Agricultural Engineering Practice Exam

Frost formation on an evaporator is known to impede its efficiency. When frost accumulates, it acts as an insulating barrier between the refrigerant and the air or fluid that is being cooled. This insulation prevents effective heat exchange, which is crucial for the evaporator's performance. As a result, the evaporator has to work harder to achieve the desired cooling effect, leading to increased energy consumption and reduced overall efficiency.

Moreover, frost buildup can restrict airflow, which further diminishes the evaporator's capability to transfer heat. If airflow is compromised, the temperature differential needed for optimal heat exchange is lessened, making it difficult for the evaporator to function efficiently.

In contrast, avoiding frost accumulation and maintaining proper airflow around the evaporator can enhance operational efficiency, leading to improved performance and energy savings. Thus, the impact of frost formation is deleterious to the functioning of the evaporator, affirming that it indeed decreases efficiency.