Which phase will refrigerants in the suction line be in?

• A. High pressure solid
• B. Low pressure vapor
• C. Liquid
• D. High pressure vapor

Answer: (B)

In a refrigeration system, the suction line carries refrigerant from the evaporator back to the compressor. This section of the system is designed to collect refrigerant that has absorbed heat from the environment, where it has transformed from a liquid into a vapor. The refrigerant in the evaporator absorbs heat and evaporates at low pressure and temperature, which is why, by the time it reaches the suction line, it is in a low pressure vapor state.

This is essential for the ongoing refrigeration cycle, as the vaporized refrigerant must be drawn back into the compressor to create a continuous flow. If the refrigerant were in a solid, liquid, or high pressure vapor state in the suction line, it would not effectively return to the compressor for re-compression and cycle continuation. Thus, the correct understanding of the refrigerant state in the suction line is crucial for anyone working with refrigeration systems.