The present disclosure relates to a heat pump system comprising an outdoor unit disposed in an outdoor space, a plurality of thermal load units supplied with cool air and hot air, and an intermediate unit disposed between the outdoor unit and the plurality of thermal load units, wherein the intermediate unit is connected to the outdoor unit through refrigerant pipes and connected to the plurality of thermal load units through thermal medium pipes.

A present heating system or heating and cooling system does not include a tank for storing potable hot water in anticipation of a potable hot water demand. Although one or more temperature sensors may be used for providing feedback to heating of the contents of a tank water heater to achieve a setpoint temperature, the effect of stratification can cause layers of fluid having different temperatures in the tank water heater. Therefore, although portions of the contents of a water heater may be disposed at a setpoint temperature that is unfavorable for Legionella proliferation, there potentially exists other portions that may be disposed at temperatures suitable for Legionella proliferation, especially when the contents have been left unused for an extended period of time.

An air conditioner includes an outdoor unit in which a refrigerant circulates; an indoor unit in which water circulates; a heat exchange device including a heat exchanger that connects the outdoor unit to the indoor unit and performs heat exchange between the refrigerant and the water; a first outdoor unit connection pipe configured to connect the outdoor unit and the heat exchange device, a high-pressure gaseous refrigerant flowing in the first outdoor unit connection pipe; a second outdoor unit connection pipe configured to connect the outdoor unit and the heat exchange device, a low-pressure gaseous refrigerant flowing in the second outdoor unit connection pipe; a third outdoor unit connection pipe configured to connect the outdoor unit and the heat exchange device, a liquid refrigerant lowing in the third outdoor unit connection pipe; a bypass pipe configured to communicate the third outdoor unit connection pipe and the second outdoor unit connection pipe; and a bypass valve provided in the bypass pipe.

A heat pump may include a compressor configured to compress a refrigerant, a first temperature sensor configured to detect an outdoor temperature, a second temperature sensor provided in heating pipes connected to a heating device that performs indoor heating and configured to detect a temperature of fluid flowing through the heating pipes, an outdoor heat exchanger configured to perform heat exchange between outdoor air and a refrigerant, a third temperature sensor configured to detect a temperature of the outdoor heat exchanger, and a controller. The controller may be configured to: control power to a boiler and/or to the compressor based on sensing values of the first, second, and third temperature sensors, calculate an expected efficiency of the heat pump based on the sensing value of the first temperature sensor and an initial target temperature, and control power to the boiler based on the expected efficiency.

A relay unit includes: a heat medium heat exchanger; a casing; a first refrigerant pipe connection port connected to one of two refrigerant pipes through which refrigerant circulates between the heat medium heat exchanger and the heat source side unit; a second refrigerant pipe connection port connected to an other of the refrigerant pipes; a first heat medium pipe connection port connected to one of two heat medium pipes through which a heat medium circulates between the heat medium heat exchanger and the load side unit; and a second heat medium pipe connection port connected to an other of the heat medium pipes. The first refrigerant pipe connection port, the second refrigerant pipe connection port, the first heat medium pipe connection port, and the second heat medium pipe connection port are provided on a top surface of the casing and face in a direction opposite to a direction of gravity.

A refrigeration cycle apparatus provided with: a compressor; a first heat exchanger; a second heat exchanger; a third heat exchanger; a first heat medium passage connecting a heat medium outlet of the third heat exchanger to a heat medium inlet of the second heat exchanger; a first bypass valve; a second heat medium passage to allow the heat medium flowing out of the second heat exchanger to flow into a second load device; a second bypass valve; a return passage; a flow path switching valve to switch between a first mode in which the heat medium flows into the first heat medium passage from the return passage without passing through the third heat exchanger and a second mode in which the heat medium flows into the third heat exchanger from the return passage.

A refrigeration cycle device includes a third refrigerant passage connecting a utilization heat exchanger to a first expansion valve, a fourth refrigerant passage connecting the first expansion valve to a receiver, a fifth refrigerant passage connecting the receiver to a second expansion valve, a sixth refrigerant passage connecting the second expansion valve to an air heat exchanger, a hot-gas bypass passage connecting a discharge passage to the sixth refrigerant passage, a hot-gas bypass valve, an internal heat exchanger to exchange heat between the liquid refrigerant inside the receiver and the refrigerant passing through the suction passage, a liquid bypass passage including an inlet portion connected to the fourth refrigerant passage, the fifth refrigerant passage, or a lower portion of the receiver, and an outlet portion connected to the suction passage upstream of the internal heat exchanger, and a liquid bypass valve.

Disclosed is a two-stage heating geothermal system using geothermal energy. The two-stage heating geothermal system includes a geothermal heat exchanger, a geothermal heat pump, a booster heat pump, a bypass line, and a bypass line opening and closing valve. The operating efficiency of the two-stage heating geothermal system using geothermal energy is significantly improved. Hot water supply, auxiliary heating, and the like are controlled to be completely independent of main heating.

A control device controls a heating capacity during a heating operation and a defrosting capacity during a defrosting operation. The defrosting capacity of the first refrigeration cycle unit is determined to fall within a range satisfying a first determination condition and within a range satisfying a second determination condition. The first determination condition is a condition that a sum of a load capacity of a load device when the first defrosting start condition is satisfied, and the defrosting capacity of the first refrigeration cycle unit does not exceed the heating capacity of a second refrigeration cycle unit. The second determination condition is a condition that a sum of an inter-unit defrosting interval and a defrosting period of the first refrigeration cycle unit does not exceed a shortest defrosting interval of the second refrigeration cycle unit.

Systems and methods for controlled subcooling of working fluid in a heating, ventilation, air conditioning and refrigeration (HVACR) system through a suction line heat exchanger are disclosed. The suction line heat exchanger may receive a first fluid flow travelling to a suction of the compressor in the HVACR system and second flow of working fluid that is travelling from a heat exchanger receiving the discharge of the compressor to an expansion device. Superheating of the first working fluid may be determined based on temperature measurements prior to and following the suction line heat exchanger. The superheating may be used to control the quantity of the second flow of working fluid introduced into the suction line heat exchanger, for example to maintain superheat that is below a threshold value. These systems may include chillers and heat pump systems, and methods may be applied to chillers or heat pump systems.