Why might a 35°F medium temperature case require defrosting?

A 35°F medium temperature case typically operates in environments meant for storing perishable items, and it is crucial for the evaporator coils to maintain specific temperature ranges to function properly. The correct response recognizes that the coil temperature operates below freezing when functioning within the design specifications of a medium temperature case set to 35°F.

When the coil temperature drops below freezing, frost can form on the coils or evaporator, which impacts the system’s efficiency in heat exchange. As frost builds up, it insulates the coils and hinders airflow, leading to reduced cooling performance and potential temperature fluctuations within the case. Eventually, this frost accumulation necessitates a defrost cycle to clear the coils, ensuring efficient operation and maintaining the desired temperature for the goods stored within.

This understanding highlights the importance of maintaining the proper temperature range for both the case and the coils in refrigeration systems, particularly in applications where consistent temperatures are vital for product safety and quality.