What is a typical issue caused by air leaking into a refrigerant system?

Air leaking into a refrigerant system typically results in a decrease in efficiency and performance. When air enters the system, it can lead to issues such as increased pressures in the condenser. This happens because the air does not participate in the refrigeration cycle like the refrigerant, and its presence can create a rise in discharge pressure as the refrigerant has to work harder to overcome the additional non-condensable gases.

The introduction of air into the system impedes the heat exchange process in the condenser, causing it to operate inefficiently and resulting in overheating. Overheating can lead to insufficient cooling or even damage the compressor due to elevated temperatures and pressures that it is not designed to handle.

In contrast, the other choices do not accurately describe the effects of air leakage. Overcooling of the evaporator does not occur from air leaks; rather, such leaks would lead to a reduction in the temperature drop. Increased compressor efficiency is contrary to reality since adding non-condensables like air reduces overall system efficiency. Finally, decreased refrigerant pressure typically would not result from air ingress, as it generally leads to increased pressure in the system instead.