These days more than ever, people are taking steps to improve their indoor air quality. And no, this isn’t just about the pandemic. While Covid has forced many businesses to improve their air filtration, homeowners have been doing it for years. This is due, first and foremost, to a growing understanding of how important air quality is. A few generations ago, we were all cooking our food on smoky, indoor wooden stoves. Nowadays, we’re concerned about dust, mold, pollen, and even airborne chemical vapors. This has forced people to take a good, hard look at their home’s air quality.
But there’s another side to the equation. In recent decades, we’ve also become more environmentally-conscious. Our homes are now wrapped with home wrap, and our windows are hermetically sealed. Great grandma’s old wooden stove might have been smoky, but her house was drafty. Even with the doors and windows shut, fresh air was always circulating in. Now, nobody’s advocating a return to the days of drafty houses. But it remains true that modern homes actually trap airborne contaminants inside. So when pollen or mold spores get inside, they can continue to float around the house for weeks.
We’re about to review the Xiaomi Mi Air Purifier 3C. Xiaomi is an up-and-coming electronics manufacturer, and we’ve reviewed their products in the past. We particularly liked their Mijia Sphere camera, so we thought we’d give their air purifier a try. That said, just because you can make a good action camera doesn’t mean you can make a good air purifier. To learn whether the Mi Air Purifier is worth using, we needed to look closer at all of its features. Here, we’ll go over the physical design, the controls, and the various filter settings. We’ll also discuss the smartphone app, and what the filter cartridge itself actually does. Only after we’ve talked about all of those things will we be able to render a fair verdict. Let’s get started!
The Xiaomi Mi Air Purifier 3C has a beefy housing, which measures 20 inches high and 9.4 to a side. The housing is constructed from durable white plastic, with an easy to clean matte finish. The corners are rounded, which keeps there from being any sharp edges. The overall weight is 12 pounds, which isn’t half bad considering the relatively large size. At any rate, it’s certainly no trouble to move around the house. At the base, there are little rubber feet, which raise the rest of the body slightly off the floor. This makes it easy to place the purifier on a carpet, as well as to prevent it from sliding.
The bottom two thirds of the unit house the actual filter cylinder. Air is sucked in through all sides, through grilles that occupy most of the sides of the housing. It passes through the filter, then up and out through the fan at the top. The top vents are shaped to distribute the air in all directions. This ensures that fresh air is constantly dispersed throughout your home. At the same time, the 360-degree intakes ensure that no dirty air is ignored. Keep in mind that the effectiveness of this design depends on placement. If the filter is sitting in a corner, it’s not going to work as well as it would in the center of the room.
As we’ll see, this large size helps you get some impressive results. But what if you want a more compact filter? In that case, consider the Acekool B-D01 instead. It’s small enough to sit on your desk or nightstand. However, it also has a correspondingly small coverage area. Even a large bedroom will exceed its specifications.
On the front of the Xiaomi Mi Air Purifier 3C’s housing, near the top, you’ll find an LED display. Here, you’ll see a readout of your air quality. This shows up to three digits, and it’s an indicator of how many particles are in the air. The more particles, the worse your air quality, and the lower the number. Above this numeric readout, there’s a small horizontal light bar. This will change color based on the relative quality. It’s green when the quality is good, yellow for moderate quality, and red for highly polluted air. Beneath the numeric readout, there are additional indicators to show the filtration mode and WiFi status. These also function as controls for power and WiFi pairing respectively.
When you turn the Xiaomi Mi Air Purifier 3C on, the fan speed will automatically adjust based on the air quality. When the quality is good, it will run at its lowest power to maintain the quality. When the quality is poor, the motor will increase speed to clean the air as quickly as possible. That said, there’s no way to manually control the motor speed directly from the purifier. To perform any types of other controls, you’ll need to install the smartphone app. Thankfully, the Xiaomi app is free on Apple and Android, and it’s easy to install. It also controls all of their devices. So if you already own anything from Xiaomi, you already have the app.
Within the app, you can change between automatic and manual mode. In manual filtration mode, you can set the fan speed however you like. This gives you more control over the filter, but it may reduce your efficiency. Night mode is a special mode that’s meant to be used when you’re going to bed. In night mode, the motor will always run at its lowest setting. This keeps it nice and quiet, reducing the volume to only 31dB. That’s literally whisper quiet, so you won’t have any trouble getting a good night’s rest. By comparison, the volume at maximum power is 61dB. This is the volume of normal human speech, when people are using their “inside voice.”
Another related app feature is the ability to turn off the LEDs. You might want to do this because they keep you up at night. However, you can also use it to save a small amount of power. Why waste money on LEDs you’re not even looking at? Another efficiency-boosting feature is the scheduling option. Here, you can set your filter to run on a daily or weekly schedule. This allows you to keep your air clean when you’re on vacation, without leaving the filter on the whole time. Finally, within the app, you can view the estimated remaining filter life. This is based not just on operating time, but also on air quality readings, so it’s pretty accurate. That said, it’s not magical. For example, if you have a small grease fire in the kitchen, the smoke will shorten your filter life.
In total, the Xiaomi Mi Air Purifier 3C is capable of treating up to 409 square feet of space. This assumes that you have standard 8-foot ceilings. If you have cathedral ceilings or drop ceilings, your square footage will be lower or higher respectively. Regardless, this is an impressive amount of coverage for all but the largest home air purifiers. That said, keep in mind that this rating assumes that the filter is running at full power. If you’ve set it to night mode, it’s not going to consistently purify a large area.
The Xiaomi Mi Air Purifier 3C utilizes a three-stage filtration system that’s similar to the filters on many home air purifiers. The outer layer of the filter is a simple pre-filter. This is a nondescript mesh that’s meant to catch the largest particles. It traps big pieces of dust, pet dander, and other junk that could clog up the finer inner filter. It’s in the area outside this pre-filter that the purifier takes its air quality readings.
Inside of the pre filter is the main high efficiency filter. This is an accordion-shaped, ultra-fine filter that’s made to capture the tiniest of particles. It’s rated to remove 99.97 percent of particles as small as 0.3 microns. That’s very small, and it includes almost every particle that can cause allergies. Pollen, mold spores, dust, and dust mites will all be removed from your air.
The inner layer of the filter is made of activated charcoal. This will capture chemicals like formaldehyde fumes that can trigger chemical sensitivities. It also helps to remove pet odors and other unpleasant smells.
As you can see, that’s a very effective filter. But what if you want an air purifier that doesn’t just remove odors, but actually makes your air smell good. If that’s what you need, check out the Elechomes OX300. It’s a small, efficient filter with a built-in essential oil diffuser. On the downside, it has only about half the rated coverage area of the Xiaomi Mi Air Purifier 3C.
The Xiaomi Mi Air Purifier 3C filter cartridge itself is a single cylinder, which sits inside the bottom half of the housing. It’s easy to replace, since it’s all one piece. You open the back of the housing, pull out the old filter, and place the new one inside. It couldn’t get any simpler. Filters can last for several months, but there are many factors involved. A lot depends on your air quality, and on how often you’re running the purifier. Replacements are readily available, but be prepared. This is an inexpensive purifier, but the filter cartridges are a little pricey.
All in all, the Xiaomi Mi Air Purifier 3C is one of the better air purifiers in its price range. To begin with, it covers an impressive amount of space for a filter of this type. For another thing, the app is easy to use, and it even works with other Xiaomi products. To be fair, nothing is perfect. We would have liked more physical controls besides a simple on/off. But all things considered, this is a well-engineered air purifier.