Internal and external air circulation in a car differ in terms of symbols, usage scenarios, and functions. The specific differences are as follows: Different symbols: Internal circulation means the air inside the car flows in a closed loop, represented by an icon of a closed car interior with a circular arrow. External circulation, on the other hand, brings outside air into the car, represented by an icon of an open car with an arrow pointing from the outside into the car. Different functions: Internal circulation refers to the process where the air inside the car is heated or cooled and then recirculated within the car. External circulation involves drawing air from outside the car, heating or cooling it, and then sending it into the car, facilitating gas exchange between the inside and outside of the car. Different scenarios: When turning on the air conditioning for cooling or heating, you can first activate the internal circulation to quickly lower or raise the temperature inside the car. Once the temperature stabilizes, you can switch to external circulation to exchange air with the outside. If the outside air quality is poor, such as in heavy traffic with high exhaust emissions or in underground parking lots with poor air, avoid using external circulation. When driving on highways, do not open the windows; instead, use external circulation. In summary, when the outside air is good and the car feels stuffy, quickly switch to external circulation for fresh air. To control the temperature inside the car, use internal circulation.
