Patent ID: 7089756

Claim:
A method of refrigerating at least one enclosure comprising: refrigerating at least one interior of the at least one enclosure in a plurality of consecutive modes comprising at least a direct passive mode, an indirect passive mode, a direct active mode and an indirect active mode, wherein the mode of refrigerating is selected at least partially based upon a temperature of a phase change material, and wherein refrigerating the at least one interior in the indirect passive mode comprises: placing a coolant in a first coolant loop in thermal communication with the at least one interior such that the coolant carries heat away from the at least one interior; absorbing the heat carried away by the coolant in the first coolant loop, wherein the heat is absorbed by the phase change material; placing a coolant in a second coolant loop in thermal communication with the phase change material such that the coolant carries away the absorbed heat; and placing the coolant in the second coolant loop in thermal communication with a cold heat sink such that the cold heat sink absorbs the heat carried by the coolant.