One-in-Three Cars Suffer Harmful In-Cabin Air: Mann+Hummel

Automotive supply giant Mann+Hummel claims vehicle owners and service shops are ignoring the essential regular replacement of in-cabin particulate filters, leading to dangerous levels of air contamination.

It points to latest industry research which suggests one-in-three cars suffer contamination from bacteria, mold, particulate matter, pollen and harmful gases.

In Germany, the company is a major contributor to the revision of the new VDI (Association of German Engineers) and the ZDK (German Association of the Motor Trade) guideline for providing healthy air in cars in the long run.

Climate control systems in modern vehicles are now the norm and seen as indispensable when driving in hot weather. Yet, the vital filters required to ensure good air quality are being ignored, says the company.

In a statement, it adds: “However, service intervals are often not adhered to since most car drivers are not aware of them. Dirty cabin air filters and poorly maintained air conditioning systems can cause health risks. The new guideline…is intended to remedy this. It regulates hygiene requirements for ventilation technology in passenger cars and trucks.”

The company points out that the heart of a cabin air filter is the filter medium. Over time and with increasing contamination, this medium slowly clogs and a “filter cake” forms in the pleats.

In heavily contaminated filters, the moisture present in the material also increases. This creates a breeding ground for germs and contaminates the filter and the immediate surroundings, even when the air conditioning system is not active.

The air flow rate also increasingly drops. If this affects the blower output, the risk of accidents increases because the windows fog up more quickly and a dangerous blinding, greasy film forms on them.

David Keerl, an expert in biofunctional filter materials at Mann+Hummel, says: “It's really essential to regularly change the cabin air filter once a year or every 15,000 km (9,300 miles).” He recommends a biofunctional type filter, adding: “By filtering out mold, germs, bacteria and pollen, it generates clean and healthy air for passengers in the vehicle and also protects the air conditioning system from contamination. This extends the lifetime of the air conditioning system because it prevents deposits from forming on the fine structure of the evaporator and also maintains the system's full cooling and heating capacity.”