A cooling system has a direct expansion mode and a pumped refrigerant economizer mode and a controller. The controller includes a load estimator that estimates real-time indoor load on the cooling system and uses the estimated real-time indoor load to determine whether to operate the cooling system in the pumped refrigerant economizer mode or in the direct expansion mode.

An ice maker for forming ice during a cooling cycle, the ice maker having a variable-speed compressor, a condenser, and an evaporator, wherein the variable-speed compressor, the condenser, and the evaporator are in fluid communication by one or more refrigerant lines. The ice maker further includes a freeze plate thermally coupled to the evaporator, a water pump, a sensing device for identifying a state of the cooling cycle, and a controller adapted to control the speed of the variable-speed compressor based on the identified state of the cooling cycle. The ice maker may also include a variable-speed condenser fan which may be controlled by the controller based on the identified state of the cooling cycle. Additionally, the water pump may be a variable-speed water pump which may be controlled by the controller based on the identified state of the cooling cycle.

A method of operating a refrigeration and heating system (2a, 2b) comprises: circulating a refrigerant through a refrigeration circuit (4) which comprises in the direction of flow of the circulating refrigerant: at least one compressor (6a, 6b, 6c); a refrigeration circuit side (8a) of a coupling heat exchanger (8); at least one gas cooler (10); at least one expansion device (12, 14); and at least one evaporator (16); circulating a heating fluid through a heating circuit (20) which comprises a heating circuit side (8b) of the coupling heat exchanger (8) and at least one heat consumer (22); wherein the coupling heat exchanger (8) is configured for transferring heat from the circulating refrigerant to the circulating heating fluid. The method further includes increasing the temperature of the refrigerant entering the at least one gas cooler (10) in order to meet increased heating demands by allowing at least a portion of the heating fluid to flow directly from an outlet to an inlet of the heating circuit side (8b) of the coupling heat exchanger (8) bypassing the at least one heat consumer (22) or by allowing at least a portion of the refrigerant circulating through the refrigeration circuit (4) to bypass the coupling heat exchanger (8).

A refrigeration cycle device is configured to be selectively switchable between an air-cooling first refrigerant circuit that causes refrigerant to flow out of a liquid-phase refrigerant outlet of a gas-liquid separator, and an air-heating second refrigerant circuit that causes the refrigerant to flow out of a gas-phase refrigerant outlet of the gas-liquid separator. In the refrigeration cycle device, an oil separator is disposed in a refrigerant passage that leads from a heat dissipation device to a first expansion valve. Thus, when the first refrigerant circuit is configured in the refrigeration cycle device, the refrigerant passing through the oil separator is in a single gas phase or in an almost gas phase, so that oil can be easily separated from the refrigerant. Furthermore, when the refrigerant circulates through the first refrigerant circuit, oil can be retained at a position other than the gas-liquid separator.

A cooling device including a freezing cycle including a compressor, a condenser, a pressure reducing means, and an evaporator is provided. In the cooling device, the condenser includes a first condenser and a second condenser independent from each other, the second condenser being positioned at a downstream side of the first condenser in a refrigerant channel, and the first condenser and the second condenser are connected to each other through a dew condensation preventing pipe.

An HVAC system is disclosed, comprising: (a) a compressor, (b) a source heat exchanger for exchanging heat with a source fluid, (c) a first load heat exchanger operable for heating/cooling air in a space, (d) a second load heat exchanger for heating water, (e) first and second reversing valves, (f) first and second 3-way valves, (f) a bi-directional electronic expansion valve, (g) a first bi-directional valve, and (h) a second bi-directional valve to modulate exchange of heat in the first load heat exchanger when operating as an evaporator and to control flashing of the refrigerant entering the source heat exchanger when operating as an evaporator, (h) a source pump for circulating the source fluid through the first load heat exchanger, (i) a water pump for circulating water through the second load heat exchanger, and (j) a controller to control operation of the foregoing.

A system for warming an engine. The system includes an engine coolant system that directs warm engine coolant to the engine to heat the engine. A heat pump system warms the engine coolant.

A refrigeration system includes a refrigeration circuit and a coolant circuit separate from the refrigeration circuit. The refrigerant circuit includes a gas cooler/condenser, a receiver, and an evaporator. The coolant circuit includes a heat exchanger configured to transfer heat from a refrigerant circulating within the refrigeration circuit into a coolant circulating within the coolant circuit, a heat sink configured to remove heat from the coolant circulating within the coolant circuit, and a magnetocaloric conditioning unit configured to transfer heat from the coolant within a first fluid conduit of the coolant circuit into the coolant within a second fluid conduit of the coolant circuit. The first fluid conduit connects an outlet of the heat exchanger to an inlet of the heat sink, whereas the second fluid conduit connects an outlet of the heat sink to an inlet of the heat exchanger.

A refrigeration system is provided that can be used to cool a plant growth chamber. The refrigeration system can include a compressor to compress refrigerant, a condenser to condense refrigerant, a compressed refrigerant line running from the compressor to the condenser, a throttling device, a condensed refrigerant line running from the condenser to the throttling device, an evaporator to evaporate liquid refrigerant, a throttled refrigerant line running from the throttling device to the evaporator, an evaporated refrigerant line running from the evaporator to the compressor, and, a by-pass line connected to the compressed refrigerant line after the condenser and running to the evaporator. A hot gas proportional valve provided inline of the by-pass line and a liquid proportional valve provided inline of the condensed refrigerant line are used to control the flow of refrigerant through the by-pass line.

In the case of a heating operation in which a use side heat exchanger functions as a condenser when the outside air has a predetermined low temperature, a low-outside-air-temperature heating operation start mode is executed in which, while a refrigerant, as discharged from a compressor, flows into the use side heat exchanger, the refrigerant is supplied to the injection port of the compressor via an injection pipe and a part of a refrigerant that is accumulated in an accumulator is supplied to the compressor via a connecting pipe, and thereafter a low-outside-air-temperature heating operation mode is executed in which the refrigerant, as discharged from the compressor, is supplied to the injection port of the compressor via the injection pipe while flowing into the use side heat exchanger.