Multi-split type air-conditioning device and connection determination method

A connection determination method of determining a connection of an indoor unit in a multi-split type air-conditioning device including an indoor hot water unit including a water circuit in which a water medium circulates as a heat exchange medium, a plurality of indoor air units each including an air heat exchanger, and an outdoor unit to which the indoor hot water unit and the plurality of indoor air units are connected,

• wherein the outdoor unit includes:
• branch ports beside which pressure reduction mechanisms are disposed after a branch of a refrigerant circuit and to which the plurality of indoor air units and the indoor hot water unit are connected through pipes;
• and
• an outdoor unit-control unit configured to control the refrigerant circuit and transmit control commands for the indoor hot water unit and the plurality of indoor air units via transmission signal lines,
• wherein the outdoor unit-control unit executes an indoor hot water unit-determination process of causing the refrigerant circuit to perform a heating operation, causing a refrigerant to flow through the branch ports sequentially using the pressure reduction mechanisms, and determining the branch port to which the indoor hot water unit is connected, and
• wherein, after the indoor hot water unit-determination process is executed, the outdoor unit-control unit executes an indoor air unit-determination process of causing the refrigerant circuit to perform a cooling operation, causing the refrigerant to flow through the branch ports to which the indoor hot water unit is not connected, and determining a connection relationship between the branch ports to which the plurality of indoor air units are connected and the plurality of indoor air units.