Abstract: A ventilation system comprises a plurality of axial fan units, each having at least one axial fan having a rotational axis generally parallel to a downstream flow caused by the axial fan, and at least one grill positioned adjacent to the at least one axial fan in a downstream flow path of the axial fan unit, the at least one grill directing an air flow of the axial fan. At least a first series of the plurality of axial fan units is adapted to be positioned at a top of a plenum arrangement extending from a bottom front of a refrigerated enclosure, to a rear back of the refrigerated enclosure, said top being at a top of the rear back. At least a second series of the plurality of axial fan units is adapted to be positioned above an area to cool and oriented to project its downstream flow in a downward direction to direct its downstream flow to said area to cool.

Abstract: A CO2 refrigeration system for an ice-playing surface comprises an evaporation stage in which heat is absorbed from an ice-playing surface. CO2 compressors in a compression stage compress CO2 refrigerant subcritically and transcritically. A gas cooling stage has a plurality of heat-reclaim units reclaiming heat from the CO2 refrigerant. A pressure-regulating device is downstream of the gas cooling stage, to control a pressure of the CO2 refrigerant in the gas cooling stage. A reservoir is downstream of the pressure-regulating device for receiving CO2 refrigerant in a liquid state. A controller operates the pressure-regulating device to control the pressure of the CO2 refrigerant in the gas cooling stage as a function of the heat demand of the plurality of heat-reclaim units, the controller causing the pressure of the CO2 refrigerant to reach a transcritical level as a function of a heat demand of the plurality of heat-reclaim units.

Abstract: A CO2 refrigeration system for an ice-playing surface comprises an evaporation stage in which heat is absorbed from an ice-playing surface. CO2 compressors in a compression stage compress CO2 refrigerant subcritically and transcritically. A gas cooling stage has a plurality of heat-reclaim units reclaiming heat from the CO2 refrigerant. A pressure-regulating device is downstream of the gas cooling stage, to control a pressure of the CO2 refrigerant in the gas cooling stage. A reservoir is downstream of the pressure-regulating device for receiving CO2 refrigerant in a liquid state. A controller operates the pressure-regulating device to control the pressure of the CO2 refrigerant in the gas cooling stage as a function of the heat demand of the plurality of heat-reclaim units, the controller causing the pressure of the CO2 refrigerant to reach a transcritical level as a function of a heat demand of the plurality of heat-reclaim units.

Abstract: An air curtain apparatus comprises a generally horizontal duct having at least one inlet and defining at least one outlet in a wall thereof. A plurality of axial fan units are mounted side-by-side across the at least one outlet defined in the wall of the duct, the axial fan units having rotational axes generally parallel to one another and side-by-side to blow air from an interior of the duct to an exterior of the duct. One or more grills are positioned adjacent to the axial fan units in a downstream flow path of the axial fan units, the grill(s) directing an air flow of the axial fan units into a downwardly directed air curtain. A method for creating an air curtain is also provided.

Abstract: A CO2 refrigeration system comprises a condensation reservoir. CO2 refrigerant is accumulated in the reservoir. The CO2 refrigerant circulates between supra-compression and evaporation loops. The supracompression loop comprises a compression stage for compression CO2 refrigerant to a supracompression state, a cooling stage in which CO2 refrigerant releases heat, and a pressure-regulating unit in a line extending from the cooling stage to the condensation reservoir. The pressure-regulating unit maintains a pressure differential between the cooling stage and the condensation reservoir. The evaporation loop comprises an evaporation stage in which CO2 refrigerant from the condensation reservoir absorbs heat in a heat exchanger. The heat exchanger is connected to an ice-playing surface refrigeration circuit. A second refrigerant cycles in the ice-playing surface refrigeration circuit. The CO2 refrigerant absorbs heat from the second refrigerant in the heat exchanger. A CO2 condensation exchanger is also provided.

Abstract: A CO2 refrigeration system for an ice-playing surface, comprising: a compression portion comprising a compression stage comprising at least one compressor in which CO2 refrigerant is compressed to a transcritical state. A gas cooling stage in which the CO2 refrigerant compressed to the transcritical state releases heat by heat exchange with a gas. Pressure-regulating means downstream of the gas cooling stage control a pressure of the CO2 refrigerant in the compression portion of the CO2 refrigeration system. An oil circuit is in the CO2 refrigeration system, the oil circuit collecting oil downstream of the at least one compressor in the compression stage, the oil circuit directing the oil upstream of the at least one compressor for the CO2 refrigerant fed to the compressor to have an oil content.

