Should You Use Internal or External Air Circulation for Car Heating in Winter?

[Leila]

Whether to use internal or external air circulation for car heating in winter depends on the situation. For short trips, internal circulation is suitable; for long-distance driving, it is recommended to use external circulation to replenish fresh air. If driving in heavy traffic, internal circulation is advisable to prevent exhaust fumes from entering the car. During winter, car air conditioning is used almost daily for both heating and cooling. The heating principle of car air conditioning is much simpler than cooling. When heating, the engine's hot coolant flows through the heater core, and the air blown by the blower passes over the heater core, allowing warm air to flow out of the vents.