Indoor unit

Abstract

The present disclosure provides an indoor unit that can appropriately control the activity of a ventilation device when a refrigerant leak has been detected within a setup in which indoor units are managed by group.　This indoor unit can instruct a ventilation device to begin activity and comprises a controller that controls the operation of the indoor unit. When a refrigerant leak detection sensor that corresponds to the indoor unit has detected a refrigerant leak or when another indoor unit that belongs to the same prescribed group as the indoor unit has detected a refrigerant leak, the controller stops the operation of the indoor unit and causes the ventilation device to operate, and when a notification that indicates that a refrigerant leak has been detected has been received from another apparatus that does not belong to the prescribed group, the controller stops the operation of the indoor unit but does not cause the ventilation device to operate.

Description

Indoor unit

[0001] This disclosure relates to an indoor unit.

[0002] Patent Document 1 discloses an air conditioning system that uses safety devices such as ventilation devices and shut-off valves as safety measures in case of refrigerant leakage. Patent Document 1 also discloses a system that prohibits the operation of the outdoor unit when it is detected that the indoor unit and the safety device are not connected.

[0003] Japanese Patent Publication No. 2021-014961

[0004] This disclosure provides an indoor unit that can appropriately control the operation of the ventilation system when a refrigerant leak is detected, in a configuration in which indoor units are managed on a group basis.

[0005] The indoor unit in this disclosure is an indoor unit capable of instructing a ventilation system to start operation, and includes a control unit that controls the operation of the indoor unit, wherein the control unit stops the operation of the indoor unit and operates the ventilation system when a refrigerant leak detection sensor corresponding to the indoor unit detects a refrigerant leak, or when another indoor unit belonging to the same predetermined group as the indoor unit detects a refrigerant leak, and stops the operation of the indoor unit but does not operate the ventilation system when it receives a notification from another device not belonging to the predetermined group indicating that a refrigerant leak has been detected. This specification includes all the contents of Japanese Patent Application No. 2025-019632, filed on February 7, 2025.

[0006] In the air conditioning system described in this disclosure, the indoor units are configured to manage the indoor units in groups, and the operation of the ventilation device can be appropriately controlled when a refrigerant leak is detected.

[0007] Figure 1 shows the configuration of the air conditioning system in Embodiment 1. Figure 2 shows the configuration of the control system for the outdoor unit in Embodiment 1. Figure 3 shows the configuration of the control system for the indoor unit in Embodiment 1. Figure 4 shows the configuration of the control system for the indoor unit remote control in Embodiment 1. Figure 5 is a sequence diagram showing an example of operation of each part of the air conditioning system in Embodiment 1. Figure 6 is a sequence diagram showing another example of operation of each part of the air conditioning system in Embodiment 1. Figure 7 is a sequence diagram showing another example of operation of each part of the air conditioning system in Embodiment 1. Figure 8 is a sequence diagram showing the configuration of the air conditioning system in Embodiment 2. Figure 9 shows the management data in Embodiment 2. Figure 10A shows the operation of each part of the air conditioning system in Embodiment 2. Figure 10B shows the operation of each part of the air conditioning system in Embodiment 2. Figure 10C shows the operation of each part of the air conditioning system in Embodiment 2. Figure 11 shows the configuration of the air conditioning system in Embodiment 3.

[0008] (Knowledge and other information forming the basis of this disclosure) At the time the inventors conceived of this disclosure, there were air conditioning systems equipped with safety devices to ensure safety from refrigerant leakage, such as those described in Patent Document 1. However, some modern air conditioning systems have multiple indoor units connected to a single outdoor unit. Furthermore, there are cases where it is desirable to manage refrigerant leakage for such indoor units in groups. However, the inventors discovered that conventional technology lacked a mechanism for efficiently managing this type of air conditioning system, and in order to solve this problem, they came to form the subject of this disclosure. Therefore, this disclosure provides an indoor unit that can appropriately control the operation of the ventilation device when refrigerant leakage is detected in a configuration in which indoor units are managed in groups.

[0009] The embodiments will be described in detail below with reference to the drawings. However, some descriptions may be omitted to avoid unnecessary detail. For example, detailed explanations of already well-known matters or redundant explanations of substantially identical configurations may be omitted. The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this disclosure and are not intended to limit the subject matter described in the claims.

[0010] (Embodiment 1) [1-1. Configuration] [1-1-1. Configuration of Air Conditioning System] The air conditioning system 100 is a system that conditions the air in the conditioned space S. The air conditioning system 100 is applied to facilities such as buildings and schools. The conditioned space S is, for example, a room in the facility.

[0011] The air conditioning system 100 of Embodiment 1 has a refrigerant system RS.

[0012] The refrigerant system RS is composed of an outdoor unit 1 and three indoor units 2, namely indoor unit 2A_1, indoor unit 2A_2, and indoor unit 2B. The outdoor unit 1 is installed outdoors of the facility. The indoor units 2A_1 and 2A_2 are installed indoors of the facility and condition the conditioned space SA. The indoor unit 2A_1 operates as a master unit, and the indoor unit 2A_2 operates as a slave unit. The indoor unit 2B is installed indoors of the facility and conditions the conditioned space SB. The outdoor unit 1, indoor unit 2A_1, indoor unit 2A_2, and indoor unit 2B are connected by a refrigerant pipe RP. The refrigerant flowing in the refrigerant pipe RP is, for example, R32 refrigerant.

[0013] In the following description, when the indoor units 2A_1, 2A_2, and 2B are not distinguished, they are expressed as "indoor unit 2" with the symbol "2". When the conditioned spaces SA and SB are not distinguished, they are expressed as "conditioned space S" with the symbol "S".

[0014] Each indoor unit 2 includes a refrigerant leakage sensor 25 for detecting refrigerant leakage. The refrigerant leakage sensor 25 will be described later.

[0015] The air conditioning system 100 includes two ventilation devices 3, namely ventilation device 3A and ventilation device 3B. The ventilation device 3 is a device for exchanging the air in the conditioned space S with the air outside the conditioned space S. When the ventilation devices 3A and 3B are not distinguished, they are expressed as "ventilation device 3" with the symbol "3".

[0016] The air conditioning system 100 includes two indoor unit remote controls 4, namely indoor unit remote control 4A and indoor unit remote control 4B. The indoor unit remote control 4A is for the conditioned space S ＡIt is a remote controller for performing various settings such as setting the set temperature for the indoor units 2A_1 and 2A_2 arranged therein. The indoor unit remote controller 4B is for the air-conditioned space S Ｂ It is a remote controller for performing various settings such as setting the set temperature for the indoor unit 2B arranged therein.

[0017] When the air conditioning system 100 does not distinguish between the indoor unit remote controllers 4A and 4B, it is expressed as "indoor unit remote controller 4" with the symbol "4".

[0018] In the air conditioning system 100, the outdoor unit 1, the indoor units 2A_1, 2A_2, and the indoor unit 2B are communicatively connected to each other by the communication line CL. In the air conditioning system 100, the outdoor unit 1, the indoor units 2A_1, 2A_2, and the indoor unit 2B are communicatively connected to each other by the communication line CL.

