The German Commission recommends that the car air conditioner be operated in the winter
The German Technical Inspectorate has advised that the air conditioner
be operated in the winter from time to time as it helps to get rid of
moisture.
The operation of the air conditioner in the winter with the fan also
helps to remove the water condensate on the glass, which allows easy
visibility through it.
Water condensation on the glass can be wiped with a cloth or tissue, but
it is important to remove the moisture from the car. Heating alone is
not enough if glass windows are locked; wet air will cool again on cold
glass after stopping the car.
Those who row the car in the garage can leave the side windows slightly
open all night to remove the damp air from the car's compartment.