Abstract: A CO2 refrigeration system comprising a transfer circuit for heat exchange between a supracompression circuit of CO2 refrigerant, and an evaporation circuit of CO2 refrigerant. A transfer circuit absorbs heat from the evaporation circuit, and releases heat to the supracompression circuit. The supracompression circuit comprises a compression stage in which CO2 refrigerant is compressed, a cooling stage in which the CO2 refrigerant from the compression stage releases heat, and a pressure-regulating unit in a line between the cooling stage and the evaporation heat exchanger to maintain a pressure differential therebetween. The evaporation circuit receives CO2 refrigerant having released heat in the condensation heat exchanger. The evaporation circuit comprises a condensation reservoir in which CO2 refrigerant is accumulated in a liquid state, and an evaporation stage in which the CO2 refrigerant from the condensation reservoir absorbs heat to cool an ice-playing surface.

Abstract: A CO2 refrigeration system comprises a CO2 circuit. In a compression stage of the circuit, CO2 refrigerant is compressed to a supracompression state. In a cooling stage, the CO2 refrigerant from the compression stage releases heat. A pressure-regulating unit in a line extending from the cooling stage to one side of a heat exchanger maintains a pressure differential. A second refrigerant cycles in a cooling circuit between a second side of the heat exchanger and an ice-playing surface. The second refrigerant absorbs heat from the ice-playing surface and releases heat to the CO2 refrigerant in the heat exchanger.

Abstract: A CO2 refrigeration system for an ice-playing surface comprises a transfer circuit, a CO2 refrigerant circuit and an independent condensation circuit. A transfer refrigerant circulates between a condensation heat exchanger and an evaporation heat exchanger. The CO2 circuit is in relation with the condensation heat exchanger to release heat from the CO2 refrigerant. The CO2 circuit comprises a CO2 condensation reservoir and an evaporation stage to receive the CO2 refrigerant from the condensation reservoir. The independent circuit is in relation with the refrigerant of the transfer circuit at the evaporation heat exchanger. The independent circuit comprises a magnetically operated compressor to compress a secondary refrigerant, a condensation stage and an evaporation stage in which the secondary refrigerant absorbs heat.

Abstract: A CO2 refrigeration system comprises a condensation reservoir. CO2 refrigerant is accumulated in the reservoir. The CO2 refrigerant circulates between supracompression and evaporation loops. The supracompression loop comprises a compression stage for compression CO2 refrigerant to a supracompression state, a cooling stage in which CO2 refrigerant releases heat, and a pressure-regulating unit in a line extending from the cooling stage to the condensation reservoir. The pressure-regulating unit maintains a pressure differential between the cooling stage and the condensation reservoir. The evaporation loop comprises an evaporation stage in which CO2 refrigerant from the condensation reservoir absorbs heat in a heat exchanger. The heat exchanger is connected to an ice-playing surface refrigeration circuit. A second refrigerant cycles in the ice-playing surface refrigeration circuit. The CO2 refrigerant absorbs heat from the second refrigerant in the heat exchanger. A CO2 condensation exchanger is also provided.

Abstract: A CO2 refrigeration system comprises a refrigeration circuit in which circulates CO2 refrigerant between a compression stage in which the CO2 refrigerant is compressed. A condensation stage is provided in which the CO2 refrigerant releases heat and is accumulated in a condensation reservoir. An evaporation stage is provided in which the CO2 refrigerant is expanded to a gaseous state to absorb heat from a fluid for refrigeration, with at least a portion of CO2 refrigerant exiting the evaporation stage being directed to a supra-compression circuit comprising a supra-compression stage in which the portion of CO2 refrigerant is compressed. A heat exchanger is provided by which the compressed CO2 refrigerant is in a heat-exchange relation with a secondary-refrigerant circuit, such that the compressed CO2 refrigerant releases heat to a secondary refrigerant used for heating purposes. Pressure-regulating means control a pressure of the compressed CO2 refrigerant being returned to the condensation stage.

Abstract: A defrost refrigeration system of the type having a main refrigeration circuit operating a refrigeration cycle. The defrost refrigeration system comprises a first line extending from the first compressor to the evaporator stage and is adapted to receive a portion of discharged low-pressure refrigerant from the first compressor. Valves are provided for stopping a suction of cooling refrigerant in an evaporator of the evaporator stage and for directing a flow of defrost refrigerant to release heat to defrost the evaporator. A second line is provided for directing the refrigerant having released heat to the expansion stage of the refrigeration cycle. A pressure reducing device is optionally positioned downstream of the condensing stage for adjusting a pressure of the refrigerant in the high-pressure liquid state mixing with the defrost refrigerant having released heat.

