We probably don’t need to remind you that defrosting and demisting all windows is an essential element of active safety that should not be neglected. If someone goes into traffic with only a tank visor on the windshield, sweep them up to the municipal office, where we recommend that the person in question hand in their driver’s license.

Photo: Vladan Laxa

Not only the windshield of the car must be clean, de-fogged and defrosted, otherwise the risk of a traffic accident increases significantly

However, you must not forget that the weather is not always to blame. High humidity in the interior, when the glass fogs up mainly from the inside, can also be caused by a leak in the car itself. In addition, a humid environment favors mold and bacteria, then the cabin smells, and we’re not even talking about potential health risks. So how are things?

Independence Road

Users of cars with built-in independent heating can have warm feet and a smile on their face, which takes care of preheating the engine or the interior itself. Some Skodas, Bavarians or even Uazes already have this feature from the factory.

Photo: Jan Majurník

Selected vehicles of the Volkswagen Group, including Škodas, can already have an independent heater with remote control from the factory

Owners of electric cars or vehicles with built-in electric heating (e.g. Opel Insginia) are the lucky ones, because they will receive warm air relatively soon after starting the car.

Photo: Jan Majurník

Most electric cars have an electric heater that heats up much earlier than the classic one, heated by the waste heat of the internal combustion engine

Another breed of people may be heartened by a heated windshield or the mere presence of a working air conditioner, however, this does not completely solve the problem of all frozen windows. In order to get rid of unwanted deposits on the windows as soon as possible, warm and dry air must be blown on them, which absorbs more moisture, thereby eliminating unpleasant fogging.

Photo: Vladan Laxa

Air conditioning will help with defogging and defrosting, as it dries the air

Pay attention to antennas and transitions

However, the basis of everything is the good technical condition of the car. In order to prevent water from entering the interior from the outside, it is necessary to have the seals of all doors and windows in good order, there must also be no wetness under the door panels (a common problem with older Volkswagens) and the drain channels under the windshield must be cleaned. Sometimes water gets into the cabin through the antenna, damaged wiring harness transitions, sunroof, improperly glued windshield, leaking radiator hose, or the (damaged) radiator itself.

Photo: Vladan Laxa

Beware of fogging from the inside, where increased humidity can also be to blame, which carries additional risks

Even the liquid lines of the windshield washers can betray you. If you add winter antifreeze late, the water or lean mixture in the hose leading to the rear window freezes, it disconnects, and after it warms up, the driver cheerfully sprays the filling into the interior.

Photo: Jan Majurník

Do you have a heated front or rear window? Be sure to turn on these appliances when defrosting

Do you change the cabin filter regularly? No? So this can be one of the reasons for the constant fogging of the windows of your car. A clogged filter lets in less air and is, among other things, a source of mold and unwanted bacteria. The heating fan, the internal air circulation flap or possibly the air conditioning must also work at 100 percent.

Photo: Vladan Laxa

The fan must work at full capacity and the internal air circulation must not be switched on. Its possible activity is indicated by an icon with a car and an arrow

How to defrost a car quickly and efficiently

The actual procedure for effective defogging and defrosting should be as follows: clear snow from the driver’s side door, the windshield, your clothes, and tap your shoes before sitting down. Start the engine, set the fan to maximum power, switch the air flow to the windows, activate the heating of the rear window and turn on the air conditioning (on some vehicles, it activates itself when the air flow is set to the windows). If your car has it, also turn on the heated seats or steering wheel. Any added electricity consumption will put a strain on the alternator and thus the engine, which will then heat up faster.

Photo: Jan Majurník

It’s easy for vehicles with automatic air conditioning. You just press one button and the electronics will take care of the correct heating and air flow settings

Also check if you have the internal air circulation on, as it must be off. Watch out for automatic rain sensors that can interpret the ice layer as drops and activate the frozen wipers, which can damage or even injure you. Before the windows warm up, do not use the washers (especially not while driving), the alcohol contained in the winter mixture evaporates in a few seconds and the water in the form of fresh frost remains on the window.

Photo: Vladan Laxa

Watch out for the automatic wiper activation sensor. Either temporarily disable the function or first (before starting) clean the sensor itself. In some cars (e.g. BMW brands) you will already find heating lines in front of the sensors and cameras of the support systems

For faster removal of the winter supply, sometimes it is enough to open the driver’s and passenger’s windows a little, because the sucked-in air leaves the cabin faster, but beware of frozen glass to the door frame or seals – the window closing mechanism may not withstand much resistance.

Photo: Jan Majurník

Sometimes it helps to slightly open the windows for the driver and passenger, however, think about the possible freezing of the windows to the frame or door seals

After that, there is nothing left to do but scrape the ice from the windows (here we praise Skoda for the ice scraper integrated in the tank cap), sweep the remaining snow from the car, including the roof (you can be fined for a snow cap), make sure that all the windows are clean, tap your clothes, shoes again and then hit the road safely.

Photo: Jan Majurník

An ice scraper integrated into the tank cap? Great idea, Škodovce really succeeded

We would like to thank Mr. Marko Mašinda, a motoring expert from Eastern Bohemia with more than 30 years of experience, for his cooperation on the article.