Air conditioner

An air conditioner, comprising:

• a controller;
• a compressor;
• an outdoor heat exchanger;
• a plurality of indoor heat exchangers;
• a switching valve that selectively guides a refrigerant discharged from the compressor to the outdoor heat exchanger or the plurality of indoor heat exchangers;
• high pressure pipes that connect the switching valve and the plurality of indoor heat exchangers;
• high pressure valves installed in the high pressure pipes;
• low pressure pipes that connect an inlet of the compressor and the high pressure pipes;
• low pressure valves installed in the low pressure pipes;
• indoor pipes, which are opposite to the high pressure pipes with respect to the plurality of indoor heat exchangers and connected to the plurality of indoor heat exchangers;
• indoor expansion valves installed in the indoor pipes;
• and
• a liquid pipe that connects the outdoor heat exchanger and the plurality of indoor pipes;
• and
• an outdoor expansion valve installed in the liquid pipe, wherein the outdoor heat exchanger serves as a condenser when the switching valve is in a first state, and serves as an evaporator when the switching valve is in a second state, wherein the controller increases a system evaporating pressure, which is a pressure of refrigerant suctioned into the compressor, before switching the switching valve from the first state to the second state, and decreases a system condensing pressure, which is a pressure of refrigerant discharged from the compressor, before switching the switching valve from the second state to the first state, wherein when a cooling load of indoor heat exchangers of the plurality of indoor heat exchangers that serve as an evaporator is greater than a heating load of an indoor heat exchanger of the plurality of indoor heat exchangers that serves as a condenser, the controller is configured to control the switching valve to switch to the first state, and wherein when a heating load of indoor heat exchangers of the plurality of indoor heat exchangers serving as a condenser is greater than a cooling load of an indoor heat exchanger of the plurality of indoor heat exchangers serving as an evaporator, the controller is configured to control the switching valve to switch to the second state.