Abstract: A method for selecting a heat medium in installing an air-conditioning system includes: determining power required for use side heat exchangers corresponding to a plurality of air-conditioned spaces; calculating a total refrigerant amount required when a refrigerant is circulated through all the use side heat exchangers having the determined power; calculating a refrigerant concentration when the total refrigerant amount leaks to each air-conditioned space using the refrigerant, for each air-conditioned space; determining the refrigerant concentration for each air-conditioned space exceeds a predetermined limit concentration; when any air-conditioned space exceeds the limit concentration, selecting, as a nontoxic medium, the circulation heat medium of the use side heat exchanger installed in one of the air-conditioned spaces; and calculating a total refrigerant amount required when the refrigerant is circulated through all other use side heat exchangers.

Abstract: An air-conditioning apparatus includes a refrigeration cycle that includes one or more intermediate heat exchangers, exchanging heat between a heat source side refrigerant and a heat medium different from the heat source side refrigerant, a heat medium circuit that includes at least one pump configured to circulate the heat medium for heat exchange by the intermediate heat exchanger, a use side heat exchanger configured to exchange heat between the heat medium and air in an air-conditioning target space, and flow switching valves configured to switch between passing the heated heat medium through the use side heat exchanger and passing the cooled heat medium through the use side heat exchanger and in which the pump, the use side heat exchanger, and the flow switching valves are connected by pipes, and a controller configured to calculate an actual temperature efficiency ratio based on a temperature at a heat medium inlet of the heat exchanger in the heat medium circuit and determine whether a flow rate of the

Abstract: When indoor units are performing a cooling operation, an air-conditioning apparatus controls third flow passage switching valves, for example a first solenoid valve, a second solenoid valve, a third solenoid valve, and a fourth solenoid valve, so that a number of intermediate heat exchangers operating as evaporators is greater than in a cooling main operation. During the cooling main operation, a target value for suction pressure or evaporating temperature at a compressor is set equal to or lower than that in a case in which the indoor units are performing the cooling operation, and a frequency of the compressor and a capacity of a heat-source-side heat exchanger are controlled.

Abstract: An air-conditioning apparatus includes a temperature sensor for detecting a temperature of the heat medium sent from each of the intermediate heat exchangers to each of the use-side heat exchangers, and a temperature of the heat medium that has exited each of the use-side heat exchangers, an opening degree controller for regulating a flow rate of the heat medium through each of the heat medium flow control devices, and a computing unit for computing a usage capacity of each of the indoor units from a rotation speed of the pump, an opening degree of each of the heat medium flow control devices, temperatures detected by the temperature sensors, and power consumption of each of the indoor units, and proportionally dividing the power consumption for a common portion among each of the indoor units based on the computed usage capacity and the power consumption of the common portion.

Abstract: An air-conditioning apparatus includes a refrigeration cycle that includes an intermediate heat exchanger configured to exchange heat between a heat source side refrigerant and a heat medium different from the heat source side refrigerant, a heat medium circuit that includes at least one pump configured to circulate the heat medium related to heat exchange in the intermediate heat exchanger, a use side heat exchanger configured to exchange heat between the heat medium and air related to an air-conditioned space, and flow switching valves. A controller is configured to perform control to activate the pump to circulate the heat medium through the heat medium circuit when, during suspension of an air conditioning operation, the detected temperature of outdoor air is at or below a first predetermined temperature and a first predetermined period of time has elapsed since the pump was stopped.

Abstract: A refrigerant circuit is configured by connecting, by pipes, a compressor that compresses a heat-source-side refrigerant, a first refrigerant flow switching device, a heat-source-side heat exchanger, an expansion device, and one or more intermediate heat exchangers that exchange heat between a heat-source-side refrigerant and a heat medium that is different from the heat-source-side refrigerant. A controller performs control of pumps to drive the pumps at a specific pump capacity or higher to circulate the heat medium at a time when a heat recovery defrosting operation for causing the heat-source-side refrigerant that has been heated by the heat medium in the intermediate heat exchangers to flow into the heat-source-side heat exchanger for defrosting purposes.

Abstract: An air-conditioning apparatus includes a refrigerant circuit including a compressor, a first refrigerant flow switching device, a plurality of intermediate heat exchangers, a first expansion device, and a heat-source-side heat exchanger, through all of which a refrigerant circulates and all of which in combination form a refrigeration cycle; and a heat medium circuit including the plurality of intermediate heat exchangers, a pump, and a plurality of use-side heat exchangers, through all of which a heat medium circulates. The air-conditioning apparatus further includes a heat medium energy storage that is connected to the heat medium circuit and stores the heat medium; and an intra-storage heat exchanger that is connected to the refrigerant circuit and heats or cools the heat medium in the heat medium energy storage by using the heat-source-side refrigerant supplied thereto.

