An adaptive demand defrost and two-zone control and monitor system for refrigeration products

A defrost system that adapts to usage patterns and ambient conditions is described. The following parameters determine the interval between defrost operations: the amount and duration of door openings, the length of previous defrost operations, and the current freezer temperature. A two-temperature control system which allows the user to independently select freezer and fresh-food compartment temperatures is also discussed. The compressor run time and the air flow to the fresh-food compartment are controlled to achieve the desired results. These controls have been incorporated in a total control and monitor system which was recently introduced. The other features of this control are also briefly described