Should You Use the External Air Circulation When Running the Car AC in Summer?
2 Answers
You should use the external air circulation when running the car AC in summer. The correct way to turn on the car AC in summer is: first turn on the external air circulation to expel the hot air inside the car. After feeling a significant drop in the cabin temperature, you can then switch to internal air circulation. Internal Air Circulation System: The air exchange channel between the inside and outside of the car is closed. When the fan is off, the airflow inside the car does not circulate. When the fan is on, the inhaled airflow comes only from inside the car, forming an internal airflow circulation. External Air Circulation System: The external air circulation mode uses the fan to draw air from outside the car into the cabin. The air blown by the fan comes from outside the car. Even if the fan is off, airflow is still drawn into the car while driving, replenishing fresh air inside the car.
Should you use the air recirculation mode when running the car AC in summer? After driving for over a decade, I believe this depends on the situation. When it's extremely hot initially, I definitely turn off the fresh air intake and use recirculation mode first. This allows the car's interior air to be repeatedly cooled, making the AC more powerful, cooling the cabin faster, and saving some fuel. Once it cools down—say after 15 minutes or when feeling slightly stuffy—I switch to fresh air mode for a few minutes to let in some outside air and prevent dizziness. However, summer street air tends to be polluted, especially during traffic jams or while waiting at red lights. In these cases, using fresh air mode might draw in exhaust fumes, so I generally avoid it and stick with recirculation for safety. Overall, recirculation mode is my go-to—convenient and efficient. Just remember to replace the cabin air filter regularly, otherwise ventilation won't be clean anyway.
