There is fog inside the headlights, what causes it?

Recently, many netizens reacted that the car was left outside overnight, and the second morning found that there was a water droplet fog inside the headlights of the car. Or is it something else?

First, the cause of fogging in the headlights

1.In winter, there is a large temperature difference, which causes condensation inside the headlights

In the structure of the headlamp, there is a ventilation line that connects to the outside, and the significance of this is that after the lamp is illuminated, the temperature rises, and the vapor that expands inside the lamp is discharged through the ventilation pipe, and after the lamp is turned off, the temperature decreases, the internal pressure difference increases, and the external gas is sucked in through the ventilation pipe.

In this "inhalation" process, wet and cold gases are also inhaled, causing the lights to condense into fog! Isn't the lamp manufacturer aware of this problem? Of course, the manufacturer is aware of the shortcomings, and in order to better prevent moisture from entering the interior of the lamp, a "dry filter" is installed in the ventilation duct for filtration.

However, if the temperature difference is large for a long time and the operation is wet and cold, the effect of the drying filter element will be reduced, and the probability of wet and cold gas entering the lamp will also increase, resulting in fog in the lamp.

2.Heavy rain makes it easy to produce fog after washing the car

Attentive car owners may find that fog may appear inside the headlights after heavy rain or car washing, but what is going on? This point can be analyzed by the owner in combination with the above insights, and there is a problem of sealing of the headlights, especially for models that are more than 7-8 years old, the rubber strip of the headlights may lose its activity, and the probability of wet and cold gas entering the headlights is relatively large, resulting in fog in the headlights is normal. In addition to the sealing strip, the plastic shell will digest and absorb the moisture in the air like a sponge when exposed to heat, but the effect is not intuitive.

2. How to solve the fogging of the headlights?

The solution is not too difficult, under normal circumstances, the lamp is used normally, the temperature generated by the lamp is used to vaporize the water, and then the air vent circulation system is used to naturally dry the water vapor inside the lamp. If the fog inside the lamp is more serious, the owner can also use the basic principles of physics to remove the rear cover of the lamp and dry the lamp, and it is recommended to dry it naturally. Forced drying will accelerate the loss of activity of the sealant.

In addition, in rare cases, there is a situation where the sealing of the car lights is not tight, and the owner should repair it in time, otherwise there is only one way to change the lights.

It is related to the humidity of the air, the temperature of the car is too low, there is no way to exhaust the moisture in the headlights, and water droplets will form in the headlights, which will also lead to fogging of the headlights.

This may be due to some dust entering the inside, or it may be caused by the humid surrounding environment.

Because your headlights are broken, the headlights are notched, and water is inside, so there will be fog.

What causes fog inside the headlights?

The first point is what is the cause of fogging of car lights? Most of the reasons for the fogging of automobile lights mainly come from the fogging in the cavity, which is floating in the lamp, which is the problem of the sealing of the headlights, which needs to be replaced and repaired in time. Air.

The humidity in the air is greater, and the humidity in the air is also related to the temperature. The second cause of fog. Even when the lights are on, we all know that the lights get hot when they are left on for a long time.

The same goes for lights. From the inside to the outside, the temperature gradually decreases, i.e. close to the other, and when the lamp is exposed to sunlight, some of the water inside the lamp evaporates.

The temperature difference with the air inside the lamp then changes, resulting in fog. A vent duct is installed on the rear cover of the headlamp assembly, through which the thermal expansion gas is exhausted, but sometimes a small amount of moisture enters the vent duct, causing a slight fogging. After this fog, there will be climatic factors; When it rains, the temperature difference increases throughout the day.

Humans also know to add two pieces of clothing to themselves, but this lamp is not smart, and the external device of the lamp is not completely sealed. The fog of the fog temperature difference is caused by the obvious accumulation of water caused by the headlamp structure and airflow.

Or if there is fog in the lamp cavity, the fog is floating in the lamp, and there is a problem with the headlamp turning off. It must be replaced and repaired in a timely manner. It has to be said that it was inevitable that the lights would not turn on before.

In addition, if the temperature difference is large, it will recur in winter and during the rainy season. When encountering water mist from the headlights of the car, it is best to raise the temperature inside the car when operating. High temperatures are mainly caused by large temperature differences.

This phenomenon is more likely to occur during the winter and rainy seasons. After the lamp is lit for a period of time, the fog will pass through the ventilation pipe along with the hot gas from a large temperature difference is the main reason for the fogging of the headlights.

This phenomenon is most likely to occur during winter and rainy seasons. Of course, there are also human factors for water ingress in the headlights, such as the exhaust of the vehicle in the wading lights. The base gas flows upwards and is exhausted from the upper duct, while the outside cold air enters the inside of the headlamp from the lower duct.

This cycle keeps the pressure within the headlamp equalized. The way to get a ventilation duct is:

The reasons for the fog in the headlights: 1. The fog caused by the temperature difference change: there is a ventilation tube on the back cover of the headlamp, and the thermally expanded gas is discharged through the channel, and there will be moisture entering the ventilation pipe, resulting in a slight fogging phenomenon, which usually occurs in winter, rainy season or foggy days; 2. Fogging caused by car washing or wading:

Due to wading or improper car washing, when cleaning the engine, it should be scrubbed with a wet towel, and cannot be directly washed with a high-pressure water gun. How to remove the fog in the headlights: If it is caused by temperature difference or moisture, turn on the low beam or high beam for about 10 minutes, the fog in the headlights will slowly disappear, and the moisture in the lights will soon evaporate under normal use of the lights or under the irradiation of daylight.

Do not bake the lights to remove the fog to avoid damaging the lights.

1. The temperature difference is caused by the chain of temperature change. When the headlights are turned on, heat is generated inside the headlights, and if the headlights are turned off immediately after a long period of use, the temperature difference between the inside and outside of the headlights will cause fogging.

2. Caused by improper car washing. If a high-pressure water gun is used to clean the car lights, it is easy to cause water to enter the shed lights from the vent of the car headlights, resulting in fogging.

3. The car wades too deeply. If the car is driving on a flooded section of the road and the water is deeper than the wheels, these droplets can easily pass through the snorkel and enter the headlights to form fog.