Defrosting Methods in Refrigeration

Refrigeration Defrost

This article is intended to introduce the defrosting methods in refrigeration equipment. More specifically in freezers. The majority of all freezers have a defrost cycle of some sort. In general the sequence of operation is the same, although components differ from unit to unit in many cases. We will explore the defrost cycle and the why it is necessary for freezers to have them. By the end of reading this you should a basic understanding of why defrost cycles are necessary, the primary methods of defrosting, as well as how they are initiated and how they are terminated.

Understanding Refrigeration Defrost Cycles – Why it’s Needed

The basic principle of refrigeration is to remove heat from the desired space or product, then get rid of the absorbed heat outside of the refrigerated area. The component responsible for absorbing the heat from the refrigerated area is called the evaporator coil. This component is nothing more than multiple loops of copper and aluminum with a fan motor to move air through it. The idea is to allow low temperature refrigerant, generally in the negative degrees, to absorb the heat from the air traveling through the evaporator coil. Continue reading “Defrosting Methods in Refrigeration”

Walk-in Freezer with Defrost Issue

Kolpak Walk-in Freezer with Defrost Issue – Evaporator is Covered with Ice

After arriving at the location and speaking with client, I found the walk-in freezer temperature at approximately 50*F. Noticed that the evaporator coil was covered with ice, blocking air flow. Looks like a possible defrost issue. Went to the roof top and found condenser operational. Placed unit into defrost and check to see if defrost heaters were pulling amps. Clamp meter reading 6 amps during defrost.  Data plate stated 6.3 heater amps. Allowed defrost to operate to melt ice from coil. After ice removal placed defrost timer at 3 pm. After 15 minutes of operation, timer clock did not move from the 3 pm position. Continue reading “Walk-in Freezer with Defrost Issue”