What does the car's internal and external circulation mean?
2 Answers
Internal and external circulation in a car refer to: Internal circulation closes the airflow passage between the inside and outside of the car. When the fan is turned on, there is no airflow circulation, and the air drawn in by the fan comes only from inside the car, forming an internal airflow cycle. External circulation uses the fan to draw air from outside the car into the interior, meaning the air passage between the outside and inside of the car is open. The air blown by the fan comes from outside the car, and even if the fan is not turned on, airflow is still drawn into the car while driving, replenishing fresh air inside. The symbols for internal and external circulation are: 1. The internal circulation symbol is a small car shape with a rotating arrow inside; 2. The external circulation symbol is an arrow passing from the front windshield into the car.
When I first started driving, I wasn't quite clear about the air recirculation function either. I just knew I had to switch it when the AC felt stuffy. Simply put, the recirculation mode keeps the air inside the car circulating - the AC keeps blowing the same air mass. This helps retain warmth in winter or cool down faster in summer while saving fuel. The fresh air mode, on the other hand, draws in outside air. It keeps you cool with AC on, though less efficient in summer and consumes more gas. I often use recirculation in traffic jams to block exhaust fumes. On highways or rainy days, I switch to fresh air mode for better ventilation and faster defogging. Just remember not to use recirculation mode continuously - stale air can cause dizziness. The fresh air mode feels most refreshing when driving in open areas.
