The compressor during its operation creates a pressure difference between the evaporator and the condenser. This removes gaseous coolant to the evaporator, resulting in a decrease in suction pressure. This mass through the work of compression undergoes a change in the enthalpy, also resulting in an increase in the properties of temperature and pressure.
Refrigerant fluid which is above room temperature as it passes through the condenser transfers an amount of heat to the air passing through the condenser, that amount of air which must correspond to the latent heat of the refrigerant so that the refrigerant to the liquid state.
The result of the passage of the refrigerant through the condenser was a decrease in its enthalpy.
But it is with this enthalpy value, in spite of a lower pressure and temperature, that the refrigerant has when passing through the expansion valve or capillary tube. In this way, it is able to absorb heat from the air passing through the evaporator, recovering much of its enthalpy from the liquid state to the gaseous state.
