Abstract: A refrigerant cycle system includes: a first refrigerant circuit; a second refrigerant circuit independent of the first refrigerant circuit; a heat source-side unit that includes a first heat source-side heat exchange unit and a second heat source-side heat exchange unit; a first use-side unit that includes a first use-side heat exchanger; a first liquid refrigerant connection pipe and a first gas refrigerant connection pipe that connect the first use-side unit to the heat source-side unit; a second use-side unit that includes a second use-side heat exchanger; and a second liquid refrigerant connection pipe and a second gas refrigerant connection pipe that connect the second use-side unit to the heat source-side unit.

Abstract: An air-conditioning system having exceptional security is provided. An air-conditioning system comprises a plurality of indoor units installed in a target space, a controller configured and arranged to control the actions of the plurality of indoor units, and a refrigerant leakage sensor configured and arranged to sense refrigerant leakage in the target space. Each of the indoor units has indoor fan. When the refrigerant leakage sensor has sensed refrigerant leakage, the controller configured and arranged to cause the indoor fan of the indoor unit that has received a refrigerant leakage signal to be driven at a predetermined first rotation speed, and cause the indoor fan of other indoor unit (emergency group indoor units) belonging to the same group as the aforementioned indoor unit to be driven at a predetermined second rotation speed.

Abstract: An air-conditioning system having exceptional security is provided. An air-conditioning system comprises a plurality of indoor units installed in a target space, a controller configured and arranged to control the actions of the plurality of indoor units, and a refrigerant leakage sensor configured and arranged to sense refrigerant leakage in the target space. Each of the indoor units has indoor fan. When the refrigerant leakage sensor has sensed refrigerant leakage, the controller configured and arranged to cause the indoor fan of the indoor unit that has received a refrigerant leakage signal to be driven at a predetermined first rotation speed, and cause the indoor fan of other indoor unit (emergency group indoor units) belonging to the same group as the aforementioned indoor unit to be driven at a predetermined second rotation speed.

Abstract: A refrigerant gas sensor is typically attached so that an opening for introducing leaked refrigerant gas into the inside faces upward. With this arrangement, however, a small amount of a different gas such as propane and pesticide, which is sucked from the outside of an air conditioner, may be erroneously recognized as refrigerant gas. On this account, a refrigerant gas sensor 9 includes a detecting element 61 for detecting leakage of refrigerant gas and a casing member 62 provided to surround the detecting element 61. The casing member 62 has a casing opening (first opening) 62a through which the refrigerant gas is introduced into the inside of the casing member 62. The casing opening (first opening) 62a is below the detecting element 61.

Abstract: A branching unit has a refrigerant pipe that is branched into a plurality of branching refrigerant pipes, and includes an insulation material resin casing and an expanded insulation material casing. The insulation material resin casing encloses branching portion while assuring an insulation space between the insulation material resin casing and the branching portion. The expanded insulation material casing is disposed on the external periphery of the insulation material resin casing.

Abstract: A branching unit has a refrigerant pipe that is branched into a plurality of branching refrigerant pipes, and includes an insulation material resin casing and an expanded insulation material casing. The insulation material resin casing encloses branching portion while assuring an insulation space between the insulation material resin casing and the branching portion. The expanded insulation material casing is disposed on the external periphery of the insulation material resin casing.