Alen air purifiers are highly regarded for their impressive design, build quality and performance. This Texas-based manufacturer has developed an excellent reputation by being at the forefront of the industry for over 15 years.
Alen is also known for its above-average prices, and the BreatheSmart 75i, with a price tag of $799, is undoubtedly high-end. You might be here because you wonder whether it’s worth spending the extra money on this device, and that is why I bought an Alen 75i to test it in the same space I’ve tested over 100 air purifiers since 2020.
The overall score of the Alen 75i incorporates first-hand data results from our battery of tests, as well as our ratings for customer service, brand transparency and design & UX. Check out the full scorecard below to see the split of categories.
By the way, I originally reviewed the older BreatheSmart 75i back in 2022 and I have now updated my original review with the data of the newer 75i V2.
The pros and cons of the Alen BreatheSmart 75i
A summary of our top-level findings after testing this air purifier following our methodology.
“For those looking for an air purifier for dealing with odors and VOCs in rooms up to 500 square feet, the Alen BreatheSmart 75i could be worth the $799 investment.
However, if you don’t have serious issues with gases and smells, then it might be overkill.”
HouseFresh Founder
& Lead Tester
CONS
PROS
| Clean air delivery rate (CADR): | – Top speed PM1 CADR: 333 cfm – Sub-45 dBA PM1 CADR: 164 cfm – AHAM PM2.5 CADR: 351 cfm (dust) |
| Filter technology: | True HEPA H13 filters with activated carbon pellets + Ionizer technology |
| Recommended room size: | 448 sq. ft. (5 air changes per hour) |
| Dimensions: | 27H x 18.5W x 11.5D inches (68.58H x 46.99W x 29.21D cm) |
| Weight: | 27 lbs (12.2 kg) |
| Noise level in decibels from 3 ft. away: | Speed 1: 36.5 dBA Speed 2: 44.7 dBA Speed 3: 51.9 dBA Speed 4: 54.6 dBA Speed 5: 57.5 dBA |
| Electricity consumption in watts: | Standby: 0.75 watts Speed 1: 5.19 watts Speed 2: 13.27 watts Speed 3: 25.85 watts Speed 4: 33.99 watts Speed 5: 47.4 watts |
| Filter lifespan: | 12 – 15 months |
| Manufacturer’s warranty: | Lifetime (with product registration & active filter subscription) |
| Country of origin: | United States |
| Country of manufacture: | China |
Filtration technology
The Dyson BP06 comes with a HEPA filter as standard, and you can choose between various options with different carbon quantities to suit your needs.
The first layer of filtration comes in the form of a removable pre-filter that sits in front of the HEPA filter.
As standard, the 75i comes with their Pure filter, which is a thick H13 HEPA filter without any carbon.
You can choose between Alen’s Fresh filter and their Odor filter if you want a combination of HEPA and pelleted activated carbon.
The Fresh filter has a thinner HEPA H13 combined with a carbon section that comes packed with 3.6 lbs of pelleted activated carbon.
The Odor filter also combines a HEPA 13 filter with less carbon but it has a catalyst to neutralize unwanted smells.
From all the air purifiers we have tested, the Alen 75i with its Fresh Filter has the third largest amount of carbon after the IQAir Healthpro Plus and Austin Air Healthmate:
We are developing our methodology for testing VOC removal and our preliminary data shows the 75i with the Fresh filter a great option for those wanting to remove orods and VOCs from the air.
Design, controls and features
The 75i is a large air purifier with a laser particle sensor, smart functions and app connectivity.
The 75i is Alen’s largest air purifier and is much bigger than the 45i and the 35i.
Build quality is solid. The plastics feel dense with no creaking, and the panel seams are tight, giving it a premium feel.
If you don’t want the plain white cover, there are five other options ranging from graphite to oak BUT you will need to pay a little extra.
Considering its size, I appreciate the large handle at the back and the wheels underneath for when you need to move it from room to room.
It comes with a laser sensor is that is much quicker to react to air pollution than the typical optical sensors we see in most air purifiers and doesn’t need to be cleaned regularly.
You also get an air quality indicator at the top. The LED ring changes color reacting to the pollution levels, going from blue (excellent) to green (good) to yellow (fair) to red (poor) and finally purple (very poor).
In terms of the control panel itself, I appreciate the clearly labelled buttons and the fact that all options are available without the need to use the smartphone app – which is a concerning trend I’ve noticed with new air purifiers.
The biggest improvement I’ve found from our older 75i is that the 75i V2 comes with app connectivity through the Alen Air app, where you can create schedules, check sensor data and you get an option to turn your phone screen into a mini remote to control your 75i
The app installed quickly (and even worked on my 5ghz network!) and I had no issues with it since I started using it. I love that it visualizes sensor readings in easy to understand charts for PM2.5, tVOC, CO2, temperature and humidity – and the data is easy to export, too.
