A car air conditioner gets the air it cools from the surrounding environment outside the vehicle. When you turn on the car's air conditioning system, it utilizes the air already present in the cabin to cool it down. The system doesn't bring in fresh air from outside; instead, it recirculates the air within the car to provide a more effective cooling process.
The process works as follows:
Air intake: The air conditioning system draws the warm air from inside the car through an intake located in the cabin. This air may be a bit hotter than the ambient air outside, especially if the car has been parked in the sun.
Cooling: The warm air is directed over the evaporator, a component within the air conditioning system that contains a refrigerant, typically a gas. As the warm air passes over the evaporator, the refrigerant absorbs the heat from the air, causing the air to cool down.
Dehumidification: In addition to cooling the air, the evaporator also acts as a dehumidifier. It removes moisture from the air, which helps to reduce the humidity level inside the car, making it feel more comfortable.
Recirculation: After cooling and dehumidification, the cold air is then blown back into the car's cabin through the vents, providing a refreshing and cool environment.
The air conditioner continues to cycle and cool the air inside the cabin until you turn off the system or adjust the temperature settings. It's important to note that the car's air conditioning system is separate from the ventilation system, which allows fresh air from outside to enter the cabin when you have the vents open or the system set to draw in outside air. However, during cooling, the AC system mainly recirculates the air within the car to achieve better efficiency and faster cooling.