What is the difference between internal and external air circulation in a vehicle?
2 Answers
The differences between internal and external air circulation in a vehicle are: 1. Different air circulation methods: External circulation draws air from outside the vehicle, which is then cooled or heated by the air conditioning system before being blown out through the vents; internal circulation draws air from inside the vehicle. 2. Different symbols on the vehicle's air conditioning panel: The external circulation symbol shows an arrow from outside to inside; the internal circulation symbol shows an arrow pointing inward. 3. Different functions: External circulation brings fresh air from outside into the vehicle to maintain air quality; internal circulation effectively blocks external dust and harmful gases from entering the vehicle, improving the cooling and heating efficiency of the air conditioning system.
The main difference between the vehicle's recirculation mode and fresh air mode is significant, and I frequently use these two modes to control the cabin environment while driving. Recirculation mode keeps the air circulating inside the car without drawing in outside air, making it suitable for highway driving or when external pollution is high, as it quickly cools or warms the cabin. However, prolonged use can make the cabin stuffy. Fresh air mode, on the other hand, introduces outside air, which is ideal during traffic jams or when the outside air quality is good, especially for preventing window fogging or improving air quality. I've noticed that using recirculation mode with the AC in summer can save some fuel, but switching to fresh air mode periodically for ventilation feels more comfortable. In winter, it's recommended to first use fresh air mode to remove moisture and then switch to recirculation mode to retain warmth. Most vehicles allow switching between these modes via buttons on the AC panel, and models with automatic AC systems can intelligently adjust the modes, which is quite convenient. In short, flexible use of these modes ensures a comfortable driving experience.
