Adaptive defrost control system for a refrigerator

摘要

An adaptive demand defrost control system controls the length of an interval between defrost operations in accordance with the number and duration of compartment door-openings, the duration of a previous defrost operation as corrected by the temperature of the evaporator prior to defrost, and the length of time the compressor has been energized. A count is stored which is varied according to a decrementing schedule, with the decrementing schedule in turn being based upon a comparison of the corrected defrost duration with either a desired defrost duration or a range of desired defrost durations. A defrost operation is initiated when the count reaches a predetermined value. An alternative embodiment of the invention develops an indication of the ambient humidity and controls humidity-dependent apparatus in accordance with the indication.