Abstract: A refrigeration unit comprises a CO2 refrigeration circuit having a CO2 compression stage in which CO2 refrigerant is compressed, a CO2 condensation stage having a tank in which CO2 refrigerant is accumulated in a liquid state, at least one of pressuring means and an expansion stage to direct the CO2 refrigerant from the CO2 condensation stage to a CO2 evaporation stage in which CO2 refrigerant absorbs energy to refrigerate. A condensation circuit has a second refrigerant being circulated between a second compression stage, a second condensation stage, a second expansion stage and a second evaporation stage. A heat-exchanger unit by which the CO2 refrigerant from the CO2 refrigeration circuit is in heat exchange with the second refrigerant in the second evaporation stage such that the second refrigerant absorbs heat from the CO2 refrigerant to at least partially liquefy the CO2 refrigerant for the CO2 condensation stage.

Abstract: A refrigerant leak-detection system is provided to monitor a level of refrigerant/refrigerant by-products in ambient air in a closed/semi-closed ventilated environment enclosing a refrigeration unit. The system comprises a sensor positioned in the ventilated environment to measure a level of refrigerant/refrigerant by-products in the ambient air, and a detection controller to receive signals associated with the level of refrigerant/refrigerant by-products in the ambient air and to perform an action as a function of the signals. The detection controller stops a ventilation unit for given periods of time to allow the sensor to measure the level of refrigerant/refrigerant by-products in the ambient air during the given periods of time. A method for monitoring the level of refrigerant/refrigerant by-products in ambient air in a closed/semi-closed ventilated environment enclosing a refrigeration unit is also provided.

Abstract: A tube and fitting assembly for refrigeration systems comprises a tube having a connection end and receiving a flow of refrigerant. A fitting has a tubular body with a connector portion adapted to sealingly connect the fitting to a device. The connector portion has a seat portion having a shape complementary to that of a connector end of the device to form a sealing surface therewith. A sealing portion projects from the connector portion to form a sleeve about a portion of the tube. A weld seam is provided between the sealing portion and the tube.

Abstract: A build-up monitoring system in combination with a refrigerated enclosure comprises a refrigerated enclosure having a drain, a drain basin and a refrigeration unit adapted to maintain refrigerating conditions in the refrigerated enclosure. A build-up detector is positioned with respect to the refrigerated enclosure so as to monitor a level of build-up in the drain/drain basin. A condition analyzer receives detection data from the build-up detector, the condition analyzer identifying from the detection data a build-up in the drain/drain basin requiring an intervention. An interface indicates the requirement for the intervention. A method is provided to identify a build-up requiring an intervention in a drain/drain basin of a refrigerated enclosure.

Abstract: A defrost refrigeration system comprises first compressors and second compressors serially positioned with respect to one another such that refrigerant going through a compression stage in the refrigeration cycle passes sequentially through the first compressors and the second compressors. A first line extends from an exit of one of the first compressor and the second compressor of the compression stage, and is in fluid communication with the evaporator stage in a defrost cycle and is adapted to receive a defrost portion of refrigerant compressed in the compression stage. Valves switch evaporators between the refrigeration cycle and the defrost cycle, by stopping/allowing a flow of refrigerant from the condensation stage to the evaporators of the evaporation stage in the refrigeration cycle, and for allowing/stopping a flow of said defrost portion of refrigerant to defrost the evaporators in the defrost cycle.

Abstract: A refrigeration system of the type having a compression stage, a condensation stage, an expansion stage and an evaporation stage, comprising a first evaporator group in the evaporation stage. The first evaporator group has two or more evaporators. A first valve is positioned upstream of the evaporators of the first evaporator group. The first valve is closeable to stop a supply of refrigerant to the evaporators of the first evaporator group simultaneously for a subsequent air defrost of the evaporators of the first evaporator group.

Abstract: A defrost refrigeration system of the type having a main refrigeration circuit comprising a first line extending from the compression stage to the evaporator stage and adapted to receive a portion of refrigerant in a high-pressure gas state. A valve system stops a flow of the refrigerant in a low-pressure liquid state to an evaporator of the evaporator stage and for conveying a flow of the refrigerant in the high-pressure gas state from the first line to release heat to defrost the at least one evaporator. A second line conveys the refrigerant having released heat directly to the condensing stage.

Abstract: A refrigeration system having a main refrigeration circuit having a condensing stage, wherein a first refrigerant in a high pressure gas state is condensed at least partially to a liquid state. The condensing stage has a pair of stand-alone condensing stage closed loops in heat exchange relation with the main refrigeration circuit. The stand-alone condensing stage closed loops are is in parallel one to another with a condenser of the condensing stage and each comprise comprises a second refrigerant circulating between at least a heat absorption stage, wherein the second refrigerant absorbs heat from the first refrigerant in the main refrigeration circuit so as to condense the first refrigerant to the liquid state, and a heat release stage, wherein the second refrigerant releases the absorbed heat. The condensing stage has modulating valves for selectively and quantitatively modulating the temperature of said first refrigerant and compressor head pressure.