[0019] Also, in the air conditioning system 100, the indoor unit remote controller 4A, the indoor units 2A_1, and 2A_2 are connected by the remote control line RL １ The indoor unit remote controller 4B and the indoor unit 2B are connected by the remote control line RL ２ When not distinguishing between the remote control lines RL １ , RL ２ it is expressed as "remote control line RL" with the symbol "RL". In Embodiment 1, the remote control line RL is formed by wire. Also, in Embodiment 1, the ventilation device 3 is also connected to the indoor unit 2A_1 by the remote control line RL.

[0020] In the air conditioning system 100 of Embodiment 1, the group of devices connected by the remote control line RL １ is regarded as the remote control group GP １ and the group of devices connected by the remote control line RL ２ is regarded as the remote control group GP ２ When not distinguishing between the remote control groups GP １ , GP ２ it is expressed as "remote control group GP" with the symbol "GP". The remote control group GP is an example of "a predetermined group".

[0021] Next, the control system configurations of the outdoor unit 1, the indoor units 2, and the indoor unit remote controller 4 will be described.

[0022] [1-1-2. Outdoor Unit Configuration] First, the configuration of the control system of the outdoor unit 1 will be explained. Figure 2 is a diagram showing the configuration of the control system of the outdoor unit 1. The outdoor unit 1 comprises an outdoor unit control unit 10 and an outdoor unit communication unit 11.

[0023] The outdoor unit communication unit 11 is equipped with communication hardware that conforms to a predetermined communication standard or a proprietary communication method, such as a communication circuit, and communicates with indoor units 2A_1, 2A_2, and 2B via the communication line CL in accordance with the control of the outdoor unit control unit 10.

[0024] The outdoor unit control unit 10 includes a processor 110 such as a CPU (Central Processing Unit) or MPU (Micro Processor Unit), a memory 120, and an interface circuit for connecting other devices and sensors. Although not shown in the diagram, various devices of the outdoor unit 1, such as a compressor, an outdoor fan, and various sensors, are connected to this interface circuit of the outdoor unit control unit 10.

[0025] Memory 120 is a storage device that stores programs and data. Memory 120 stores the control program 121, management data 122, and data to be processed by the processor 110. Memory 120 has a non-volatile storage area. Memory 120 also has a volatile storage area and constitutes the work area of ​​the processor 110. Memory 120 is composed of, for example, ROM (Read Only Memory) or RAM (Random Access Memory).

[0026] The outdoor unit control unit 10 controls various parts of the outdoor unit 1 and performs various operations by having the processor 110 read and execute a control program 121 stored in the memory 120. The management data 122 is data that manages information about the indoor unit 2 which is part of the same refrigerant system RS as the outdoor unit 1, and information about the outdoor unit 1 itself. In other words, the management data 122 is data that manages information about the indoor unit 2 which is connected to the outdoor unit 1 by refrigerant piping RP. The management data 122 manages information on an indoor unit basis. That is, one record of the management data 122 corresponds to one indoor unit. Each record contains information such as the indoor unit model number, the indoor unit address, the remote control group to which the indoor unit belongs, and the type of master / slave unit. The address is the address assigned to each device that communicates via the communication line CL.

[0027] Instead of managing one indoor unit as one record in the management data 122 as described above, one remote control group may be managed as one record.

[0028] [1-1-3. Indoor Unit Configuration] Next, the configuration of the control system of the indoor unit 2 will be described. Figure 3 is a diagram showing the configuration of the control system of the indoor unit 2. The indoor unit 2 comprises an indoor unit control unit 20, a first indoor unit communication unit 21, a second indoor unit communication unit 22, an indoor blower fan 23, an indoor expansion valve 24, and a refrigerant leak sensor 25.

[0029] The first indoor unit communication unit 21 is equipped with communication hardware such as a communication circuit and communicates mainly with the outdoor unit 1, which is connected to the indoor unit 2 by a communication line CL, according to the control of the indoor unit control unit 20.

[0030] The second indoor unit communication unit 22 is equipped with communication hardware such as a communication circuit and communicates with other indoor units 2, ventilation devices 3, and indoor unit remote controls 4 connected to the indoor unit 2 by remote control wires RL, in accordance with the control of the indoor unit control unit 20.

[0031] The indoor blower fan 23 rotates according to the control of the indoor unit control unit 20 and sends air to the heat exchanger of the indoor unit 2. The indoor expansion valve 24 is a valve that adjusts the flow rate of refrigerant to the heat exchanger of the indoor unit 2. The opening degree of the indoor expansion valve 24 is adjusted according to the control of the indoor unit control unit 20. The refrigerant leak sensor 25 is a sensor that detects the occurrence of refrigerant leakage. When the refrigerant leak sensor 25 detects the occurrence of refrigerant leakage, it outputs a signal to the indoor unit control unit 20 indicating that refrigerant leakage has been detected.

[0032] The indoor unit control unit 20 includes a processor 210 such as a CPU or MPU, a memory 220, and an interface circuit for connecting other devices and sensors. Although not shown in the figures, various devices of the indoor unit 2, such as a temperature sensor, are connected to this interface circuit of the indoor unit control unit 20. The indoor unit control unit 20 can communicate with the outdoor unit 1 via the first indoor unit communication unit 21, and can communicate with other indoor units 2, the ventilation device 3, and the indoor unit remote control 4 via the second indoor unit communication unit 22.

[0033] Memory 220 is a storage device that stores programs and data. Memory 220 stores the control program 221 and data processed by the processor 210. Memory 220 has a non-volatile storage area. Memory 220 also has a volatile storage area and constitutes the work area of ​​the processor 210. Memory 220 is composed of, for example, ROM and RAM.

[0034] The control program 221 is a program for controlling each part of the indoor unit 2. The indoor unit control unit 20 controls each part of the indoor unit 2 by having the processor 210 read and execute the control program 221 stored in the memory 220. The indoor unit control unit 20 controls the operation of the indoor unit 2 by controlling, for example, air conditioning-related mechanisms such as the indoor blower fan 23 and the indoor expansion valve 24.

[0035] [1-1-4. Configuration of the Indoor Unit Remote Control] Next, the configuration of the control system of the indoor unit remote control 4 will be described. Figure 4 is a diagram showing the configuration of the control system of the indoor unit remote control 4. The indoor unit remote control 4 comprises a remote control control unit 40, a remote control communication unit 41, a remote control display unit 42, a remote control operation unit 43, and a refrigerant leak sensor 44.

[0036] The remote control communication unit 41 is equipped with communication hardware such as a communication circuit that conforms to a predetermined communication standard or a proprietary communication method, and communicates with the indoor unit 2 and the ventilation device 3 connected by the remote control line RL, according to the control of the remote control control unit 40. The remote control control unit 40 can also communicate with the indoor unit 2 via the remote control communication unit 41.

[0037] The remote control display unit 42 is equipped with LEDs and a display, and displays various information on the LEDs and display according to the control of the remote control control unit 40. The remote control display unit 42 also notifies the user of alarms. For example, when the refrigerant leak sensor 25 of the indoor unit 2 detects a refrigerant leak, an alarm is transmitted from the indoor unit 2 to the indoor unit remote control 4. By displaying this alarm on the remote control display unit 42, the user is notified of the refrigerant leak alarm.

