Air-conditioning apparatus

Abstract

All of pumps are in operation for a predetermined period of time in an air-conditioning apparatus and, after that, the number of pumps in operation is changed depending on an operation capacity for indoor units each including a use side heat exchanger.

1 . An air-conditioning apparatus comprising:
 at least one intermediate heat exchanger that exchanges heat between heat source side refrigerant and a heat medium different from the heat source side refrigerant;   a refrigeration cycle including a compressor, a heat source side heat exchanger, at least one expansion valve, and a refrigerant passage of the intermediate heat exchanger connected by pipe through which the heat source side refrigerant flows; and   a heat medium circuit including a heat medium passage of the intermediate heat exchanger, a plurality of pumps, and a plurality of use side heat exchangers connected by pipe through which the heat medium flows, wherein   the air-conditioning apparatus includes a heating only operation mode for supplying only heating energy to the use side heat exchangers and a cooling only operation mode for supplying only cooling energy to the use side heat exchangers,   all of the pumps are in operation for a predetermined period of time and, after that, the number of pumps in operation is changed depending on an operation capacity for indoor units each including the use side heat exchanger, and   during the heating only operation mode or the cooling only operation mode, when the operation capacity for the indoor units is greater than the predetermined value X, and is greater than or equal to a value C determined based on a differential, and any of the pumps is in non-operation, the number of pumps in operation is changed by actuating the pump in non-operation at minimum input power.   
     
     
         2 - 5 . (canceled)