Air conditioning is a complex system comprising an air circuit and a closed fluid circuit (air conditioning loop). The objective of this system is to remove heat from air entering the cabin (through the evaporator). As a result, this heat is delivered to the outside air under the bonnet (through the condenser).

Air conditioning uses a simple principle of physics in the closed fluid circuit: The refrigerant absorbs heat by changing from a liquid to a gas state and releases heat by changing from a gas to a liquid state.

Whilst circulating inside the air conditioning loop, the refrigerant changes successively from gas to liquid states. These changes of state in the fluid enable the air circuit surrounding it to:

- cool the external air (or internal air if the recycling mode is in operation) and to send it into the interior of the cabin in a cooled state.