Patent ID: 9459013
Filing Date: 2016-10-04
CPC Classification: F24F,F25B

Claim Text:
1. An air-conditioning apparatus, comprising: a refrigeration cycle including a refrigerant circuit for circulating a refrigerant, the refrigerant circuit being constituted by connecting with pipes a compressor that sends out a combustible refrigerant, a refrigerant flow switching device configured to switch circulation paths of the refrigerant, a heat source side heat exchanger configured to exchange heat of the refrigerant, a refrigerant expansion device configured to control a pressure of the refrigerant, and a plurality of heat exchangers related to heat medium capable of exchanging heat between the refrigerant and a heat medium that is different from the refrigerant; and a heat medium side circuit constituted by a heat medium circulating circuit that is constructed by connecting a plurality of heat medium sending devices configured to circulate the heat medium pertaining to heat exchange of the heat exchangers related to heat medium, and a plurality of use side heat exchangers exchanging heat between the heat medium and air related to a space to be air-conditioned, with pipes, wherein at least the compressor, the refrigerant flow switching device, the heat source side heat exchanger are housed in an outdoor unit, at least the heat exchangers related to heat medium and the refrigerant expansion device are housed in a heat medium relay unit, and the use side heat exchangers are housed in corresponding indoor units, each of the outdoor unit, the heat medium relay unit, and the indoor units being separately formed and being allowed to be disposed at separate positions, a housing of the heat medium relay unit includes an opening allowing ventilation between an inside of the housing and an outside of the housing, and a relay-unit air-sending device that sends air, a controller configured to perform a control operation of the relay-unit air-sending device such that refrigerant concentration inside the housing of the heat medium relay unit is maintained under a predetermined concentration, the controller is configured to the heat medium circulating circuit includes heat medium flow switching devices being connected by pipes to the corresponding use side heat exchangers to perform switching such that the heat medium that passes through each of the heat exchangers related to heat medium is selected and is caused to flow into the use side heat exchangers.