[0038] The remote control unit 43 has multiple operation keys that receive various user commands. The remote control unit 43 outputs a signal corresponding to the operated operation key to the remote control control unit 40. The refrigerant leak sensor 44 is a sensor that detects the occurrence of a refrigerant leak. When the refrigerant leak sensor 44 detects the occurrence of a refrigerant leak, it outputs a signal to the remote control control unit 40 indicating that a refrigerant leak has been detected.

[0039] The remote control unit 40 includes a processor 410 such as a CPU or MPU, a memory 420, and an interface circuit for connecting other devices and sensors.

[0040] Memory 420 is a storage device that stores programs and data. Memory 420 stores the control program 421 and data to be processed by the processor 410. Memory 420 has a non-volatile storage area. Memory 420 also has a volatile storage area and constitutes the work area of ​​the processor 410. Memory 420 is composed of, for example, ROM and RAM.

[0041] The remote control unit 40 controls each part of the indoor unit remote control 4 and performs various operations by reading and executing the control program 421 stored in the memory 420. The remote control unit 40 displays various information using the remote control display unit 42. The remote control unit 40 also receives various instructions from the user based on the signals output by the remote control operation unit 43.

[0042] [1-2. Operation] Next, the operation of each part of the air conditioning system 100 in Embodiment 1 will be described.

[0043] [1-2-1. When indoor unit 2A_2 detects a refrigerant leak] The operation of the air conditioning system 100 when indoor unit 2A_2, which is a sub-unit of indoor unit 2, detects a refrigerant leak will be explained. Figure 5 is a sequence diagram showing the operation of each part of the air conditioning system 100 in this case. Figure 5 shows the operation of outdoor unit 1, indoor unit 2A_1, indoor unit 2A_2, ventilation device 3A, indoor unit remote control 4A, indoor unit 2B, ventilation device 3, and indoor unit remote control 4B.

[0044] When the indoor unit control unit 20 of indoor unit 2A_2 detects a refrigerant leak using the refrigerant leak sensor 25 (step S101), the indoor unit control unit 20 stops the operation of indoor unit 2A_2 (step S102). Then, the indoor unit control unit 20 transmits a notification to indoor unit 2A_1 via the second indoor unit communication unit 22 indicating that indoor unit 2A_2 has detected a refrigerant leak (step S103). This notification is transmitted via the remote control line RL １ This is transmitted to the indoor unit 2A_1. Upon receiving this notification, the indoor unit control unit 20 of the indoor unit 2A_1 stops the operation of the indoor unit 2A_1 (step S104).

[0045] Next, the indoor unit control unit 20 of indoor unit 2A_1 transmits an operation instruction to the ventilation device 3A via the second indoor unit communication unit 22 (step S105). This instruction is transmitted via the remote control line RL １ This is transmitted to the ventilation device 3A. Upon receiving this instruction, the ventilation device 3A starts operation (step S106). Also, the indoor unit control unit 20 of the indoor unit 2A_1 sends a notification to the indoor unit remote control 4A via the second indoor unit communication unit 22 indicating that the indoor unit 2A_2 has detected a refrigerant leak (step S107). This notification is transmitted via the remote control line RL １ This is transmitted to the indoor unit remote control 4A. Upon receiving this notification, the remote control control unit 40 of the indoor unit remote control 4A will send a notification to the same remote control group GP. １ A first alarm indicating that a refrigerant leak has been detected inside the system is displayed on the remote control display unit 42, thereby notifying the user of the first alarm (step S108). The remote control display unit 42 is an example of a "notification unit".

[0046] Furthermore, the indoor unit control unit 20 of indoor unit 2A_1 transmits a notification to the outdoor unit 1 via the first indoor unit communication unit 21 indicating that indoor unit 2A_2 has detected a refrigerant leak (step S109). This notification is transmitted to the outdoor unit 1 via the communication line CL. Next, the outdoor unit control unit 10 of outdoor unit 1 transmits a notification to all indoor units 2, i.e., indoor unit 2A_1, indoor unit 2A_2, and indoor unit 2B, via the outdoor unit communication unit 11, indicating that indoor unit 2A_2 has detected a refrigerant leak (step S110). This notification is transmitted to each indoor unit 2 via the communication line CL. Upon receiving this notification, the indoor unit control unit 20 of indoor unit 2B stops the operation of indoor unit 2B (step S111). Indoor units 2A_1 and 2A_2 also receive this instruction, but since indoor units 2A_1 and 2A_2 have already stopped operating, the indoor unit control units 20 of indoor units 2A_1 and 2A_2 do not perform any new actions in response to the instruction in step S110.

[0047] Next, the indoor unit control unit 20 of the indoor unit 2B transmits a notification to the indoor unit remote control 4B via the second indoor unit communication unit 22 indicating that the indoor unit 2A_2 has detected a refrigerant leak (step S112). This notification is transmitted via the remote control line RL ２ This is transmitted to the indoor unit remote control 4B. Upon receiving this notification, the remote control control unit 40 of the indoor unit remote control 4B will send another remote control group GP ２ A second alarm, indicating that a refrigerant leak has been detected inside the unit, is displayed on the remote control display unit 42 to notify the user of the second alarm (step S113).

[0048] Thus, the indoor unit 2A_1 is an indoor unit capable of instructing the ventilation device 3A and another indoor unit 2A_2 of the same refrigerant system RS to start operation, and includes a refrigerant leak sensor 25 for detecting refrigerant leaks and an indoor unit control unit 20 that controls the operation of indoor unit 2A_1 and the operation of ventilation device 3A, and the indoor unit control unit 20 is in the same remote control group GP as indoor unit 2A_1. １ If a notification is received indicating that a refrigerant leak has been detected from another indoor unit belonging to the same group, namely indoor unit 2A_2, the operation of indoor unit 2A_1 is stopped and the ventilation system 3A is activated.

[0049] According to this, they are the same refrigerant system RS and the same remote control group GP. １ When indoor unit 2A_2, which belongs to the same remote control group GP, detects a refrigerant leak, the indoor unit control unit 20 of indoor unit 2A_1 operates the ventilation system to discharge the refrigerant that has leaked into the air-conditioned space to the outside. In addition, the indoor unit control unit 20 also stops the operation of indoor unit 2A_1, thereby suppressing the flow of refrigerant in the refrigerant piping RP of the refrigerant system RS, and thus suppressing further refrigerant leakage from indoor unit 2A_2. １ If refrigerant leakage occurs from another indoor unit belonging to the same group, namely indoor unit 2A_2, then safety measures can be taken for indoor unit 2A_1.

[0050] In step S109, the indoor unit control unit 20 of the indoor unit 2A_1 may also send a notification to the outdoor unit 1 indicating that the indoor unit 2A_1 has stopped operating.

[0051] [1-2-2. When indoor unit 2A_1 detects a refrigerant leak] The operation of the air conditioning system 100 when indoor unit 2A_1, which is the master unit of indoor unit 2, detects a refrigerant leak will be explained. Figure 6 is a sequence diagram showing the operation of each part of the air conditioning system 100 in this case.

