Air conditioning apparatus

An air-conditioning apparatus, comprising:

• indoor units including a plurality of use side heat exchangers that exchange heat between air with which heat is to be exchanged and a heat medium;
• a heat medium relay unit including a plurality of heating/cooling units that heat or cool the heat medium, a plurality of heat medium pumps that deliver the heat medium involved in heating or cooling performed by the heating/cooling units to circulation passages corresponding to the heating/cooling units respectively and circulate the heat medium in each of the circulation passages, and a plurality of heat medium flow switching devices that each perform switching so that at least one heat medium in the plurality of passages corresponding to the heating/cooling units flow into and flow out of the corresponding use side heat exchanger;
• a pressure absorber that connects to one of the passages, the pressure absorber alleviating a pressure change caused by a volumetric change of the heat medium;
• and
• a pressure equalizer consisting of a pipe branched between an inlet passage of one pump corresponding to one circulation passage and an inlet passage of another pump corresponding to another circulation passage or branched between an outlet passage of the one pump corresponding to one circulation passage and an outlet passage of the another pump corresponding to the another circulation passage, the pressure equalizer pipe configured to eliminate a pressure difference caused by a temperature difference of the heat medium in the circulation passages, wherein the pressure equalizer pipe is sized so that a flow rate of the heat medium in the pressure equalizer pipe is less than or equal to ⅓ of the flow rate of the heat medium in the circulation passages.