Should the Air Conditioning Be Set to Internal or External Circulation in Winter?

[DeEmersyn]

In winter, it is advisable to use the external circulation mode for the air conditioning. Due to the cold weather, car windows are usually kept closed, which can lead to an increase in carbon dioxide levels inside the vehicle over time, making the driver drowsy. Prolonged inhalation of stagnant air can also affect the health of the occupants, increasing the risk of respiratory diseases. The external circulation mode works by using a fan to draw outside air into the car. Even if the fan is not turned on, the movement of the vehicle will still allow some outside air to enter, replenishing the fresh air inside. On the other hand, the internal circulation mode closes off the airflow passage between the inside and outside of the car. Without the fan, there is no air circulation, and when the fan is on, the air drawn in comes solely from inside the vehicle, creating an internal airflow cycle.