The many Xiaomi Mi Air Purifiers compared

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Late last year, I finally took the decision to buy myself an air purifier. The model I went with was the Mi Air Purifier 3H, and it is sitting next to me, whirring away, as I type out these very words. As an asthmatic, staying indoors for a prolonged period of time has had a detrimental effect on my lungs. I decided that enough was enough and set out to clean up the air I am breathing in on a daily (and nightly) basis, with the help of an air purifier.

As I was researching the numerous models Xiaomi has on offer, I couldn’t find any decent comparisons of the different models. Even figuring out that the H in 3H and 2H meant that it came with a HEPA filter preinstalled took far too long to figure out. Having a simple table listing all the specifications would have greatly accelerated my decision-making. In the end, I had to create one myself, which wasn’t the easiest thing I have ever done. You will find out why that is, as you read this article.

As I already had my table in place, I’m happy to announce that there now is a full comparison to be found online, and you’re looking at it right now. Please note that Xiaomi has been blacklisted in the USA and thus their products are currently banned from being sold. It is impossible for me to add Amazon Affiliate links to the US store, but there are other ways of supporting this blog. I do not recommend attempting to purchase them using any illegal or forbidden practices.

The Xiaomi Mi Air Purifier series

The most known series air purifiers made by Xiaomi are those that carry the Mi Air Purifier branding. I won’t be including the Pro models, as they will be the subject of another article. I will also not be including the Viomi and Smartmi models, but they may be added later (let me know in a comment if you want this to happen right now).

Five Xiaomi Mi Air Purifiers have been released so far (from oldest to newest): The Mi Air Purifier 1, Mi Air Purifier 2/2H, Mi Air Purifier 2S, Mi Air Purifier 2C, Mi Air Purifier 3/3H, and finally the Mi Air Purifier 3C. Of these, the Mi Air Purifier 1 has become almost impossible to track down, and the series 2 models are also becoming ever harder to find, too.

The Mi Air Purifier 3 and 3H are the same device. The H indicates that it ships with a HEPA filter preinstalled, instead of a more basic EPA filter. The same applies to the Mi Air Purifier 2 and 2H. However, the Pro and Pro H are different devices, so don’t get them mixed up. Why Xiaomi chooses to name their devices in this manner I do not know, and things are about to get even more complicated.

Two Mi Air Purifiers that aren’t identical are the 3/3H and 3C. The 3C is a slightly modified version of the 3/3H and has slightly different specs. It is slightly quieter but also less powerful. The Mi Air Purifier 2C is a slightly beefed up version of the 2/2H and the 2S has the same specs as the 2/2H but also includes a screen.

How to identify a Xiaomi Mi Air Purifier

Before getting in to the comparison, you might want to know how to identify each Xiaomi Mi Air Purifier model. This can be useful because depending on where you are buying it from, the listing might not be complete, or you might want to confirm whether what you received is exactly what you ordered.

In the following paragraphs I will only be describing external differences of the devices and not go too deep into the specs. The most relevant numbers and features will be listed in the comparison table further down.

Xiaomi Mi Air Purifier 1: Larger than the rest

The Xiaomi Mi Air Purifier 1 is an outlier in the Xiaomi Mi Air Purifier series and is technically more comparable to the Pro models. Still, I’m including it in this list as its name suggests I should. The Xiaomi Mi Air Purifier 1 is a whopping 60% larger in volume compared to its successors but shares many of their design elements.

It’s not like you would need any more details to be able to recognize it, but another unique thing about the Xiaomi Mi Air Purifier 1 is the mi logo on the front panel.

The Mi Air Purifier 1 does not include a screen and features a single push button next to the air exhaust with which you can select its speed.

The Mi Air Purifier 1 is significantly larger compared to its successors
The single button on the Xiaomi Mi Air Purifier 1
The single button on the Mi Air Purifier 1

Xiaomi Mi Air Purifier 2/2H: The new standard

With the Mi Air Purifier 2/2H, Xiaomi shrunk the non-perforated top part of the Mi Air Purifier 1 down to around half its size. The Mi Air Purifier 2/2H is smaller, lighter, and less powerful than its predecessor, but it did set the blueprint for all future models.

It is much more efficient than the first generation, with Xiaomi claiming it will only use 58% power of what its predecessor did. I wasn’t able to figure out whether that statistic was at the same volume of air output or if it was just marketing talk.

When set to night-mode, the Mi Air Purifier 2/2H produces only 30 dB of noise (comparable to someone whispering), which is 11% quieter than the first generation.

How to identify the Xiaomi Mi Air Purifier 2/2H and 2C

The difference between the Mi Air Purifier 2 and 2C lies in their respective construction. The perforated area on the Mi Air Purifier 2 purifier extends slightly further up and there are no visible breaks or borders to it. The filter is changed using a door on the back of the device whereas the Mi Air Purifier 2C’s filter is changed by removing the top part.

