Air conditioning device and control method

The invention provides an air conditioning device and a control method, which can suppress intermittent operation of indoor units and maintain comfort when a plurality of indoor units with different air conditioning loads or rated capacities are in operation. An air conditioning device is provided with a plurality of indoor units (11a-11c) and an outdoor unit (12), each of the indoor units (11a-11c) includes an indoor heat exchanger (20a-20c), a room temperature sensor (21a-21c) for detecting the indoor temperature, and an indoor expansion valve (22a-22c) for adjusting the flow rate of a refrigerant flowing in the indoor unit, the outdoor unit (12) includes an outdoor heat exchanger (32) and a compressor (30), and the air conditioning device includes a controller (34). And a controller that calculates the difference between the load of the indoor units (11a-11c) and the air conditioning capacity on the basis of the deviation between the room temperature detected by the room temperature sensors (21a-21c) and t