What causes car windows to fog up Why do car windows fog up

The temperature inside the car is low, the temperature outside the car is high, and the water vapor in the air outside the car condenses into small water droplets attached to the glass, which becomes the so-called fog, and the fog is composed of small water droplets.

1.Introduction: When the relative humidity reaches 100%, the water vapor in the air will condense into fine water droplets suspended in the air, reducing the visibility at the ground level, this weather phenomenon is called fog.

Fog is more common in spring from February to April.

Whenever the visibility in the atmosphere is less than 1 km due to the condensation of suspended water vapor, meteorology calls this weather phenomenon fog.

Conditions for the formation of fog:

One is cooling, and the other is humidification to increase the water vapor content.

The types of fog are radiation fog, advection fog, mixed fog, evaporative fog, and smoke.

2.Cause: Saturation is reached when the water vapor contained in the air reaches its maximum. And the temperature of the air.

The higher it is, the more water vapor can be contained in the air. 1 cubic meter of air, when the air temperature is 4, the maximum amount of water vapor that can be contained is grams; When the air temperature is 20, 1 cubic meter of air can contain a maximum of grams. If the air contains more water vapor than the amount of saturated water vapor at a certain temperature, the excess water vapor will condense and when enough water molecules combine with the tiny dust particles in the air, and the water molecules themselves will bond to each other, becoming small water droplets or ice crystals.

The amount of water vapor in the air exceeds the saturation amount and condenses into water droplets, which is mainly caused by the drop in air temperature. This is also the reason why autumn and winter mornings are foggy.

3.Formation conditions: The conditions for the formation of fog are cooling, humidification, and condensation nuclei to increase the water vapor content.

A kind of fog is formed by radiative cooling, and most of them appear at night and early in the morning when it is clear, breezy, and the water vapor near the ground is relatively abundant and stable, or there is a temperature inversion, which is called radiation fog in meteorology; The other is the fog formed by the horizontal movement of warm and moist air, passing through the cold ground or water surface, and the water vapor in the air is gradually liquefied by cold, which is called advection fog in meteorology; Sometimes fog formed by both causes is called mixed fog. It can be seen that these conditions can be met in late autumn and early winter, especially in the morning of late autumn and early winter.

4.Color: Experimentally Proven:

When white light hits a transparent object, the light it passes through is mainly the same color as the transparent object, and the other colors are absorbed by the transparent object. If a transparent object can transmit light of all colors, then the transparent object is colorless, such as ice. However, when the water turns into fog, many reflective surfaces are formed.

At this time, the light cannot pass through, but is reflected, that is, the light of various colors is reflected, so the fog becomes white.

Fogging occurs when the windows of a car are fogged because of the condensation of water vapor caused by the difference in temperature between the inside and outside of the car. You can use the air conditioner to remove the fog with cold and warm air, and when the wind is hot, remove the fog, and open the window to remove the fog.

Because the temperature difference of the car is relatively large, it is very cold outside and warm inside, so it is foggy. After the car window is fogged, be sure to spray the anti-fog agent in time, you can also turn on the air conditioner for refrigeration, or turn on the air conditioning heater, you can also use dish soap, soapy water, mobile phone to replace the anti-fogging agent, and then wipe it clean with a dry cloth.

Because the temperature difference between the inside and outside of the car is quite large, there will be such a phenomenon, you can turn on the car air conditioner in the car, so that you can defog, and the effect is also very good.

The reason for the fogging of the car window is that the contact temperature between the window glass and the outside world is low, and the temperature difference between the inside and outside of the car is large, which is easy to fog up, and the vapor in the car condenses on the glass to form fog.

Ways to avoid fogging up windows:1Preventive measures such as spraying anti-fogging agents.

Spray a little mist remover on the windows and wipe them clean so you can remove dirt and spots from the windows. When polishing glass, a thin transparent protective film is formed on the glass, which can effectively prevent water vapor from condensing on the glass to form a fog layer, which is especially suitable for cold winters. 2.

Air-conditioning cooling method. The cooling and dehumidification function of the air conditioner system is used to reduce the humidity of the air and remove the mist steam. Turn on the air to blow cold air forward, and use the air conditioning dehumidification function to remove fog and vapor from the front windshield.

However, if the humidity is too high and the use effect of air conditioning is not obvious, you can open a small window slightly to quickly reduce the humidity of the cab. 3.Air heater adjustment method.

Reduces the temperature difference and eliminates fogging. In winter, the warm air is used to blow hot air air on the glass, which can quickly increase the temperature of the front glass, reduce the temperature difference between the inner and outer surfaces of the window, and prevent fogging of the front windshield in time. But the temperature on the back and sides of the glass rises slowly, so it takes a long time to remove all the fog.