[0052] When the indoor unit control unit 20 of indoor unit 2A_1 detects a refrigerant leak using the refrigerant leak sensor 25 (step S201), the indoor unit control unit 20 stops the operation of indoor unit 2A_1 (step S202). Then, the indoor unit control unit 20 transmits a notification to the indoor unit remote control 4A via the second indoor unit communication unit 22 indicating that indoor unit 2A_1 has detected a refrigerant leak (step S203). This notification is transmitted via the remote control line RL １ This is transmitted to the indoor unit remote control 4A. Upon receiving this notification, the remote control control unit 40 of the indoor unit remote control 4A will send a notification to the same remote control group GP. １ A first alarm indicating that a refrigerant leak has been detected inside the unit is displayed on the remote control display unit 42, thereby notifying the user of the first alarm (step S204).

[0053] Furthermore, the indoor unit control unit 20 of indoor unit 2A_1 transmits an operation instruction to the ventilation device 3A via the indoor unit communication unit 22 (step S205). This instruction is transmitted via the remote control line RL １ This is transmitted to the ventilation device 3A. Upon receiving this instruction, the ventilation device 3A starts operating (step S206).

[0054] Furthermore, the indoor unit control unit 20 of indoor unit 2A_1 transmits a notification to the outdoor unit 1 via the indoor unit communication unit 21 indicating that indoor unit 2A_1 has detected a refrigerant leak (step S207). This notification is transmitted to the outdoor unit 1 via the communication line CL. Next, the outdoor unit control unit 10 of outdoor unit 1 transmits a notification to all indoor units 2, i.e., indoor unit 2A_1, indoor unit 2A_2, and indoor unit 2B, via the outdoor unit communication unit 11, indicating that indoor unit 2A_1 has detected a refrigerant leak (step S208). This notification is transmitted to each indoor unit 2 via the communication line CL. Upon receiving the instruction in step S208, the indoor unit control unit 20 of indoor unit 2A_2 stops the operation of indoor unit 2A_2 (step S209). Also, upon receiving the instruction in step S208, the indoor unit control unit 20 of indoor unit 2B stops the operation of indoor unit 2B (step S210). Although indoor unit 2A_1 also receives the instruction in step S208, indoor unit 2A_1 has already stopped operating, so the indoor unit control unit 20 of indoor unit 2A_1 does not perform any new actions in response to the instruction in step S208.

[0055] Next, the indoor unit control unit 20 of the indoor unit 2B transmits a notification to the indoor unit remote control 4B via the indoor unit communication unit 22 indicating that the indoor unit 2A_1 has detected a refrigerant leak (step S211). This instruction is transmitted via the remote control line RL １ This is transmitted to the indoor unit remote control 4B. Upon receiving this notification, the remote control control unit 40 of the indoor unit remote control 4B will send another remote control group GP ２ A second alarm, indicating that a refrigerant leak has been detected inside the unit, is displayed on the remote control display unit 42 to notify the user of the second alarm (step S212).

[0056] Thus, the indoor unit 2A_1 is an indoor unit capable of instructing the ventilation system 3A and another indoor unit 2A_2 of the same refrigerant system RS to start operation, and includes a refrigerant leak sensor 25 for detecting refrigerant leaks and an indoor unit control unit 20 that controls the operation of the indoor unit 2A_1 and the ventilation system 3A. When the refrigerant leak sensor 25 of the indoor unit 2A_1 detects a refrigerant leak, the indoor unit control unit 20 stops the operation of the indoor unit 2A_1 and starts the ventilation system 3A.

[0057] According to this, when the indoor unit control unit 2A_1 detects a refrigerant leak using the refrigerant leak sensor 25, the indoor unit control unit 20 stops the operation of the indoor unit 2A_1 to prevent further refrigerant leakage. In addition, the indoor unit control unit 20 operates the ventilation device 3A to discharge the refrigerant that has leaked into the air-conditioned space SA to the outside. Therefore, even if a refrigerant leak occurs from the indoor unit 2A_1 itself, safety measures can be implemented for the indoor unit 2A_1.

[0058] In the above example, the outdoor unit 1 sends a notification to each indoor unit 2 indicating that indoor unit 2A_1 has detected a refrigerant leak. Alternatively, indoor unit 2A_1 may send this notification to all other indoor units 2, including indoor unit 2B, via the communication line CL.

[0059] [1-2-3. If indoor unit 2B detects a refrigerant leak] Remote control group GP is different from indoor unit 2A_1. ２ The operation of the air conditioning system 100 when indoor unit 2B, which belongs to the air conditioning system, detects a refrigerant leak will be explained. Figure 7 is a sequence diagram showing the operation of each part of the air conditioning system 100 in this case.

[0060] When the indoor unit control unit 20 of indoor unit 2B detects a refrigerant leak using the refrigerant leak sensor 25 (step S301), the indoor unit control unit 20 stops the operation of indoor unit 2B (step S302). Next, the indoor unit control unit 20 of indoor unit 2B transmits an operation instruction to the ventilation device 3B via the second indoor unit communication unit 22 (step S303). This instruction is transmitted via the remote control line RL ２ The instruction is transmitted via [device name]. Upon receiving this instruction, the ventilation device 3B starts operating (step S304). Also, the indoor unit control unit 20 of the indoor unit 2B sends a notification to the indoor unit remote control 4B via the second indoor unit communication unit 22 indicating that the indoor unit 2B has detected a refrigerant leak (step S305). Upon receiving this notification, the indoor unit remote control 4B, which belongs to the same remote control group GP, ２ A first alarm indicating that a refrigerant leak has been detected inside the unit is displayed on the remote control display unit 42, thereby notifying the user of the first alarm (step S306).

[0061] Furthermore, the indoor unit control unit 20 of indoor unit 2B transmits a notification to the outdoor unit 1 via the first indoor unit communication unit 21 indicating that indoor unit 2B has detected a refrigerant leak (step S307). This notification is transmitted to the outdoor unit 1 via the communication line CL. Upon receiving this notification, the outdoor unit control unit 10 of outdoor unit 1 transmits a notification to indoor units 2A_1, 2A_2, and 2B via the outdoor unit communication unit 11 indicating that indoor unit 2B has detected a refrigerant leak (step S308). This notification is transmitted to each indoor unit 2 via the communication line CL.

[0062] Upon receiving this notification, the indoor unit control unit 20 of indoor unit 2A_1 stops the operation of indoor unit 2A_1 (step S309). Also upon receiving this notification, the indoor unit control unit 20 of indoor unit 2A_2 stops the operation of indoor unit 2A_2 (step S310). Furthermore, the indoor unit control unit 20 of indoor unit 2A_1 transmits a notification to the indoor unit remote control 4A via the second indoor unit communication unit 22 indicating that indoor unit 2B has detected a refrigerant leak (step S312). This notification is transmitted via the remote control line RL １ This is transmitted to the indoor unit remote control 4A. Upon receiving this notification, the indoor unit remote control 4A will then send another remote control group GP ２ A second alarm indicating that a refrigerant leak has been detected inside the unit is displayed on the remote control display unit 42, thereby notifying the user of the second alarm (step S312).

[0063] Thus, the indoor unit 2A_1 is an indoor unit capable of instructing the ventilation device 3A and another indoor unit 2B of the same refrigerant system RS to start operation, and includes an indoor unit control unit 20 that controls the operation of indoor unit 2A_1 and the operation of ventilation device 3A, and the indoor unit control unit 20 is a remote control group GP to which indoor unit 2A_1 does not belong ２ If a notification is received indicating that a refrigerant leak has been detected from another indoor unit belonging to the same group, indoor unit 2A_1 will be shut down, but the ventilation system 3A will not be operated.

