Xiaomi’s ecosystem accessories have, over the past few years, done to the smart home what their phones had originally done for the smartphone market – democratize access to categories like robotic vacuum cleaners, security cameras, smart lights and the one where it all started – air purifiers.
At the recent Smarter Living 2023 event, Xiaomi unveiled the latest generation of air purifiers – a Smart Air Purifier 4 (Rs. 13,999) and an entry-level Smart Air Purifier 4 Lite ( ₹9,999). I’ve tested out the Air Purifier 4 for about a month to see just how much it has changed, and whether the bump up in price is justified.
Call it a familiar design or a dated look, Xiaomi’s opted for the same general design as the previous generations, with the tall cuboid shape with curved corners, 360-degree air intake and the grille-protected fan at the top that pushes out clean air. Some tightening of design elements has taken place – the fan area is now easily accessible for cleaning, the grille is smaller and more kid-friendly and the monochrome touch-enabled circular OLED screen (with a color-coded indicator for air quality levels) on the front is larger, to quickly change modes or show glanceable information about the air quality, temperature, humidity and filter life.
It may not seem like a huge upgrade visually over the previous generation, but the ability to access the fan for cleaning is a huge win, as the fans tend to pick up a lot of dirt. It’s a clean design otherwise, with not too many buttons to fiddle around with, but the all-white design will stand out in some interiors.
Setup is straight forward, more so if you have the Xiaomi Home app in place for other Xiaomi products. Slot in the filter in the housing without the protective casing, plug in the power and add the device in the Xiaomi Home app. If you’re not in front of the air purifier to operate it, the app lets you control the air purifier, say if you want to start the air purification process before you reach home. Plus, there’s the option of basic control via Alexa- or Google Assistant-enabled devices as well.
Inside, the filter module houses a set of three filters – a primary filter and a True HEPA filter (with anti-bacterial and anti-viral coating) for a claimed removal of 99.97% of particles, down to 0.3 microns, plus an activated carbon filter, the latter for odor removal. The filter set is estimated to last for anywhere between 6 months and a year of use and will cost Rs. 2,299 for each replacement.
New in this generation is the inclusion of a negative ion generator - in theory, several millions of negatively charged ions are shot out of the air purifier, which then attach themselves to airborne particles like pollen, dust and animal dander and attract them to surfaces and away from the air you breathe. They’re also a quick and easy way to increase the Clear Air Delivery Rate (CADR), a measure of how effective an air purifier is. Now, there’s some debate on the use of ionisers – while they certainly attack suspended particulate matter, there’s research that points to a marginal increase in formaldehyde levels without a significant drop on PM2.5 particles. You can, of course, turn off the ionizer in the Air Purifier 4, if you wish.
In my testing, the choice of using the ionizer didn’t really impact the speed with which the Smart Air Purifier 4 did its job. The CADR sees a small bump up to 400 cubic meters per hour, from 380 in the previous generation, and with an AQI ranging between 50-70 in the area of Bengaluru that I stay, the air purifier brought the PM2.5 levels down to sub-20 levels within 10 minutes in a 200 sq. ft room, which had been exposed to the outside air all morning. The levels further dropped to single digits and stayed put, and I didn’t notice the pace of air purification to be any faster with the ionizer turned on. The effect was far more pronounced in the kitchen when there are heavy fumes from deep frying, and the air purifier amps up the air cleaning process over using a chimney alone.
Using it in auto mode, one barely notices the sound levels once the air quality has stabilized, and there’s a night mode which goes as low as 32.1 decibels. It’s only when I bumped it up to maximum mode (in the aforementioned kitchen) did I hear the full volume of the fans, but it’s not something you end up hearing often. Maybe in Delhi in the thick of winters.
Keeping aside my slight misgivings about the Xiaomi smart home ecosystem, particularly around their ready availability of spares (over the long term), the Smart Air Purifier 4 is a good option, even as the price has seen a bump up from last time around. It does the basics well without reinventing the wheel in terms of design or capabilities and earns an easy recommendation if you’re living in an area that has a lot of vehicular traffic or construction going on.
The smart app convenience is really what seals the deal when you compare it to entry-level offerings from Philips and Honeywell. There’s also the option to consider the LED-screen-toting Smart Air Purifier 4 Lite, which is meant for smaller rooms and offers many of the Air Purifier 4’s features at a sub-10,000 price point.
Tushar Kanwar, a tech columnist and commentator, tweets @2shar.