The Alen BreatheSmart FLEX is an air purifier with a mission. It wants to trick people into thinking you spent the cost of the Alen BreatheSmart Classic when you actually only forked out less than $200. It does a good job too. And you will find out how in our today Alen BreatheSmart FLEX Review.
Alen BreatheSmart FLEX ranks C+ in our air purifier ranking list. We give the biggest and most thorough database of air purifier reviews in the world.
The Alen BreatheSmart FLEX is superseded by the Alen BreatheSmart 45i, with better performance and a brand new Smart Sensor. Also, I recommend you to check the Alen BreatheSmart 35i for a more affordable option with new smart features.
In Breathe Quality, we have reviewed all air purifiers under these sections. Also, we guarantee that:
- We do give honest reviews (both pros and cons) so anyone will guarantee to have the wisest choices.
- We do not (and never) exaggerate one product just to let you click the links and buy that product blindly.
Sections
- Customizable color options
- Large room coverage
- Now with True HEPA filter
- Still low CADR rating for room coverage
- Lacks of features
Alen is a strong name in the American air purifier industry, with the first and certain lifetime warranty. They want to deliver the best customer services to compare with other American rivals like Rabbit Air, Honeywell and Levoit, and keep the strong foothold on the air purifier market. However, their air purifiers all demand the mid-range and high-range level, because buying an Alen’s product is a sign of lifetime commitment. Today we have Alen BreatheSmart FLEX Review, an air purifier which is the entry-level to mid-range budget.
Other Alen’s Air Purifier Reviews:
Alen BreatheSmart FLEX Price
I’d hate to be an air purifier designer, trying to achieve unique and exciting features in a jaw dropping package for what is essentially a device with good air flow system. In terms of design, the modern American air purifiers are trying to prove their best, from the Rabbit Air BioGS 2.0, GermGuardian AC9200WCA or Levoit LV-H134.
So it’s all the more impressive that Alen managed to make the Alen BreatheSmart FLEX, an air purifier with lots of improvements in design that won it so many awards. Right as its name suggests, the Alen BreatheSmart FLEX indicates the flexibility it gives to any room decoration. A selection is 14 colors is what can fit everyone’s tastes. But yes, it is not cheap.
The Alen BreatheSmart FLEX starts with $349, a price that could bring this air purifier to the entry-level of mid-range. Alen needs to sort out its efforts in the mid-range, but that’s a topic for a different day. The Alen BreatheSmart FLEX is an air purifier that’s supposed to offer the best of the air purifier market, one that can survive the onslaught of the Rabbit Air BioGS 2.0, Levoit LV-H133 and Blue Pure 121, while begin the Alen’s heritage and bringing the bottom line closer to something more healthy.
Thanks to the new commercial True HEPA filter, it appears the company has managed an upper advantage to compete against the others through a clever combination of appearance and customer services. And in today’s impossibly congested air purifier market (especially at the high end) that’s something to be applauded.
Alen BreatheSmart FLEX Air Purifier for Bedrooms & Living Rooms.
HEPA Filter for Allergies & Dust. With Big Power, but Small Footprint. Stainless Steel Edition.
Related post: Best air purifier 2026.
Alen BreatheSmart FLEX Design and Size
The Alen BreatheSmart FLEX is an air purifier with quite a lot of metal on its body, which is different from the previous Alen Paralda and Alen T500. You’ll see this sort of construction in many mid-range air purifiers, like the Rabbit Air BioGS 2.0 or GermGuardian AC9200WCA. That’s a good reason to cost more in mid-range level.
Probably the most significant change is forming the Alen BreatheSmart FLEX as a full-size air purifier instead of an usual tower one. It will help the air purifier to hold inside a much broader fan, and therefore increase the cleaning rate of the device. Alen is obviously proud of the Alen BreatheSmart FLEX’s design, as it retained it for the Alen BreatheSmart 45i, while sticking closely to the look for the Alen BreatheSmart FIT50 and Alen BreatheSmart Classic as well.
Despite of being a full-size air purifier, the Alen BreatheSmart FLEX has a height of 25 inches, which is even taller than the current Alen Paralda. That means a bigger size air filter will be applied to capture more allergens for you. Moreover, the air flow system concept has changed, to a common bottom-to-top. With a big air intake grill behind the panel, the Alen BreatheSmart FLEX draws in polluted air, purifies it and releases back through the top air vent. A typical air flow concept which are used widely in price range of $300 to $400, from the Blueair Classic 205 to the Rabbit Air BioGS 2.0 and GermGuardian AC9200WCA.
