During my commute to work the other day I saw a person wearing a surgical style mask driving a newer Porsche. I assumed the mask was worn to prevent the spread of germs. My first thought was if the driver had any knowledge about the interior micro-filter or air recirculation system in their vehicle.
The recirculation system and microfilter work as an integral part of the automobiles ventilation system which allows the operator to choose whether they want interior or exterior air supplied to the passenger compartment of their automobile. If the recirculation feature is chosen, this literally re-circulates the interior air back through the ventilation system and again into the passenger compartment, this also impedes the entry of particulate matter from the exterior of the car. If the recirculation feature is not chosen then exterior air will be supplied through the ventilation system and into the passenger compartment.
The 1992 928 was the first Porsche to utilize a replaceable interior (pollen) microfilter. Starting with model year 1997, all Porsche’s have been equipped with a microfilter. There are mainly two different types of interior pollen micro filters, paper and charcoal activated. The paper works fairly well but if you prefer the best quality of filtration then the charcoal activated type is the route to take. Since charcoal has a very large porous surface area, it is able to clean the air in a much better fashion than paper, cloth or cotton mesh but it is a more costly option. The pollen microfilter(s) should be replaced every 12-15k miles or once a year to be most effective.
There is a lot of particulate matter in the air, especially in the cities. Every time I see a freeway, I imagine the massive amounts of dust, dirt and even tire (rubber) debris floating in the air. When the tires are rolling on the pavement or concrete, this acts just like a huge cheese grater as the tires are being ground into the pavement from a heavy vehicle. That rubber must go somewhere and the end result is that it turns into a fine black particulate matter that we end up breathing. In an effort to combat this, we recommend everyone utilize the recirculation feature in their automobile and remember to change their pollen filters on a frequent basis.
Tony Callas & Tom Prine