What issue can be caused by excessive frost buildup on evaporator coils?

Excessive frost buildup on evaporator coils can lead to reduced cooling capacity. This frost acts as an insulator, which impedes the efficient transfer of heat between the air and the refrigerant flowing through the coils. As a result, the system struggles to effectively absorb heat from the space being cooled, leading to an overall decrease in the cooling performance of the refrigeration system.

Additionally, as the frost accumulates, it can result in the coils becoming unable to cool the air effectively, which may cause the temperature of the refrigerated space to rise and affect the items being stored. This buildup can also lead to increased operational strain on the system, further compromising its performance.

In contrast, the other options suggest positive outcomes (such as improved heat transfer and increased energy efficiency) that are not achievable when frost accumulation obstructs proper airflow and heat exchange. An increase in energy efficiency or a longer equipment lifespan would typically be associated with optimal functioning rather than complications from frost buildup.