The fog outside the front windshield of a car is caused by the temperature difference between the inside and outside of the car.

The temperature inside the cab is cooler than outside, causing moisture outside the cab to condense and form a water mist outside the windshield. This phenomenon is more common in winter.

Here's how to fix fogging outside your car's windshield:

1. Air conditioner defogging: This is the easiest way. Just turn on the front window defogging mode, then turn on the wind speed to the maximum, turn on the AU002FC switch, and then adjust the temperature to the minimum.

After a while, the fog on the glass will disappear. In addition, many vehicles now have a one-key defogging function, which can be turned on again when fogging, which is convenient and fast.

2. Air convection: This method is suitable for very few cases. When the windows are opened, air convection can be increased, reducing the temperature difference between the inside and outside of the car, and reducing the conditions for fog formation.

This approach may seem economical, but there are too few situations where it is really suitable. If it's raining outside, it's impossible to open the windows. In addition, the wind blowing in is quite limited.

3. Mist eliminator: The market of mist eliminator ranges from tens of yuan to hundreds of yuan, and the composition is not much different. Perhaps the only difference is persistence.

To use, simply spray it evenly on the glass surface and wipe it clean with a dry towel. The principle is to use surfactants to retain a certain protective film on the surface of the glass, change the surface tension of water molecules, and make the fog droplets condense into large water droplets, so as not to block the line of sight. Other automotive glass can also be used, especially on exterior mirrors.

In summer, fog only occurs on rainy days, because the outside air is humid at that time, but the temperature is not low, and when the humid air meets the cool glass, the water vapor will condense into small water droplets, forming fog on the outside of the glass.

The principle is the same as that of fogging the inside of the glass in winter, which is due to the high humidity in the cabin and the cold glass forms fog. So if the air conditioner is turned on in the summer, the windshield will be cooler and more prone to fogging.

Therefore, if the outside of the glass is fogged, do not turn on the air conditioner and use cold air to blow the windshield, it will blow more and more seriously. This is different from defogging the inside of the glass in winter, which can be defogged with a cold wind on, except that the wind blows the glass dry.

The most important thing is to use the dehumidification function of the air conditioner to remove the moisture in the cabin, and the water vapor concentration is low, so the air conditioning compressor must be turned on in winter.

Precautions for driving on rainy days:

1. Of course, turn on the windshield wipers when driving on rainy days. This depends on the amount of rain to adjust the speed of the wipers. Some cars have an automatic adjustment function.

2. If the weather is overcast and the clouds are thick. At this time, if the vision is not good, turn on the running lights. This is generally known to veteran drivers, which can increase driving safety.

3. Slow down when driving in rainy days, because if the rain is heavy, there will be a hydroplaning phenomenon. Although this situation is not common, it is also necessary to pay attention to the heavy precipitation in the period, and when the car turns a corner, you must slow down and pay attention to slow down in advance.

What is the cause of fogging outside the car window In fact, the car window is always fogging due to the large temperature difference between the inside and outside. If it is foggy outside the window, it is generally formed by rainwater condensation, and it can be scraped with a wiper: 1. The reason for the formation of fog is also mentioned above, and the most fundamental solution is to open the window to form a convection, so that the ambient temperature in the car is the same as that outside the car, and the fog has no reason to attach to the glass.

This method can indeed solve the problem, but there are also drawbacks, generally foggy days are accompanied by rain, and it is not suitable to open windows; 2. The principle of cold air defogging is actually similar to convection defogging, so that the internal and external temperatures are kept the same, so that the fog has no reason to adhere to the glass, so it seems that it is not suitable for cold air defogging in winter; 3. The effect of hot air defogging is the best, it uses the principle of hot air to evaporate the fog to achieve defogging, the time is shorter than that of cold air defogging, and the immediate effect is hot air defogging. @2019

In fact, the windows are always fogged up due to the large temperature difference between the inside and outside. If it is foggy outside the window, it is generally formed by rainwater condensation, and it can be scraped with a wiper: 1. The reason for the formation of fog is also mentioned above, and the most fundamental solution is to open the window to form a convection, so that the ambient temperature in the car is the same as that outside the car, and the fog has no reason to attach to the glass.

This method can indeed solve the problem, but there are also drawbacks, generally foggy days are accompanied by rain, and it is not suitable to open windows; 2. The principle of cold air defogging is actually similar to convection defogging, so that the internal and external temperatures are kept the same, so that the fog has no reason to adhere to the glass, so it seems that it is not suitable for cold air defogging in winter; 3. The effect of hot air defogging is the best, it uses the principle of hot air to evaporate the fog to achieve defogging, the time is shorter than that of cold air defogging, and the immediate effect is hot air defogging.