Patent attributes
An outdoor unit includes a compressor that compresses a flammable refrigerant, a heat source side heat exchanger that exchanges heat between the refrigerant and air in an unconditioned space, an outdoor unit air-sending device disposed at a position where the air is enabled to flow out of a housing to the outside, the outdoor unit air-sending device being driven to maintain the concentration of the refrigerant in the housing at or below a predetermined concentration, and an outdoor unit controller that controls an operation of the compressor and an operation of the outdoor air-sending device. The outdoor unit controller allows the outdoor unit air-sending device to operate in order to maintain the concentration of the refrigerant at or below the predetermined concentration even when the compressor is stopped.