A refrigeration cycle apparatus includes an indoor heat exchanger, a water heat exchanger, a pump, an outdoor heat exchanger, a compressor, an expansion valve, a four-way valve, a third pipe, and an open/close valve, and configured to enable hot-gas defrosting and reverse cycle defrosting. A controller selects, based on the indoor load, either one of the hot-gas defrosting and the reverse cycle defrosting to be performed. In this way, defrosting can be performed with a minimum decrease of the chiller water temperature.

An air conditioner and a method for controlling an air conditioner. The method may include detecting an outlet temperature of a compressor; detecting a change in temperature of a hot water supply pipe; determining a system error based on the outlet temperature of the compressor; and determining an abnormality in an adjustment valve based on the temperature of the hot water supply pipe when a system error is determined.

An air conditioner includes an outdoor unit for circulating refrigerant, a plurality of indoor units for circulating water, and a heat exchange device configured to connect the outdoor unit to the plurality of indoor units and perform heat exchange between the refrigerant and the water. The heat exchange device includes a plurality of ports to which the plurality of indoor units are connected. The air conditioner further includes a controller configured to control flow of the water between the heat exchange device and the plurality of indoor units, and to search pipes respectively connected to the plurality of ports. The controller can control the flow of water such that water at a first temperature flows to some of the plurality of ports and the water at a second temperature lower than the first temperature flows to other some of the plurality of ports.

An air conditioning system can be toggled between a heating mode, in which heat is withdrawn from a source (e.g., a geothermal source) and deposited into a conditioned space (e.g., a building), and a cooling mode, in which heat is withdrawn from the conditioned space and deposited into the source.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 heat pump including a housing configured to be disposed outdoors; a compressor that compresses a refrigerant; a fluid refrigerant heat exchanger configured to perform heat exchange between the refrigerant and a fluid; an outdoor heat exchanger configured to perform heat exchange between the refrigerant and outdoor air; a pressure sensor configured to detect a pressure of the refrigerant flowing between the compressor and the fluid refrigerant heat exchanger; a first shut-off valve disposed in a pipe connected to a discharge of the compressor; a second shut-off valve disposed between the outdoor heat exchanger and the compressor; and a controller configured to: determine whether the refrigerant leaks, control the first shut-off valve to be closed, when the refrigerant leaks, and control the second shutoff valve to be closed, when the pressure sensed by the pressure sensor is less than a predetermined reference pressure.

An outdoor unit includes at least one heat exchanger, a first motor including a first fan, a second motor including a second fan, an inverter that applies voltage to the first motor and the second for respectively, a connection switching unit that switches the voltage applied to the second motor between on and off, and a control unit that controls the inverter and the connection switching unit. The inverter is disposed closer to the first motor than to the second motor.

In a motor driving apparatus having an inverter which can drive n (n being an integer not smaller than 2) motors each having a permanent magnet in its rotor, and a connection switching device for switching the connection state of the n motors, the connection switching device is operated to change the number of the motors connected to the inverter thereby to change the impedance as seen from the inverter towards the motors. When i (i being any of 2 to n) motors among the n motors are concurrently driven by the inverter, the voltage outputted by the inverter may be controlled such that the inductance values of the i motors are identical. It is possible to prevent hunting and step-out due to the phase difference between the motors driven by the inverter.

A heat pump system and a cooling/heating system using same, the heat pump system being able to prevent the occurrence of a vortex in a process in which fluid flows into a heat storage tank, and to supply and maintain constant-temperature cooling and heating. The heat pump system according to the present invention includes: an indoor unit which functions as a condenser during heating and functions as an evaporator during cooling; an outdoor unit which functions as an evaporator during heating and functions as a condenser during cooling; a heating medium for heat exchange; and a heat storage tank in which the heating medium for cold/hot water is stored.

A heat medium relay device includes: a valve block provided in a third space, and including a plurality of valves to allow a secondary heat medium subjected to the heat exchange at a first heat exchanger and a secondary heat medium subjected to the heat exchange at a second heat exchanger to flow to at least one indoor unit, the valve block being lighter in weight than each of the first heat exchanger, a first pump, the second heat exchanger, and a second pump.

An ice supply device includes an ice storage tank, a supply path, and a water flow path. The ice storage tank is configured to store sherbet ice. The sherbet ice may be taken out of the ice storage tank through the supply path. The water flow path joins the supply path. The water flow path is configured to carry flow of water there through.