Abstract: An air conditioning system includes a refrigerant circuit (20) in which a compressor (21), an indoor radiant panel (23), a first expansion valve (24), a room air heat exchanger (25), a second expansion valve (26) and an outdoor air heat exchanger (27) are connected in this order and which operates in a refrigeration cycle by reversibly circulating refrigerant therethrough. During a defrosting operation, the first expansion valve (24) is controlled to reduce the refrigerant pressure so that in a cooling cycle the refrigerant releases heat in the outdoor air heat exchanger (27) and the room air heat exchanger (25) and evaporates in the indoor radiant panel (23). Thus, the air conditioning system concurrently provides the defrosting of the outdoor air heat exchanger (27) and the room heating of the room air heat exchanger (25).

Abstract: A refrigerant charging method for an air conditioning device in which carbon dioxide is used as a refrigerant includes a connecting step and a refrigerant charging step. In the connecting step, a cylinder containing the refrigerant is connected to a space in the air conditioning device intended to be charged by the refrigerant. A heater is interposed between the cylinder and the air conditioning device. In the refrigerant charging step, the refrigerant is moved to the intended charging space from the cylinder, via the heater. In the refrigerant charging step, further, the refrigerant that has exited the cylinder is heated by the heater so that a specific enthalpy of the refrigerant when it enters the intended charging space will be 430 kJ/kg or higher.

Abstract: A method of cleaning an air conditioner utilizing carbon dioxide as a working refrigerant includes three steps. In a charging step, a refrigeration cycle is charged with carbon dioxide. In a venting step, a charging target with which the refrigeration cycle is charged is vented after the charging step. In a repeating step a unit operation is performed at least one time or more. The unit operation includes the charging step and the venting step. An air conditioner includes a refrigeration cycle configured to perform the unit operation at least one time, and a counter configured to count and output the number of times that the unit operation has been performed.

Abstract: An air conditioning system includes a compressor, a first heat source-side heat exchanger for heating or cooling a refrigerant, a second heat source-side heat exchanger for exchanging heat between the refrigerant and a heat delivery medium, a first utilization-side heat exchanger for performing indoor cooling by using the refrigerant cooled in the first heat source-side heat exchanger, a second utilization-side heat exchanger for performing indoor heating by using the heat delivery medium subjected to heat exchange in the second heat source-side heat exchanger, and a connection mechanism.

Abstract: A pipe joint and a method of joining pipes using the pipe joint prevent loss of a sleeve, enhance workability in the pipe joining operation, and ensure sealing performance. The pipe joint may be utilized in a refrigerant device, a heat pump hot water supply device, a closing valve and a water supply piping. The method for connecting piping may be used in an in-the filed piping method. The pipe joint includes a joint body, a fastening member such as a nut, and a sleeve. The sleeve is integrated with the fastening member or the joint body before the fastening member is attached to the joint body. When the fastening member is attached to the joint body, the sleeve is cut off and separated from the fastening member or joint body. When the nut is fully attached, the sleeve bites into the pipe, and the pipe is joined to the joint body.

Abstract: An air conditioner is installable in a ceiling of an air-conditioned room and is disposed with a casing in whose top surface is formed a suction opening and in whose bottom surface are formed blowout openings, and in which is formed an air flow path that leads from the suction opening to the blowout openings, a blow fan that is disposed in the air flow path, and a heat exchanger that is disposed in the air flow path.

Abstract: An air conditioner has a heat source unit with a compressor and a heat source heat exchanger and utilization units with utilization expansion valves and utilization heat exchangers. The heat source unit and the utilization unit are interconnected via refrigerant communication pipes. The air conditioner is capable of switching and operating between a normal operation mode in which control of the respective devices is performed depending on the operation loads of the utilization units and a refrigerant quantity judging operation mode in which the utilization units perform cooling operation. The utilization expansion valves are controlled such that degrees of superheating at outlets of the utilization heat exchangers become a positive value, and an operation capacity of the compressor is controlled such that evaporation pressures in the utilization heat exchangers become constant.

Abstract: The present invention includes foundation legs of an outdoor unit that are made of a relatively thin plate material, and can reduce cost. This outdoor unit includes a compressor, an outdoor refrigerant circuit that includes pipes and a heat exchanger, a case that houses the refrigerant circuit, and a plurality of supports provided so that they protrude downward from the bottom part of the case. Furthermore, foundation legs are provided at the lower ends of the plurality of supports for fixing such, so that they extend towards the inner side of the case.

Abstract: A pipe joint and a method of joining pipes using the pipe joint prevent loss of a sleeve, enhance workability in the pipe joining operation, and ensure sealing performance. The pipe joint may be utilized in a refrigerant device, a heat pump hot water supply device, a closing valve and a water supply piping. The method for connecting piping may be used in an in-the filed piping method. The pipe joint includes a joint body, a fastening member such as a nut, and a sleeve. The sleeve is integrated with the fastening member or the joint body before the fastening member is attached to the joint body. When the fastening member is attached to the joint body, the sleeve is cut off and separated from the fastening member or joint body. When the nut is fully attached, the sleeve bites into the pipe, and the pipe is joined to the joint body.

Abstract: A refrigerant charging method in an air conditioner using carbon dioxide as a refrigerant includes a first refrigerant charging step and a second refrigerant charging step. The first refrigerant charging step is a step of charging a refrigerant charging target portion including refrigerant communication pipes with refrigerant in a gas state until the pressure of the refrigerant charging target portion rises to a predetermined pressure after the start of charging. The second refrigerant charging step is a step of charging the refrigerant charging target portion with refrigerant in a liquid state until the amount of refrigerant charging the refrigerant charging target portion becomes a predetermined amount. The second refrigerant charging step occurring after the first refrigerant charging step.

