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Lately, it seems like everyone’s paying more attention to indoor air, and for good reason. Between pets, allergy season, and everyday dust, it’s no surprise more people are picking up air purifiers. The hard part is figuring out which one is best for your style.
Two popular choices in the premium category are the Windmill Air Purifier and the Mila Air 3. The former is a newcomer that focuses on simplicity and performance with a quiet, innovative, design-forward build. The other is geared towards filter customization and data. So, which one is the better investment?
We put them side by side to compare real specs, day-to-day performance, smart features, and long-term ownership, with a clear verdict for different types of users.
Quick Verdict
We love Windmill for its strong filtration performance with verified CADR ratings.
| Windmill Air Purifier | Mila Air 3 | |
|---|---|---|
| Filter Type | HEPA-13, 3-in-1 system | Modular filters (user-selected) |
| CADR (smoke/pollen) | 286 CFM / 343 CFM | ~271 CFM (combined, no pollutant breakdown) |
| Noise Level | As low as 16 dB | As low as 23 dB |
| Smart Features | App; Works with Alexa & Google | App; Works with Alexa, Google, & Apple |
| Maintenance | One filter, 6-month lifespan; subscription available | Multiple filters types; 6-month lifespan |
| Warranty | Lifetime (direct); 3-year (retail) | 2-year |
| Price (as listed in May 2025) | Starts at $399 | Starts at $349 |
Filtration Performance
- The Windmill Air Purifier uses a HEPA-13 filter that captures 99.97% of particles down to 0.3 microns. That’s the same grade used in medical environments, and not a fluffed marketing claim: Windmill shares detailed CADR scores, including 286 CFM for smoke and 343 for pollen.
- Mila Air 3 uses a modular filter system, with options tuned for different concerns, like mold or pet allergens. That’s helpful if you know exactly what you’re trying to filter out, but it also means performance depends on which filter you pick. The brand lists a total airflow CADR of 460 m³/h (about 271 CFM), but doesn’t share pollutant-specific scores.
Smart Features and App Integration
- Windmill‘s app shows your air quality and gives you a few basic controls. You can turn on Auto Mode or adjust the fan yourself, and it connects with Alexa and Google if they’re something you use. It quietly takes care of things in the background, which is kind of the point.
- Mila gives you more to work with, as the app shows detailed sensor data, including carbon dioxide and humidity levels. It also works with Apple HomeKit, along with Alexa and Google. But it does ask more of you. There’s more setup, more options, and more to keep track of.
Noise Levels: Bedroom-Ready or Not?
- On low, Windmill runs at 18 dB, and if you switch to sleep mode, it drops even lower, at just 16 dB. The fan pushes air upward, so there’s no direct draft, and you can set the lights to fade out in 3 seconds. If you prefer a bit of background sound at night, there’s also a sleep setting that creates gentle white noise at 47 dB, which research suggests can help people fall asleep faster.
- Mila Air 3 also has quiet modes, and it does a good job of staying unobtrusive in smaller spaces. However, the starting noise level is around 23 dB.
Filter Changes and Total Cost of Ownership
- Windmill uses a 3-in-1 filter (HEPA, activated carbon, and pre-filter) that needs replacing every 6 months. You can set up a subscription through the brand’s site to simplify maintenance. Replacement medical-grade HEPA filters cost $60, which brings the estimated two-year cost to about $529, assuming regular filter changes and the starting price of $349.
- Mila Air 3 filters also last around 6 months and the starting price is the same, but the total cost depends on the filter you choose. Filters range from $59 to $99, which puts the two-year cost in the $526–$646 range.
Note: Mila Air 3 comes with a 24-month warranty, and Windmill with a lifetime warranty when purchased directly from their website.
Energy Efficiency and Environmental Considerations
- Windmill is Energy Star certified, which means it’s been tested for low power use. The fan adjusts automatically depending on the air in the room, so it’s not running harder than it needs to. That helps with energy bills and keeps things more efficient over time.
- Mila Air 3 has Auto and Sleep modes that can help save power, but there’s no Energy Star certification listed on the site.
What Real Users Are Saying
- Windmill users frequently mention its quiet performance, sleek design, and how easy it is to set up and use. It’s often described as ideal for bedrooms or small apartments.
- Mila Air 3 has a loyal following among users who want in-depth data and customization. They highlight the strength of its app and environmental sensors, though some say the feature set can feel overwhelming.
Which Air Purifier Is Right for You?
| Windmill Air Purifier | Mila Air 3 | |
|---|---|---|
| Filtration System | HEPA-13 (captures 99.97% >0.3 um); 3-in-1 filter includes carbon + prefilter | Modular HEPA system; filter performance depends on selection |
| CADR Ratings | 343 CFM (pollen), 286 CFM (smoke), 284 CFRM (dust), PM2.5 (260 CFM) | ~271 CFM; no pollutant-specific ratings |
| Noise Levels | 18dB on low, 16dB in sleep mode; 47dB white noise option available | Starts around 23 dB; varies by filter and settings |
| Smart Features | Auto Mode, app control, Alexa and Google Assistant integration | Sensor-rich app with CO2, humidity, VOCs; supports Alexa, Google, Apple |
| Maintenance & Filters | 6-month lifespan; subscription option simplifies upkeep | 6-month lifespan; multiple filters available may require more planning |
| Warranty | Lifetime warranty (directly); 3-year limited warranty from retailers | 2-year warranty |
| Energy Use | Certifications: ETL, Energy Star, AHAM Verified | No certification listed |
| 2-year Ownership Cost | $529 (purifier + 6-month medical-grade HEPA filter refills) | $526-$646 (purifier + 6-month refills, depending on filter type) |
Both purifiers do their job well, but they seem made for different types of users. Mila Air 3 is better suited to those who enjoy more customization and tracking more data, while Windmill is the better fit if you want a smart purifier that blends quietly into your space and works without much fiddling. (Not to mention its lifetime warranty.)
Choose Windmill today for its strong filtration performance with verified CADR ratings, and subscribe for HEPA 3-in-1 filters to ensure long-term performance!
FAQs
Q: How frequently do I need to replace the filters?
Both Windmill and Mila Air 3 recommend changing the HEPA filters every 6 months.
Q: Do these purifiers remove pet hair and dander?
Yes. Windmill’s HEPA-13 filter captures pet dander effectively. Mila Air 3 offers specialized filter options that target pet allergens.
Q: Can I use either one in the bedroom?
Windmill is especially well-suited for bedrooms thanks to its ultra-quiet operation and dimmable display. Mila Air 3 also supports quiet operation.
Q: What’s the room size recommendation?
Windmill covers rooms up to 442 sq ft. Mila Air 3 supports up to 400 sq ft at five air changes per hour.
