What is the most important line to ensure proper oil return during piping installation?

The suction line is critical for ensuring proper oil return during piping installation because it is responsible for transporting refrigerant vapor from the evaporator back to the compressor. A well-functioning suction line enables the return of oil mixed with the refrigerant from the evaporator, ensuring that the compressor is adequately lubricated.

Proper oil return is essential for the longevity and efficiency of the compressor, as insufficient oil can lead to increased wear, higher operating temperatures, and potential compressor failure. In systems where oil is trapped in the evaporator or within the piping, a properly designed and installed suction line will facilitate moving that oil back to the compressor, maintaining optimal performance and preventing oil starvation.

Other lines serve different functions; for instance, the liquid line carries refrigerant in liquid form to the expansion device, and the discharge line carries high-pressure vapor from the compressor to the condenser. While all these components are vital to the refrigeration cycle, the suction line specifically plays a major role in oil management.