What is the typical amount of sub-cooling for liquid refrigerant after leaving the condenser?

• A. 5K to 10K
• B. 10K to 20K
• C. 20K to 30K
• D. 15K to 25K

Answer: (B)

The typical amount of sub-cooling for liquid refrigerant after leaving the condenser is generally in the range of 10K to 20K. Sub-cooling refers to the process of cooling a liquid refrigerant below its condensation temperature at a given pressure. This additional cooling enhances the efficiency of the refrigeration cycle by ensuring that the refrigerant enters the expansion device in a completely liquid state, minimizing the risk of vaporizing during the expansion and ensuring that all the refrigerant is available for heat exchange in the evaporator.

If the amount of sub-cooling is insufficient, it can lead to issues such as reduced efficiency and potential compressor damage due to vapor entering the system where it should only find liquid refrigerant. While some variations in sub-cooling may occur depending on specific system designs and operational parameters, the range of 10K to 20K is a widely accepted standard in HVAC systems.