Abstract: An air conditioner includes a main refrigerant circuit and a liquid level detection circuit. The main refrigerant circuit includes a compressor that compresses gas refrigerant, a heat source side heat exchanger, a receiver that stores liquid refrigerant, and user side heat exchangers. The liquid level detection circuit is arranged so as to be capable of drawing out a portion of the refrigerant in the receiver from a first predetermined position of the receiver, reducing the pressure of the refrigerant and heating it, measuring the temperature of the refrigerant, and then returning the refrigerant to the intake side of the compressor, in order to detect whether the liquid level in the receiver is at the first predetermined position.

Abstract: When a refrigeration device in which CO2 is used as a refrigerant is to be charged with a refrigerant, the time required for charging and the time that elapses after charging until operation can recommence can be reduced. A refrigerant charging method for an air conditioning device (10) in which carbon dioxide is used as a refrigerant comprises a connecting step and a refrigerant charging step. In the connecting step, a cylinder (81) containing the refrigerant is connected to a space in the air conditioning device 10 intended to be charged by the refrigerant, a heater (83) being interposed therebetween. In the refrigerant charging step, the refrigerant is moved to the intended charging space from the cylinder (81), via the heater (83). In the refrigerant charging step, further, the refrigerant that has exited the cylinder (81) is heated by the heater (83) so that a specific enthalpy of the refrigerant when it enters the intended charging space will be 430 kJ/kg or higher.

Abstract: A method of cleaning an air conditioner utilizing carbon dioxide as a working refrigerant includes three steps. In a charging step, a refrigeration cycle is charged with carbon dioxide. In a venting step, a charging target with which the refrigeration cycle is charged is vented after the charging step. In a repeating step a unit operation is performed at least one time or more. The unit operation includes the charging step and the venting step. An air conditioner includes a refrigeration cycle configured to perform the unit operation at least one time, and a counter configured to count and output the number of times that the unit operation has been performed.

Abstract: An air conditioning system includes a compressor, a first heat source-side heat exchanger for heating or cooling a refrigerant, a second heat source-side heat exchanger for exchanging heat between the refrigerant and a heat delivery medium, a first utilization-side heat exchanger for performing indoor cooling by using the refrigerant cooled in the first heat source-side heat exchanger, a second utilization-side heat exchanger for performing indoor heating by using the heat delivery medium subjected to heat exchange in the second heat source-side heat exchanger, and a connection mechanism.

Abstract: An air conditioning system includes a refrigerant circuit (20) in which a compressor (21), an indoor radiant panel (23), a first expansion valve (24), a room air heat exchanger (25), a second expansion valve (26) and an outdoor air heat exchanger (27) are connected in this order and which operates in a refrigeration cycle by reversibly circulating refrigerant therethrough. During a defrosting operation, the first expansion valve (24) is controlled to reduce the refrigerant pressure so that in a cooling cycle the refrigerant releases heat in the outdoor air heat exchanger (27) and the room air heat exchanger (25) and evaporates in the indoor radiant panel (23). Thus, the air conditioning system concurrently provides the defrosting of the outdoor air heat exchanger (27) and the room heating of the room air heat exchanger (25).

Abstract: An air conditioning apparatus is capable of being mounted on the ceiling of an air-conditioned room. The air conditioning apparatus includes a casing in which an intake port is formed in a bottom surface, a filter provided in the intake port, a cleaning mechanism for removing dust collected by the filter from the filter, and a dust box provided at the bottom of the casing to collect dust removed by the cleaning mechanism. A nozzle insertion hole through which a nozzle of a vacuum cleaner can be inserted is formed facing downward in the dust box.

Abstract: An air conditioner is installable in a ceiling of an air-conditioned room and is disposed with a casing in whose top surface is formed a suction opening and in whose bottom surface are formed blowout openings, and in which is formed an air flow path that leads from the suction opening to the blowout openings, a blow fan that is disposed in the air flow path, and a heat exchanger that is disposed in the air flow path.

Abstract: A refrigerant charging method in an air conditioner using carbon dioxide as a refrigerant includes a first refrigerant charging step and a second refrigerant charging step. The first refrigerant charging step is a step of charging a refrigerant charging target portion including refrigerant communication pipes with refrigerant in a gas state until the pressure of the refrigerant charging target portion rises to a predetermined pressure after the start of charging. The second refrigerant charging step is a step of charging the refrigerant charging target portion with refrigerant in a liquid state until the amount of refrigerant charging the refrigerant charging target portion becomes a predetermined amount. The second refrigerant charging ster occuring after the first refrigerant charging step.

Abstract: In a refrigeration device including a refrigeration circuit having a compressor and a receiver, the present invention will improve the ability of a liquid level detection circuit to accurately determine whether or not liquid refrigerant is stored up to a predetermined position of the receiver. An air conditioner includes a main refrigerant circuit and a liquid level detection circuit. The main refrigerant circuit includes a compressor that compresses gas refrigerant, a heat source side heat exchanger, a receiver that stores liquid refrigerant, and user side heat exchangers.

Abstract: A refrigeration device is provided that has a compressor, a heat source side heat exchanger, and a user side heat exchanger. The refrigeration device also has a condenser arranged between the compressor and the user side heat exchanger. The condenser is arranged to condense a portion of the refrigerant that is compressed in the compressor and that is sent to the user side heat exchanger.