PURPOSE: To make it possible to fairly share the expense for operating a heat source by time-integrating machine types transmitted by an indoor unit and set notch data at every section, and counting up to display every time the total sum of these integral quantities reaches a reference integral quantity.

CONSTITUTION: An output signal of a set notch detecting part 14 detecting the set notch of a fan motor is inputted to a control part 16. In a machine type setting part 15, the machine types of the indoor unit are encoded and set in respective switches 31W33 and inputted to the control part 16. When the outputs from the notch from the control part 16 and data of machine type setting, and the time of using the indoor unit 11 are integrated by integrating means 36 and the total sum of the integral quantities reaches a reference integral quantity, a signal of a high level is outputted to a driver circuit 38 of a counter part 18 and the driver circuit 38 is turned ON, a current is allowed to flow in a relay coil 39 and a relay contact 39a is turned ON, an electromagnetic counter 41 connected to a power source 40 counts up and displays. By these procedures, the consumption of the air conditioners in respective houses are displayed in the quantity of heat, and the operation expense of the heat source is fairly shared.