What is the main purpose of a purge unit in a low-pressure refrigeration system?

The main purpose of a purge unit in a low-pressure refrigeration system is to remove non-condensables. Non-condensable gases, such as air and moisture, can enter the refrigeration system and reduce its efficiency. These gases do not condense within the refrigeration cycle and can lead to issues such as higher system pressures, decreased heat transfer efficiency, and potential damage to the compressor over time.

By effectively removing these non-condensables, the purge unit helps maintain optimal operating conditions within the refrigeration system, ensuring it functions efficiently and prolonging the lifespan of the equipment. This process is essential for the performance of low-pressure systems, where the presence of non-condensables can significantly impact system effectiveness and reliability.