Once connected, the app allows you to monitor the air quality in your room and control the unit settings from anywhere in the world. When it comes to the control panel, the winner has to be the 45i thanks to its extra features, including an auto mode, ionizer and display brightness control. 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. 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).
The technology inside these two units may differ, but looking at them side-by-side, you’ll see they are practically exactly the same. When it comes to specifications, the 45i is the winner as it’s lighter, quieter and, due to its higher CADR, tackles pollutants in larger rooms than the Flex. In 2024, 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. 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.
Alen® air purifiers are engineered to outperform by combining power with efficacy and superb filtration technology. And our beautifully designed, whisper-quiet units do it without disrupting your conversations or your lifestyle. We don’t all know how loud decibels are and what some people consider loud, others may not. That’s why we take videos of all the air purifiers we review, recording each unit at their different fan speeds. Both units come with an AQI (Air Quality Indicator) color wheel in the center of the control panel. Using data provided by the air purifier sensors, this light displays the air quality in your room using five colors.
Choose from five high quality finishes in warm oak, weathered gray, brushed stainless, graphite and espresso. While I still wouldn’t call the app intuitive, it does provide pretty seamless alen breathesmart operation of the 75i once you get your bearings. And Alen says more improvements are coming, including the ability for users to create custom schedules for their purifiers.
It was a close call between the 45i and the Flex regarding design, filters and the numbers, with only one minute to separate them in our cleaning performance tests. The difference comes with the features included and the annual running costs. When you compare these two to some of the other air purifiers we’ve reviewed of similar size, you’ll see they are a little louder.
This is called CADR (Clean Air Delivery Rate) and is measured in CFM (Cubic Feet per Minute) to show us how effective an air purifier is at its job. When it comes to design and filters, both units are almost identical. 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. 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.
Space inside the filter gets smaller as more and more pollutants become trapped, making the filter less effective. Both units performed well in our performance testing room, with the 45i clearing all of our simulated contaminants from the air in 33 minutes and the Flex in 34 minutes. If you’ve read a review on HouseFresh before, you’ll know that we test every air quality product we recommend in our own home lab. The 45i may have been faster by one minute, but the Flex has a lower CADR, so it worked much harder to get its result.
The Classic is a very reliable model but it’s better to be safe than sorry. 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.
On Auto mode, a built-in dirt sensor or other inputs will allow the fan to run on a higher fan speed when the air is determined to be dirty and on a lower speed when clean. That means your Alen air purifier is guaranteed for life with a convenient filter subscription. If you ever have issues with your purifier, we’ll fix it or replace it for FREE. This review is part of TechHive’s in-depth coverage of the best air purifiers. HEPA filters trap airborne pollutants in their tightly woven maze of fibers (think of a fly in a spider’s web), removing them from the air.