Clean mobility – Focus on the future with MANN-FILTER

Ludwigsburg, 05. September 2023 – Millions of people around the world are suffering from the effects of polluted air, not only outdoors in spaces with a lot of traffic, but also inside vehicles. It is therefore becoming essential to improve air quality by reducing particulate matter and harmful gasses. With its latest innovation in cabin air filtration, global filtration expert MANN+HUMMEL is concentrating on a particle size that is becoming increasingly important – so-called ultra-fine particles (less than 0.1 micrometer). These can get particularly deep into the human body and cause harmful damage there. The World Health Organization (WHO) is also paying particular attention to ultra-fine particles and in its latest air quality guideline has called for this particle size to be included in routine measurements.

Regardless of the drive system, cabin air filters play a major role in providing drivers and occupants with clean and healthy air. In electric vehicles, there is also a trend toward improving air quality through multi-stage filter systems.

The future of cabin air filtration: multi-stage HEPA filter systems

MANN+HUMMEL has developed HEPA filter systems to effectively protect people from these microscopic impurities. The abbreviation HEPA stands for High Efficiency Particulate Air. It is not a protected term, so special care must be taken here. The addition of “in accordance with DIN EN 1822 and ISO 29463” indicates whether a filter actually meets the high requirements of European and international standards. “Our filter media meet these requirements,” explains Christiane Michel, Business Development Manager Cabin Air Quality at MANN+HUMMEL. 

"Our multi-stage cabin air filter systems with highly efficient HEPA filters offer protection through clean room quality air filtration, as is also the case in operating rooms, for example. Depending on the HEPA class, at least 99.95% of the particles are reliably removed from the air, including harmful bacteria, viruses and other microorganisms, even the previously mentioned ultra-fine particles. These are so small that they can easily penetrate into the bloodstream, cause severe damage to organs and be carcinogenic," Michel adds. "We now know that more than 90 percent of the particles in the air are ultra-fine particles. Whether they are safe or not depends on their source and chemical composition."

MANN+HUMMEL uses the HEPA filter as part of a three-stage system along with a prefilter and a cabin air filter. Both can be equipped either as pure particle filters, in combination with activated carbon or as a third version with biofunctional and microbial coating. The particle filter uses a special nonwoven material that efficiently retains dust, soot and pollen, while the activated carbon filter adsorbs harmful gasses and odors. A biofunctional coating binds allergens that can be released from pollen and provides additional protection against the growth of mold and bacteria on the filter medium.

Michel describes the situation: "Since a HEPA filter can capture much finer particles than a conventional cabin air filter, its fiber structure is significantly denser, which results in significantly lower air permeability. To compensate for this, a HEPA filter has more media surface area and thus achieves the lowest possible pressure drop. In fact, the surface area of the filter media in our HEPA filters is about five times larger than in a conventional element, thanks to a smaller pleat spacing. It is therefore currently not possible to replace a standard cabin air filter with a HEPA element. Air conditioning systems are not built for these high efficiency filters. Instead, the HEPA filter is located in a separate system – usually outside the air conditioning system – together with a prefilter, as protection for the HEPA filter." 

Smart solution to prevent air pollution in vehicle interiors

Smart multi-stage HEPA filter systems are also designed to ensure that filtration only takes place when it is needed. An intelligent control system records the air quality and provides data on the basis of which the system decides which of the three filters the air should flow through. "This ensures that the HEPA filter is activated automatically as the final filtration stage only when required, for example, when the outside air is heavily contaminated, such as in tunnels or in traffic jams. This allows the size of the system to be kept small and extends the life of the HEPA filter," according to Michel.