What is a common sign of a low refrigerant charge in a system?

A common sign of a low refrigerant charge in an air conditioning system is the presence of bubbles in the sight glass. The sight glass is a visual inspection point where the technician can observe the flow of refrigerant. When the refrigerant level is low, the refrigerant may not fully condense back into a liquid state in the sight glass, leading to the formation of bubbles. A steady stream of bubbles indicates that the system is not adequately charged with refrigerant, which can impair the cooling process and affect system performance.

In a fully charged system, the sight glass should ideally show a clear, uninterrupted view of liquid refrigerant. The presence of bubbles serves as a crucial diagnostic tool that helps technicians quickly identify refrigerant issues, allowing for prompt maintenance or repairs to restore system efficiency.