Non-condensables in a refrigerant system cause the pressure to be what?

In a refrigerant system, the presence of non-condensables, such as air or other gases that do not condense at refrigerant temperatures, causes the pressure within the system to rise above normal operating levels. This is because non-condensables occupy space in the refrigerant circuit and reduce the overall efficiency of the system. When non-condensables are present, the system's ability to transfer heat is compromised, leading to higher pressures within the condenser.

Specifically, during the condensation process, the non-condensable gases do not change state and thus create an additional pressure that prevents the refrigerant from properly condensing. As a result, the system operates under higher pressure conditions, which can lead to overheating, decreased efficiency, and increased wear on components.

This situation is typically detected when monitoring pressures in the system, where elevated readings in the condenser indicate the presence of non-condensables. Therefore, understanding the role of non-condensables is crucial for maintaining the efficiency and functionality of refrigerant systems.