Where does the low side of the system start and end?

The chosen answer accurately outlines the flow of refrigerant in a typical refrigeration cycle. In this cycle, the low side of the system is defined as the section where the refrigerant is in a low-pressure, low-temperature state. This flow starts at the hand expansion valve, where the refrigerant experiences a drop in pressure as it expands.

From the expansion valve, the refrigerant then enters the evaporator, absorbing heat and thus cooling the surrounding environment. After the refrigerant absorbs heat and changes from a liquid to a vapor, it makes its way to the compressor, where it is compressed back into a high-pressure state, completing the cycle. Hence, defining the low side's start at the hand expansion valve and ending at the compressor aligns perfectly with the operational principles of a refrigeration system.

Understanding the flow direction and pressure states of refrigerants is crucial for those involved in high-pressure piping and refrigeration practices, ensuring proper functioning and safety within these systems.