Air conditioner and outdoor unit therefor

An outdoor unit for an air conditioner, said outdoor unit comprising:

• a compressor;
• an outdoor heat exchanger that exchanges heat between a refrigerant and external air;
• a four-way valve positioned adjacent to the compressor, that changes a flow-path of the refrigerant and circulates the refrigerant according to one of a heating cycle and a cooling cycle;
• a first refrigerant path that connects the outdoor heat exchanger to an indoor unit;
• a second refrigerant path that connects the four-way valve to the indoor unit;
• a refrigerant detouring path connected to the first refrigerant path by a first three-way valve and connected to the second refrigerant path by a second three-way valve, that detours the refrigerant during a defrosting cycle;
• an outdoor expansion device positioned along the refrigerant detouring path, that lowers a pressure of the refrigerant in the refrigerant detouring path;
• and
• a heat exchanging unit installed between the outdoor expansion device and the second three-way valve, that exchanges heat with the refrigerant which has passed through the outdoor expansion device.

An air conditioner comprising an outdoor unit and an indoor unit provided with an indoor heat exchanger and an indoor expansion device, said outdoor unit comprising:

• a compressor that compresses a refrigerant;
• an outdoor heat exchanger that exchanges heat with the refrigerant;
• a four-way valve positioned adjacent to the compressor, that circulates the refrigerant discharged from the compressor according to one of a heating cycle and a cooling cycle;
• and
• a refrigerant detouring path that extends between a first refrigerant path, that connects the outdoor heat exchanger and the indoor unit by a first three-way valve, and a second refrigerant path, that connects the four-way valve and the indoor unit by a second three-way valve.