Air freshening tips for the passenger cabin from MAHLE

Change your cabin air filter only in spring? Definitely not! It is just as important in the autumn, to remove the pollen and pollutants that have accumulated over the summer. Why? We explain it all here.

Good and healthy through the cold season

If you ask a repair shop when the best time to change the cabin air filter is, you will usually be told: in spring. The filter ultimately helps the HVAC system to operate efficiently in summer. However, the air is particularly heavy with pollen and pollutants during the warm, dry months. They become firmly deposited in the filter and then become really noticeable in winter. Fogged, icy window panes can no longer be cleared by the blower, heating performance decreases, and the level of pollution increases, producing unpleasant odors. This is especially bothersome in the cold season, when the windows stay closed.

For direct comparison: on the left is a brand-new cabin air filter; on the right, one that has been replaced after 10,000 km

Fogged again: stop the germs!

But where do the above-mentioned unpleasant odors come from? From the evaporator! This is the part of the HVAC system that cools the air in the cabin. The humidity of the ambient air condenses on its closely set cooling fins. This condensation is, in itself, unproblematic. But an old, severely contaminated filter, which reduces air permeability, can cause an increased level of germs. And this can, under some circumstances, quickly lead to the formation of mold. On the moist surface of the evaporator, they combine with various other microorganisms to form living deposits, causing unpleasant odors.

Structure of an HVAC system with components. The pollen filter protects the directly underlying evaporator and heat exchanger from contamination of any kind.

Interior CareMetically sealed

About odors: Since the beginning of this year, MAHLE has been marketing its cabin air filter innovation, CareMetix®. This filter not only protects against bacteria, pollen, mold, and fine dust, but also against the unpleasant odors that they produce. Discover air freshening protection for your customers—and a health bonus for all passengers. All the info can be found at Just check whether CareMetix® is also available for the cars in your shop, and find the CareMetix® wholesaler nearest to you.



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