[0064] According to this, the indoor unit control unit 20 of indoor unit 2A_1 is the same refrigerant system RS, but is in a different remote control group GP. ２When indoor unit 2B, which belongs to the refrigerant system, detects a refrigerant leak, the operation of indoor unit 2A_1 is stopped, thereby suppressing the flow of refrigerant in the refrigerant piping RP of the refrigerant system RS and preventing further refrigerant leakage from indoor unit 2B where the leak occurred. On the other hand, since no refrigerant leak has occurred in the air-conditioned space SA where indoor unit 2A_1 is installed, and there is no need to operate the ventilation device 3A, the ventilation device 3A is not operated. Therefore, the operation of the unnecessary ventilation device 3A is suppressed, and the increase in power consumption is also suppressed.

[0065] As shown in the example above, using ventilation device 3 for safety measures has the following advantages. Let's consider a case where an air conditioner using R32 refrigerant is installed in a building where 24-hour ventilation is in place. As a safety measure for using R32 refrigerant, it is conceivable to utilize 24-hour ventilation, but the ventilation device used for 24-hour ventilation is not designed to be linked with the air conditioner. Therefore, if 24-hour ventilation is to be used for safety measures against R32 refrigerant, the ventilation volume of the 24-hour ventilation must be set to a larger level to prepare for refrigerant leaks that may occur at any time. This is because in most cases the ventilation volume required for safety measures against R32 refrigerant is greater than the ventilation volume required for 24-hour ventilation. Setting the ventilation volume of the 24-hour ventilation to a larger level increases the power consumption for 24-hour ventilation, and also reduces the efficiency of cooling or heating the room. Therefore, by ensuring the necessary ventilation volume with ventilation device 3 in conjunction with refrigerant leak detection, rather than relying on 24-hour ventilation, it is possible to prevent increased power consumption for 24-hour ventilation and a decrease in the efficiency of cooling or heating the room. Furthermore, 24-hour ventilation systems are often designed so that the ventilation volume is near the specified lower limit, depending on conditions such as the size of the room. If bookshelves or partitions are placed in the room, localized stagnation of air is likely to occur, and 24-hour ventilation with a ventilation volume near the specified lower limit is unsuitable as a safety measure for R32 refrigerant. Therefore, instead of 24-hour ventilation, the necessary ventilation volume can be ensured by the ventilation device 3 in conjunction with the detection of refrigerant leaks, thereby making the safety measures for R32 refrigerant more robust.

[0066] [1-3. Effects, etc.] As explained above, the indoor unit 2A_1 is an indoor unit 2A_1 that can instruct the ventilation device 3A to start operation, and is equipped with an indoor unit control unit 20 that controls the operation of the indoor unit 2A_1, and the indoor unit control unit 20 will activate when the refrigerant leak sensor 25 corresponding to the indoor unit 2A_1 detects a refrigerant leak, or when the same remote control group GP as the indoor unit 2A_1 １ If another indoor unit belonging to the same group, indoor unit 2A_2, detects a refrigerant leak, the operation of indoor unit 2A_1 will be stopped, and the ventilation device 3A will be activated, and the remote control group GP １ If a notification is received indicating that a refrigerant leak has been detected from indoor unit 2B, which does not belong to the specified unit, the operation of indoor unit 2A_1 will be stopped, but the ventilation system 3A will not be operated.

[0067] According to this, in a configuration where indoor units 2 are managed in groups, the operation of the ventilation device 3 can be appropriately controlled when a refrigerant leak is detected.

[0068] Furthermore, the indoor unit control unit 20 will, if the refrigerant leak sensor 25 detects a refrigerant leak, or if it is in the same remote control group GP as indoor unit 2A_1 １ If a refrigerant leak is detected from another indoor unit 2A_2 belonging to the same group as indoor unit 2A_1, the remote control group GP will be activated. １ A first alarm indicating that a refrigerant leak has been detected inside is sent to the remote control display unit 42, and the remote control group GP １ If indoor unit 2B, which does not belong to the group, detects a refrigerant leak, remote control group GP １ A second alarm is triggered on the remote control display unit 42, indicating that a refrigerant leak has been detected outside. According to this, the indoor unit 2A_1 is notified that the indoor unit 2 in which the refrigerant leak was detected is in the remote control group GP １ Is it the remote control group GP? １ Since the remote control display unit 42 displays different warnings depending on whether the source is external, users of the air conditioning system 100 can take appropriate action according to the location of the refrigerant leak source.

[0069] (Embodiment 2) Next, Embodiment 2 will be described. In the air conditioning system in Embodiment 2, the outdoor unit 1 determines whether the refrigerant system RS uses a shut-off valve or a ventilation device as a safety device, and the processing performed by the outdoor unit 1 and the indoor unit 2 differs depending on whether a shut-off valve or a ventilation device is used. Regarding the configuration of each part of the air conditioning system in Embodiment 2, detailed explanations of the same configurations as the air conditioning system 100 in Embodiment 1 will be omitted as appropriate.

[0070] [2-1. Configuration] In Embodiment 2, if the refrigerant system RS uses a shut-off valve as a safety device, the configuration of the air conditioning system 200 is as shown in Figure 8. On the other hand, in Embodiment 2, if the refrigerant system RS uses a ventilation device as a safety device, the configuration of the air conditioning system is the same as the air conditioning system 100 according to Embodiment 1 shown in Figure 1.

[0071] However, the management data 122 managed by the outdoor unit 1 in Embodiment 2 differs from the management data 122 managed by the outdoor unit 1 in Embodiment 1, and has the contents shown in Figure 9. That is, in Embodiment 2, the management data 122 also manages whether each indoor unit 2 belonging to the refrigerant system RS uses a ventilation device or a shut-off valve as a safety device.

[0072] Referring to Figure 8, the configuration of the air conditioning system 200 will be explained. Shut-off valves 5A and 5B shut off the flow of refrigerant in the refrigerant piping RP. Shut-off valve 5A shuts off the inflow of refrigerant from the outdoor unit 1 to indoor units 2A_1 and 2A_2. Shut-off valve 5B shuts off the inflow of refrigerant from the outdoor unit 1 to indoor unit 2B. In the air conditioning system 200, when shut-off valves 5A and 5B are not distinguished, they are referred to as "shut-off valve 5" with the designation "5". Furthermore, shut-off valve 5 is connected to indoor unit 2A_1 by the remote control wire RL. That is, the remote control group GP １ This includes indoor unit remote control 4A, indoor unit 2A_1, indoor unit 2A_2, and shut-off valve 5A. Remote control group GP ２ This includes the indoor unit remote control 4B, the indoor unit 2B, and the shut-off valve 5B.

[0073] [2-2. Operation] Figures 10A to 10C are sequence diagrams showing the operation of each part of the air conditioning system in Embodiment 2. This embodiment relates to the operation of the air conditioning system when the indoor unit 2A_2 detects a refrigerant leak.

