The compression refrigeration cycle which is described earlier is also used in air-conditioner. The basic components are compressor, condenser, capillary and evaporator in addition to filters, accumulators, motors, fan and controls. High pressure, high temperature refrigerant gas coming out of compressor is condensed in the condenser using outside air as coolant. The liquid refrigerant is further passed through capillary to reduce the pressure and then it is passed through the evaporator. The air from the room is passed over the evaporator where it is cooled to require temperature and then discharged in the room itself. The evaporator refrigerant vapour coming out at lower pressure from the evaporator is compressed in the compressor and cycle is repeated. The arrangement of the refrigeration system using a sealed unit in air-conditioner is shown in figure..
The window-unit compressor is of the hermetic type. This kind of unit has the compressor, its motor, and all moving parts operating within a sealed gas tight housing which is welded and closed.
The copper capillary tube is 40 cm long with an inside diameter of 0.75 mm. The dimensions are based upon the desired pressure difference between evaporator and condenser.