An air conditioning apparatus has a first mode and a second mode as operation modes. In the first mode, a degree of opening of a first flow rate adjustment valve is fixed to a first degree of opening smaller than 100% and greater than 0%, and an operation frequency of a compressor is varied in accordance with air conditioning performance required of a third heat exchanger. In the second mode, the degree of opening of the first flow rate adjustment valve is varied in accordance with air conditioning performance required of the third heat exchanger. When a difference between the air conditioning performance required of the third heat exchanger and air conditioning performance offered by the third heat exchanger becomes greater than a determination value, the operation mode is changed from the first mode to the second mode.