Climate control systems and methods of operating them are provided that circulate a working fluid including a high glide refrigerant blend having first and second refrigerants with a difference in boiling points about 25 F. at atmospheric pressure. The system includes a gas-liquid separation vessel that generates a vapor stream and a liquid stream. A compressor receives the vapor stream and generates a pressurized vapor stream. A liquid pump receives the liquid stream and generates a pressurized liquid stream. A condenser is disposed downstream of the compressor and liquid pump and receives and cools the pressurized mixed vapor and liquid stream. An evaporator receives and at least partially vaporizes the multiphase working fluid and directs it to the gas-liquid separating vessel. An expansion device between the condenser and the evaporator processes the multiphase working fluid stream. Lastly, a fluid conduit for circulating the working fluid through the components is provided.

The air conditioner has a configuration such that, in an air-warming operation: the average refrigerant exit temperature, which is obtained by averaging the temperature of the refrigerant exits of indoor heat exchangers 7 in a plurality of indoor units 10, as detected by heat-exchanger-refrigerant-exit temperature probes 34 in the indoor units 10, is determined; the temperature difference between the average refrigerant exit temperature and the refrigerant exit temperatures of the indoor heat exchangers 7 of each of the indoor units 10 is determined; and the degree to which indoor expansion valves 9 of the indoor units 10 are open is controlled such that the determined temperature difference falls within a predetermined temperature difference range.

A refrigeration cycle apparatus includes a heat source unit configured to supply refrigerant, a first distribution unit and a second distribution unit respectively connected to the heat source unit, and a distribution pipe located between the heat source unit and the first distribution unit and the second distribution unit for distributing the refrigerant flowing from the heat source unit into the first distribution unit and the second distribution unit. Further, the first distribution unit and the second distribution unit individually include a heat exchanger configured to serve as a condenser. Further, if the refrigerant flowing through the distribution pipe is unevenly distributed into the first distribution unit and the second distribution unit, a degree of subcooling at an outlet of the heat exchanger of one of the first distribution unit and the second distribution unit of which the distributed refrigerant is of high quality is increased.

An outdoor unit of an air conditioner coupled to an indoor unit by a liquid pipe and a gas pipe, includes: a compressor; an outdoor heat exchanger; a discharge pipe coupled to a refrigerant discharge side of the compressor; an intake pipe coupled to a refrigerant intake side of the compressor; an outdoor-unit high-pressure gas pipe coupled to the discharge pipe; an outdoor-unit low-pressure gas pipe coupled to the intake pipe; an outdoor-unit liquid pipe that couples a first refrigerant entry/exit opening of the outdoor heat exchanger and the liquid pipe together; a bypass pipe coupled to the outdoor-unit liquid pipe; a first flow-passage switcher coupled to a second refrigerant entry/exit opening of the outdoor heat exchanger, the discharge pipe, the intake pipe, and the bypass pipe; and a second flow-passage switcher coupled to the gas pipe, the outdoor-unit high-pressure gas pipe, and the outdoor-unit low-pressure gas pipe.

A cooling/heating switching unit is provided that is capable of simply and reliably detecting leak of refrigerant. The switching unit includes: first and second fittings having a high/low-pressure-gas main pipe and a low-pressure-gas main pipe connected thereto, respectively, wherein the main pipes are linked to an outdoor unit; a third fitting having an indoor-unit connection pipe connected thereto, wherein the connection pipe is linked to indoor units; an expansion valve for high/low-pressure-gas pipe, an expansion valve for low-pressure-gas pipe, and expansion-valve driving sections that selectively connect the first or second fitting with the third fitting via a refrigerant pipe to control a flow direction of refrigerant; a housing that houses the refrigerant pipe; a heat insulating material that fills inside of the housing to insulate the refrigerant pipe arranged inside of the housing from heat; and a refrigerant leak detection sensor installed outside of the housing to detect leaked refrigerant.

A valve system is disclosed for use with a compressor, an indoor heat exchange coil, and an outdoor heat exchange coil. The valve system may include a first reversible valve and a second reversible valve. The first reversible valve may be configured to receive heated refrigerant from the compressor. The second reversible valve may be configured to provide cooled refrigerant to the compressor. In a heating mode, the first reversible valve may be configured to provide the heated refrigerant to the indoor heat exchange coil. In the heating mode, the second reversible valve may be configured to receive the cooled refrigerant from the outdoor heat exchange coil.

An air conditioner is disclosed. The air conditioner includes an indoor unit, a first outdoor unit including a first outdoor heat exchanger and a first compressor to be driven by electricity, a second outdoor unit including a second outdoor heat exchanger and a second compressor to be driven by an engine, a cooling water line, through which cooling water to cool the engine flows, and at least one waste heat-recovering heat exchanger for exchanging heat between refrigerant to be introduced into at least one of the first outdoor heat exchanger and the second outdoor heat exchanger and the cooling water flowing through the cooling water line. By provision of the waste heat-recovering heat exchanger, which heat-exchanges hot cooling water with refrigerant flowing through the first and second outdoor heat exchangers, frost formed on the first and second outdoor units during low-temperature heating is removed. It is possible to cope with a wide range of heating loads while achieving high efficiency, using both the electric heat pump (EHP) system and the gas engine-driven heat pump (GHP) system.

A heating and cooling system that can efficiently and effectively heat a pool and cool a home simultaneously or independently with one compressor and one condenser. The present invention uses a combination of four-way valves to selectively activate the system's components depending on instructions sent by the home or pool thermostats.

Disclosed are refrigerant systems for conditioning air and/or items located within a dwelling occupied by humans or other animals preferably including at least a first heat transfer circuit containing a first heat transfer fluid in a vapor/compression circulation loop located substantially outside of the dwelling and at least a second heat transfer circuit, which contains a second heat transfer fluid different than the first heat transfer fluid, located substantially inside of the dwelling. In preferred embodiments, the second heat transfer circuit does not include a vapor compressor, but the system includes at least one intermediate heat exchanger which permits exchange of heat between the first heat transfer fluid and the second heat transfer fluid such that heat is transferred to the first heat transfer fluid, preferably thereby evaporating the first heat transfer fluid, and from the second heat transfer fluid, thereby condensing the second heat transfer fluid. Preferably, the intermediate heat exchanger is located outside the dwelling. The first heat transfer fluid comprises a refrigerant which has a GWP of not greater than about 500 and that the second heat transfer fluid comprises a refrigerant that also has a GWP of less than 500 and which has a low flammability and a low toxicity, and even more preferably a flammability that is substantially less than the flammability of the refrigerant in the first heat transfer fluid and/or a toxicity that is substantially less than the toxicity of the refrigerant in said first heat transfer fluid.

An outdoor unit of an air-conditioner and two-pipe and three-pipe air-conditioning systems having the same are provided. The outdoor unit includes a compressor defining an outlet and an inlet; a first four-way valve defining a first valve communicated with the outlet, second and third ports communicated with the inlet; a second four-way valve defining second and third ports communicated with the inlet; an outdoor heat exchanger defining a first refrigerant valve Communicated with the fourth port of the first four-way valve; a first gas pipe defining a first end connected with the second and third ports of the first and second four-way valves and, the inlet; a second gas pipe defining a first end connected with the fourth port of the second four-way valve; a third gas pipe defining a first end connected with the outlet and a second end connected with the first port of the second four-way valve.