On low-pressure chillers, how does moisture typically enter the refrigerant system?

The correct choice indicates that moisture typically enters the refrigerant system on low-pressure chillers through tube leaks. This understanding is crucial because low-pressure systems are more susceptible to absorption of moisture due to their operating characteristics.

When there are leaks in the tubes, atmospheric moisture can seep into the system. This moisture can lead to serious problems, such as corrosion and the formation of acids, which can compromise the integrity and efficiency of the refrigeration cycle. Because low-pressure systems operate below atmospheric pressure, they can draw in air and moisture, which further compounds issues related to contamination.

The other potential sources for moisture entry, while relevant in different contexts, do not primarily account for moisture entry in the same notable way as leaks do. For example, while improper servicing can introduce contaminants, it is less direct than the persistent issue of ongoing tube leaks. Similarly, refrigerant line connections can be a source of leaks, but they typically represent a smaller risk compared to systemic failures in the tube integrity. Malfunctions in the evaporator can create other operational issues but do not inherently relate to the influx of moisture in the refrigerant. Thus, pinpointing tube leaks as the primary way moisture enters the system is important for maintaining the performance and longevity of low-pressure chillers.