The source of automobile warm air is the coolant water temperature. When using it, you only need to adjust the internal and external circulation and pay attention to ventilation. The automobile air conditioner itself has no heating function, and the compressor compresses the refrigerant, which is also commonly known as snow. It is completely unnecessary to use the compression mechanism to heat.
The source of warm air is the temperature of coolant, which comes from the temperature generated by engine operation. After the vehicle is started, the engine will generate a certain amount of heat every time it explodes. Coolant plays a role in cooling the engine, and cooling is heat absorption.
After heat is absorbed, it will continue to accumulate. However, after the coolant flows to the radiator water tank in front, the water temperature can be reduced by the fan and natural wind, so that the circulation ensures that the engine is always at a reasonable temperature. Actually, the heat of coolant is wasted, so it is better to make good use of it in winter than to waste it. Therefore, there is a warm air tank, and its principle design is the same as that of the front radiator water tank, except that it does not need active heat dissipation.
The high-temperature coolant continuously flows through the warm air tank to heat the water tank, and then the fan blows natural wind through the high-temperature water tank to heat the air, and finally it is sent into the car, which is the source of warm air for the car.
As for the precautions for using warm air, there is nothing for the car, except that there is no warm air when the water temperature is too low after cold start, and the fan can be turned on normally after the water temperature rises.
However, if you drive a vehicle for a long time and use warm air, you should use more external circulation and less internal circulation. Otherwise, there are too many people in the car, the driving time is too long, and the oxygen content in the car is low. That's why driving for a long time makes you feel a little groggy. However, after switching the external circulation, the mixing of hot air and natural air will increase the oxygen content in the air.
Unpopular knowledge: most models will not completely shut down the vehicle, leaving about 10% natural air intake to prevent the oxygen content from being too low, but the actual effect depends on the number of passengers in the vehicle.
Safety precautions: turn on the warm air to rest in the car, and choose a ventilated place outside. In places without ventilation, such as parking lots, the gap of 10% will still lead to exhaust gas entering the car, and once carbon monoxide poisoning occurs, the consequences will be very serious.