Using External or Internal Air Circulation in Winter?

[Ezekiel]

It is better to use external air circulation in winter. Here is extended information about internal and external circulation: 1. Internal circulation means the air circulates inside the vehicle without exchanging with the outside air, resulting in higher heating efficiency. However, since vehicles are usually in a closed state during winter driving, prolonged use of internal circulation will degrade the air quality inside the car. For short trips, using internal circulation is sufficient. 2. External circulation exchanges air with the outside, so heating efficiency is slower, but the air quality inside the car will be better. For long-distance driving, you can consider using internal circulation first and switching to external circulation periodically. If the outside air quality is poor, be cautious when using external circulation.