true that at Speed 1, it will need only 1.6 watts to run.
However, at the highest speed – Turbo Speed – it consumes 105W of energy. It is a large room air purifier, larger air consumption is expected, but the Classic model does drain more energy than comparable energy-efficient large room air purifiers.
Let’s do a simple calculation to figure out how much electricity will the Classic model need. We’ll presume it runs continuously for a week at peak speed.
It needs 105 W.
Here’s how much it spends per day: 105 W * 24 h = 2,52 kWh.
Here’s how much electricity Alen BreatheSmart Classic spends per week: 2,52 kWh/day * 7 days = 17,64 kWh.
The average cost per kWh is about $0.13. 17,64 kWh costs about $2.30. In short, the Classic model will use up to $2.30 worth of electricity every week. In a year, that’s more than $100 just for powering it (albeit you don’t always have to set it to Turbo Speed).
This is a notable con of the Classic model.
Alen BreatheSmart Classic Noise Levels
Sadly, the noise levels are also a bit of a con for the Classic model, paradoxically so I may add. Alen BreatheSmart Classic was created as a large bedroom air purifier. It should be quiet as a mouse; high noise levels and sleeping don’t go well together.
While the new flagship 45i and 75i models achieved the super quiet operation (below 50 dB), the Classic doesn’t share the same noise profile.
Even at the lowest Speed 1, the Classic generates 45 dB of noise. This is quite a lot; comparatively, as we have discussed in the Alen BreatheSmart 75i review, that air purifier generates only 25 dB at Speed 1.
At the top fan speed setting, the noise levels rise to 56 dB which is not ideal. Granted, the smaller Alen BreatheSmart FLEX also has 55 dB noise levels at Turbo Speed but the new 45i and 75i models have managed to reduce that number to 49 dB, a considerable difference.
Alen BreatheSmart Classic Special Features
With the BreatheSmart series, Alen has introduced the Smart Sensor technology. That’s the key special feature that separates the Alen BreatheSmart Classic large room air purifier from the competition.
The point here is that you know how dirty or clean your indoor air is. Here’s how this features looks on the Alen BreatheSmart Classic control panel:
If the circle is red, you have ‘dirty air’ or poor air quality. The Classic model will, as a result of its filtration of indoor air, increase the air quality to standard quality (yellow light) and finally to healthy air quality (blue light).
This indicates at what fan speed setting you should run the Classic large air purifier. If you see the red light, you run it on Turbo Speed. If you see the blue light, you can lower the speed to Speed 2 or even Speed 1.
It’s vital for you to know how well the air purifier performs, and this indicator is the simplest way to know that.
On top of that, Alen is the first air purifier brand to introduce a lifetime warranty. By buying the Alen BreatheSmart Classic, you’re playing it safe; the warranty covers all the problems you may have. The Classic is a very reliable model but it’s better to be safe than sorry.
Alen BreatheSmart Classic Price
Alen BreatheSmart air purifiers do have a premium price tag, and the Classic model is not exempt. BreatheSmart is, after all, the best-of-the-best air purifier series in the world.
Alen BreatheSmart Classic costs $649.
You do need to take the price of the unit with some consideration. The cost of replacement filters is the true cost of any air purifier. Some companies do have a ridiculously low price of the air purifier itself because they earn money on the replacement filters.
Alen is different. They have the H13 HEPA main filter that may cost about $100 but needs to be changed only once per year. With other air purifiers, you’re looking at 3-5 filter replacements per year, and a total cost of about $300.
In the short-term the cost of Alen BreatheSmart Classic might appear quite high but the important part – the long-term cost – is minimal. This makes the Classic model moderately affordable.
Alen BreatheSmart Classic Sale
We try to keep up with sales for every air purifier we review; Alen BreatheSmart Classic sales included.
You can check any current Alen BreatheSmart Classic sales on Alen’s website here:
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Final Verdict On Alen BreatheSmart Classic
In 2018, Alen BreatheSmart Classic was one of the best large room air purifiers. High CADR rating, aesthetic design, the addition of real-time indoor air quality sensors, and the advanced H13 medical-grade filter were great qualities back then.
In 2023, however, the Classic model is far surpassed by the superior Alen BreatheSmart 75i model; the best-of-the-best air purifier in general, not only among Alen Air purifiers.
Overall Alen BreatheSmart Classic rating: