What to Do When the Car Windows Fog Up on Both Sides?
3 Answers
When the car windows fog up on both sides, you can use the following methods to defog: One-touch activation of the interior defogging button: Most cars are equipped with a rear window electric heating function. The button location may vary, but the function is the same. Turn on the window heating switch, and the fog on the rear window will disappear in about a minute. Air conditioning cooling: Use the air conditioning's dehumidification function to reduce air humidity and remove fog. In summer, especially when multiple people enter the car, if the air conditioning is not turned on promptly, the high humidity of exhaled air can quickly cause the front windshield to fog up. At this point, turn on the air conditioning to blow cold air toward the front windshield, utilizing the dehumidification function to remove the fog quickly. If the humidity is too high and the air conditioning is not effective, slightly open a window to rapidly reduce the humidity inside the cabin. Combining this with the air conditioning can yield faster results. Air conditioning heating: Use the method of reducing the temperature difference to eliminate fog. In winter, blowing warm air onto the glass quickly raises the temperature of the front windshield, reducing the temperature difference between the inner and outer surfaces of the window. This helps prevent excessive fogging on the front windshield. However, the rear and side windows heat up more slowly, so it takes longer to remove all the fog. Whether the air conditioning is automatic or manual, turning it on aids in dehumidification. Avoid setting the air conditioning temperature to the coldest position, as prolonged use can cause the outer surface of the windshield to fog up. Applying anti-fog spray for prevention: Spray a small amount of defogging agent onto the car windows and wipe it clean to remove dirt and stains. While polishing the glass, a thin transparent protective film forms, effectively preventing moisture condensation and fogging, especially useful in cold winters. Alternatives to anti-fog spray include dish soap, soapy water, glycerol, alcohol, or saltwater. After applying and letting it dry, wipe off any excess residue with a chamois or soft dry cloth. This can keep the windows fog-free for several days. Opening windows for air circulation: If the fog inside the car is not too heavy, opening the side windows allows air to circulate between the inside and outside of the car, reducing the temperature difference and gradually eliminating the fog. The principle is the same as using the air conditioning's cold air. However, this method has obvious drawbacks—it is not suitable during rain, snow, on highways, or when the fog is heavy. Causes of car window fogging: There is a temperature difference between the inside and outside of the car. If the temperatures differ, the surface with the lower temperature has a lower saturation vapor pressure than the surrounding environment, causing moisture to accumulate on the glass surface in tiny droplets, forming fog.
Car window fogging can be really frustrating, especially during rainy days or in winter when there's a big temperature difference. My usual method is to immediately turn on the car's air conditioning, directing cold or hot air towards the windows at the highest fan speed to quickly disperse the fog. If there's a defog button, pressing it works even better. At the same time, opening the windows to allow air circulation speeds up the dehumidification process. In emergencies, use a clean cloth to wipe the windows, but make sure to stop the car safely first. For prevention, avoid bringing wet items into the car and place some desiccants inside to control humidity. Regular maintenance of the air filter and checking the seals to prevent aging and moisture ingress is also important. Fogged-up windows severely impair visibility, which is extremely dangerous, so always clear them before driving—safety comes first. I often share these handy tips with friends, and everyone says they work well.
Don't panic when the car windows fog up on both sides. Here's what I do: As soon as I see the white haze, I immediately press the defog button or turn on the air conditioner to blow air at the windshield. Toggle the A/C to dry the air. Increase the fan speed, and the windows will clear up quickly. Opening the windows for ventilation also helps remove fog—even a small crack for air circulation works. Avoid keeping wet items in the car to maintain dryness and reduce fog buildup. For prevention, dry the doors and windows after washing the car to prevent leaks. Stay focused while driving; if the fogging is severe, pull over to handle it before continuing. Safety comes first—never drive in an unclear state. These small steps are practical and simple. I've taught them to new drivers, and the results have been great.