I gave you lots of air purifiers to compare with the Alen BreatheSmart FLEX, but the most special thing in this device is its range of colors and textures in panel. These 14 colors offer the flexibility for you to complement your home’s new look as quick as possible. There will be very few brand-agnostic people that wander into their local air purifier emporium, look at the Alen BreatheSmart FLEX and a couple of competitors, and don’t find that the American brand’s device is more gorgeous in the design stakes than others. And I’d bet that most would be unable to resist a purchase after that.
On top of this air purifier, we will have a brand new control panel, with 5 basic function buttons. A logo of the Alen BreatheSmart FLEX is also found here, which is the only way to be sure that you purchase the right air purifier.
Bigger in size, the Alen BreatheSmart FLEX is only 15 lbs. With a necessary handle on top of this air purifier, you can easily grab it and move it anywhere in your home.
Related post: Best air purifier for bedroom.
Alen BreatheSmart FLEX Filters
As the decisive criteria for the performance of one air purifier, by default we look at the quantity and the quality of its air filters, and what the air filter types are using. There is only a 2-stage air cleaning system in this Alen BreatheSmart FLEX, without the classic ionizer in the Alen Paralda and Alen T500.
- Pre-filter – Simple pre-filter that traps large pollutants.
- True HEPA filter – The Alen BreatheSmart FLEX captures 99.97% of particles as small as 0.3 microns. Choose from 3 specialized configurations:
- HEPA-Pure – The standard HEPA filter of the Alen BreatheSmart FLEX.
- HEPA-Fresh – The next level HEPA filter will improve the first HEPA-Pure to deal with the household odors like cooking smells and light smoke, with an addition of Activated Carbon filter.
- HEPA-OdorCell – The ultimate level HEPA filter of the Alen BreatheSmart FLEX, using the ultimate Alen’s Molecular Conversion Powder. This air filter is the final defense against all allergens as well as smoke and pet odors.
There are enough negative reviews about the ionizer of Alen air purifiers making a crackling of noise, and people are more and more to stay away from any ion generators because it can emit ozone and irritate internal asthma and other breathing issues. As a response, Alen removes the ionic feature from the Alen BreatheSmart FLEX. It is mostly for marketing purpose, because the actual ozone emission from other Alen’s air purifiers is still within the common standard level.
Also, the Alen BreatheSmart FLEX welcomes back the pre-filter which is necessary to capture the large objects of pollutants. This preliminary filter will reduce the amount of pollutants that HEPA filter needs to capture, and therefore prolong its lifetime. The pre-filter is washable and permanent to use.
There are lots of work in the next-gen HEPA filter of Alen. Of course, it is the certified True HEPA filter, because Alen has finally listened to the community. At least that is the thing Alen said. To know if it is the truth or not, at Breathe Quality, we still put everything in a test.
With new True HEPA filter from the Alen BreatheSmart 45i, and because we reworked the air purifier ranking list, time to check the Alen BreatheSmart FLEX again.
Air Purifier Efficiency — 400 sq ft Room, 1 Hour
Exponential decay model: C(t) = C₀ × e−ACH × t | 8 ft ceiling (3,200 ft³), closed room, perfect mixing
Alen BreatheSmart FLEX
Breathe Quality98.989%
particles removed after 1 hr
Alen BreatheSmart 45i
Breathe Quality97.368%
particles removed after 1 hr
AirDoctor AD2000
Breathe Quality95.205%
particles removed after 1 hr
AirDoctor AD1000
Breathe Quality94.216%
particles removed after 1 hr
Particle concentration decay over 60 minutes
Assumptions: smoke CADR used for all models; 8 ft ceiling assumed; perfect room mixing assumed.

We will now use the same True HEPA filter for both Alen BreatheSmart FLEX and Alen BreatheSmart 45i. It is now balance to have a HEPA-Pure from $59, and up to $89 with the HEPA-OdorCell. In this price range, the air filter cost from Blue Pure 121 is $109, and Levoit LV-H133 is $84. You need to change the air filter after 6 months or 1 year, depending on the using frequency.
Related post: Best air purifier for allergies.
Alen BreatheSmart FLEX Room Coverage
Again, Alen announced that their Alen BreatheSmart FLEX can deal with a very large room. The number is impressive, with a room coverage of 700 square feet. This room coverage is even larger than the 625 square feet from the Rabbit Air BioGS 2.0, or 620 square feet from the Blue Pure 121.
The ACH of the Alen BreatheSmart FLEX is up to 4X. This Alen BreatheSmart FLEX can clean your room up to 4 times per hour, depending on your room size.
The CADR of the Alen BreatheSmart FLEX is 245 cfm overall. Alen has a tradition to make low CADR air purifiers for a large room. With such low CADR rating, the Alen BreatheSmart FLEX will take longer time to clean a room of 700 square feet effectively.
Related post: Best large room air purifier.
