Multi-air conditioner for heating and cooling and method for controlling multi-air conditioner for heating and cooling

A method for controlling a multi-air conditioner for heating and cooling, the multi-air conditioner comprising at least one indoor unit installed in an indoor space and comprising an indoor heat exchanger and an indoor expansion valve, an outdoor unit connected to the indoor unit via a refrigerant pipeline and comprising at least one outdoor heat exchanger, at least one compressor, at least one outdoor expansion valve, and at least one four-way valve, and at least one leak shut-off valve provided on the refrigerant pipeline, the method comprising:

• detecting a refrigerant leak from the refrigerant pipeline in the indoor space;
• upon detecting the refrigerant leak, blocking a flow of refrigerant by closing the at least one leak shut-off valve installed on the refrigerant pipeline;
• and
• decreasing a pressure of the refrigerant in the refrigerant pipeline while the at least one leak shut-off valve is closed.

A multi-air conditioner for heating and cooling, comprising:

• a plurality of indoor units installed in indoor spaces, each of the plurality of indoor units comprising an indoor heat exchanger and an indoor expansion valve;
• an outdoor unit connected to the plurality of indoor units via a refrigerant pipeline and comprising at least one outdoor heat exchanger, at least one compressor, at least one outdoor expansion valve, and at least one four-way valve;
• and
• at least one leak shut-off valve provided on the refrigerant pipeline for each of the plurality of indoor units, wherein the at least one leak shut-off valve blocks a flow of refrigerant in the refrigerant pipeline when a refrigerant leak from the refrigerant pipeline occurs in the respective indoor space, wherein the outdoor unit decreases a pressure of the refrigerant pipeline when the refrigerant leak occurs from the refrigerant pipeline, wherein the at least one leak shut-off valve is installed outside of the respective indoor space in which the respective indoor unit is installed.