welcome to the refrigeration fundamentals video series there are three videos in this series the refrigeration cycle the PT chart and the pressure endp diagram in this video we will explore the refrigeration cycle every refrigeration cycle has at least these four components the compressor the compressor increases the refrigerant temperature through compression the condenser the condenser rejects heat the metering device the metering device decreases the refrigerant temperature the evaporator the evaporator absorbs heat let's define a few basic Refrigeration terms saturated refrigerant a condition where both liquid and Vapor phases coexist in equilibrium at a specific temperature and pressure saturated temperature the temperature at which a refrigerant changes its States from Vapor to liquid or liquid to Vapor at a given pressure when heat is rejected the vapor will condense into a liquid and not change temperature when heat is absorbed the liquid refrigerant will boil to a vapor and not change temperature boiling point is used interchangeably with saturated temperature the super heat is the temperature above the boiling point at any given pressure any superheated refrigerant will be 100% Vapor the subcooling is the temperature below the boiling point of a given pressure any subcool refrigerant will be 100% liquid [Music] the metering device and the compressor divide the circuit between a high pressure high temperature side and a low pressure low temperature side the refrigeration cycle process begins with the compressor the compressor receives a low pressure low temperature superheated refrigerant vapor from the suction line and compresses it into a high press high temperature superheated refrigerant Vapor the high pressure high temperature superheated vapor from the compressor is then sent to the condenser through the hot gas discharge line the condenser rejects heat the superheated refrigerant drops in temperature until the first drop of liquid refrigerant is formed the refrigerant is now saturated this process is known as desuperheating as more heat is rejected the refrigerant undergoes a phase change without any change in temperature the saturated refrigerant condenses to 100% high-press subcooled liquid the high-press subcooled liquid refrigerant moves through the metering device rapidly reducing its pressure this sudden pressure drop causes refrigerant to expand and cool rapidly transforming it into a saturated low pressure low temperature refrigerant the saturated low temperature refrigerant now enters the evaporator through the distributor tube as the saturated low pressure low temperature refrigerant enters the evaporator it absorbs heat and undergo a phase change from a liquid to a low pressure low temperature superheated vapor and then the cycle repeats itself [Music]