The dimension of both the 2/2H and 2C are identical at 24 cm * 24 cm * 52 cm and both are controlled using a single push button next to the air exhaust.

On the inside, the Mi Air Purifier 2C is slightly more powerful than the 2/2H and 2S. And both the Mi Air Purifier 2/2H and 2C are easily distinguishable from all other models: They don’t feature a screen.

The Xiaomi Mi Air Purifier 2 compared to the Mi Air Purifier 2C
The top part of the Xiaomi Mi Air Purifier 2C (right) can be removed. Please note that the colour difference is due to the images used.

Xiaomi Mi Air Purifier 2S: The screen is introduced

With the Xiaomi Mi Air Purifier 2S what is now a mainstay of the series, was first introduced: The round screen. I’m assuming that is what the S in the name stands for. Spec wise, the 2S and the 2/2H are identical. The Mi Air Purifier 2S’ screen additionally has a feature which was sadly removed in the succeeding generation: It can auto-adjust its brightness depending on the ambient light.

New Xiaomi Mi Air Purifier 2S for Formaldehyde cleaning Intelligent Household Hepa Filter Smart APP WIFI RC
  • {OLED Digital Display} Clear OLED screen displays the real-time PM 2.5 index, temperature, humidity, WiFi link and...
  • {Ultimate Triple-layered Filter }- 360-degrees barrel filter for Xiaomi Air Purifier - Integrated early effect, three...
  • {Smartphone App Control} You can monitor your house air quality easily through the smartphone Mi Home App, and it will...

The Mi Air Purifier 2S and the 3/3H share some similarities, such as the identical dimensions, but once you know what to look out for, you will easily be able to differentiate them.

Other than the succeeding models, the Mi Air Purifier 2S keeps the control button it inherited from its siblings: A single push button next to the exhaust. On the 3/3H the exhaust extends to the edges of the top panel as the button was removed and integrated in to the display. Additionally, the air quality is highlighted using a bar on the 2S and on the 3/3H it is a circle.

The Xiaomi Mi Air Purifier 2S compared to the Xiaomi Air Purifier 3(H).
The Mi Air Purifier 2S’ display (left) features a slightly different design. Please note that the colour difference is due to the images used.

Xiaomi Mi Air Purifier 3/3H/3C: Same size, more power

The 3 series are the newest additions to the Xiaomi Mi Air Purifier family. With this generation, the Mi Air Purifier 3 and 3H are once again identical in specs, but feature a different preinstalled filter. The H in 3H stands for HEPA, and thus it will come with a higher quality filter than the non-H version.

Mi Air Purifier 3H with 3 layers of purification, HEPA Filter, Delivers 6330 liters of purified air per minute, New powerful air duct system, APP+AI smart voice control
  • Delivers 6330 liters of purified air per minute
  • 3 purification layers, each highly efficient
  • Sensitively detects even slight pollution

As with the 2/2H and 2C, the main outer differentiator between the Mi Air Purifier 3/3H and the 3C is the chamber design. The panels on the 3/3H stretch from the bottom of the air purifier to the top. The Mi Air Purifier 3C features a two-chamber design. The filter in the 3/3H can be changed using a door on the backside while the top part of the 3C can be removed to gain access.

Other than that, the screen on the 3C is slightly different to the one found on the 3/3H. Instead of an OLED panel it uses a grid of LEDs to display the air quality in numerals and a coloured bar helps you understand what those numbers mean.

Unfortunately, all models have done away with the automatic display brightness adjustment. Instead, you will have make manual adjustments using the app or the button located on the back of the device.

A comparison of the Xiaomi Mi Air Purifier 3/3H and 3C
The Mi Air Purifier 3C (left) and 3H (right)
A comparison of the screens on the Mi Air Purifier 3C and Mi Air Purifier 3/3H
The Mi Air Purifier 3C (left) and Mi Air Purifier 3/3H feature different screens

About the Xiaomi Mi Air Purifier filters

I have mentioned the filters of these devices numerous times but not yet explained that all of them, except for the Mi Air Purifier 1, use the same size filter. Were you to buy a non-H Mi Air Purifier, you could easily upgrade to a HEPA filter, and you also don’t have to worry about an older device no longer being supported.

