ESCO Air Conditioning Practice Exam

In what state is refrigerant in the suction line during normal operation?

1. High pressure liquid

2. High pressure vapor

3. Low pressure liquid

4. Low pressure vapor

The correct answer is: High pressure liquid

During normal operation, the refrigerant in the suction line is in a low-pressure vapor state. This is because the refrigerant has absorbed heat from the space being cooled and has evaporated into a vapor form. The suction line connects the evaporator coil to the compressor, carrying the low-pressure refrigerant vapor back to the compressor for compression and subsequent heat rejection in the condenser coil. Therefore, option A (High pressure liquid) is incorrect as the refrigerant in the suction line is a low-pressure vapor, not a high-pressure liquid. Options B (High pressure vapor) and C (Low pressure liquid) are also incorrect as the refrigerant in the suction line is not in these states during normal operation.