What type of refrigerating systems require an automatic purge unit?

An automatic purge unit is crucial for systems operating below atmospheric pressure because these systems can accumulate non-condensable gases, such as air or moisture, which can negatively impact performance and efficiency. The presence of these gases can lead to higher pressures and affect the refrigerant cycle, resulting in reduced cooling capacity and potentially causing damage to the compressor.

Automatic purge units help maintain system efficiency by regularly removing these non-condensable gases from the refrigerant loop, ensuring that the system operates as intended. This is particularly important in low-pressure systems since they are more susceptible to contamination from unwanted gases. Therefore, the inclusion of a purge unit in these systems is vital for optimal operation and reliability over time.

Other systems, such as those operating at atmospheric pressure or above, typically have different mechanisms or do not face the same level of risk from non-condensable gases. Consequently, they don’t require automatic purge units in the same essential way as systems operating below atmospheric pressure.