Abstract: An air conditioner has a refrigeration circuit formed by sequentially connecting a compressor 1, a condenser 2, an electronic expansion valve 4 and an evaporator 7 by pipes (6, 10). A compressor bypass pipe 12 is provided to connect an outlet of the evaporator 7 with an inlet of the condenser 2. A first on-off valve 11 is located in the bypass pipe 12. The air conditioner is controlled to switch to either a forced circulation operation or a natural circulation operation. In the forced circulation operation, the first on-off valve 11 is closed, the expansion valve 4 is opened to a first degree to allow refrigerant to pass therethrough, and the compressor 1 is operated in a running state. In the natural circulation operation, the first on-off valve 11 is opened, the expansion valve 4 is opened to a second degree, different from the first degree, to allow refrigerant to pass therethrough, and the compressor 1 is stopped.

Abstract: A blowoff orifice is constituted by an upper wall, a lower wall and a vertical wind deflecting plate. The upper wall inclines so that a flow passage becomes narrow toward downstream and provided with a protrusion at its end portion. The lower wall has a horizontal linear portion on the downstream side and an end portion forming an acute angle at the tip of the linear portion. The vertical wind deflecting plate is provided between the upper wall and the lower wall, and capable of changing an airflow from a horizontal direction to a downward direction. The upper wall protrusion is located more downstream than the lower wall end portion.

Abstract: A blowoff orifice is constituted by an upper wall, a lower wall and a vertical wind deflecting plate. The upper wall inclines so that a flow passage becomes narrow toward downstream and provided with a protrusion at its end portion. The lower wall has a horizontal linear portion on the downstream side and an end portion forming an acute angle at the tip of the linear portion. The vertical wind deflecting plate is provided between the upper wall and the lower wall, and capable of changing an airflow from a horizontal direction to a downward direction. The upper wall protrusion is located more downstream than the lower wall end portion.