[0074] When the indoor unit control unit 20 of indoor unit 2A_2 detects a refrigerant leak using the refrigerant leak sensor 25 (step S401), the indoor unit control unit 20 stops the operation of indoor unit 2A_2 (step S402). The indoor unit control unit 20 then sends a notification to indoor unit 2A_1 via the second indoor unit communication unit 22 indicating that indoor unit 2A_2 has detected a refrigerant leak (step S403). Next, the indoor unit control unit 20 of indoor unit 2A_1 sends a notification to outdoor unit 1 via the first indoor unit communication unit 21 indicating that indoor unit 2A_2 has detected a refrigerant leak (step S404). The indoor unit control unit 20 of indoor unit 2A_1 then stops the operation of indoor unit 2A_1 (step S405).

[0075] Next, the outdoor unit control unit 10 of the outdoor unit refers to the management data 122 and the outdoor unit 1 determines whether the refrigerant system RS uses a shut-off valve or a ventilation device as a safety device (step S501).

[0076] [2-2-1. When a shut-off valve is used as a safety device] In step S501, the operation when the outdoor unit control unit 10 determines that the refrigerant system RS uses the shut-off valve 5 will be described below with reference to Figure 10B.

[0077] Following step S501, the outdoor unit control unit 10 of the outdoor unit 1 transmits a first notification regarding refrigerant leak detection to indoor units 2A_1 and 2A_2 via the outdoor unit control unit 10 (step S406). This first notification is transmitted to indoor units 2A_1 and 2A_2 via the communication line CL. The content of the first notification includes information indicating that a refrigerant leak has been detected from an indoor unit belonging to the same remote control group, an instruction to stop the operation of the indoor unit, and an instruction to close the shut-off valve.

[0078] The indoor unit control unit 20 of indoor unit 2A_1 receives a first notification that includes an instruction to stop the operation of the indoor unit. However, since indoor unit 2A_1 has already stopped operating, the indoor unit control unit 20 does not take any new actions based on the first notification. Similarly, the indoor unit control unit 20 of indoor unit 2A_2 also does not take any new actions based on the first notification because indoor unit 2A_2 has already stopped operating. The indoor unit control unit 20 of indoor unit 2A_1 also transmits an instruction to the shut-off valve 5A to close the valve via the indoor unit communication unit 22 (step S407). Upon receiving this instruction, the shut-off valve 5A closes the valve (step S408). The indoor unit control unit 20 of indoor unit 2A_1 also transmits the contents of the first notification to the indoor unit remote control 4A via the indoor unit communication unit 22 (step S409). Upon receiving the first notification, the remote control unit 40 of the indoor unit remote control 4A notifies the user of the contents of the first notification as an alarm by displaying it on the remote control display unit 42 (step S410).

[0079] Furthermore, the outdoor unit control unit 10 of the outdoor unit 1 transmits a second notification regarding refrigerant leak detection to all outdoor units, namely indoor units 2A_1, 2A_2, and 2B, via the outdoor unit communication unit 11 (step S412). The content of the second notification includes information indicating that a refrigerant leak has been detected from an indoor unit belonging to the same refrigerant system, and information regarding an inspection code prompting inspection of the indoor unit. Next, the indoor unit control unit 20 of the indoor unit 2B transmits the content of the second notification to the indoor unit remote control 4B via the indoor unit communication unit 22 (step S413).

[0080] Upon receiving the second notification, the remote control unit 40 of the indoor unit remote control 4B informs the user of the contents of the second notification as a notification concerning the inspection code (S414).

[0081] Thus, the outdoor unit 1 includes an outdoor unit control unit 10 that controls the indoor unit 2 connected by the same refrigerant system, and when the outdoor unit control unit 10 receives refrigerant leakage information from the indoor unit 2A_1, it controls the same remote control group GP as the indoor unit 2A_1. １ The shut-off valve 5A, which belongs to the same remote control group GP as indoor unit 2A_1, is instructed to close. １ The system does not instruct the closing of shut-off valve 5B, which does not belong to the specified category.

[0082] According to this, the outdoor unit 1 closes the shut-off valve 5A of the remote control group to which the indoor unit 2A_2, which is leaking refrigerant, belongs, thereby blocking the flow of refrigerant to the indoor unit 2A_2, which is leaking refrigerant, and preventing further refrigerant leakage. On the other hand, the outdoor unit 1 closes the remote control group GP to which the indoor unit 2A_2, which is leaking refrigerant, does not belong. ２ The shut-off valve 5B is not closed. By closing the shut-off valve 5A, the indoor unit 2A_2, which is leaking refrigerant, can be isolated from the refrigerant system, so there is no disruption to the operation of indoor unit 2B in another remote control group. Therefore, even if a refrigerant leak occurs, it is possible to suppress further refrigerant leaks while minimizing the number of indoor units that have to shut down.

[0083] In the example above, the second notification is sent to all indoor units 2, but to the same remote control group GP as indoor unit 2A_1. １ It is also possible to configure the system to transmit only to indoor unit 2B, which does not belong to the other unit.

[0084] [2-2-2. When a ventilation device is used as a safety device] Next, the operation when the outdoor unit control unit 10 determines in step S501 that the refrigerant system RS will use the ventilation device 3 will be described below with reference to Figure 10C.

[0085] First, the indoor unit control unit 20 of indoor unit 2A_1 performs the operations from steps S105 to S107, and the remote control unit 40 of indoor unit remote control 4A performs the operation in step S108. These operations are the same as in Embodiment 1. Next, the outdoor unit control unit 10 of outdoor unit 1 sends a notification to all indoor units 2 indicating that indoor unit 2A_2 has detected a refrigerant leak (step S110). The operation in step S110 is the same as in Embodiment 1. Then, the indoor unit control unit 20 of indoor unit 2B performs the operations in steps S111 and S112, and the remote control unit 40 of indoor unit remote control 4B performs the operation in step S113. These operations are the same as in Embodiment 1.

[0086] According to this, in a configuration where indoor units 2 are managed in groups, similar to Embodiment 1, the operation of the ventilation device 3 can be appropriately controlled when a refrigerant leak is detected.

[0087] [2-3. Effects, etc.] As explained above, the outdoor unit 1 is equipped with an outdoor unit control unit 10 that controls indoor units 2 connected by the same refrigerant system RS. The outdoor unit control unit 10 determines whether the refrigerant system RS is a system that uses shut-off valves or a system that uses ventilation devices. If it is a system that uses ventilation devices 3, it stops the indoor unit 2 belonging to the same remote control group GP as the equipment where the refrigerant was detected, and also stops the ventilation device 3. It also stops the indoor unit 2 belonging to a remote control group GP to which the equipment where the refrigerant was detected does not belong, but does not stop the ventilation device 3. On the other hand, if it is a system that uses shut-off valves, the outdoor unit control unit 10 stops the indoor unit 2 belonging to the same remote control group GP as the equipment where the refrigerant was detected, and closes the shut-off valve 5. It does not stop the indoor unit 2 belonging to a remote control group GP to which the equipment where the refrigerant was detected does not belong, and does not close the shut-off valve either.

[0088] According to this, in the event of a refrigerant leak, appropriate safety measures can be taken against the leak regardless of whether the refrigerant system uses a shut-off valve or a ventilation system. Furthermore, by controlling the indoor unit while taking into account the differences in characteristics between shut-off valves and ventilation systems, the impact can be minimized and power consumption can be reduced.

[0089] (Embodiment 3) Next, Embodiment 3 will be described.

