Under what circumstances are the internal circulation and external circulation of automobiles used?

There are many buttons in the car, but some people may not pay special attention. Do not enter wind direction, air volume, internal and external circulation, air conditioning, defogging, etc. If there are too many buttons, sometimes the points will not be particularly clear.

Especially the internal and external circulation, many people may not pay special attention to it, resulting in improper driving or poor cooling effect when turning on the air conditioner.

For example, if we turn on the air conditioner in summer, we should choose internal circulation. Internal circulation is equivalent to closing doors and windows and opening air conditioners at home, while external circulation is equivalent to opening doors and windows and opening air conditioners. This is the difference between before and after. As a car, it consumes gasoline instead of electricity. Therefore, when you turn on the air conditioner, you should turn on the internal circulation to ensure that the air conditioner in the car will not leak. If the external circulation is turned on, the hot air outside the car will continue to enter the car, and the cold air inside the car will continue to be exhausted, which will not achieve the cooling effect and will consume more gasoline fearlessly.

If it's sunny and the temperature is right, and driving in the suburbs, then I think it's better to circulate outside and improve the air inside the car. There is no automobile exhaust at this time, or there is less turbid air and dust in the city. Turning on the external circulation can let more fresh air and oxygen into the car. In this way, drivers will be more energetic and less likely to feel sleepy.

Usually, many people may use the internal and external circulation improperly and sleep in the car with the internal circulation on. As a result, the air was not circulating and the concentration of carbon dioxide was too high. Unfortunately, they died in the car because of lack of oxygen. Such cases are not uncommon, and many such cases occur every year. Therefore, we should also use internal and external circulation reasonably and scientifically.