Do you know that too: Just got into the car and the windows are already fogging up. But why actually? This is due to your warm breath, which condenses on the cold window glass due to strong temperature differences. But what if the car windows are already fogged up before you get in the vehicle? The assumption here is that there is too much residual moisture in your car. In both cases, a dehumidifier is supposed to help, but what exactly is that? And how can moisture in the car be avoided or at least reduced? We’ll tell you.

A vehicle dehumidifier is a type of cushion filled with special granules or leak-proof gel. You place this in the car (e.g. on the dashboard) to pull the moisture out of the air. This should not only reduce fogged windows and bad smells, but also prevent mold, rust and mold stains. Depending on the manufacturer, the duration of the effect is between several weeks and up to three months – this always depends on the size of the vehicle interior. What is particularly practical about this type of dehumidifier is that it can be used not only in cars: the cushions serve the same purpose in caravans or motorhomes, in (closed) garages or even inside a boat.

And the best thing about it is that once the pillow is soaked and no longer absorbs moisture, it only needs to be dried in the microwave (or on the heater) for a few minutes – and then it is ready for use again.

If the windows in your car fog up as soon as you drive off, the first thing you should do is turn on the fan and point it specifically at the windshield. It is also helpful to briefly turn the heating up to full power so that the outflowing air warms up more quickly. However, if the windows gradually fog up while driving, this could be due to the air recirculation switch – in this case it is advisable to turn this off and switch on the air conditioning (if one is available) instead. It transports the humid air from the vehicle interior directly to the outside.

In addition to the dehumidifier for cars described above, you can also use other tools to prevent windows from fogging up: such as an anti-fog spray for glass and plastic windows, which, however, has to be applied every one to two weeks to be effective . Alternatively, you can also use a microfibre window sponge in the vehicle – or a special anti-fog sponge. In any case, it is important that you only use clean rags or cloths, as dirty windows will fog up more quickly due to the film of dirt than clean ones.

According to the ADAC, you can take a number of preventive measures to prevent moisture from collecting inside the vehicle and promoting fogged windows and mold:

Sources: ADAC, Autobild

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