It’s a typical cold and damp morning in Germany. You get into your car, start the engine, and within seconds, all the windows are completely fogged up from the inside. You turn the blower to full blast, but it feels like an eternity before you have even a small clear patch. Most drivers now grab a cloth and smear the windshield, making everything worse.
What if there was a button that could solve this problem in seconds? That button exists, but most people only associate it with summer heat: the A/C button on your air conditioner. Using the A/C in winter sounds counterintuitive, but it's the most effective way to get clear visibility and can even save you from expensive repairs. Here's everything you need to know.
The main reason for foggy windows in winter is moisture. We bring it into the car with wet jackets and shoes, and our own breath also contains a lot of water vapor. When this warm, moist indoor air hits the ice-cold windows, the water condenses—the window fogs up.
The heater alone combats this problem very slowly. It warms the air, but the air remains moist. This is where the air conditioner comes in. Its main function is not just cooling, but primarily dehumidifying the air.
You'll be amazed at how quickly your windows clear compared to using just the heater. This is not only comfortable but also a huge safety gain.
"But I don't want to run the A/C in winter, it just costs fuel and might break!"—this is a common argument. The opposite is true: not using the air conditioner in winter can lead to expensive damage.
An A/C system is a closed circuit that contains not only refrigerant but also a special oil. This oil's job is to keep the many seals and hoses in the system lubricated and supple. If the system stands still for months, the oil is no longer distributed. The seals can dry out, become brittle, and leak.
Experts, like the ADAC, recommend running the air conditioner at least once a month for about 10 minutes—even in the dead of winter. This ensures that the oil circulates in the system and all seals are lubricated. This keeps the system intact and ready for use in the spring.
Yes, running the air conditioner does increase fuel consumption. However, modern A/C compressors are very efficient. They don't run continuously at full power but cycle on and off as needed. The extra consumption is minimal, especially compared to the safety risk of poor visibility.
Conclusion: The minimal extra fuel consumption is disproportionate to the enormous safety gain from clear visibility and the savings from avoiding expensive repairs.
An often-overlooked benefit: the A/C system filters the air drawn from outside. The cabin air filter (pollen filter) traps dust, pollen, and other pollutants. By operating the ventilation with the A/C on, you also ensure cleaner air in the car during winter. This is particularly beneficial for allergy sufferers.
Make it a habit: as soon as the windows fog up from the inside, press the A/C button. And on a longer drive, let the system run for a few minutes once a week. Your car—and your wallet—will thank you for it.