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Xiaomi Mi 3H: an air purifier with built-in sensors

The Xiaomi Mi 3H is an air purifier capable of covering a room of 45 square metres. Minimal in design but premium in feel, the Xiaomi Mi 3H is a connected device with its own mobile app (available on Android and iOS) and voice control (Google Assistant and Alexa).

Our opinion on the Xiaomi Mi 3H

Air filtration




The Xiaomi Mi 3H is a powerful air purifier with many features not found in the competition. This affordable, connected device offers excellent value for money whether it's to remove smoke, purify the air or protect your baby and their room.

Designed to purify areas of up to 45 m², you will have no difficulty installing it in your home. Its multitude of options, numerous speeds and minimal design make it a simple, yet complete device. In addition, the Xiaomi Mi 3H air purifier proves to be excellent in terms of air purification as evidenced by its CADR certification.

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How does the Xiaomi Mi 3H work?

The Xiaomi Mi 3H is a powerful performance device with an aerodynamic ventilation system similar to aircraft turbines. Featuring a True HEPA filter, it is able to monitor and share the quality of the air in the room via its app or directly from its screen. Both Alexa and Google Assistant compatible, it is a smart connected air purifier with multiple options.

Very quiet, the Xiaomi Mi 3H emits a noise level of only 40 dB in standby mode and 65 dB at maximum speed. Simply put, this product will not interfere with your daily activities or your sleep if you decide to use it in your bedroom to purify the air.

Efficient air filtration

Avis Express | Xiaomi Mi Air Purifier 3H

The Xiaomi Mi 3H uses a 2-in-1, cylindrical, 360° integrated HEPA filter that effectively removes cigarette smoke, PM 2.5 particles, pollen, dust, pet dander and other allergens as small as 0.3 microns from the air. In addition to the default HEPA filter, different filters can be purchased: an anti-formaldehyde filter and an antibacterial filter to purify the air.

There is also an activated carbon filter that absorbs formaldehyde, volatile organic compounds (VOCs) and other harmful gases.

Finally, the filters have a lifespan of approximately 6 months to 12 months and you can check their remaining lifespan via the mobile app or via the touch screen display of the purifier. Just like other purifiers, after this time the filters of the Xiaomi model will be significantly less effective in terms of air filtration.

Air quality displayed in real time

Smart, the Xiaomi Mi 3H has several sensors to measure air quality:

  • A sensor for air quality This is located on the back of the unit. It is a laser particle sensor that detects the amount of dust in the air in real time. It can also detect smoke and certain volatile organic compounds (VOCs).
  • Sensors for temperature and relative humidity These are located just above the particle sensor on the back of the product. This is a perfect addition, as you will have a complete picture of the air quality in your room.

Xiaomi Mi Smart Air Purifier 3H Air Purifier with OLED touch screen, high precision PM laser sensor, APP Smart Control, 360° HEPA filter, 380 m³/h PM-CADR

The air quality is displayed in real time on the screen and on the mobile application. In addition, around the "on" button there is an indicator that changes colour depending on the ambient pollution:

  • If the amount of PM 2.5 is between 0-75, the air quality is good and the indicator around the ignition button lights up green.
  • If the amount of PM 2.5 is between 76-150, the air quality is moderate and the indicator will light up orange.
  • If the amount of PM 2.5 particles exceeds 150, the indicator will light up red: it is time to clean the air.

Interesting point You can set the Xiaomi to start cleaning the air as soon as the household air pollution exceeds a certain level.

Many useful options

The Xiaomi Mi 3H air purifier has a wide range of options and is very practical for everyday use:

  • Voice control The air purifier can be controlled using the Xiaomi Mi Home app which can be connected to Google Home or Alexa. So, all you have to do is add the Mi-Home app to Google Home and you can control the Mi 3H by voice.
  • The auto mode Air quality sensor: coupled with the air quality sensor, this option is very useful to modify the speed of the air treatment according to the surrounding pollution.
  • Parental control This is useful if you want to lock the touch display and prevent any action. You can also activate it from the mobile application.
  • Standby mode This is ideal if you want to use the air purifier in a bedroom. In sleep mode, the machine produces ultra-low noise for a comfortable sleeping environment. However, when in standby mode, the screen does not turn off. If you want to turn it off, you can use the mobile app or press the screen off button on the back of the device.
  • Switching off the OLED touch screen OLED display: This option allows you to reduce the brightness or turn off the OLED display completely. You can do this in two ways: either by pressing the button on the back of the device, just above the smart sensor, or via the mobile app.
  • Programmed power on/off Time: You can set the time or period when you want the air purifier to turn on or off.


Xiaomi 23853 / FJY4031GL Mi Air Purifier 3H White, SingleThe Xiaomi Mi 3H air purifier is a minimalist design air purifier made with white materials, except for the grey grills on top and its black screen. The plastics are solid and all the elements are well put together.

From an overall point of view, this air purifier is beautiful and modern. It can be easily integrated into any space. Its only flaw is the power cord: it is a bit short, which limits the possibility of placing the air purifier in the desired location without the use of an extension cord.

There is an easy to read OLED touch screen on the front of the machine. A single button on the display is used for full control of the machine and its indicators. The control button can be used to change modes, connect to Wi-Fi, or turn on and off. The indicators displayed on the screen are PM 2.5, temperature, humidity and wifi mode.

Regarding the suction flow: the Xiaomi Mi 3H sucks in air on its underside and on the sides. The air is filtered in a circular filter and then exits through a grille on the top of the device. Xiaomi uses the new air duct system with a flow rate of 6,330 litres of purified air per minute.

The CADR of the Xiaomi Mi 3H is 380 m³/h. The company has developed a backward tilting centrifugal fan that can move air more efficiently than its competitors, as well as a brushless DC motor. The pressurised air duct and its grille form an airflow path that significantly increases the performance of the purifier.