Provided is an air conditioning apparatus. The air conditioning apparatus includes an outdoor unit which includes a compressor and an outdoor heat exchanger and through which a refrigerant is circulated, an indoor unit through which water is circulated, a heat exchanger in which the refrigerant and the water are heat-exchanged with each other, a water tube configured to guide the water circulated through the indoor unit and the heat exchanger, a pump installed in the water tube, and a controller configured to analyze an output signal of the pump so as to calculate a ration of an air layer in the water tube, the controller being configured to control a target supercooling degree or target superheating degree of the heat exchanger according to the calculated ratio of the air layer.

The disclosed invention is a relay switch that is capable of controlling the sequence in which a multi-unit heat pump system where the relay device determines which of the units act as primary and which a secondary. The disclosed switch is capable of reconfiguring the sequencing with a mere flip of a switch or a toggle of an actuator. There is a protective case enclosing the actual switch. The casing carries the dual role of insulating the switch and electrical connectors, as well as providing instructions on how to integrate the disclosed device into an existing heat pump system, as well as how to operate the device after successful integration. The wiring to the switch is accomplished via a panel of clearing marked external connectors. The switch can then operate via a mechanical or electronic actuator exposed on the surface of the protective case, or remotely via a connection module.

A system controls a multi-zone vapor compression system (MZ-VCS). The system includes a controller to control a vapor compression cycle of the MZ-VCS using a set of control inputs determined by optimizing a cost function including a set of control parameters. The optimizing is subject to constraints, and wherein the cost function is optimized over a prediction horizon. The system also includes a memory to store an optimization function parameterized by a configuration of the MZ-VCS defining active or inactive modes of each heat exchanger, the optimization function modifies, according to a current configuration, values of the control parameters of the cost function determined for a full configuration that includes all heat exchangers in the active mode. The system also includes a processor to determine the current configuration of the MZ-VCS and to update the cost function by submitting the current configuration to the optimization function.

A refrigerant loop of a vapor injection heat pump includes a compressor, first and second expansion valves, and first and second separator valves. The separator valves allow an entire refrigerant flow to pass therethrough or operate to separate vapor and liquid components of expanded refrigerant and inject the vapor component into a suction port of the compressor. Vapor injection occurs in both heating and cooling modes of operation and may depend upon an ambient condition (e.g., high or low ambient temperatures). An accumulator receives an output refrigerant of the heat exchangers dependent upon the mode and directs a vapor component into another suction port of the compressor. A control module controls at least the first and second expansion valves and first and second separator valves dependent upon the mode of operation which include, among others, heating, cooling, and dehumidification and re-heating.

An outdoor unit includes a casing having a bottom plate and is configured such that at least a part thereof is made of metal, a compressor provided within the casing to compress a flammable refrigerant, an outdoor heat exchanger provided within the casing to exchange heat between the refrigerant and outside air, and an electric heater provided on an upper surface of the bottom plate. The power consumption of the electric heater is 250 W or less.

Stress to be imposed on a compressor in reverse cycle operation is reduced. A cycle controller causes an outdoor heat exchanger to function as a condenser and an indoor heat exchanger to function as an evaporator when a reverse cycle executing condition is met, so that a refrigerant circulates in reverse of a heating cycle. A rotation speed controller adjusts a rotation speed of a compressor in a reverse cycle, depending on an index correlated with an amount of frost on the outdoor heat exchanger at a start of the reverse cycle. The rotation speed controller decreases the rotation speed of the compressor in the reverse cycle as the index at the start of the reverse cycle indicates that the amount of the frost on the outdoor heat exchanger is smaller.

One aspect presents a controller that comprises a control board, a microprocessor located on and electrically coupled to the control board, and a memory coupled to the microprocessor and located on and electrically coupled to the control board. The controller is configured to receive an operating parameter signal and recalculate a first maximum heating % demand to a second maximum heating % demand that is greater than the first maximum heating % demand, when a value of the operating parameter signal exceeds a predetermined value, and operate the HP system based on the second maximum heating % demand.

Disclosed herein are evaporator assemblies for heat pump systems. The evaporator units can comprise a housing defining an interior chamber, an air inlet and an air outlet. The air inlet and the air outlet can form an air flow path through the interior chamber, and an evaporator unit can be positioned within the interior chamber such that the air flow path contacts the evaporator unit. The air inlet having a semi-circular cross section through which air flows into the interior chamber, the semi-circular cross section having a straight edge and a curved edge. A velocity magnitude of the air flowing from the air inlet into contact with the evaporator unit can deviate less than 0.1 m/s from the average air velocity across the surface area of the evaporator.

A refrigeration cycle apparatus includes a refrigerant circuit, by pipes, connecting a compressor, a flow switching device, a first heat exchanger, an expansion device, and a second heat exchanger. As refrigerant to be circulated through the refrigerant circuit, any one of a refrigerant having saturated gas temperature under standard atmospheric pressure that is higher than that of R32 and a refrigerant mixture mainly composed of the refrigerant is used. The refrigerant circuit includes an internal heat exchanger configured to exchange heat between the refrigerant flowing through a refrigerant-inlet side of the second heat exchanger and the refrigerant flowing through a refrigerant-outlet side of the second heat exchanger.

An air conditioning apparatus includes: an outdoor unit configured to circulated refrigerant; a first pipe and a second pipe that are connected to the outdoor unit; an indoor unit configured to circulate water; and a heat exchange device that connects the outdoor unit to the indoor unit. The heat exchange device includes a first heat exchanger and a second heat exchanger that are each configured to perform heat exchange between the refrigerant and the water, a plurality of connection pipes, a bypass pipe configured to guide the refrigerant passing through the first heat exchanger to the second heat exchanger, and a bypass valve installed at the bypass pipe.