[0090] [3-1. Configuration] Figure 11 shows the configuration of the air conditioning system 300 according to Embodiment 3. The air conditioning system in Embodiment 3 differs from the air conditioning system 100 of Embodiment 1 in that the ventilation device 3 is connected to the indoor unit 2 by an external signal line EL instead of a remote control line RL.

[0091] In Embodiment 1, the ventilation device 3 is connected to the indoor unit 2 by a remote control wire RL. With the remote control wire RL, each device is connected by jumper wiring without branching. Therefore, when using the remote control wire RL, there is a problem in that it is difficult to provide multiple ventilation devices within one remote control group. Also, for example, if the ventilation device 3 is manufactured by a different company than the outdoor unit 1 or indoor unit 2, and is not compatible with the remote control wire RL, it cannot be connected to the indoor unit 2 with the remote control wire RL. Therefore, in Embodiment 3, each indoor unit 2 and each ventilation device 3 are connected by an external signal wire EL.

[0092] Here, in order for the indoor unit 2 and equipment such as the ventilation device 3 to communicate using the external signal line EL, it is necessary to provide the indoor unit 2 with a third indoor communication unit that uses a communication circuit compatible with communication on the external signal line EL. As the communication circuit that constitutes the third indoor communication unit, for example, a relay circuit can be used that has two terminals for applying a DC voltage (for example, 12 volts) to drive the ventilation device 3. A specific example is a voltage-free A contact. Unlike equipment connected to the remote control line RL, the indoor unit 2 cannot communicate with the ventilation device 3 using the external signal line EL. Therefore, by employing a voltage-free A contact, it becomes possible to drive various ventilation devices 3. For example, the indoor unit 2 can drive a ventilation fan.

[0093] [3-2. Operation] The operation of the air conditioning system 300 according to Embodiment 3 will be described. Here, the operation when the refrigerant leak sensor 25 of the indoor unit 2A_2 detects a refrigerant leak will be described.

[0094] The indoor unit control unit 20 of indoor unit 2A_2 stops the operation of indoor unit 2A_2 based on the detection of a refrigerant leak by the refrigerant leak sensor 25. Next, the indoor unit control unit 20 of indoor unit 2A_2 notifies the outdoor unit 1 and the master indoor unit 2A_1 of the detection of the refrigerant leak via the first indoor unit communication unit 21 or the second indoor unit communication unit 22. Based on this notification, the indoor unit control unit 20 of indoor unit 2A_1 stops the operation of indoor unit 2A_1, activates the ventilation device 3A, and displays the first alarm on the remote control control unit 40 of remote control 4A. In addition, the indoor unit control unit 20 of indoor unit 2A_1 also communicates with the same remote control group GP１ The remote control wire RL is connected to indoor units 2A_2 and 2A_3. １ The system instructs the ventilation devices 3B and 3C to operate via the external signal line EL. Based on this instruction, the indoor unit control units 20 of indoor units 2A_2 and 2A_3 operate the ventilation devices 3B and 3C, respectively, using the external signal line EL.

[0095] Furthermore, the outdoor unit control unit 10 of the outdoor unit 1 notifies all indoor units 2 via the communication line CL that it has detected a refrigerant leak. Based on this notification, all indoor units 2 stop operating. In this case, indoor units 2A_3 and 2B stop as well. Indoor units 2A_1 and 2A_2 have already stopped. The indoor unit control unit 20 of indoor unit 2B stops the operation of indoor unit 2B and displays a second alarm on the remote control 4B, but does not activate the ventilation device 3D.

[0096] Furthermore, when the indoor unit control unit 20 of indoor unit 2A_1 receives a notification from indoor unit 2A_2 that refrigerant leakage has been detected, the remote control line RL １ This confirms whether a communication-enabled ventilation device 3 is connected, and the remote control wire RL １ If a ventilation device capable of communication is connected, the operation described in Embodiment 1 is performed, and the remote control line RL １ If a ventilation device capable of communication is not connected, the operation of this embodiment may be performed.

[0097] Also, the remote control wire RL １ Even when a ventilation device 3 capable of communication is connected, indoor unit 2A_1 will not communicate with indoor units 2A_2 and 2A_3 via the remote control wire RL. １ The ventilation device 3 may be instructed to operate using the remote control. For example, depending on the conditions of the installation space of the indoor unit 2, it is conceivable to use one ventilation device capable of communication via the remote control line RL based on the specifications of the air conditioning system, and one or more ventilation devices that do not support communication via the remote control line RL, within the remote control group GP. This embodiment can accommodate such applications.

[0098] [3-3. Effects, etc.] With the above configuration and operation, one remote control group GP １Multiple ventilation devices 3A to 3C can be installed inside, or ventilation devices 3A to 3C that do not support the remote control wire RL can be used.

[0099] (Other Embodiments) As described above, Embodiments 1 to 3 have been explained as examples disclosed in this application. However, the technology in this disclosure is not limited thereto and can be applied to embodiments that have been modified, replaced, added, or omitted. Furthermore, it is possible to create new embodiments by combining the components described in Embodiments 1 to 3. Therefore, other embodiments are described below as examples.

[0100] In the embodiment described above, the number of remote control groups GP formed in the air conditioning system is two. In other embodiments, the number of remote control groups GP formed in the air conditioning system may be three or more.

[0101] In the embodiment described above, the air conditioning system has one refrigerant system RS. In other embodiments, the air conditioning system may have two or more refrigerant systems RS.

[0102] In the embodiment described above, there is one outdoor unit 1 belonging to the refrigerant system RS. In other embodiments, there may be two or more outdoor units 1 belonging to the refrigerant system RS.

[0103] In the above-described embodiment, the remote control group GP １ The number of indoor units 2 belonging to this group is two. In other embodiments, the remote control group GP １ There may be two, three or more indoor units belonging to this group, or there may be just one. Also, in the above-described embodiment, the remote control group GP ２ In this embodiment, there is one indoor unit 2 belonging to the remote control group GP2. In other embodiments, there may be two or more indoor units 2 belonging to the remote control group GP2.

[0104] In the above-described embodiment 2, there is one shut-off valve 5 included in one remote control group GP, but there may be multiple shut-off valves 5 included in one remote control group GP. For example, if there are multiple indoor units 2 included in one remote control group GP, one shut-off valve 5 may be provided corresponding to each indoor unit 2.

[0105] In the above-described embodiment 1, one ventilation device 3 is included in one remote control group GP, but multiple ventilation devices 3 may be included in one remote control group GP.

[0106] In the embodiment described above, the remote control group GP was given as an example of the "predetermined group". In other embodiments, the "predetermined group" may be any of the refrigerant system group, the shut-off valve group, and the air-conditioned space group. The refrigerant system group is a group that includes the outdoor unit 1, the shut-off valve 5 which belongs to the same refrigerant system RS as the outdoor unit 1, the indoor unit 2 which belongs to the same refrigerant system RS as the outdoor unit 1, and the equipment connected to the indoor unit 2. The shut-off valve group is a group that includes the shut-off valve 5, the indoor unit 2 which is connected to the shut-off valve 5, and the equipment connected to the indoor unit 2. The air-conditioned space group is a group that includes the indoor unit 2 which air-conditions the air-conditioned space, the shut-off valve 5 which is connected to the indoor unit 2, and the equipment connected to the indoor unit 2.

