Smartmi Air Purifier review

 

Introduction

Smartmi, also known as Zhimi, is a Chinese manufacturer of smart home devices. Just as expected from a Xiaomi subsidiary, Smartmi’s devices are reasonably priced, well designed, and they integrate with the other Xiaomi smart home products.

Smartmi’s headline products are the air purifiers they make – they offer a few distinct models on their Chinese website. Still, the single model they offer internationally has just had its Kickstarter campaign finished.

It’s aptly named the Smartmi Air Purifier, and this is the device we have for review today.

We got our review unit early on while the crowd-funding campaign was still underway, but air quality around our parts was already excellent in the warmer months.

However, now that winter has settled in, the air outside has steadily deteriorated to levels where the Air Purifier really comes in handy.

Smartmi Air Purifier key specs:

• Size: 31cm diam x 63cm high, 5.2kg, 220V.
• Display and controls: OLED touchscreen with optional OFF mode, gesture or touch control, Auto/Sleep mode, Wi-Fi connection and Mi Home app control.
• Filter: 3-stage filtration system: H13 True HEPA filter for fine particle removal and an activated carbon filer for removing odors and inactivating formaldehyde and other VOCs.
• Sensors: Temperature, laser particle sensor, Total VOC, humidity.
• Performance ratings: 400m3/h CADR, 6660L of purified air per min, for rooms 29-48m2, purifies a 30m2 room in 5min

If you have not heard of Smartmi before, that’s understandable. Their range of products is not that large. Smartmi's website in English features a couple of standing home fans, a few humidifiers and a few electric heaters, and also a heated bidet seat. They also have a portable PM 2.5 detector, which can also be found selling under the Mijia brand. On the other hand, Zhimi's website in Chinese shows a few wall-mount split-type air conditioners additionally, and a few Mijia devices related to air quality measurement.

Design and controls

Smartmi is a Xiaomi company. Their Air Purifier shares a lot of its design language with Xiaomi’s own air purifiers. This model here, though, is slightly more powerful than the widely available Xiaomi Mi Air Purifier 3H. The two have the same general footprint, albeit in a different shape. More distinctly, perhaps, Smartmi has placed the control screen on top of its device.

The jury is still out on which display placement is more practical. The Xiaomi's side-mounted screen is easier to keep an eye on if you are sitting down, but the Smartmi’s top-mounted screen can be seen at any angle from any corner of the room as it doesn't have to be turned to face you.

And since the air purifier is knee-high, I’d say that operating the controls is more comfortable.

The OLED screen and the simple UI on the Smartmi look and feel just like on any Xiaomi air purifier. The screen is not touch-enabled, but it is coupled with a touch button for turning the unit on or off or changing modes.

A colorful LED ring around the screen serves as a visual indicator of PM2.5/TVOC content in the air.

Upon a closer look, the screen will give you more detailed measurements of your environment variables - the actual PM2.5 level, the air temperature, and air humidity.

There are not many modes available – beyond Automatic fan speed, you can also have the Favorite mode with your preferred constant fan speed or the Sleep mode, which optimizes the fan speed for quiet operation. You can also turn off the screen if you sleep in the same room and the light bothers you - but only through the app.

In contrast to the Xiaomi Mi-branded air purifiers, the Smartmi Air Purifier's top-mounted controls have an extra feature - gesture control. An IR sensor will spot your hand movement, allowing you to change modes with a flick of a hand (no touching involved). Yes, it is gimmicky, but it works. You can even turn off the air purifier by hovering your hand long enough above the sensor.

Of course, you can control all these options from the Xiaomi Mi Home app, too, and use it to integrate the air purifier as part of your smart home setup – even with support for Alexa or Google’s Assistant voice commands.

But despite the myriad of control options – I found myself rarely needing to resort to any of these, so I find them of little practical importance.

It’s because the air purifier is meant to be always on, so in time, you forget it’s even there until you open the window and bad air flows in. You can hear the fan immediately ramping up its speed in these cases, and the air quality indicator turns red, making the health threat abundantly clear.

I began to appreciate how having an always-on air measurement device really makes you aware of the quality of the air you breathe in. Air pollution is not always noticeable, and where I live, some days are definitely much better than others. So I really appreciated the peace of mind that I can air the apartment freely when the air pollution was low, and I made sure to keep the windows closed when the air outside was bad.

So the air purifier not only does manage to stay out of sight and keep a generally low profile, but it’s also always there to remind you of the quality of air that you are letting in from the outside - truly an air guardian - as Smartmi's advertisement goes.

Does it do its job well?

Aside from the type of filter used, the single most crucial metric about the sort of a job an air purifier can do is its Clean Air Delivery Rate or CADR. It’s the amount of filtered air it can pump out expressed in cubic meters/hr or in cubic feet per minute. The higher the CADR, the faster it cleans the air in the room from airborne contaminants or particles.

 
The laser particle sensor is at the back

The Smartmi Air Purifier has an excellent CADR rating of 400 cubic meters/hr (235cfm). It’s slightly higher than Xiaomi’s widely available Mi Air Purifier 3H, rated at 380 cubic meters/hr.

The Smartmi’s CADR translates into a recommended room size between 29 and 48 m2. It all depends on how many times per hour, you expect the air purifier to recycle the room’s air volume.

Most sources agree that people with allergies or asthma require about 4 or 5 Air Changes per Hour (ACH) in the room they occupy, so for that group, the CADR 400 air purifier will serve a room at the bottom of that advertised range – so around 32-40 m2 (with a 2.5m ceiling height).

Your hand needs to be at a distance of about 10cm for the gestures to register. There is also a child lock for the controls for extra peace of mind, and you can disable the gesture control altogether if you like.