One thing this app is lacking is the option to adjust the sensitivity in the auto mode to make sure it hits top speed when it needs to. This is something that other manufacturers like Levoit, Xiaomi and IQair have introduced that I really like. However, to be fair to Alen, the auto mode in the 75i reaches full speed when there is a high level of pollutants in the air by default.
Air cleaning performance
We tested the 75i V2 in our 728 cubic ft. test room, tracking how fast it removed all PM1 particles from the air after we filled the space with incense stick.
First, we tested 75i V2 running at each of its fan speeds in the same 728 cubic ft. test room where we have tested over 100 air purifiers.
When running at top speed, our PurpleAir Zen sensor shows the 75i needed 18 minutes to reach PM1 zero – and we estimate a PM1 CADR of 333 cfm which would be good enough to provide five air changes per hour in rooms up to 448 sq. ft.
For raw performance to $ spend, the Alen 75i provides more value for raw CADR than the IQAir Atem X, the Dyson BP06 and the Rabbit Air A3 but sits behind the Levoit EverestAir and the Smart Air Blast Mini.
But results at top speed won’t tell us the full story…
Sound levels
The sound levels of the Alen 75i range from 36.5 dBA to 57.5 dBA — quieter than popular models like the Winix 5510, the IQAir Atem X, and the Rabbit Air A3.
As part of our testing, I used a sound level meter to measure how much noise the Alen 75i generates at each of it fan speeds.
Reaching 57.5 dBA at top speed, the 75i is quieter than the Levoit EverestAir, the IQAir Atem X and the Rabbit Air A3 but it is louder than the Dyson BP06, the Airmega ProX and the Blast Mini from Smart Air.
At speed 2, it cleared our test room from all PM1 pollutants in 36 minutes, so we estimate a PM1 CADR at sub-45 dBA of 164 cfm based on the natural ventilation of the room. At this sub-45 dBA speed, it can provide five air changes per hour in rooms up to 246 square feet.
So when it comes to quiet air cleaning performance, the 75i outperforms the Dyson Big+Quiet BP06 but its performance is worse than every other large air purifier on the table:
Long-term running costs
Running a 75i will cost you $170.23 per year, combining energy consumption costs and filter replacement prices.
We measured how much energy the 75i uses when running at speed 1 (5.19 watts), speed 2 (13.27 watts), speed 3 (25.85 watts), speed 4 (33.99 watts), speed 5 (47.4 watts) and on standby (0.75 watts).
If you were to leave your 75i running at top speed 24/7 for one year, it would pull 411.7 kWh and add $52.21 to your annual energy bill, assuming an average U.S. electricity prices as of August 2025.
But energy costs are not the only thing you need to budget for – the filters need to be replaced, and this can become a significant expense, depending on the lifespan of the filter and how expensive replacements are.
Alen says you need to replace the filters for the 75i every 12-15 months, and as always, we will take the lowest estimate.
So you will need to buy one Pure Filter for $99 each year as a minimum, which leads us to a yearly running cost of $151.21 combining this with the electricity cost:
Thanks to the low energy usage and fair filter costs, the Alen 75i has the lowest running costs of all the large air purifiers we have benchmarked it against for this review.
And you can drop those yearly costs even further if you decide to go with a generic filter replacement from PUREBURG, which cost $75. That said, you will lose Alen’s lifetime warranty if you go the generic filter route, so you would need to decide if those $25 savings are worth losing that.
Bottom line: Should you get an Alen BreatheSmart 75i?
A powerful air purifier that can be customized with filters packed with carbon for serious odors and VOCs.
I have used Alen air purifiers for many years and something I can vouch for is how they continue to support older models. I still have my old A350 here in the basement and it not only works but I can still buy filters for it from Alen directly!
This means that when you choose to spend more on an air purifier from Alen, you know that you are investing in a device you will be able to run for as long as Alen exists.
And the fact that you can choose to go with the Fresh filter and get 3.6 lbs of activated carbon is a pro for me as it is a lot of carbon compared to what you get with most other air purifiers on the market today.
So for those looking for an air purifier for dealing with odors and VOCs in rooms up to 500 square feet, then the 75 could be worth the $799 investment.
The app is simple but works really well and the data you get from the laser onboard sensor offers accurate readings similar to those from a high-end air quality monitor.
So if that initial price doesn’t put you off, the Alen 75i is a solid contender for those looking for a premium air purifier.
But if odors are not a concern and you’re looking for a more powerful particle removal performance at a cheaper price, then look into the Levoit EverestAir (which sells for $499.99) or the Blast Mini which you can buy from Smart Air for around $700.
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