Generation of automobile fog and defogging methods

The generation of car fog and defogging methods

The cold air not only brings humidity and coldness, but also the trouble of fogging the front windshield. Faced with this serious impact Driving safety is an old problem. Let’s take a look at the causes of fog and some tips for defogging.

1. Generation of fog

We will not go into complicated details about the principle of fog generation in car windows. Simply put, it is caused by the temperature difference of "cold outside and hot inside". The temperature inside the car is higher than the outdoor temperature, and fog forms. The water mist mentioned in this article refers to the inside of the glass, so the wiper is not very effective.

2. Defogging methods

There are many ways to defogging. In fact, they can be simply divided into two types: spending money and not spending money. Window convection will not bring additional costs, but it is subject to many constraints. The use of air conditioners to defogging should be the most common, but there are also considerations whether to turn on cold air or hot air, which will be introduced to you later. The market for special defogging agents is mixed, and the price range is also large and difficult to distinguish. It is recommended that you make your own defogging agent. The specific methods will be introduced in detail.

1. Open windows for convection

If you find that there is not much fog in the car, you can open a gap on both sides of the car windows, so that the air inside and outside the car will form convection, and the temperature difference will also be reduced. Small, the fog will slowly disappear. The principle of this method is the same as turning on the air conditioner to cool down the air, but it does not increase fuel consumption. The disadvantages of opening windows for convection are very obvious. It is not suitable in rainy and snowy weather, on highways, or when there is heavy fog. Moreover, opening windows will lower the temperature inside the car.

2. Air conditioning system

For most car owners, it is most common to use the air conditioning system to defogging. Nowadays, almost all cars on the market have air-conditioning outlets under the front windshield. You only need to select the corresponding gear of the air conditioner to use the wind blown by the air conditioner to remove fog. But should you use cold air or warm air? Both cold and warm air have their own advantages and disadvantages. If you are in a hurry to hit the road, you can use cold air for emergencies. In most cases it is recommended that you use warm air.

Turn on the fan and refrigeration switch in the car. The cold air will blow onto the front windshield and the fog will disappear quickly. The effect is very direct. But the biggest drawback of this method is that the people in the car will feel very cold. In the already cold winter, the cold air from the air conditioner is unpleasant. And after turning off the cold air, the fog may appear again. Therefore, we do not recommend using cold air to remove fog.

3. Defogger

It is sold in many places such as auto parts stores and supermarkets. Spray the defogging agent onto the inner surface of the car glass and wipe it clean. While removing the dirt on the glass, it can also form a protective film to prevent the fog layer formed by the condensation of water vapor on the glass. Spraying it once can prevent fogging for ten days. Left.

Cars currently on the market basically have the "rear windshield electric heating" function. The button positions will be different, but the functions are the same. Turn on the "rear windshield heating" switch, and the fog on the rear windshield will disappear in just a minute or so. It is worth noting that when you wipe the rear windshield, you must follow the direction of the resistance wire.

In dry climates, exterior rearview mirrors are generally less prone to fogging. Even if it occurs, the removal method is very simple. If your car is equipped with electric heating function for the exterior rearview mirror, just turn on the switch and the fog will disappear quickly. Without this function, you can only defog "manually".

Comprehensive comparison of these defogging methods, the two more recommended methods are homemade defogging and warm air defogging. This method is better both from an economic point of view and from a comfort point of view. The purpose of defogging is to improve driving safety, so please remember: no matter which method is used to defogging, it must be done before driving.