What Causes Car Windows to Freeze in Winter?
3 Answers
Car windows freeze in winter due to residual heat inside the vehicle after parking. Methods to remove ice from car windows: 1. Start the car and wait for the water temperature to rise, then use warm air to blow on the windshield; 2. Use a hard plastic scraper to scrape off the ice; 3. Use a spray de-icer; 4. Cover the windows with a layer of newspaper after parking. The production of car windows involves heating the glass in a furnace to near its softening temperature, then transferring it to air grids with varying cooling intensities for uneven cooling. This creates different stresses between the main viewing area and the peripheral areas, producing zone-tempered glass.
Frozen windshields are a common issue in winter, primarily caused by temperature differences. After parking at night, temperatures drop sharply outside to below freezing, while residual heat and moisture remain inside the car. People and breathing release moisture, and if parked outdoors or in a leaky underground garage, moisture can condense on the windshield. Just like water droplets freezing in a fridge, when the temperature difference is large, the air can't hold as much moisture, causing water to directly turn into frost. I often remind friends to open the windows for a few minutes before parking to ventilate the cabin and let it dry before turning off the engine—this significantly reduces the chance of freezing. Of course, if you find thick ice in the morning, use a dedicated ice scraper and scrape slowly without rushing. Hitting it hard can damage the windshield surface or the wiper blades.
I've experienced several times when the car windows were completely frozen in the early morning during winter, which was really frustrating. The reason is actually quite simple—it's due to the significant temperature difference between the inside and outside of the car. When parked on the roadside overnight, the exterior gets cold enough to freeze, while the warm moisture inside the car seeps out through the air conditioning system or door gaps, instantly freezing into a layer of ice upon contact with the cold glass. Parking location also plays a crucial role—if parked in a windy or damp area, this happens more frequently. Later, I developed a habit of cleaning out the car before parking at night, ensuring no food or wet items are left inside to create excess moisture. This saves a lot of time the next morning, avoiding the hassle of frantic de-icing. Everyone says winter driving comes with minor annoyances, so taking preventive measures is essential.
