"Fog in Winter" * * * Enjoy: There are two ways for four windows.
Content summary:
The reason why the window fogged.
Correct defogging method
Fog is a very common natural phenomenon, generally described as "fog", but the water in fog is not gaseous, but liquid; It is the result of water content exceeding the air bearing limit and water droplets suspended in the air.
But the fog on the window is not caused by the fog near the window, which is only the first step; The core factor is that the air with relatively high temperature has too high humidity and contacts with the low temperature front gear, resulting in "condensation water phenomenon". Water vapor will condense into liquid water when it is cold, and the front block will be continuously blown by the low-temperature air outside when driving, so it becomes a good "natural evaporator" (condenser). What about water vapor?
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Basic knowledge of warm air defogging
Standard answer: from our breath! It is said that women are made of water. In fact, everyone is made of water, and more than 70% of the human body is water. Refer to the comparison table of inhaled and exhaled air components below, with emphasis on carbon dioxide and water vapor.
The H2O content in the exhaled air is increased by 15 times, so the humidity of the air will be high. But there will be no fog in the car, because the warm air system heats the temperature of the air, and the ability of high-temperature air to carry water molecules is stronger than that of low-temperature air, which is why there will be no fog in the car.
However, these hot air are "wet", and when they contact with the low temperature front gear, the condensed water droplets will condense; Therefore, the essence of the fog in the front block is the refraction of a large number of water droplets into the air, so how should we clean up these water droplets?
The quick and effective way is to turn on the front defogging switch (sector button), at which time the compressor will be activated to start cooling, and the air will only be discharged from the front outlet. Using cold air to reduce the temperature of the air around the front bumper can really reduce the condensation efficiency, but what is the feeling of always using cold air to demist in winter? I believe it is self-evident.
The correct way: If you want to defog effectively and for a long time, the option you want to fight for should be "warm air+front foot wind"; Because the warm air blowing from the pipeline is dry, the moisture contained in the external low-temperature air will be dried by the warm air tank of several hundred degrees Celsius. Then, if these warm air continues to the inside of the front bumper, it will form a "wind wall", which makes the warm air in the car with high humidity unable to contact the front bumper effectively, and at the same time, the warm air can dry the moisture in the front bumper in time.
However, the air conditioning circulation mode should be external circulation, and the humid air with high carbon dioxide concentration in the car can be discharged through the fresh warm air coming in. The higher the CO2 concentration, the lower the O2 concentration in the inhaled air, and the CO2 in the exhaled air increases by 1.33 times, so the air quality inside the car will decrease rapidly.
Theoretically speaking, driving for several hours is not a high-intensity job, and the core factor that makes you feel tired and sleepy after driving for several hours is actually the "hypoxia" caused by the increase of CO2 concentration.
The reason why people feel energetic at low temperature in winter is because the intensity of blood circulation on the body surface is reduced and the brain is not easy to lack oxygen; On the contrary, in hot seasons such as spring, summer and autumn, the brain is prone to lack of oxygen, which is the reason of the body itself. The lack of oxygen in the car is caused by the lack of air circulation, but the state is the same no matter what the reason, so it is still very important to use external circulation. (Warm air preheating will not be affected after hot operation)
Electric heating demisting
Let's talk about the method of defogging the front block first. Just remember "external circulation+front foot air+warm air". The density of high-temperature warm air is lower than that of high-humidity air in the car. The air will rise after coming out of the feet, and the whole car will feel warm. Don't worry about the side windows of the two cars in the front row, because the front gear air outlet mode will vent from the air outlets of the two cars at the same time, and the position used to observe the situation of the two cars can be clear enough.
However, the front defogging switch is not completely useless, because the "electric heating defogging" of the rearview mirrors of the two cars is linked with the front defogging switch, and only by turning on the switch can the function of effectively heating and evaporating water vapor be exerted. Then, after the defogging switch is turned on, the air conditioner is automatically turned on, and all that needs to be done is to manually turn off the air conditioner (compressor).
"Electric wire defogging" is a common way to defog both the rearview mirror and the rear gear, and the rear gear is a square defogging button; After opening, the current will be input to the high resistance wire through the wire, and the yellow silk wire with regular layout that can be observed later is the wire. When current passes through a high-resistance conductor, high temperature will be generated due to electron collision. When the glass is heated, it will reduce the light gathering ability and evaporate water vapor to some extent.
The rearview mirror lens can't see the wires, because they are all hidden designs; This is the defogging method for front and rear windows and front windows of automobiles for reference.