Which button in the car is for internal circulation and which is for external circulation?
1 Answers
A circular arrow inside the car represents internal circulation, while an arrow pointing from outside into the car indicates external circulation. Internal circulation, which does not involve external air, offers advantages such as fuel efficiency and faster cooling (or heating). External circulation can replenish fresh air inside the car even when the fan is not turned on. Internal circulation means air circulates only within the car, driven by the blower to maintain airflow inside. External circulation connects the interior with the outside environment, allowing airflow to automatically enter the car due to wind pressure while driving. When stationary, outside air can still flow through the ducts into the blower and then into the car. Car air conditioning systems generally include cooling, heating, and ventilation functions, with modes for internal and external circulation. Internal circulation is typically used during traffic jams. When cooling, it's best to start with internal circulation to lower the cabin temperature quickly, then switch to external circulation after some time. Besides cooling and maintaining air circulation inside the car, the car air conditioning system also helps defog windows in winter or humid conditions when fogging can obstruct the driver's view. Pressing the AC button activates the defogging function, effectively solving the issue of fogged windows.
