Defrosting (refrigeration)

In refrigerators, defrosting (or thawing) is the removal of frost and ice.

A defrosting procedure is generally performed periodically on refrigerators and freezers to maintain their operating efficiency.

Over time, as the door is opened and closed, letting in new air, water vapour from the air condenses on the cooling elements within the cabinet.

[1] The resulting ice inhibits heat transfer out of the cabinet increasing running costs.

Although, in some cases, users of Frost Free fridge/freezers have noted ice blocking the vent that allows air into the refrigerator compartment.