It is the periodic removal of forming ice from the evaporator. After a certain period of use of the refrigerator or freezer, a layer of ice forms on the walls of the evaporator. Contrary to popular belief that the more ice in the evaporator, the better its operation, we can say that when the ice sheet formed on the surface of the evaporator walls reaches 5mm, it acts as a thermal insulation. This results in a drop in evaporator efficiency and therefore an increase in the internal temperature of the cabinet.
Periodic defrosting is therefore essential for efficient and economical operation of the refrigerator or freezer. In general, the evaporator should be defrosted once a week. When large amounts of moist food are stored in the refrigerator, or if the weather is exceptionally humid, it becomes necessary to defrost more frequently.
Some refrigerators or freezers have automatic defrost system that works with time control or by the number of times the external door is opened.
As the ice formed in the evaporator results from the freezing of the moisture of the food from the liquids and the air, they must be protected with aluminum foil, plastic bags and containers with a lid. And the outer door should be opened in moderation. It is always good to clean the refrigerator during the defrost. The internal cabinet should be rinsed with sodium bicarbonate solution or similar product and lukewarm water and properly wiped.
