Abstract: A high performance refrigerator includes a cabinet with a refrigerated interior and a refrigeration fluid circuit having first and second evaporators located within the cabinet and separated from the refrigerated interior by an insulating cover. The refrigerator also includes a first damper controlling flow from the refrigerated interior into the first evaporator, a second damper controlling flow from the first evaporator to the second evaporator, and a third damper controlling flow from the second evaporator to the refrigerated interior. The first evaporator operates with refrigerant at a lower temperature than the second evaporator such that substantially all frost formed on the first and second evaporators is collected on a first evaporator coil in the first evaporator. Thus, the first evaporator acts as a sacrificial evaporator that undergoes defrost more frequently than the second evaporator.

Abstract: In coolness storage apparatus wherein brine in heat exchange tubes freezes and melts water and air is bubbled up through the water during the melting cycle to enhance heat exchange efficiency by gently circulating the water, vertical heat transfer strips in thermal conducting contact with the tubes for accelerating melting along each strip early in the discharge cycle to open channels through which the air bubbles stream to the top zone of the tank.