Abstract: A refrigeration system includes a primary refrigeration circuit configured to circulate a CO2 primary refrigerant and a secondary refrigeration circuit separate from the primary refrigeration circuit. The primary refrigeration circuit includes a compressor assembly, a condenser assembly, a receiver, and one or more refrigeration loads having an evaporator assembly. The secondary refrigeration circuit includes a thermal storage unit and a heat exchanger. The thermal storage unit contains a phase change material. The secondary refrigeration circuit is in thermal communication with the primary refrigeration circuit through the heat exchanger. The primary refrigerant includes a critical temperature. The primary refrigeration circuit is configured for subcritical operation. The primary refrigeration circuit and the secondary refrigeration circuit are configured such that the phase change material provides cooling to the primary refrigerant during a first operating condition.

Abstract: A heat exchanger includes fins that are spaced apart from each other, and that each include one or more tube slots. A coil is coupled to the fins and includes a tube section extending through axially aligned tube slots. A heater insert extends through one or more of the axially aligned tube slots adjacent an exterior of the tube section to defrost the heat exchanger.

Abstract: A refrigeration system includes a primary refrigeration circuit configured to circulate a CO2 primary refrigerant and a secondary refrigeration circuit separate from the primary refrigeration circuit. The primary refrigeration circuit includes a compressor assembly, a condenser assembly, a receiver, and one or more refrigeration loads having an evaporator assembly. The secondary refrigeration circuit includes a thermal storage unit and a heat exchanger. The thermal storage unit contains a phase change material. The secondary refrigeration circuit is in thermal communication with the primary refrigeration circuit through the heat exchanger. The primary refrigerant includes a critical temperature. The primary refrigeration circuit is configured for subcritical operation. The primary refrigeration circuit and the secondary refrigeration circuit are configured such that the phase change material provides cooling to the primary refrigerant during a first operating condition.

Abstract: A refrigeration system having a refrigerant circuit including a condenser, a flow control device, an evaporator, and a compressor connected in series. The compressor is configured to circulate a cooling fluid through the refrigerant circuit. The refrigerant circuit has an inlet line fluidly connecting the condenser to the evaporator and a suction line fluidly connecting the evaporator to the compressor. A heater is positioned to heat the cooling fluid during a defrost mode, and a pressure control is coupled to the refrigerant circuit downstream of the evaporator. In the defrost mode, the pressure control apparatus is configured to increase system pressure during the defrost mode to maintain flow of refrigerant into the evaporator and to control flow of cooling fluid to the compressor.

Abstract: A heat exchanger for use in a refrigeration system and including a heat transfer coil and fins coupled to the coil to facilitate heat transfer between the coil and a surrounding ambient environment. The heat exchanger also includes a printed heater element that is disposed on one or more of the fins in a non-linear pattern to defrost the coil.

Abstract: A heat exchanger includes fins that are spaced apart from each other, and that each include one or more tube slots. A coil is coupled to the fins and includes a tube section extending through axially aligned tube slots. A heater insert extends through one or more of the axially aligned tube slots adjacent an exterior of the tube section to defrost the heat exchanger.

Abstract: A heat exchanger for use in a refrigeration system and including a heat transfer coil and fins coupled to the coil to facilitate heat transfer between the coil and a surrounding ambient environment. The heat exchanger also includes a printed heater element that is disposed on one or more of the fins in a non-linear pattern to defrost the coil.

Abstract: A method of controlling a refrigerated merchandiser. The method includes refrigerating a product display area of the merchandiser using a refrigerant, detecting a presence of an air-refrigerant mixture in the refrigerated merchandiser, activating a fan in response to detecting the presence of an air-refrigerant mixture, and at least partially evacuating an interior of the merchandiser in response to fan activation.