In the suction line, which phase will refrigerant typically be in?

• A. Cold Vapor
• B. High Pressure Liquid
• C. Superheated Liquid
• D. Mixed Phase

Answer: (A)

In the suction line, the refrigerant typically exists as a cold vapor. This is because the suction line is where the refrigerant is returning to the compressor after it has absorbed heat from the conditioned space. As the refrigerant evaporates in the evaporator coil, it changes from a low-pressure liquid to a vapor.

The vapor in the suction line is at low pressure and low temperature, which allows it to effectively carry the heat absorbed from the surroundings back to the compressor. This is crucial for the refrigeration cycle to function efficiently, as the compressor requires a vapor to compress in order to convert it back into a high-pressure liquid in the condenser.

While other phases like high-pressure liquid or mixed phase can be present in different parts of the system, the suction line primarily contains the cold vapor form of the refrigerant, facilitating the necessary thermodynamic processes in the system.