Should the Car Air Conditioner Use Internal or External Circulation?

[SanBrynlee]

Whether to use internal or external circulation in a car's air conditioning depends on the situation: use internal circulation for short trips and external circulation for long trips. Internal and external circulation in cars refer to: 1. Internal circulation means the air conditioning system is closed to outside air and only recirculates the air inside the car; 2. External circulation means the car's air conditioning system is open to outside air, drawing in and circulating air from outside the car. The functions of a car's air conditioning are: 1. To cool, heat, ventilate, and purify the air inside the car; 2. To provide a comfortable environment for passengers, reduce driver fatigue, and improve driving safety.