What effect do non-condensables have in a refrigeration system?

Non-condensables in a refrigeration system can significantly impact its performance and efficiency. When non-condensables, such as air or other gases that do not condense under system pressures, are present in the refrigeration circuit, they interfere with the normal operation of the system.

Higher discharge pressure is a result of non-condensables being present. These gases accumulate in the condenser section where the refrigerant normally releases heat and changes from vapor to liquid. Since non-condensables do not condense, they take up space in the condenser, causing the refrigerant to face increased pressure as it attempts to flow through the system. This elevated pressure can lead to higher operating temperatures and an increased load on the compressor. Ultimately, this situation decreases the overall efficiency of the system.

While the other options mention effects that are generally negative aspects of non-condensables, none of them correctly capture the primary impact, which is the increase in discharge pressure, leading to a less efficient system.