Abstract: An apparatus includes a separator tank, a heat exchanger, a compressor-less heat separator, and a fluid cooler. The separator tank separates a first refrigerant into a vapor component and a liquid component. The heat exchanger is exposed to a load. The heat exchanger uses the liquid component of the first refrigerant to remove heat from a space proximate the load. The space includes at least one of a refrigeration unit and walk-in cooler or freezer. The compressor-less heat separator extracts heat from the vapor component of the first refrigerant and uses electrical power to move the heat to a second refrigerant. The fluid cooler removes heat from the second refrigerant.

Abstract: An apparatus includes a separator tank, a heat exchanger, a compressor-less heat separator, and a fluid cooler. The separator tank separates a first refrigerant into a vapor component and a liquid component. The heat exchanger is exposed to a load. The heat exchanger uses the liquid component of the first refrigerant to remove heat from a space proximate the load. The space includes at least one of a refrigeration unit and walk-in cooler or freezer. The compressor-less heat separator extracts heat from the vapor component of the first refrigerant and uses electrical power to move the heat to a second refrigerant. The fluid cooler removes heat from the second refrigerant.

Abstract: An improved defrost controller is provided for a space cooling system of the type having an evaporator in heat exchange relationship with a space to be cooled, a condenser external to the space, a compressor for circulating heat transfer fluid between the evaporator and condenser, an expansion valve located between an outlet from the condenser and an inlet to the evaporator, and a defroster operatively associated with the evaporator. The expansion valve is positionable in a plurality of positions between a fully open position and a fully closed position to maintain a desired level of superheat across the evaporator. The defrost controller monitors the expansion valve position and activates the defroster in response to the expansion valve being in a more closed position than a predetermined defrost target position.

Abstract: An improved defrost controller is provided for a space cooling system of the type having an evaporator in heat exchange relationship with a space to be cooled, a condenser external to the space, a compressor for circulating heat transfer fluid between the evaporator and condenser, an expansion valve located between an outlet from the condenser and an inlet to the evaporator, and a defroster operatively associated with the evaporator. The expansion valve is positionable in a plurality of positions between a fully open position and a fully closed position to maintain a desired level of superheat across the evaporator. The defrost controller monitors the expansion valve position and activates the defroster in response to the expansion valve being in a more closed position than a predetermined defrost target position.

Abstract: A heat exchanger fin having enhanced corrugations is provided. The corrugations define a generally sinusoidal wave pattern in a transverse direction across the fin. The fin is particularly well-suited for use in a heat exchanger, such as an evaporator or condenser, in a refrigeration system where the spacing between adjacent fins tends to be greater than in an air conditioning system. For example, when the spacing between adjacent fins is in a range from about 2 to 8 fins per inch, the height of the corrugations is greater than the fin spacing. The greater corrugation height bends the air passing between adjacent fins to a greater extent than prior art corrugated fins, thereby causing a greater volume of air to follow the contours of the corrugations and to come into contact with the surfaces of the fins to enhance heat transfer between the air and the fins. Further, the airflow upstream of the fin collars is defined by a larger vortices than in prior art corrugated fins, which further improves heat transfer.