PropertyBluePurpleGreenGrey
First layerPrimary filter for large particlesPrimary filter for large particlesPrimary filter for large particlesPrimary filter for large particles
Second layerEPA filter (less efficient than HEPA)Antibacterial layerH11-grade HEPA filterH13-grade True HEPA filter
Third layerActivated carbon filterHigh efficiency filter materialActivated carbon filterActivated carbon filter
Fourth layerActivated carbon filter
TargetBesides the HEPA filter, this filter targets formaldehyde, benzene, and volatile organic compounds (VOCs).Besides the HEPA filter, this filter targets formaldehyde, benzene, and volatile organic compounds (VOCs).
Compatibility2/2H, 2C, 2S, 3/3H, 3C2/2H, 2C, 2S, 3/3H, 3C2/2H, 2C, 2S, 3/3H, 3C2/2H, 2C, 2S, 3/3H, 3C
Buy nowAliExpressAliExpressAliExpress

On paper, the grey filter featuring an H13-grad True HEPA layer appears to beat the alternatives. However, there have been tests done that show how an H11-grade HEPA filter can actually deliver more clean air.

All Xiaomi Mi Air Purifiers compared

In the following tables you will see a full comparison of all the Xiaomi Mi Air Purifiers. Keep in mind, that every model shares the same dimensions (26 cm * 26 cm * 52 cm) and is compatible with the same filters.

Xiaomi Mi Air Purifier performance

CADR: The Clean Air Delivery Rate tells you how efficient the air purifier is at removing certain contaminants from the indoors. The three pollutants that are measured are pollen, smoke, and dust. While still broadly used, the CADR rating system has many weaknesses. Higher is better.

Room area: The area in which the air purifier can deliver clean airflow. Higher is better.

Noise level: The minimum noise level represents how quiet the device is in its sleep mode. The maximum noise level represents how loud the device is at full power.

Power: The power consumption of the device from sleep mode to full power. In sleep mode we can assume that no more than ~2 W are used on all Xiaomi Mi Air Purifier models.

PM Sensor: Laser sensor deliver more accurate readouts than those utilizing infrared. The laser sensors have a small fan to help provide airflow to the sensor. Infrared sensors use a heater element which provides a draft to the sensor. While it has fewer moving parts, the infrared sensor isn’t as fast to react as the laser sensor.

ModelCADRRoom areaNoise levelPowerPM SensorBuy
3C320 m³/h38 m²31 – 61 dB29 WHigh-precision laserAliExpress
3/3H380 m³/h44 m²32 – 64 dB1.5 – 38 WHigh-precision laserAliExpress
2C350 m³/hr42 m²63 dB *33 WInfrared
2S310 m³/h37 m²32 – 66 dB1.5 – 29 WHigh-precision laserAliExpress
2/2H310 m³/h **37 m²33.5 – 66 dB1.5 – 31 WInfraredAliExpress
* I wasn’t able to find the lowest noise level
** 388 m³/h in active mode

Xiaomi Mi Air Purifier features

While Xiaomi calls it a touch display, the Mi Air Purifier 3/3H features a single capacitive button that sits underneath the same glass as the screen. You can’t swipe through the different settings or adjust the fan’s speed using a slider. You can only adjust the settings using the single capacitive button.

ModelFanControlFilter access
Mi Air Purifier 3CUnknownDigital LED display, two push buttonsTop
Mi Air Purifier 3/3HRear-tilting centrifugal fanOLED “touch” screen display, button for brightness controlBack
Mi Air Purifier 2CUnknownSingle push button without displayTop
Mi Air Purifier 2SEddy: Mixture of axial and turbine bladesOLED display with automatic brightness adjustment, single push button.Back
Mi Air Purifier 2/2HEddy: Mixture of axial and turbine bladesSingle push button without displayBack
* 388 m³/h in active mode

Which Xiaomi Mi Air Purifier is the best?

Based on the specs, the Xiaomi Mi Air Purifier 3/3H has the best performance out of the lot. The 3C delivers a similar performance at a slightly lower noise level, but it also covers less room area. While the Xiaomi Mi Air Purifier 2/2H/2S can occasionally be found at a lower price point, they are louder and less powerful than their successor. The Xiaomi Mi Air Purifier 2C sits somewhere between the 3/3H and 3C and could be considered a decent alternative to both, when found for at a lesser price.

Things are never straight-forward with Xiaomi

What wasn’t covered in this article were air purifiers from Xiaomi’s various sub-brands and closely related vendors. The Viomi Air Purifier Pro is a large and powerful air purifier which also includes an insect trap. Mijia sells a desktop Air Purifier which also acts as a fan. The Smartmi Air Purifier is shaped like a tube and features gesture controls along with the “touch” screen found in the Xiaomi Air Purifier 3/3H. Finally, there’s the Mijia Air Purifier F1 which has a similar design to the aforementioned 3/3H but is slightly more powerful.

About Liam Alexander Colman

Liam Alexander Colman has been using Home Assistant for various projects for quite some time. What started of with a Raspberry Pi quickly became three Raspberry Pis and eventually a full-blown server. I now use Unraid as my operating system and Home Assistant happily runs in a Docker container. My personal setup includes many Zigbee devices as well as integrations with existing products such as my Android TV box. Read on to find out more on how I got started with Home Assistant.

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