Alen BreatheSmart 75i Review: Big-Room Purifier, Big-Room Price
Alen BreatheSmart 75i review: Alen's 347 cfm CADR, 1.36 to 55 W, filters from $99 lasting 12 to 15 months, the Forever Guarantee's conditions, and certified rivals.
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Specs at a glance
- CADR (Alen)
- 347 cfm (375 cfm is Alen's turbo airflow, not CADR)
- AHAM Verifide listing
- No Alen models in AHAM's directory (checked November 3, 2026)
- Alen coverage
- 1,300 to 1,400 sq ft every 30 minutes; 2,800 sq ft an hour
- Noise
- About 25 to 49 dBA (Alen, 75i V2)
- Power
- 1.36 to 55 W (Alen, 75i V2)
- Filters
- $99 to $139; about 12 to 15 months at 24/7 use (Alen)
- Ionizer
- Yes; California lists the 75i V2 as an electronic air cleaner
- Warranty
- Forever Guarantee with registration and an active filter subscription (Alen)
The Alen BreatheSmart 75i is a quiet, efficient purifier for open plan rooms of up to about 540 square feet at the air change rate we recommend for allergies. Alen states a CADR of 347 cfm and a power draw of 1.36 to 55 W for the current V2 model, and like the smaller 45i it takes a choice of filters for particles, odors or smoke.
It is also expensive, its CADR is Alen's own (Alen is not in the AHAM Verifide directory), and the lifetime warranty depends on an Alen filter subscription. For a certified number at this size, the Blueair Blue Pure 211i Max (435 cfm) and the Levoit Core 600S-P (391 to 394 cfm) move more air for less money.
Alen 75i CADR and coverage
Alen's support page lists a CADR of 347, and Alen's pages describe coverage of 1,300 to 1,400 sq ft every 30 minutes and 2,800 sq ft an hour. A 375 cfm figure that appears in some listings is the purifier's top airflow, not a CADR. Alen does not say whether 347 is the smoke, dust or pollen figure; with no AHAM listing, we treat it as Alen's best-case number.
| Room | Floor area | Air changes an hour |
|---|---|---|
| Living room, 16 x 22 ft | 352 sq ft | 7.4 |
| Open plan, 20 x 25 ft | 500 sq ft | 5.2 |
| Open plan, 22 x 25 ft | 550 sq ft | 4.7 |
| Large open plan, 25 x 30 ft | 750 sq ft | 3.5 |
Our sizing calculator runs the same arithmetic for your room.
Filters
The 75i takes the same family of filter types as the 45i in a larger size: a particle filter and versions with carbon aimed at odors, smoke and VOCs. Alen prices them from $99 to $139 with 10% off on subscription, and says a filter lasts about 12 to 15 months at 24/7 operation. That is a long interval for a filter this size, which keeps the yearly cost reasonable despite the price per filter. Amazon sells the 75i in Essential, Advanced and Ultimate filter bundles, so check which one is in the box.
The Forever Guarantee
As with the 45i, Alen's lifetime guarantee is conditional: it requires registering the purifier and keeping an active Alen filter subscription. If you would buy Alen filters every year anyway, the subscription costs you little and buys a long warranty. If you want the freedom to stop, the warranty stops with it. Read Alen's current terms before you buy.
Noise, power and the ionizer
For the 75i V2, Alen gives about 25 dBA on the lowest speed and 49 dBA on the highest, and 1.36 to 55 W; older pages for the first 75i cite 1.8 to 45 W and 51 dB on top. The 75i includes an ionizer, and California's Air Resources Board lists the 75i V2 as an electronic air cleaner (certification G-24-038), meaning it was tested against the 0.050 ppm ozone emission limit. The filter, not the ionizer, does the work a CADR measures; our ionizer guide covers the debate.
Three-year running cost
| Item | Particle filter | Premium filter |
|---|---|---|
| Filters, 3 years | $297 | $417 |
| Electricity, 3 years (worst case) | up to $124 | up to $124 |
| Running cost, 3 years | about $421 | about $541 |
Alen 75i vs the alternatives
| Model | Smoke CADR | Room size | Notes |
|---|---|---|---|
| Alen BreatheSmart 75i | 347 cfm (Alen) | About 540 sq ft at 4.8 ACH (our arithmetic) | Filter choice, long filter life |
| Blueair Blue Pure 211i Max | 435 cfm | 674 sq ft | 46 W |
| Levoit Core 600S-P | 391 to 394 cfm | 606 to 611 sq ft | Laser sensor |
| Coway Airmega 400 | 328 cfm (Coway) | About 500 sq ft (our arithmetic) | 5-year warranty |
| Winix C909 | 337 cfm | 522 sq ft | AHAM listed |
Who should buy the Alen BreatheSmart 75i
- Buy it for an open plan room of 400 to 540 sq ft if you want filter choice, a long filter life and a quiet low setting, and you will buy Alen filters.
- Skip it if certified airflow per dollar matters; the Blueair 211i Max and Levoit Core 600S-P beat it on paper for less.
- Skip it for one bedroom; it is far more machine than you need.
See the best air purifiers for large rooms for more choices.
Frequently asked questions
What is the CADR of the Alen 75i?
Alen lists a CADR of 347 cfm; the 375 cfm figure seen in some listings is its top airflow. No Alen model was in AHAM's Verifide directory when we searched on November 3, 2026.
What size room does the Alen BreatheSmart 75i cover?
Alen says 1,300 to 1,400 sq ft every 30 minutes and 2,800 sq ft an hour. At about five air changes an hour, 347 cfm suits a room of roughly 540 sq ft with 8 ft ceilings.
How long do Alen 75i filters last?
Alen says about 12 to 15 months at 24/7 operation, and prices them from $99 to $139 with 10% off on subscription.
Does the Alen 75i have an ionizer?
Yes. California lists the 75i V2 as an electronic air cleaner, which means it was tested against the 0.050 ppm ozone limit.
Is the Alen 75i worth it?
If you value filter choice, a long filter life and Alen's conditional lifetime warranty, it can be. On certified airflow per dollar, AHAM-listed machines like the Blueair 211i Max offer more.
What is the difference between the Alen 75i and 75i V2?
The V2 is the current version; Alen lists 1.36 to 55 W and 25 to 49 dBA for it, against 1.8 to 45 W and up to 51 dB on older pages for the first model.
Sources
- BreatheSmart 75i - Alen air purifier, Alen
- BreatheSmart 75i V2 - Alen air purifier, Alen
- Getting the Best out of Your 75i, Alen
- AHAM Verifide Directory: Certified Room Air Cleaners, Association of Home Appliance Manufacturers
- List of CARB-Certified Air Cleaning Devices, California Air Resources Board
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