Xiaomi Mi 3H Auto air purifier review: Best for large space

Xiaomi Mi 3H

After testing many air purifiers, I found the Xiaomi Mi 3H to be the best air purifier for larger rooms, offering an exceptional balance of functionality, design, and value for money.

As a technology enthusiast with a passion for clean air solutions, I have spent several years reviewing and comparing different air purifiers on the market. Leveraging my deep understanding of the subject and hands-on experience with the devices, I strive to offer comprehensive, unbiased reviews to help you make informed decisions. You can trust my recommendations because they’re based on rigorous testing and careful comparison of a wide range of features, from filtration efficiency and air change rates to noise levels and energy consumption.

The Xiaomi Mi 3H outperformed many other models in my tests. Its high Clean Air Delivery Rate (CADR) and exceptional airflow due to its quality fan make it ideal for rooms up to 484 sq. ft. But what sets it apart is not just its performance, but also the impressive array of features it offers for its price range. This model is equipped with smart app connectivity that allows for convenient control and monitoring, making it one of the most user-friendly models on the market.

While the Mi 3H is an excellent choice for larger rooms, I understand that different people have different needs. For those in smaller spaces, or those who require an air purifier with specific features such as a quieter operation or a specialized filtration system, other models may be more suitable. Rest assured, though, each recommendation I make takes into account a variety of needs and circumstances.

If you’re interested in learning more about the Mi 3H, my full tests and comparisons, or how it stacks up against other models in various ‘best for’ scenarios, continue reading. The nuanced world of air purifiers has a lot to offer, and finding the right one can make a significant difference in your indoor air quality.

Xiaomi Mi 3H

Best Air Purifier for Overall performance

The Xiaomi Mi 3H is one of the smartest air purifiers I’ve ever had the opportunity to use and test. The smart and excellent performance

Xiaomi 3H air purifier Summary

  • After having the chance to use it, I can confidently say that the Xiaomi 3H is an exceptionally Transformative air purifier.
  • Build for large rooms up to 484 sq. ft. (45 m2).
  • You can use it with voice control with Google Assistant and Amazon Alexa.
  • It includes 12 month’s warranty


Manufacturer Xiaomi
Model Mi
Dimensions 9.5 x 9.5 x 20.5 inches (24 x 24 x 52 cm)
FiltersPre-filter, True HEPA and Active Carbon Filter
Filter Longevity6-12 months (150 days)
Coverage484 sq. ft. (45 m2)
Power Consumption38W

Design and Size

Xiaomi Mi 3H Auto



  • Color: White
  • Product Dimensions: 9″D x 9″W x 20″H
  • Item Weight:14.08 Pounds
  • Control Method: App, Touch
  • Wattage: 38

The Xiaomi 3H air purifier is a sleek, minimal device that boasts high-quality plastic components and top-notch manufacture. With a white body accented by gray grilles on the top and a black display panel, this stylish gadget delivers purer air without sacrificing aesthetics.

With a sleek and contemporary design, this device will fit in with any surroundings. It’s easy to use while also providing a pleasant experience.

One of the main cons to this design is that there isn’t a handle. This can make it difficult to move from room to room, even if you don’t need to transport it very often due to its larger size and intended space. In my opinion, having an optional handle wouldn’t hurt the device at all!

In addition to the design flaws, I must add that the power cord of this air purifier is exceptionally short, prohibiting it from being placed in ideal locations.

OLED Display for Device Control

Xiaomi Mi 3H

The OLED display is a notch above the Xiaomi 2 series air purifier. Its screen clarity gives you all the information you need at your fingertips, while its practicality and location on the front of the device make it easily accessible to view.

The control button is your only means of managing the device and all its indicators. You can use it to switch between different modes, connect to Wi-Fi, or turn the on/off the device. The display reveals a collection of indicators such as PM2.5, temperature, humidity, Wi-Fi connection strength, and mode status – providing you with in-depth insight into how your device is operating!

Size & dimensions

At 10.6lbs (4.8kgs) and measuring 9.5×9.5×20.5 inches (24cm x 24cm x 52 cm), the air purifier is lightweight yet durable enough to provide premium filtration services in any room of your home or office space!


so talking about the Xiaomi 3H features it has an advanced display controlling option, Although certain models require you to connect the air purifier to a smart app, I always recommend it anyways. To demonstrate what features are significant in the Mi 3H air purifier, I have provided an overview below.

Air Quality Sensor and Indicator

Out of all the other sensors of Mi 3H, The Air Quality Sensor is very important. It is placed at the back of the device. It uses a laser to detect how much dust is in the air and also detect smoke and some VOCs.

