Apparatus for refrigerating, namely refrigerators; apparatus for ventilating, namely ventilating fans for commercial and industrial use; apparatus for professional refrigerating, namely refrigerating machines; food and beverage chilling units in the nature of blast chillers, freezers, shock freezers, refrigerating counters, refrigerated tables; refrigerated retarder-prover apparatus, namely refrigerating and heating machines for the control of leavening processes