In addition to the compressor, condenser, receiver, and evaporator, several auxiliaries are required for proper operation of an air conditioning system. Certain devices must be furnished for the controlled expansion of the refrigerant from the high condenser pressure to the low evaporator pressure. Controls are also necessary for the on-off operation of the compressor, flow of the condensing medium, and safety purposes. Proper piping is required for interconnection of the various parts of the system.
