Where Does the Air for the Car Air Conditioning Enter the Vehicle?
3 Answers
There are two air intakes for the car air conditioning system. One is the external circulation intake, located in the box with the cabin air filter beneath the windshield. The other is the internal circulation intake, which consists of two circular openings on either side of the dashboard inside the cabin. Most vehicles' external circulation intakes are equipped with air filtration devices, such as pollen filters or dust filters. However, most internal circulation systems do not have air filtration devices. Here is an extended explanation: 1. Internal Circulation: Internal circulation means the air blown by the blower only circulates inside the vehicle. Since no external air is involved, it can quickly heat up or cool down the cabin. This mode is suitable when first turning on the air conditioning, but it should not be used for too long, as prolonged use may affect the air quality inside the vehicle. 2. External Circulation: External circulation means the blower draws air from outside the vehicle and blows it into the cabin. This mode should generally be kept on, as it introduces fresh external air to maintain cabin air quality. When the external air quality is poor (e.g., on dusty roads), the external circulation can be temporarily turned off and switched to internal circulation.
I commute by car every day, and the air intake for the car's air conditioning is usually located in the small grille at the front of the vehicle, near the front bumper where those tiny gaps are. External air is drawn in from here. When the air conditioning is set to the external circulation mode, it pulls in outside air, which passes through the filter before entering the cabin, so dust or small insects often get brought in and need regular cleaning. The internal circulation mode, on the other hand, recirculates the air inside the car to avoid external pollutants. I remember one summer when leaves blocked the air intake, and the air conditioning started smelling strange. It wasn’t until I took it to the repair shop that the issue was resolved. This experience has made me check the air intake passage during every car maintenance to ensure it’s clear, avoiding any impact on the air conditioning’s efficiency and health.
As an experienced truck driver for many years, I believe the air in the air conditioning system primarily comes from two sources: the intake vents in the vehicle structure and the recirculation system. The intake vents are usually located under the front hood or at the base of the windshield, responsible for drawing in fresh air. When set to external circulation, the fan pulls in outside airflow, filtering impurities through the filter. When switched to internal circulation, it draws and reuses existing air from the cabin seating area. These intake designs consider aerodynamic efficiency but can accumulate dust and cause odors if not cleaned regularly. I usually use compressed air to blow out the ports to maintain fresh airflow. Regularly replacing the filter is also crucial to prevent respiratory issues, especially when driving in dusty areas.
