Abstract: An air conditioner is provided with a plurality of outdoor heat source units, an indoor unit, a liquid refrigerant communication pipe and gas refrigerant communication pipe, and a controller. Each heat source unit has a compressor, an outdoor heat exchanger, and an accumulator. The indoor unit has an indoor expansion valve and an indoor heat exchanger. The controller starts an other of the heat source units in a stopped state when it is determined that the amount of refrigerant is excessive in a first heat source unit in an operating state.

Abstract: An air conditioning apparatus includes a refrigerant circuit and an operation control section. The operation control section is capable of performing a refrigeration cycle for causing an outdoor heat exchanger to function as a refrigerant condenser and an indoor heat exchanger to function as a refrigerant evaporator, while performing superheat degree control for controlling the aperture of an indoor expansion valve so that the degree of superheat of the refrigerant at the outlet from the indoor heat exchanger is constant. The operation control section means sets a lower aperture limit for the indoor expansion valve to perform the superheat degree control, and reduces the lower aperture limit when the refrigerant at the outlet from the indoor heat exchanger is detected to be wet.

Abstract: An outdoor control unit includes a first control unit, a second control unit, and a switching unit. The outdoor control unit controls the rotational speed of an outdoor fan. The first control unit executes a first control for controlling the rotational speed of the outdoor fan based on the operation frequency of the compressor. The second control unit executes a second control for controlling the rotational speed of the outdoor fan based on a parameter other than the operation frequency of the compressor. The switching unit executes a switching control for switching between the first control and the second control according to a predetermined switching condition, when a cooling mode is being operated under a low outside air condition. The low outside air condition refers to a state that the outside air temperature is lower than a first temperature.

Abstract: A humidity control apparatus (10) alternately performs first and second operations at predetermined switching intervals. In the first operation, a first adsorption heat exchanger (51) serves as a condenser, and a second adsorption heat exchanger (52) serves as an evaporator, thereby humidifying second air by the first adsorption heat exchanger (51), and dehumidifying first air by the second adsorption heat exchanger (52). In the second operation, the second adsorption heat exchanger (52) serves as the condenser, and the first adsorption heat exchanger (51) serves as the evaporator, thereby humidifying the second air by the second adsorption heat exchanger (52), and dehumidifying the first air by the first adsorption heat exchanger (51). The switching intervals between the first and second operations are shorter in dehumidification operation of supplying the dehumidified first air to the inside of a room than in humidification operation of supplying the humidified second air to the inside of the room.

Abstract: A humidity control apparatus (10) includes: a casing (11); exhaust and air-supplying fans (25, 26) and dampers (41-48, 83, 84) for exchanging the outside air and the room air with each other via air passageways (31-34, 37, 38, 81, 82) of the casing (11); and a refrigerant circuit (50) for controlling the humidity of the air passing through the air passageways. The humidity control apparatus (10) further includes a controller (60) for monitoring an abnormality inside the apparatus and determining the type of the detected abnormality. When the detected abnormality is an abnormality related to the refrigerant circuit (50) and is not an abnormality related to the exhaust and air-supplying fans (25, 26) and the dampers (41-48, 83, 84), the controller (60) stops the refrigeration cycle of the refrigerant circuit (50) to shut down the humidity-controlling mode, and keeps the ventilation mode available.

Abstract: During a simple ventilation operation, in an outdoor-air conditioner (10) which is a humidity control apparatus, a first bypass damper (83) is opened to supply outdoor air to a room in unchanged form. When the outdoor temperature exceeds 35° C. during the simple ventilation operation, an operation of the outdoor-air conditioner (10) is forcibly switched to a dehumidification/ventilation operation, and then outdoor air passing through an adsorption heat exchanger (51, 52) operating as an evaporator is supplied to the room. When the outdoor temperature falls below 5° C. during the simple ventilation operation, the operation of the outdoor-air conditioner (10) is forcibly switched to a humidification/ventilation operation, and then outdoor air passing through the adsorption heat exchanger (51, 52) operating as a condenser is supplied to the room.

Abstract: An air conditioner is provided with a plurality of outdoor units, an indoor unit, a liquid refrigerant communication pipe and gas refrigerant communication pipe, and a controller. The outdoor unit has a compressor, an outdoor heat exchanger, and an accumulator. The indoor unit has an indoor expansion valve and an indoor heat exchanger. The controller starts another of the heat source units in a stopped state when it is determined that the amount of refrigerant is excessive in a heat source unit in an operating state, or performs refrigerant accumulation control for accumulating refrigerant in an accumulator in a heat source unit other than a first heat source unit in an operating state.

Abstract: An outdoor unit of an air conditioner includes a plurality of constant capacity compressors, a variable capacity compressor and a controller. The plurality of constant capacity compressors compress refrigerant in a predetermined capacity. The variable capacity compressor is capable of having its capacity changed and compressing varying amounts of refrigerant. The controller sequentially causes the plurality of constant capacity compressors to start up and regulates the operating frequency of the variable capacity compressor after start up of the plurality of constant capacity compressors.

Abstract: An air conditioning apparatus includes a refrigerant circuit and an operation control section. The operation control section is capable of performing a refrigeration cycle for causing an outdoor heat exchanger to function as a refrigerant condenser and an indoor heat exchanger to function as a refrigerant evaporator, while performing superheat degree control for controlling the aperture of an indoor expansion valve so that the degree of superheat of the refrigerant at the outlet from the indoor heat exchanger is constant. The operation control section sets a lower aperture limit for the indoor expansion valve to perform the superheat degree control, and reduces the lower aperture limit when the refrigerant at the outlet from the indoor heat exchanger is detected to be wet.

Abstract: An outdoor control unit includes a first control unit, a second control unit, and a switching unit. The outdoor control unit controls the rotational speed of an outdoor fan. The first control unit executes a first control for controlling the rotational speed of the outdoor fan based on the operation frequency of the compressor. The second control unit executes a second control for controlling the rotational speed of the outdoor fan based on a parameter other than the operation frequency of the compressor. The switching unit executes a switching control for switching between the first control and the second control according to a predetermined switching condition, when a cooling mode is being operated under a low outside air condition. The low outside air condition refers to a state that the outside air temperature is lower than a first temperature.