The interior fan moves outside air into the cabin. The occupants of the vehicle can control the temperature by heating or cooling the air. The latter is possible when the vehicle is equipped with air conditioning. Today, almost all passenger cars and commercial vehicles come standard with air conditioning. The operating principle of air conditioning is based on the state changes of the refrigerant, in which it changes from vapor to liquid and vice versa in different parts of the system. During the phase transition from liquid to vapor (evaporation process), heat is absorbed, cooling the incoming air and creating a refreshing effect in the interior.
As early as 1939, the car brand Packard was the first car manufacturer to use air conditioning in a car. From the 1960s onwards, air conditioning became popular in American cars and from the 1990s also in European cars. Almost all cars currently being produced are standard equipped with air conditioning.
The tiles below show the different processes and components that are part of the air conditioning system. On the page “Air conditioning introduction” the general operation of the air conditioning system is described. The topics that can be accessed via the other tiles go into more detail about the respective component, describing the different designs and any fault symptoms that may be encountered in the workshop.