Cars and trucks will soon be filtering ambient air

If Markus Kolczyk has his way, cars will soon become mobile air filters – analogous to the filter columns that improve the ambient air at the Neckartor in Stuttgart. The development manager for original equipment at the globally active Ludwigsburg filter manufacturer Mann + Hummel and his team have built active and passive devices with which cars and trucks can, among other things, pull the dust out of the air that arises when braking.

With the passive filter, the brake system or the entire wheel is enclosed in a housing. The brake dust is caught by a filter that has to be changed at longer intervals in the workshop – similar to an air conditioning system.

The active filter, on the other hand, draws in the ambient air around the vehicle with a fan and cleans it. Whether the filter separates the brake dust of your own car or that of the neighboring car no longer plays a major role – the bottom line is that the pollution caused by fine dust should be reduced.

Tests in snow, sand and high speed

“We have developed the product ready for the market,” says Kolczyk in an interview with Tagesspiegel Background. The engineers not only tested the filters on the test bench, but also in intensive driving tests in snow, sand, high speed and on the Grossglockner. The technology passed all tests.

Now Mann + Hummel is in talks with all car manufacturers. The passive filters could even be retrofitted to existing vehicles. All manufacturers know that the upcoming Euro 7 emissions standard (Background reported) will also have 99 percent specifications for brake dust. Nevertheless, they would still wait as long as they did not know the exact limit values ​​from Brussels.

They wanted the most cost-effective solutions possible. With a view to the past, Kolczyk allows himself to criticize the industry quietly: “You could approach this topic more proactively compared to exhaust gas and make more of it.”

In his opinion, Euro 7 will make the installation of filters for brake dust compulsory in 2025. This is why car manufacturers would have to include the technology in their design plans for new models in 2022. Kolczyk knows from experience that the experts at the EU Commission are very well informed about what is technically feasible. That is why he expects specifications that are realistic but demanding – not a placebo solution.

Only 15 percent of the fine dust emissions from the exhaust

Kolczyk says that in modern passenger cars with internal combustion engines, only around 15 percent of the total fine dust emissions come from the exhaust. Now the other 85 percent have to be addressed: “We want zero emissions, not just zero tailpipe emissions.” Mann + Hummel is also advancing the topic in a research project with the German Aerospace Center; DLR also deals with challenges close to the ground.

As the proportion of electric cars increases, the problem due to nitrogen oxides becomes smaller, but brake dust still plays a role despite recuperation – as does tire wear. In the spring, an expert from the EU Commission said that her authority had the clear goal of significantly reducing the pollution of people and the environment from these sources. It also linked it to Euro 7 and the more ambitious air quality targets of the World Health Organization (WHO). The EU Commission plans to publish a scientific study on tire and brake wear in the near future.