How smart is your air-purifier?

In India’s intensely polluted cities, how well an air purifier cares for itself can be almost as important as how well it clears the air in the room. A smart air-purifier, for instance, will tell you when to change the filters. This is crucial because, while filters must be changed once a year, they need to be changed much more often if one lives in a polluted or dusty region (a description that covers most of India’s cities). At their most basic, smart air-purifiers also offer remote and voice controls via a smartphone, app or smart assistant.

An added advantage: They can tell users what’s in their air. Smart sensors track air quality in a room in real time, with some models generating graphic charts that represent the levels of different pollutants, from fine dust and smoke to formaldehyde, exhaust fumes, standard dust and pollen.

There is a range of companies operating in this segment in India (Xiaomi, Philips, Dyson, Electrolux and Aura Air, with prices ranging from Rs 11,000 to Rs 60,000). As the country’s struggles with air pollution stretch on — India accounted for six of the world’s 10 most polluted cities, as of 2021, with Delhi coming in at No. 4 and Bhiwadi in Rajasthan taking the top spot — expect more models on the market, and heightened competition among brands.

Already, prices have begun to level out. Which is a good thing because, within the smart air-purifiers segment, essential function doesn’t change much across models. Sensors detect air quality, temperature and pollutants. A fan pulls unclean air in, passes it through multi-layered filters (the standard is three layers), and pushes clean air out.

The first is a pre-filter layer that captures larger dust particles; the second is a high-efficiency particulate arrestance (HEPA) layer for particles as small as 0.3 microns; and the third is an activated carbon layer that eliminates odour and volatile organic compounds or VOCs (an example of these are chemicals such as hydrocarbons released by paint). The best air-purifiers have five layers of thick filters. The more filters a purifier contains, the more quickly it can cleanse the air in a room and keep it clean through the day.

In terms of design, three companies hold an edge. The Aura Air smart air-purifier (about Rs 37,500) looks like a really large puck. It can be mounted on a wall or tabletop, leaving the floor clear. It also uses a multi-coated ultraviolet or UV-C filter meant to tackle airborne germs. The Aura Air app has ironed out bugs over time, but some functionality remains perplexing. Fan speed controls, for instance, seem limited to the rather vague Low, High, Silent and Auto modes.

British company Dyson’s purifiers have a unique look: a standing tower that uses a circular tube (called a bladeless fan) to eject air through narrow vents with such force that the models offer a range of projection options (forward, diffused, etc). The MyDyson app works smoothly, and prices start at about Rs 28,000.

Electrolux’s new Well A7 is unusual too. Inspired by Scandinavian design philosophy, it looks like a little suitcase, complete with tiny peg legs and an integrated handle. It offers five-stage filtration and an ioniser that battles bacteria. But with prices starting at about Rs 40,000, it’s up to the buyer to decide how badly they wants visitors to say, “Oh, is that an air-purifier? It really doesn’t look like one.”