Our digital display showcases real-time air quality and its PM2.5 particles, while the accompanying smart app lets you monitor it anywhere. Moreover, a luminous indicator situated by the “turn on” button changes colors depending on how polluted or to clean your air is.

When the amount of PM2.5 is under 75, you have excellent air quality and the power button indicator will turn green signaling its pristine condition.

When it lands between 76-150, a moderate level of pollution exists and the indicator turns orange to alert users.

Above 150? Red signals danger for your health with an unhealthy airborne environment!

Smart APP (Mi Home)

This air purifier also has a smart application for controlling the air purifier. This application is convenient, full of unique features, and user-friendly. Below I will elaborate more on the superb options that truly captivated my attention.

Temperature and Humidity Meter

By positioning the temperature and humidity sensors just above the particle sensor on the back of the device, you are guaranteed to receive a full account of your room’s air quality. The temperature and humidity in real-time on the smart Mi home app.

Auto Mode

The Mi 3H’s auto mode is a practical choice for anyone, because of its high-grade sensitivity and exact smart sensor. This feature collaborates with a specific sharp sensor to detect the air quality in your room and automatically adjust the fan speed accordingly. Thanks to this powerful technology, you can be sure that optimal ventilation is always achieved based on the current conditions!

Manual Mode

With the manual mode, you can control your speed with a convenient slider located within the application.

This mode offers you unprecedented freedom to choose your own motor speed, in addition to the already offered speeds. With this feature, you can customize your experience and discover a whole new level of control over movement.

Manual mode grants you the ability to adjust your room coverage by implementing a fan speed alteration. This enables the device itself to customize its current setting in order to best fit your environment.

Parental Controls

Prevent your device from unintended changes in settings or accidental button presses. Furthermore, if you have little ones around it’s the perfect way to protect them against any bumps on buttons and other misadventures!

By activating the parental control feature, you can easily disable any action from being taken on your device by simply clicking the control button which is located on its front panel. It’s worth noting that this mode of operation must be enabled through a compatible app.

Sleep Mode

When sleep mode is on, the device produces very low noise so you can sleep comfortably. However, when sleep mode is on, the display will not turn off.

If you want to turn off the display, you can do so by using the smart app or pressing the display off button on the back of the device.

Display Off Button

If you’re looking for a way to dim or turn off the display completely of your Mi 3H, look no further. This device features two easy methods

– one is pressing the button on its back just above the Smart Sensor, and the second is with a smart application.

Either way is sure to give you what you need when it comes to conserving energy while keeping your device secure!

Scheduled Power On/Off

With this application, you have the freedom to customize your air purifier according to what works best for you. You can set specific times when it turns on or off and even decide how long it runs. This flexibility allows each user to easily program their device in a way that suits them perfectly.

Google Assistant and Amazon Alexa Integration

The Xiaomi air purifier can be controlled with the Xiaomi Mi Home App. You can add the Mi-Home app to Google Home. Then you can launch Mi 3H by voice. by choosing between google assistant or Alexa.

Room Coverage

Xiaomi Mi 3H is designed for rooms up to 484 sq. M. ft. (45 m2). This device is good for a large room, such as a living room or a large bedroom.

The Mi 3H model boasts a remarkable CADR of 380 m³/h, thanks to the rear-tilting centrifugal fan that the company specially designed for efficiency and maximum air movement.

check the battle between mi 3H auto vs blueair 411 auto


Image source: airpurifierfirst.com

Xiaomi mi 3H has 3 in 1 True HEPA filter, The 3H device features an Integrated 360° cylindrical HEPA filter, ensuring complete air purification within your space.

With the Xiaomi Mi 3H, you get a big upgrade from your older model with its true HEPA Class 13 filter. Plus, this incredible filter is compatible with other versions of the Xiaomi air purifier!

The first stage of filtration

The pre-filters primary purpose is to eliminate hair, dust, and cotton fibers from the incoming air stream as well as other larger particles.

The second stage of filtration

The True HEPA filter is an incredible way to get rid of cigarette smoke, PM2.5 particles, pollen, dust, pet dander, and other allergens as small as 0.3 microns from the air for a better breathing environment!

The third and final stage of filtration

The active carbon filter is an incredibly powerful tool that effectively absorbs formaldehyde, volatile organic compounds (VOCs), and toxic fumes. Unlike other filters composed of mere carbon pellets, this specific type of filter consists of a fibrous material coated with activated charcoal for maximum efficiency.


The Xiaomi 3H is an impressive piece of tech, perfect for larger-sized spaces. In all the trials we conducted, it truly shone – take a look below at two of its most outstanding results in our review!

