With a NoFrost model, the humidity in the air is collected on the central fin evaporator rather than building up in the applicance or on the foods. This chiller, which draws the wamth out of the freezer area, automatically defrosts from time to time. The resultant condensation is taken to the outside and evaporated using the compressor warmth in a special collecting pan. This lowers humidity in the appliance, which means that almost no ice forms. So you don't need to worry about defrosting any more.