In order to avoid fogging in the car when the weather is cold, should I turn on external circulation or internal circulation?

Fogging inside the car proves that the air humidity inside the car is high, so under normal circumstances, we only need to open the external circulation, introduce dry outside air into the car, and discharge the high-humidity air inside the car, then it can be effectively Suppress the problem of fogging in the car. Generally, fogging will occur in the car when the inside is hot and the outside is cold. As long as the humidity in the car is reduced, the generation of fog can be suppressed. If necessary, the defroster can be turned on to quickly clear the fog!

Image source from the Internet

Fogging in the car is caused by the humid air in the car, which encounters the cold car windows and condenses into a dense layer of water droplets on the surface of the car windows. It is also called fog; then one thing is certain, that is, the inside of the car is hot, the outside is cold, the inside is humid, and the outside of the car is dry, so this situation usually occurs in late autumn, early winter and other seasons, and it is necessary to use a heater inside the car. time; in fact, this is because the air humidity in the car is too high. If the external circulation is maintained all the time, the air humidity can be reduced anytime and anywhere, and the interior will not fog up; if it is snowing and raining outside the car, another Don't worry; turn on the defroster if necessary (the defroster itself is an external circulation)!

Picture source: Internet fogging outside the car

The reasons for fogging outside the car are opposite to those inside. Fogging outside the car often occurs when the temperature outside the car is high, the temperature inside the car is low, and the air outside the car When the humidity is high, it can be simply understood as the dog days and rains in summer. The air outside the car is hot and humid, while the inside of the car is cold due to the air conditioning. In this way, when the humid air outside the car touches the cold glass, the condensation layer The water droplet layer is the so-called external fogging. For this external fogging, it is very simple. The front guard can be wiped off directly with a wiper, and the glass on both sides can be lifted and lowered once, and it can also be cleaned. Therefore, the fogging on the outside of the car is better than the fogging on the inside. Fog is easier to deal with!

Image source from the Internet

In short, the most troublesome thing is fogging inside the car. The principle is very simple: the air humidity inside the car is too high, it is cold outside, and there is warm air inside the car. Many friends I don’t like to adjust the air conditioner when driving, such as internal circulation (or external circulation) all year round. I default to it and keep it. If the internal circulation is used for a long time, the air humidity in the car will become larger and larger (human breath is mixed with water vapor). The front windshield will naturally produce a lot of fog. In fact, this is caused by some bad car usage habits. The solution is also very simple. Turn on the external circulation, introduce external dry air, and discharge the high-humidity air in the car. This can be solved; For rapidly generated fog, the best way is to turn on the defroster, and the effect will be immediate!