Alen BreatheSmart FLEX Sound
One reason Alen gave to public for not having True HEPA filter is because they don’t want the True HEPA filter restricts airflow. It is quite reasonable, and with less restriction in the air flow, you don’t need a powerful fan to cover a large space. Now with a real True HEPA filter, can the Alen BreatheSmart FLEX be any better?

Source: Amazon.com
With the improvement from the Alen Paralda, I have high hope that the Alen BreatheSmart FLEX will be better in terms of the noise level. This air purifier still runs at 4 fan speeds, with the lowest setting is only 39 decibels. This is the standard library noise level, and can be acceptable by almost users.
And at the highest setting, I recorded an impressive noise level of only 55 decibels. This is the standard highest noise level from many brands, like Rabbit Air, Blueair and Levoit. You can imagine that the noise level is nearly as the normal conversation at home. Moreover, the Alen BreatheSmart FLEX produces the pink noise, which can aid you to sleep faster.
That’s why the Alen BreatheSmart FLEX is truly a device for bedroom. Even if you are trying to run this air purifier in quiet places like the office, it is a great idea.
Related post: Best air purifier for baby.
Alen BreatheSmart FLEX Power Consumption
One of our most FAQs is “Do air purifiers use a lot of energy?” An air purifier is meant to run for a long time to be efficient, that’s why many air purifier brands consider the energy-saving standard, mostly in the rate of Energy Star, is one important selling point.
I’ve recorded the power consumption of the Alen BreatheSmart FLEX as only 56 watts on the highest speed. Compare to the 80 watts from the Blueair Classic 205 and 61 watts from the Blue Pure 121, you had better run this Alen BreatheSmart FLEX to save the energy.
For using a Alen BreatheSmart FLEX 8 hours per day, it would cost you about $20 per year.
Related post: Best air purifier for pets.
Alen BreatheSmart FLEX Additional Features
The Alen BreatheSmart FLEX is not a budget air purifier anymore, but still, we don’t have the necessary Smart Sensor for this device. For that reason, I am a bit disappointed with this air purifier, as I need to manually change the fan speeds.
But thanks Alen, because we rejoice with the classic Timer function as missing from the Alen Paralda. In real-world use, I don’t use the Timer function at all, but maybe there are many people out there who are in need of this feature.
You don’t want to miss the lock, to prevent your children to press the control panel and ruin your setting. This lock function is available in every Alen device from now on.
The last but not least, we have a LED indicator for filter replacement. That’s great, I don’t need to remember the date to change my air filter anymore.
Related posts:
1, Best air purifier for smoke.
2, Best air purifier for dust.
3, Best air purifier for mold.
Alen BreatheSmart FLEX Customer Service
Running through a very long review about Alen air purifiers, you may question us: “Why I need to buy Alen air purifier?” Yes, if it is not for the outstanding performance, or the top-class fan power, then there is must be something really, really important. What I’m trying to say here is the perfect customer service from the Alen Corporation.
Alen doesn’t hide the intent to speak high of their customer services. Look at their website, there are full of content to support the customers. You will have their phone, their emails, and of course, their support policies without any hindrance. To reach the Alen, you can contact them 6/7 days per week. They provide the best fast and free shipping for any products, as long as the orders are placed before 3 PM, they will guarantee to ship in the same day. Impressive, right?
They expand the refund time up to 60 days, or 2 months. You won’t need to worry about the quality of your air purifiers, because Alen will back you up with 3-year warranty (not Forever Guarantee anymore). Whenever your personal Alen air purifier doesn’t operate as normal in the third year, you will have a same refurbished air purifier with free shipping. To do this, please call 512-436-0457.
There are a lot of good reviews for the Alen customer services, that’s why I highly recommend to look for the brand if you need better air quality for your home.
Alen BreatheSmart FLEX Air Purifier for Bedrooms & Living Rooms.
HEPA Filter for Allergies & Dust. With Big Power, but Small Footprint. Stainless Steel Edition.
Our verdict
I hope that you read the Customer service part of the Alen BreatheSmart FLEX first, because that’s the most noticeable advantage of this air purifier. Other than that, we have a better fan (as usual) and better quality air filter from this device, thanks to the new upgrade.
Alen BreatheSmart FLEX Air Purifier: Trusted Review in 2026
Alen BreatheSmart FLEX Reviews and Specs (Air Purifier Trusted Reviews in 2026). ✓ Cleaning Power: HEPA ✓ Lifetime Warranty ✓ Value: 3.4/5 ✓Certified Review.
Product Brand: Alen
Product Currency: USD
Product Price: 349
Product In-Stock: https://schema.org/InStock
3.4
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Summary
This Alen BreatheSmart FLEX is beautiful, but is that the reason why you buy an air purifier?




