What's with the fog in the headlights?

When the Pacific Auto Network is opened in car headlights, it will generate a lot of heat, and the air in the lampshade will become hot. When the car stops, especially at night, the water vapor in the air will attach to the lampshade and form fog.

car headlights is a semi-sealed structure design, and the headlight lampshade shell is sealed, but there is a vent hole for dust prevention on the headlight assembly. When the weather is hot, or the sun shines, or the lights are turned on for a period of time, the fog will evaporate and go out through the exhaust hole.

there is another abnormal situation that the headlights are foggy, that is, the headlights are flooded. This is the case that the water intake is relatively large. Some car lamps are not well sealed, and they will generate a lot of heat when they are working. Therefore, the internal temperature of the car lamps will increase the air pressure in the lampshade, which will open the gaps that are not tightly sealed, and the rain will flow into the lampshade along these gaps. When washing the car, some water may also enter the interior of the lamp through cracks, and the water will be atomized when heated. If there are a lot of water droplets or water vapor in the headlight, you can see liquid droplets, which is abnormal, indicating that the headlight is not tightly sealed. (Photo/Text/Photo: Pacific Auto Network Wu Binbin)