As part of a pilot project, Audi work with the supplier Mann Hummel to the development of a fine particle filter for electric cars, capable of collecting surrounding particulate matter.
Both while driving and charging, the fine particulate filter for electric cars helps improve air quality in cities.
Regardless of the vehicle’s drivetrain, 85% of fine dust in traffic is caused by brakes, tires or road abrasion..
Barely visible to the naked eye, the finest particles measure just a few micrometers, with a diameter of 10 micrometers, and can be easily inhaled.
In 2021, the World Health Organization (WHO) significantly lowered the recommended limits. According to experts, the new WHO values would be impossible to comply with in many urban areas of Germany.
Together with supplier Mann Hummel, Audi is developing a particulate filter for the front of the electric vehicle, which collects particulate matter from the environment, foperating like the stationary filtration systems installed in some cities.
This one portable filtration system ensures that fine particulate emissions from the electric car are absorbed, but also from other vehicles where they are generated.
The filter is integrated into the electric vehicle’s existing airflow in front of the radiator, so few modifications need to be made to the car, keeping costs down. The filter element is controlled through the inlet of cold air and its mechanical function is comparable to that of a vacuum cleaner: fine particles are trapped in the filter, while air continues to circulate through it.
While driving, the filtering is done passively thanks to the movement of the electric vehicle; the air circulates through the filter, which captures the fine particles. Filtration can also occur during stationary charging. A fan, already integrated into all electric vehicles, circulates ambient air through the radiator: the system takes advantage of this process to actively filter the air that passes through, and the fine dust filter ensures that most of the fines are absorbed, even when stationary.
The evaluations carried out on the test electric vehicles made it possible to analyze the effectiveness of the filters, but also to determine whether the technology affected the use of the electric vehicle as a whole.
After more than 50,000 km of endurance tests on the Audi e-tron, the answer is clear: the filters have no negative effect on the electric vehicle’s operation, even in hot weather or during fast charging.
The efficiency of the system is such that, depending on the usage scenario, the particles from the Audi e-tron are completely filtered out in a highly polluted city like Stuttgart. In even more polluted cities like Beijing, fine dust emissions can be actively and passively absorbed by up to three vehicles in a common scenario.
To make the system even more efficient, Audi is working with Mann Hummel to link the mobile fine particulate filter to existing sensors such as those in weather stations.
The filter is easy to maintain and should only be replaced at the time of technical inspection.
A life cycle analysis of the entire filtration system showed that it is capable of filtering 14.9 kg of CO2 equivalents.
The filter itself is 15% recycled material and the entire system is 60% recycled.
Launched in 2020, the pilot project will last four years.
Fabian Groh, project manager for the development of fastening systems at Audi, explains: “This particulate filter is the result of a successful collaboration with specialist suppliers and illustrates our pursuit of innovation for the benefit of all. We are already doing a lot today on our own. We believe this will also become a legal requirement…”