The air conditioning equipment you can find in your vehicle is made up of compressors, condensers, evaporators, orifice tubes or expansion valves, and an accumulator or receiver-drier. These all play a different role within your AC system. Refrigerant is required to remove hot air and moisture. The vehicle's compressor compresses the refrigerant into a liquid, putting it in a high-pressure state. Because of this pressure, the liquid is forced out of your compressor and into the hoses within your AC hose assembly to carry the refrigerant through the system.