Which of the following is NOT a thermodynamic property of refrigerants?

The critical point, saturation point, and enthalpy are all recognized thermodynamic properties of refrigerants. Understanding each of these properties is essential for the efficient design and operation of HVAC systems.

The critical point refers to the specific pressure and temperature at which a refrigerant can no longer exist as a liquid and vapor in equilibrium. This point is crucial for determining the limits of operation for refrigerants in a thermodynamic cycle.

The saturation point is another important property, as it signifies the conditions under which refrigerants transition between liquid and vapor phases. This understanding helps in optimizing the heat exchange processes within systems.

Enthalpy is a key thermodynamic property that represents the total heat content of a refrigerant. It plays a critical role in calculations for heating and cooling loads, ensuring that systems can efficiently transfer energy.

In contrast, while density is an important physical property of refrigerants, it is not classified as a thermodynamic property since it does not directly relate to heat and work interactions in the same way as the other options. Therefore, it does not fit within the framework of thermodynamic analysis as the others do.