Normally when we hear of car manufacturers talking about air purifiers, it usually (if not always) means some kind of cabin filter. HEPA and N95 became common terms in the auto industry, especially in the last two years.
This, however, is the first time we're hearing of an air filter that isn't meant to clear the air inside; rather, it's meant to clear the air outside.
Audi has announced that they're working with Mann+Hummel for something called the Audi Urban Purifier. The intent is that the device collect dust particles from the air as you drive around, and it's something they've been working on since 2020.
“This particulate filter is an example of our pursuit of innovation for everyone’s benefit and a successful collaboration with specialized suppliers.,” said Fabian Groh, one of Audi's project managers. “We are already doing a lot today on our own initiative. We anticipate it will also become a legal requirement in the future.”
The device they developed is effectively a filter that will placed behind the front grille and in front of the radiator and condenser assembly. It's not complicated to surmise that the system works by basically turning a car into a vacuum cleaner of sorts because there are fans just behind the radiator/condenser.
According to Audi, they are doing this to contribute to cleaning the air beyond just coming up with electric drive technology. They say that 85% of fine dust during road traffic is caused by the brakes (brake dust), tires, and road abrasion. These dust particles are just a few micrometers in size and can be inhaled. The WHO has been recommending lower particulate matter limits. It would be difficult if not impossible to comply in many urban areas in Germany, what more in other countries where emissions and environmental regulations aren't as strict or as much of a priority.
Audi is testing the system on their e-tron electric vehicle line, and after 50,000 kilometers of endurance testing, they have found no negative effects on the vehicle (e.g. excessive heat due to reduced air flowing through the radiator). Of course the cooling demands of an EV are generally far less than that of internal combustion engine (ICE) vehicles, but the technology is promising.
Audi says the the filter is easy to maintain and must only be replaced when the regular service interval has been reached. The filter itself consists of 15% recycled material and the entire system is 60% recycled.