320 sq. ft. (30 m2) Room Test

I tested the device in a room of 320 sq. ft., which is somewhat smaller than what’s suggested, for an entire hour and it was certainly remarkable! Even if you have a slightly more cramped space, 3H could be immensely useful for many users.

The device operated at optimum velocity throughout the assessment. Subsequently, Xiaomi 3H was able to reduce air quality in the room by an astonishing 95%, decreasing AQI from 126 to a mere 6.

Astonishingly, the Mi 3H brought down AQI to 11 in just 30 short minutes. This result surpassed my expectations and proves that it doesn’t take much time for this device to reduce PM2.5 particle levels in the air. Truly remarkable!

560 sq. ft. (52 m2) Room Test

In the second experiment conducted in a 560-square-foot room, the device operated at its maximum velocity for 60 minutes and ultimately enhanced air quality by 90%.

Not only does this room meet the recommended dimensions of the Mi 3H, but it is truly impressive that these results have been achieved – serving as a testament to how competitive and effective Xiaomi’s Mi 3H air purifier really is.

Power consumption

Despite its greater size, this device’s 38W power is slightly weaker than comparable air purifiers on the market. Nevertheless, I was expecting a bit more strength from an even larger machine.

Although the Mi 3H can run 24 hours a day for an entire month, it is virtually impossible to keep this device running at its peak performance all that time. Even if you achieve that feat, you need not worry about electricity costs as they will only amount up to around $3.4 in such conditions.

Pros & Cons

  • Best for Large Rooms
  • Has Smart App
  • integration with Assistant and Amazon Alexa
  • CARB Certified
  • Covers up to 484 sq. ft. (45 m2)
  • 3 Stage Filtration
  • Low Energy Consumption (38W) with Excellent Performance
  • Touch OLED controlling Display
  • Sleek Design
  • Great Value for Money
  • No handle
  • The device’s display has a slightly awkward orientation, making it difficult to control


The Xiaomi Mi 3H is one of the smartest air purifiers I’ve ever had the opportunity to use and test. The smart app is brilliant, fully functional, and full of advanced options. The multitude of options, the variety of speeds, and the minimal design are primarily responsible for this.

In addition, the Mi 3H air purifier is excellent in terms of performance; it has produced fantastic results in all tests. Noise contamination will not be a problem for this model, mainly because it offers the possibility of choosing many different speeds. A replacement filter is a bit more expensive. Still, given the less frequent need for a replacement, even that isn’t too expensive. Buy Now!


Does the Xiaomi 3H generate ozone?

The Xiaomi 3H does not produce ozone as it doesn’t utilize ionization, UV light, or similar filtration methods that could lead to ozone production. Moreover, the device holds a CARB certification, affirming its safety and ozone-free operation.

When should I replace the filters on the Mi 3H?

The filters on the Mi 3H are designed to last approximately 150 days. However, from personal experience, I suggest changing the filters every 6-12 months depending on the purifier’s usage and your maintenance habits.

Is the Xiaomi 3H an effective air purifier?

Indeed, the Xiaomi 3H is a highly efficient air purifier, delivering exceptional performance coupled with a range of sophisticated features.

Do I need to use the app to operate the Mi 3H?

While it’s not mandatory to use the accompanying app, it can significantly enhance your experience with the device. The app provides access to a range of advanced settings that aren’t available through the display interface.

Does the Xiaomi Mi 3H have a sleep mode?

Yes, the Xiaomi Mi 3H has a sleep mode feature. When activated, it operates more quietly, making it ideal for use at night or in quiet environments.

Can the Xiaomi Mi 3H handle allergens?

Absolutely, the Xiaomi Mi 3H is equipped with a HEPA filter, which is capable of capturing small particles, including common allergens like dust, pollen, and pet dander.

How loud is the Xiaomi Mi 3H when it’s operating?

The noise level of the Xiaomi Mi 3H depends on the operating mode. In sleep mode, it’s virtually silent. On the highest setting, it produces some noise but is still quieter compared to many other air purifiers on the market.

Can I control the Xiaomi Mi 3H remotely?

Yes, the Xiaomi Mi 3H is compatible with the Mi Home App, which allows you to control the air purifier remotely using your smartphone.

Is the Xiaomi Mi 3H energy efficient?

Yes, the Xiaomi Mi 3H is designed to be energy-efficient. It has a rated power of 38W, which is relatively low compared to other air purifiers in its category. Its energy efficiency will help you save on electricity costs in the long run.

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The author is an Air purifier expert with overall knowledge of air and ionizers.