That, a Micro-electrostatic Precipitator or MESP filter, is at the core of their indoor air purifier. The name’s a mouthful but leaves little ambiguity – MESP Portable Air Sterilizing Purifier With Washable Filter (the KJ series). It is an attempt to draw your attention to its big change, that’ll help save money in the long term and reduce worn out filters ending up in landfills. HEPA filters are a composition of fibers, mostly polypropylene, borosilicate and fiberglass. They cannot be washed (at the most, cleaned once with high pressure air jets) and once the filter warning light blinks, it is time to replace. MESP is a honeycomb structure of metallic tubes that have an insulation coating generating electrical fields within the tubes – pollutants are charged particles and get pulled towards these tubes (eventually stuck). Periodically, wash this with running water.

Mind you, HEPA filters (as essential as they are in our polluted cities), aren’t recyclable. Though material composition suggests they can be, but you’ve to factor in all the dangerous pollutants, bacteria and virus they’ve captured within themselves, during their serviceable lifetime. They can only be disposed of, an unavertable contribution to the world’s growing e-waste problem. Research firm Statista suggests in 2023, the world 61.3 million metric tonnes of e-waste. That’s to rise to 74.7 million metric tonnes by 2030.

Another advantage is this technology, unlike HEPA filters that can trap 0.3 micron or larger sized particles, can also trap pollutants, virus, bacteria and germs as small as 0.1 micron. Broad(er) spectrum cleaning capabilities if you may. The fact that MESP filters can be washed periodically, means little resistance to airflow – input and subsequently, output. You’ll theoretically encounter more efficient room air purification, and since the fans don’t have to speed up again and again, there’s logically lower power consumption over the period of usage.

Setting this up is simple, though the app for this to be a smart home device, takes some effort to get to. The app is called Smart Life, but the QR code on the purifier itself only takes us to a broken webpage (at least it did, when we were setting this up). Following the on-screen guidance will get you to set this into pairing mode (select Wi-Fi as the mode of setup) and takes a few minutes to connect with the home Wi-Fi network. We’ve not received any firmware updates in the duration we tested the Nirvana Being MESP Portable Air Sterilizing Purifier With Washable Filter. The app is easy enough to navigate but doesn’t feel premium in the way Dyson’s companion app does, for example. For a purifier that costs a similar amount of money, we’d expect an app that’s more refined and visually appealing.

A very noticeable shortcoming, which is nevertheless surprising it even exists in this era, is the fact that the MESP Portable Air Sterilizing Purifier doesn’t power on or resume its earlier state of use, in case of a power cut. Be it for a few seconds, or a handful of minutes. It requires manual intervention to power on the purifier, every time the electricity supply drops.

The Nirvana Being MESP Portable Air Sterilizing Purifier With Washable Filter in auto mode takes about 10 minutes to bring the AQI reading from a very unhealthy 362 on the meter in an active living room, to a properly healthy 57. It is at this point I noticed how sensitive this purifier is to even the slightest of changes in the air composition around it – walk past it or open a room at the far end of the hall, and depending on how it detects changes, the fan speeds up for different durations. This active response is good for rooms that tend to have constant activity. The big light ring around the touch control console at the top is a visual indicator of what’s happening.

You’d want the colours to be green or blue (good and excellent, respectively), and not orange or red (polluted and poor). At this point, I must point out there are three fan speed modes – low, medium and high, and anything other than low, is perceptively audible to occupants even in medium sized hall. At night, the trick is to shift this to sleep mode (it too can be automated too in the app, with specific time guidance), and then it is whisper silent with the console lights off. For large bedroom spaces, this is the ideal mode for a peaceful sleep.

Design, form factor, filter layers and extensive smart connectivity features see quite a bit of creative approach, but it is not often we see underlying technology changes with indoor air purifiers. The shift from HEPA (it works effectively, just that it must be replaced periodically) to MESP filter tech means you’ve a filter layer that simply needs to be washed under running water to be cleaned (do not forget to thoroughly dry this, before putting this back in the purifier), and the company claims this has a life of 10 years or so. Average that with swapping out HEPA filters once a year at least, and assuming the average cost of the replacement filters to be around ₹3,000 per change, that’s an expense of around ₹30,000 over the same period.

Tech layers that can be cleaned, and reused, is a good idea. Always. Isn’t it?