What is the primary purpose of oil in a refrigeration machine?

• A. Reduce wear and friction in the compressor parts
• B. Increase cooling capacity
• C. Improve refrigerant flow
• D. Seal gaps in tubing

Answer: (C)

Oil’s primary role is to lubricate the compressor, reducing wear and friction on the moving parts and helping seal the cylinder clearances. When the compressor is well-lubricated, it can move smoothly and maintain the proper pressure differential, which keeps the refrigerant flowing through the evaporator, compressor, condenser, and piping with less resistance. That smoother, more consistent operation directly supports better refrigerant flow through the system. While oil also aids sealing and cooling in some ways, the most direct impact on how the refrigerant moves is through lubrication that minimizes internal losses and leakage.