Delhi pollution makes comeback: Do in-car air purifiers really work?

Pollution levels have once again started deteriorating across many parts of the country with air quality index (AQI) entering the relatively high triple-digit figures in Delhi, many parts of northern India and even Mumbai. Toxic air isn't a new challenge for people even if it remains as alarming as ever. And while there are plenty of air purifiers in the market that claim to work wonders to clean the ambient air in closed spaces, the viability of buying one isn't quite well established. yet. And this may be most true for in-car air purifiers.

Air purifiers in newer vehicles have become a rather common offering from several brands and is advertised prominently by manufacturers. Usually offered in upper variants of a car model, these built-in air purifiers claim to filter out particulate matter and significantly improve cabin air. For vehicles that do not have an in-built air purification system, there are many consumer electronics' brands that are in the playfield, each claiming to be better than the next.

Whether one relies on an in-built car purifier or purchases an air purification device, it is important to note that none of these offer a comprehensive protection against toxic ambient air. In-built car air purifiers do show PM2.5 or at least AQI levels in a vehicle but since a vehicle is meant to be on the move, these levels may keep fluctuating depending on the conditions around.

How to get the best from your car air purifier?

Much like air purification devices meant for homes and office spaces, car air purifiers work best when all the windows are completely shut. These also work at optimal conditions if the filtration system is periodically checked and replaced, if required. In cities like Delhi, a car's air purifier may require its filter to be changed at least once every polluting season.

Also note that those with the notorious habit of smoking, lighting up in a car will exponentially increase the air toxicity within the vehicle and will require the purification system to work harder still.

But do car air purifiers actually work?

The jury is still out on whether any air purifier works enough to protect people from toxic air. While brands make lofty claims, scientists are divided over how much protection such devices offer, especially in a moving vehicle.

There are several studies to show that HEPA-based air purifiers do indeed work to bring down ambient pollution in small and closed spaces. But as mentioned earlier, the effectiveness would largely depend on how well the filters are maintained, by the user/driver/owner.