Abstract: In an air conditioner provided with an oil-return-operation control portion that performs an oil-return operation, when oil-return conditions are satisfied, by controlling the rotational speed of a compressor, the degree of opening of an expansion valve, etc., with a predetermined refrigerant cycle and provided with high-outdoor-air-temperature oil-return operation means for performing a forced oil-return operation via the oil-return-operation control portion when an outdoor temperature increases and a state in which a detection value of an outdoor air temperature sensor is higher than a set value continues for a predetermined period of time, the oil-return operation is prohibited for a certain period of time after performing the forced oil-return operation via the high-outdoor-air-temperature oil-return operation means.

Abstract: In an air conditioner provided with an oil-return-operation control portion that performs an oil-return operation, when oil-return conditions are satisfied, by controlling the rotational speed of a compressor, the degree of opening of an expansion valve, etc., with a predetermined refrigerant cycle and provided with high-outdoor-air-temperature oil-return operation means for performing a forced oil-return operation via the oil-return-operation control portion when an outdoor temperature increases and a state in which a detection value of an outdoor air temperature sensor is higher than a set value continues for a predetermined period of time, the oil-return operation is prohibited for a certain period of time after performing the forced oil-return operation via the high-outdoor-air-temperature oil-return operation means.

Abstract: There is provided a multiform gas heat pump type of air conditioning system having: a plurality of indoor units that are each provided with an indoor heat exchanger and that perform a heat exchange between air inside a room and refrigerant; an outdoor unit provided with a compressor driven by a gas engine and an outdoor heat exchanger for performing a heat exchange between outside air and the refrigerant; and a split flow control unit for controlling a flow direction of the refrigerant in each of the indoor units and for performing a selection switching between cooling and heating operations. The outdoor heat exchanger that switches selection between cooling and heating operations is divided into a plurality of units that are connected in parallel and there is also provided a refrigerant supply switching means that controls the refrigerant flow in each of the divided portions of the outdoor heat exchanger.

Abstract: In order to enhance air heating capacity during low outdoor air temperature, a gas heat pump type air conditioning device comprises a compression device having a gas engine driving source and forming a refrigerating cycle by circulating a refrigerant, an engine-coolant-water system, a channel change switching device, a bypass channel which is provided with the channel change switching device in the engine-coolant-water system downstream of the gas engine, and an engine-coolant-water heating device provided in the bypass channel, and waste heat exhausted from the gas engine is collected in the engine-coolant-water, and the refrigerant is heated by the engine-coolant-water so as to enhance air-heating-capacity.

Abstract: In order to enhance air heating capacity during low outdoor air temperature, a gas heat pump type air conditioning device comprises a compression device having a gas engine driving source and forming a refrigerating cycle by circulating a refrigerant, an engine-coolant-water system, a channel change switching device, a bypass channel which is provided with the channel change switching device in the engine-coolant-water system downstream of the gas engine, and an engine-coolant-water heating device provided in the bypass channel, and waste heat exhausted from the gas engine is collected in the engine-coolant-water, and the refrigerant is heated by the engine-coolant-water so as to enhance air-heating-capacity.

Abstract: In order to provide a gas heat pump type air conditioning device in which accessibility and maintenance operation are not disturbed due to snow in snowy areas, a gas heat pump type air conditioning device comprises a compression device for which the driving source is a gas engine and forms a refrigerating cycle by circulating a refrigerant, a bypass pipe channel section which is provided around space where an outdoor unit is installed and is separated from an engine-coolant-water system of the gas engine via a channel change switching device, wherein waste heat exhausted from the gas engine is collected back into the engine-coolant-water, and the refrigerant is heated by the engine-coolant-water so as to enhance air heating capacity.

Abstract: In order to obtain more enhanced air heating capacity during low outdoor air temperature, a gas heat pump type air conditioning device which circulates refrigerant by a compressing device of which driving source is a gas engine, forms a refrigerating cycle, collects waste heat of exhaust gas exhausted from the gas engine to engine coolant water by an exhaust gas heat exchanging device, and heats the refrigerant by the engine coolant water to enhance the heating capacity, the exhaust gas exhausted from the gas engine is heated, and a heating device for increasing amount of thermal energy which can be collected in the exhaust gas heat exchanging device is provided.

Abstract: There is provided a multiform gas heat pump type of air conditioning system having: a plurality of indoor units that are each provided with an indoor heat exchanger and that perform a heat exchange between air inside a room and refrigerant; an outdoor unit provided with a compressor driven by a gas engine and an outdoor heat exchanger for performing a heat exchange between outside air and the refrigerant; and a split flow control unit for controlling a flow direction of the refrigerant in each of the indoor units and for performing a selection switching between cooling and heating operations. The outdoor heat exchanger that switches selection between cooling and heating operations is divided into a plurality of units that are connected in parallel and there is also provided a refrigerant supply switching means that controls the refrigerant flow in each of the divided portions of the outdoor heat exchanger.