Basic Mechanical Refrigerant System Schematic

HVAC Systems & Components

Basic Refrigeration Cycle Explanation:

As the piston moves down, low-pressure gas (refrigerant) is emitted through the compressor valve to fill up the cylinder. As the piston starts up, compression takes place because the gas is forced into a smaller space. As the gas is compressed, heat of compression is added. At the top most position of the piston, the gas is forced through the exhaust valve into the condenser The gas is at its highest pressure. The condenser is a series of tubes surrounded by a cooling medium (air). As the gas is forced through the tubes, the heat of compression plus the latent heat of vaporization from the evaporator is dissipated into the surrounding cooling medium. The removal of heat causes the gas to condense to a high-pressure liquid. This liquid flows into a receiver, which is merely a storage space for the refrigerant. The liquid leaves the receiver and moves up the liquid line to the expansion valve, where the pressure of the liquid is reduced. As a result, it absorbs heat through the walls of the evaporator, lowering the temperature of the compartment to be cooled. As the liquid boils, which is caused by the heat picked up from the cooling compartment, it changes into a low-pressure gas. This low-pressure gas now enters the suction line leading to the compressor. The cycle is now complete.