Patent attributes
In a multi-type air conditioner, the adequacy of the refrigerant quantity charged in the air conditioner can be accurately determined, even when the refrigerant quantity charged on site is inconsistent, or even when a reference value of the operation state quantity, which is used for determining the adequacy of the refrigerant quantity, fluctuates depending on the pipe length of the refrigerant communication pipe, combination of utilization units, and the difference in the installation height among each unit. In an air conditioner (1) including a refrigerant circuit (10) configured by the interconnection of a heat source unit (2) and utilization units (4, 5) via refrigerant communication pipes (6, 7), a refrigerant quantity determining system determines the adequacy of the refrigerant quantity and includes a state quantity storing means and a refrigerant quantity determining means. The state quantity storing means stores the operation state quantity of constituent equipment or the refrigerant flowing in the refrigerant circuit (10) in which refrigerant is charged up to an initial refrigerant quantity by on-site refrigerant charging. The refrigerant quantity determining means compares the operation state quantity during test operation as a reference value with a current value of the operation state quantity, and thereby determines the adequacy of the refrigerant quantity.