Abstract: An air-conditioning apparatus has a heating only temporary operation mode in which, in changing from a heating main operation mode to a heating only operation mode, when an outside air temperature is at or above a predetermined temperature, at least one of heat exchangers functioning as a condenser in the heating main operation mode continues functioning as the condenser, and the refrigerant is not supplied to the intermediate heat exchanger functioning as an evaporator in the heating main operation mode and a cooling only temporary operation mode in which, in changing from a cooling main operation mode to a cooling only operation mode, when the outside air temperature is at or below a predetermined temperature, at least one of heat exchangers functioning as the evaporator in the cooling main operation mode continues functioning as the evaporator, and the refrigerant is not supplied to the intermediate heat exchanger functioning as the condenser in the cooling main operation mode.

Abstract: An air conditioning apparatus has plural indoor units having: plural heat exchangers; and flow controllers respectively corresponding to the heat exchangers. In each of the indoor units, one heat exchanger is used as a condenser, and another heat exchanger is used as an evaporator, thereby causing the indoor unit to perform a temperature and humidity controlling operation. An indoor unit(s) which is not set to perform the temperature and humidity controlling operation may be caused to perform a heating operation or a cooling operation. Capacity controls on the condensers and the evaporators are performed by corresponding flow controllers. Gas refrigerants ejected from plural heat exchangers serving as evaporators are joined together, and then distributed to plural heat exchangers serving as condensers.

Abstract: An air conditioning apparatus has plural indoor units having: plural heat exchangers; and flow controllers respectively corresponding to the heat exchangers. In each of the indoor units, one heat exchanger is used as a condenser, and another heat exchanger is used as an evaporator, thereby causing the indoor unit to perform a temperature and humidity controlling operation. An indoor unit(s) which is not set to perform the temperature and humidity controlling operation may be caused to perform a heating operation or a cooling operation. Capacity controls on the condensers and the evaporators are performed by corresponding flow controllers. Gas refrigerants ejected from plural heat exchangers serving as evaporators are joined together, and then distributed to plural heat exchangers serving as condensers.

Abstract: An air conditioning apparatus has plural indoor units having: plural heat exchangers; and flow controllers respectively corresponding to the heat exchangers. In each of the indoor units, one heat exchanger is used as a condenser, and another heat exchanger is used as an evaporator, thereby causing the indoor unit to perform a temperature and humidity controlling operation. An indoor unit(s) which is not set to perform the temperature and humidity controlling operation may be caused to perform a heating operation or a cooling operation. Capacity controls on the condensers and the evaporators are performed by corresponding flow controllers. Gas refrigerants ejected from plural heat exchangers serving as evaporators are joined together, and then distributed to plural heat exchangers serving as condensers.

Abstract: An air conditioning apparatus has plural indoor units having: plural heat exchangers; and flow controllers respectively corresponding to the heat exchangers. In each of the indoor units, one heat exchanger is used as a condenser, and another heat exchanger is used as an evaporator, thereby causing the indoor unit to perform a temperature and humidity controlling operation. An indoor unit(s) which is not set to perform the temperature and humidity controlling operation may be caused to perform a heating operation or a cooling operation. Capacity controls on the condensers and the evaporators are performed by corresponding flow controllers. Gas refrigerants ejected from plural heat exchangers serving as evaporators are joined together, and then distributed to plural heat exchangers serving as condensers.

Abstract: In a refrigerating apparatus using a non-azeotropic refrigerant, the composition is included among the quantities of state of a refrigerant, so that it is difficult to detect the state of the interior of the refrigerant circuit. For this reason, it is difficult to stabilize the operation of the refrigerating apparatus by detecting the state of the interior of the refrigerating apparatus, and avoid the malfunction of the refrigerating apparatus. The cyclic composition of the refrigerating apparatus is detected, and the state of the interior of the refrigerating apparatus is detected accurately by using this cyclic composition. In addition, the refrigerating apparatus is arranged such that in a case where there is a quantity of state which cannot be detected accurately owing to an error or the like of the detected cyclic composition, that value can be detected directly. As a result, it is possible to accurately detect the malfunction of the refrigerating apparatus and avoid this state.