In a refrigeration system, the presence of bubbles in the sight glass typically indicates what?

The presence of bubbles in the sight glass of a refrigeration system typically indicates insufficient refrigerant. A sight glass is a clear viewing window that allows operators to observe the state of the refrigerant as it flows through the system. When refrigerant levels are proper, the sight glass should appear clear or show a steady fluid without bubbles. The appearance of bubbles suggests that there is not enough refrigerant in the system to maintain the necessary pressure to keep it fully liquid in the sight glass.

This condition can lead to inefficient cooling and potential damage to the compressor, as it may be forced to operate with vapor instead of liquid refrigerant. Thus, monitoring the sight glass for bubbles is important in maintaining the efficiency and longevity of the refrigeration system.