Abstract: A multiple-compressor refrigeration system for use in commercial refrigeration applications includes a plurality of compressors of unequal refrigeration capacity connected in a refrigeration circuit that includes a condenser and a plurality of associated evaporators and expansion devices in remotely located refrigerated enclosures. A system controller is connected to a pressure responsive transducer that measures the suction pressure of the system and compares the so-measured suction pressure to a desired suction pressure and selects one of a plurality of 2.sup.n available compressor operating states in accordance with the measured difference. The system advantageously increases overall system efficiency by providing increments or decrements of compressor capacity that are more precisely matched to system load changes as compared to prior multiple-compressor systems.

Abstract: Foam plastic is injected into a hollow space between the inner and outer skin of a refrigeration unit. Contained in the foam plastic are metal plates positioned at points where walls, dividers or shelves may be attached to the refrigeration unit. The foam plastic hardens around the metal plates. Self taping screws drill through the skin, foam plastic and plate to rigidly attach structure being supported to the plate with a minimum amount of heat transfer through the foam plastic and metal plates.