[0107] In the embodiment described above, the devices included in remote control group GP1 are installed in the air-conditioned space SA, and the devices included in remote control group GP2 are installed in the air-conditioned space SB. That is, remote control group GP and the air-conditioned space group are substantially the same. In other embodiments, multiple remote control groups may be formed in one air-conditioned space, or one remote control group may be formed in multiple air-conditioned spaces.

[0108] In the above-described embodiment, the refrigerant flowing through the refrigerant piping RP is assumed to be R32 refrigerant, but other refrigerants such as R410A or R22 may also be used. In the above-described embodiment, the shut-off valve 5 is connected to the indoor unit 2 by a remote control wire RL, but it may also be connected to the outdoor unit 1 by a communication wire CL. In the above-described embodiment 1, the indoor unit 2 includes a refrigerant leak sensor 25, and the indoor unit remote control 4 includes a refrigerant leak sensor 44. In other embodiments, the refrigerant leak sensor 25 may not be built into the indoor unit 2, but may be provided, for example, on the wall of the room which is the air-conditioned space in which the indoor unit 2 is installed, or it may be connected to the indoor unit by a remote control wire RL. Such refrigerant leak sensors provided on the wall of the room and refrigerant leak sensors connected to the indoor unit by a remote control wire RL are also examples of "refrigerant leak detection sensors corresponding to an indoor unit". The refrigerant leak sensor 44 is also an example of "refrigerant leak detection sensors corresponding to an indoor unit".

[0109] Processors 110, 210, and 410 may consist of a single processor or multiple processors. These processors may also be hardware programmed to implement the corresponding functional units. That is, these processors may consist of, for example, an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0110] The configurations of the air conditioning system components shown in Figures 2 to 4 are examples only, and the specific implementation is not particularly limited. In other words, it is not necessarily required that each component have its own corresponding hardware; it is also possible to configure the system so that a single processor executes a program to realize the functions of each component. Furthermore, some of the functions realized by software in the above-described embodiment may be implemented as hardware, or conversely, some of the functions realized by hardware may be implemented as software.

[0111] The operational step units shown in Figures 5, 6, 7, 9, and 10 are divided according to the main processing content to facilitate understanding of the operation, and the operation is not limited by the way the processing units are divided or the names of the processing units. Depending on the processing content, it may be further divided into more step units. Alternatively, it may be divided so that one step unit includes even more processing. Furthermore, the order of the steps may be changed as appropriate, as long as it does not impede the intent of this disclosure.

[0112] Since the embodiments described above are for illustrative purposes of the technology described herein, various modifications, substitutions, additions, omissions, etc., can be made within the claims or their equivalents.

[0113] (Note) The above description of embodiments discloses the following technology.

[0114] (Technology 1) An indoor unit capable of instructing a ventilation system to start operation, comprising a control unit that controls the operation of the indoor unit, wherein the control unit stops the operation of the indoor unit and operates the ventilation system when a refrigerant leak detection sensor corresponding to the indoor unit detects a refrigerant leak, or when another indoor unit belonging to the same predetermined group as the indoor unit detects a refrigerant leak, and stops the operation of the indoor unit but does not operate the ventilation system when it receives a notification from another device not belonging to the predetermined group indicating that a refrigerant leak has been detected.

[0115] (Technical 2) The indoor unit according to claim 1, wherein the equipment is an outdoor unit with the same refrigerant system as the indoor unit. This also produces the same effects as technical 1.

[0116] (Technology 3) The indoor unit described in Technology 1 or 2, wherein the other equipment not belonging to the predetermined group is another indoor unit not belonging to the same predetermined group as the indoor unit. This also produces the same effects as Technology 1.

[0117] (Technical 4) An indoor unit according to Technical 1 or 2, wherein the predetermined group to which the indoor unit belongs includes other indoor units arranged in the same air-conditioned space as the indoor unit. This also produces the same effects as Technical 1.

[0118] (Technical 5) The indoor unit according to Technical 1 or 2, wherein the control unit causes the notification unit to issue a first alarm indicating that a refrigerant leak has been detected within the same predetermined group as the indoor unit when the refrigerant leak detection sensor detects a refrigerant leak, or when another indoor unit belonging to the same predetermined group as the indoor unit detects a refrigerant leak, and causes the notification unit to issue a second alarm indicating that a refrigerant leak has been detected outside the predetermined group when another device not belonging to the predetermined group detects a refrigerant leak. According to this, since different warnings are issued depending on whether the indoor unit from which the refrigerant leak has been detected is within or outside the predetermined group, users of the air conditioning system can take appropriate action according to the location of the source of the refrigerant leak.

[0119] As described above, the indoor unit according to the present invention can be used in applications where indoor units are managed in groups.

[0120] 1 Outdoor unit 2 Indoor unit 2A Indoor unit 2B Indoor unit 3 Ventilation device 3A Ventilation device 3B Ventilation device 3C Ventilation device 3D Ventilation device 4 Indoor unit remote control 4A Indoor unit remote control 4B Indoor unit remote control 5 Shut-off valve 5A Shut-off valve 5B Shut-off valve 10 Outdoor unit control unit 11 Outdoor unit communication unit 20 Indoor unit control unit 21 First indoor unit communication unit 22 Second indoor unit communication unit 23 Indoor blower fan 24 Indoor expansion valve 25 Refrigerant leak sensor 40 Remote control control unit 41 Remote control communication unit 42 Remote control display unit 43 Remote control operation unit 44 Refrigerant leak sensor 100 Air conditioning system 110 Processor 120 Memory 121 Control program 122 Management data 200 Air conditioning system 210 Processor 220 Memory 221 Control program 300 Air conditioning system 410 Processor 420 Memory 421 Control program CL Communication line EL External signal line GP Remote control group GP RL Remote control line RL1 Remote control line RL2 Remote control line RP Refrigerant piping RS Refrigerant system S Air conditioning space SA Air conditioning space SB Air conditioning space

Claims

1. An indoor unit capable of instructing a ventilation system to start operation, comprising a control unit that controls the operation of the indoor unit, wherein the control unit stops the operation of the indoor unit and operates the ventilation system when a refrigerant leak detection sensor corresponding to the indoor unit detects a refrigerant leak, or when another indoor unit belonging to the same predetermined group as the indoor unit detects a refrigerant leak, and stops the operation of the indoor unit but does not operate the ventilation system when it receives a notification from another device not belonging to the predetermined group indicating that a refrigerant leak has been detected.

2. The indoor unit according to claim 1, wherein the equipment is an outdoor unit of the same refrigerant system as the indoor unit.

3. The indoor unit according to claim 1 or 2, wherein the other equipment not belonging to the predetermined group is another indoor unit not belonging to the same predetermined group as the indoor unit.

4. The indoor unit according to claim 1 or 2, wherein the predetermined group to which the indoor unit belongs includes other indoor units arranged in the same air-conditioned space as the indoor unit.

5. The indoor unit according to claim 1 or 2, wherein the control unit causes the notification unit to issue a first alarm indicating that a refrigerant leak has been detected within the same predetermined group as the indoor unit when the refrigerant leak detection sensor detects a refrigerant leak, or when another indoor unit belonging to the same predetermined group as the indoor unit detects a refrigerant leak, and causes the notification unit to issue a second alarm indicating that a refrigerant leak has been detected outside the predetermined group when another device not belonging to the predetermined group detects a refrigerant leak.

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