What is the correct method for defogging a car?
3 Answers
Methods for defogging a car are as follows: 1. Air conditioning defogging: Turn on the front window defogging mode, set the fan speed to maximum, turn on the A/C switch, and then adjust the temperature to the lowest setting. The fog on the glass will be eliminated shortly. Additionally, some models are equipped with electric heating for the rear windshield and exterior rearview mirrors. Simply click the switch to turn it on, and the fog will be cleared in about a minute. 2. Air convection: Opening the windows can increase air convection, reduce the temperature difference between the inside and outside of the car, and weaken the conditions for fog formation. 3. Defogging spray: When using, simply spray it evenly on the glass surface and then wipe it clean with a dry towel. The principle is to use surfactants to leave a protective film on the glass surface, altering the surface tension of water molecules and causing fog droplets to coalesce into larger droplets, thus not obstructing vision. This can also be used on other car glass surfaces, especially the exterior rearview mirrors. 4. Homemade defogging spray with dish soap: Mix dish soap and water in a 1:6 ratio in a bottle, spray and wipe before traveling. The effect is comparable to commercially available defogging sprays, though the durability is slightly inferior.
I haven't been driving for long. At first, I was really panicked when I couldn't see the road clearly in foggy conditions. Later, I figured out a simple and correct defogging method: as soon as I start the car, I immediately press the windshield defogging button—the icon usually looks like a windshield with wavy lines—or manually adjust the air direction to the front window at maximum airflow and turn on the AC for dehumidification. If the weather isn't cold, I crack the windows open for two or three seconds to let air circulate and reduce the temperature difference. When the fog is heavy, I use a defogging spray bought from the supermarket to wipe the interior as a preventive measure. The key is not to just turn on the heater or recirculation mode, as this will increase humidity inside the car and cause fogging faster. Keeping a soft cloth in the car for quick wiping is also useful, especially on rainy days when visibility is poor and dangerous. Make it a habit to check before getting in the car, keep the interior dry, and avoid leaving wet items inside. This way, your driving safety factor will skyrocket.
I pay special attention to these small operations as soon as I get in the car. Correct defogging relies on the air conditioning system for quick results: first, turn on the fan and direct it towards the windshield with medium or higher wind speed, while pressing the AC button to enhance dehumidification efficiency with cold air—the one-touch defogging feature is very convenient. Sometimes, if the temperature difference is too large, I open the window briefly to balance it out, but not for too long to save fuel. For older cars without automatic functions, I manually control the air direction to avoid blowing cold air directly on my face. For prevention, I keep the car clutter-free to reduce humidity and minimize fogging, and regularly clean the interior. When taking kids out, their warm breath increases humidity, so I prefer to preheat and defog the car before setting off to save time. Safety comes first—only hit the road with clear visibility. These methods are simple and practical.
