A hydronic economizer module configured for use in a chiller system having a vapor compression cycle including a housing having at least a first air inlet. A heat exchanger assembly located within said housing. The heat exchanger includes at least one heat exchanger coil. A fan assembly includes at least one fan generally aligned with the at least one heat exchanger coil. At least one valve is movable between a plurality of positions to control a flow of fluid into said heat exchanger assembly. When said at least one valve is in a first position the economizer module is arranged in parallel with a component of the vapor compression cycle. When said at least one valve is in a second position the economizer module is arranged in series with said component of the vapor compression cycle.

An air-conditioning device includes a heater unit that heats the air to be lead to a vehicle cabin using the heat of the refrigerant compressed by a compressor, a liquid receiver arranged at the downstream side of an outside heat exchanger, a liquid receiver separating the refrigerant lead from the outside heat exchanger into a liquid-phase refrigerant and a gaseous-phase refrigerant and storing the liquid-phase refrigerant, and a restrictor mechanism provided between the heater unit and the outside heat exchanger, the restrictor mechanism decompressing and expanding the refrigerant. When there is a dehumidification request, the operation mode is temporarily switched from a dehumidifying cabin-heating mode which evaporates the refrigerant by an evaporating unit and radiates heat by the heater unit in the state in which the restrictor mechanism restricts the flow of the refrigerant, to the cabin-cooling mode which evaporates the refrigerant by the evaporating unit while promoting the storage of the liquid-phase refrigerant in the liquid receiver.

A dual reclaim coil with a smart control application is provided that allows the refrigerant inlet to the HVAC unit switch between the two sides of the condenser is aimed to use the high temperature and pressure of the condenser/gas cooler outlet while a CO.sub.2 refrigerant system is operating above critical point. This occurs in hot ambient conditions, when the need for heating in the space is not as great as in the wintertime and the available heat at the condenser/gas cooler's outlet is sufficient to satisfy the heating load. This also mitigates space overcooling, while increasing the CO.sub.2 transcritical system's efficiency by subcooling the refrigerant for applications involving dehumidification HVAC systems which often results in a phenomenon called “overcooling” during the dehumidification season.

A cooling system includes a second receiver that receives refrigerant from a low side heat exchanger. A pipe connects the second receiver to a first receiver. A vapor portion of the refrigerant in the first receiver can flow through the pipe to the second receiver. A compressor is used to create a pressure differential in the second receiver relative to the first receiver such that the pressure in the first receiver is greater than the pressure in the second receiver. This pressure differential effectively acts as a pump that pushes the liquid refrigerant in the first receiver towards the low side heat exchanger.

A multi-type air conditioner is provided including an outdoor unit and a plurality of indoor units connected to the outdoor unit by a liquid pipe and a gas pipe. The plurality of indoor units includes a first indoor unit including first and second heat exchangers and first and second heat exchanger connecting pipes, and a second indoor unit. An indoor heat exchanger connecting pipe connects the first and second indoor units, and a liquid pipe connecting tube connects the first indoor unit and the liquid pipe. Opening amounts of a first indoor expansion valve, and first and second bypass expansion valves provided in the first indoor unit are opened selectively to operate the first heat exchanger as a condenser and the second heat exchanger as an evaporator to continuously drive a dehumidification mode while maintaining a room temperature within a predefined range.

An air conditioning system can be toggled between a heating mode, in which heat is withdrawn from a source (e.g., a geothermal source) and deposited into a conditioned space (e.g., a building), and a cooling mode, in which heat is withdrawn from the conditioned space and deposited into the source. The air conditioning system uses a combination of efficiency-enhancing technologies, including injection of superheated vapor into the system's compressor from an economizer circuit, adjustable compressor speed, the use of one or coaxial heat exchangers and the use of electronic expansion valves that are continuously adjustable from a fully closed to various open positions. A controller may be used to control the system for optimal performance in both the heating and cooling modes, such as by disabling the economizer circuit and vapor injection when the system is in the cooling mode.

A refrigeration system includes an expansion valve downstream of one or more medium temperature compressors. The expansion valve is configured to decrease pressure of a portion of refrigerant output by the one or more medium temperature compressors. When defrost operation of an evaporator is indicated, the refrigerant with decreased pressure from the expansion valve is provided to the evaporator for at least a period of time sufficient to defrost the evaporator.

An economizer module for increasing energy efficiency of a pumped refrigerant cooling system is connected to a refrigerant pumping unit including a primary pump connected with heat extractor(s) via a primary circuit and a primary heat exchanger connected with a condensing unit via a secondary circuit. The economizer module includes a control panel with control software, a secondary heat exchanger connected with the heat extractor(s) via the primary circuit and with the primary heat exchanger, a cooler connected with the secondary heat exchanger via an economizer circuit, and a secondary pump connected between the cooler and the secondary heat exchanger. The control panel executes the control software to control fluid flow in the economizer circuit via the secondary pump so as to use ambient air to reject heat from working fluid being used to collect heat from refrigerant in said primary circuit before said heat travels to said secondary circuit.

The disclosed technology includes systems and methods for a heat pump water heater. The disclosed technology can include a heat pump water heater system having an evaporator, a condenser, a vapor injection line, a compressor, and a multi-fluid heat exchanger. The vapor injection line can include an expansion valve to transition refrigerant received from the condenser at a first pressure to a second pressure. The compressor can be configured to circulate refrigerant through the condenser, the multi-fluid heat exchanger, the vapor injection line, and the evaporator. The multi-fluid heat exchanger can be configured to receive refrigerant at a first pressure from the condenser, refrigerant at a second pressure from the vapor injection line, and water. The multi-fluid heat exchanger can further facilitate heat transfer between the refrigerants at the first and second pressures and the water to preheat the water before the water is passed through the condenser.

An integrated system floods an air conditioning low side heat exchanger such that the air conditioning low side heat exchanger does not evaporate all the liquid refrigerant entering the air conditioning low side heat exchanger. As a result, both liquid and vapor refrigerant leave the air conditioning low side heat exchanger. The system includes an additional receiver that stores the refrigerant leaving the air conditioning low side heat exchanger. To prevent the liquid refrigerant in the receiver from overflowing, the liquid refrigerant in the receiver is used in a refrigeration system when the level of liquid refrigerant in the receiver exceeds a threshold (e.g., as detected by a sensor in the receiver).