An air conditioner is provided. The air conditioner may include at least one indoor device, an electric heat pump (EHP) outdoor device connected with the at least one indoor device, and having a first compressor driven using electric power and a first outdoor heat exchanger, and a gas heat pump (GHP) outdoor device connected with the at least one indoor device, and having an engine that drives a second compressor using a combustion gas and a second outdoor heat exchanger. The GHP outdoor device may include an exhaust gas heat exchanger that performs heat exchange between a refrigerant flowing through the EHP outdoor device and an exhaust gas of the engine.

A low-cost and highly-efficient air-conditioning system including an AHU using refrigerant of a heat pump cycle as a heat source, and capable of reducing an on/off cycle operation of compressors at a time of a low load, the system including: a plurality of outdoor units; an air handling unit; a plurality of independent heat pump cycles formed by connecting the plurality of outdoor units and the air handling unit by refrigerant pipes, each of the plurality of independent heat pump cycles including a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger; and a number control unit controlling, to satisfy a capacity demand corresponding to an air-conditioning load, based on a particular frequency range associated with the compressor, in which a certain compressor efficiency or more is obtained, a number of the compressors in operation and operating frequencies of the respective compressors in operation.

A low-cost and highly-efficient air-conditioning system including an AHU using refrigerant of a heat pump cycle as a heat source, and capable of reducing an on/off cycle operation of compressors at a time of a low load, the system including: a plurality of outdoor units; an air handling unit; a plurality of independent heat pump cycles formed by connecting the plurality of outdoor units and the air handling unit by refrigerant pipes, each of the plurality of independent heat pump cycles including a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger; and a number control unit controlling, to satisfy a capacity demand corresponding to an air-conditioning load, based on a particular frequency range associated with the compressor, in which a certain compressor efficiency or more is obtained, a number of the compressors in operation and operating frequencies of the respective compressors in operation.

An air conditioner for conditioning a space inside a building comprises a heat source unit and at least one indoor unit. The heat source unit has a heat exchanger unit comprising a first heat exchanger disposed in a first casing and configured to exchange heat with a heat source and a compressor unit comprising a compressor disposed in a second casing separate from the first casing. The at least one indoor unit has a second heat exchanger configured to exchange heat with the space to be conditioned and being fluidly communicated to the heat exchanger unit and/or the compressor unit. The heat exchanger unit is disposed inside the building and fluidly communicated to the outside of the building.

An air conditioner for conditioning a space inside a building comprises a heat source unit and at least one indoor unit. The heat source unit has a heat exchanger unit comprising a first heat exchanger disposed in a first casing and configured to exchange heat with a heat source and a compressor unit comprising a compressor disposed in a second casing separate from the first casing. The at least one indoor unit has a second heat exchanger configured to exchange heat with the space to be conditioned and being fluidly communicated to the heat exchanger unit and/or the compressor unit. The heat exchanger unit is disposed inside the building and fluidly communicated to the outside of the building.

An air conditioner comprises a compressor to compress a refrigerant, a heat exchanger to move heat of the refrigerant, and a blower to blow air. The blower comprises a fan rotatable about a rotation axis, and a plurality of stationary blades installed to be a radial shape about the rotation axis in a direction in which the airflow generated by the rotation of the fan is discharged, and are curved in a direction opposite to the rotation direction of the fan from an inner circumferential portion to an outer circumferential portion. The stationary blades comprise an inlet edge, and an outlet edge, and an inlet angle formed by the inlet edge and the rotation axis and a chord angle formed by a chord connecting the inlet edge and the outlet edge and the rotation axis are larger at the inner and outer circumferential portions than at a radial center portion.

A compressor unit for an air conditioner includes a compressor disposed in a first casing, and first and second heat source heat exchanger unit ports configured to connect the compressor unit to a heat source heat exchanger of a heat source heat exchanger unit of the air conditioner, the heat source heat exchanger being disposed in a second casing separate from the first casing and being configured to exchange heat with a heat source, first and second indoor unit ports configured to connect the compressor unit to an indoor heat exchanger of at least one indoor unit of the air conditioner, a first refrigerant piping fluidly connecting the first heat source heat exchanger unit port and the first indoor unit port, and a sub-cooling heat exchanger disposed inside the first casing and fluidly connected to the first refrigerant piping for heat transfer with the refrigerant to be flown through the first refrigerant piping.

A compressor unit for an air conditioner includes a compressor disposed in a first casing, and first and second heat source heat exchanger unit ports configured to connect the compressor unit to a heat source heat exchanger of a heat source heat exchanger unit of the air conditioner, the heat source heat exchanger being disposed in a second casing separate from the first casing and being configured to exchange heat with a heat source, first and second indoor unit ports configured to connect the compressor unit to an indoor heat exchanger of at least one indoor unit of the air conditioner, a first refrigerant piping fluidly connecting the first heat source heat exchanger unit port and the first indoor unit port, and a sub-cooling heat exchanger disposed inside the first casing and fluidly connected to the first refrigerant piping for heat transfer with the refrigerant to be flown through the first refrigerant piping.

A compressor assembly includes a first compressor, a second compressor, a first oil separator, a second oil separator, a storage container, a gas-liquid separator, a liquid balance pipe, and a gas balance pipe. The first compressor has a first air return port, and the second compressor has a second air return port. The first oil separator has a first oil outlet, the second oil separator has a second oil outlet, and the storage container has a refrigerant inlet, the first oil outlet and the second oil outlet both being in communication with the refrigerant inlet. The gas-liquid separator has a first gas separation outlet, a second gas separation outlet, a first oil return hole and a second oil return hole, the first gas separation outlet and the first oil return hole both being in communication with the first gas return port.

A residential HVAC system includes, a compressor, and an outdoor unit controller in communication with the compressor. The outdoor unit controller is configured to receive an indoor ambient temperature and a temperature set point. The outdoor unit controller is further configured to determine an outdoor ambient temperature, and to determine an operating value for the compressor based on a percentage of a delta between a minimum operating value of the compressor and a maximum operating value of the compressor, plus the minimum operating value. The minimum operating value and the maximum operating value are based on the determined outdoor ambient temperature. The percentage of the delta is based on a predefined temperature differential multiplier and one or more time dependent multipliers. The outdoor unit controller is further configured to modify the current operating value of the compressor with the determined operating value.