Red Seal Appliance Service Technician Practice Exam

What is the importance of a defrost cycle in frost-free refrigerators?

1. To maintain the structural integrity of the appliance

2. To prevent the refrigerator from freezing

3. To remove frost accumulation on the evaporator coil to maintain efficient cooling

4. To save energy consumption

The correct answer is: To remove frost accumulation on the evaporator coil to maintain efficient cooling

The defrost cycle in frost-free refrigerators is crucial for the efficient functioning of the appliance. During operation, moisture in the air can condense on the evaporator coil, leading to frost build-up. If this frost accumulates, it can insulate the coil, hindering the heat exchange process necessary for effective cooling. By initiating a defrost cycle, the refrigerator periodically melts any accumulated frost, ensuring that the evaporator coil remains clear. This process helps to maintain optimal airflow and cooling performance, which is essential for preserving food and preventing spoilage. While there are other benefits associated with a defrost cycle, such as potential energy savings and maintenance of appliance integrity, the primary purpose remains focused on the efficient cooling process by ensuring that frost does not interfere with the heat exchange required for optimal performance.