AIR CONDITIONER

摘要

An air conditioner in which generation of passing sound of refrigerant is suppressed in an expansion valve and a utilization-side heat exchanger or in the refrigerant piping from an expansion valve to a utilization-side heat exchanger. The air conditioner comprises a main refrigerant circuit having a compressor, a heat source-side heat exchanger, a utilization-side heat exchanger and an expansion valve, a bypass refrigerant circuit for returning a part of refrigerant supplied from the heat source-side heat exchanger to the expansion valve back to the suction side of the compressor after branching it from the main refrigerant circuit, a cooler for cooling refrigerant being supplied from the heat source-side heat exchanger to the expansion valve by refrigerant flowing through the bypass refrigerant circuit, and a control section for controlling a bypass expansion valve in the bypass refrigerant circuit such that the degree of superheat of refrigerant flowing through the bypass refrigerant circuit has a predetermined value at the outlet of the cooler. If the outdoor air temperature is lower than a predetermined level when the compressor is started or the number of operating utilization-side heat exchangers is altered, the control section closes the bypass expansion valve until a predetermined time elapses.