a cold - accumulation type refrigerator having variable length cycle for cooling by means of the cold - accumulation material . the cycle length is a function of refrigerator load . the refrigerator includes a refrigerating cycle to cool a refrigerator compartment and the cold - accumulation material , a load detecting device , such as a room temperature detecting device , to measure an amount of a load to be cooled , clock counting device to generate a time data , and a control device , such as microcomputer . the control device controls the operation of the refrigerator which operates in a first mode , a second mode wherein the refrigerator compartments are cooled by means of the cold accumulation material and a third mode wherein the cold accumulation material is cooled . the control device controls the time period for second and third mode operation as a function of load to be cooled .