LOW-CAPACITY INDOOR UNIT

Abstract

 A low-capacity indoor unit (20C) having a rated cooling capacity of less than 2.2 kW includes an announcement unit (100d) that announces an abnormality when the low-capacity indoor unit (20C) is connected to an outdoor unit other than a dedicated outdoor unit (10) with which the low-capacity indoor unit (20C) is permitted to be combined.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to low-capacity indoor units.

BACKGROUND ART

[0002] Some conventional air conditioners are equipped with a ceiling-mounted indoor unit embedded in a ceiling of a room, and an outdoor unit connected to the indoor unit (for example, see JP 2016-148510 A (Patent Literature 1)).

[0003] When a flammable refrigerant is used in such an air conditioner, the indoor unit is installed at a specified installation height so as to meet "allowable floor area based on a refrigerant charge amount" specified in an international standard. This prevents, even when the refrigerant leaks from the indoor unit, the concentration of the refrigerant in the room from exceeding a certain level.

CITATION LIST

PATENT LITERATURE

[0004] Patent Literature 1: JP 2016-148510 A

SUMMARY OF INVENTION

TECHNICAL PROBLEMS

[0005] The above-described conventional air conditioner typically has a rated cooling capacity of 2.2 kW or more. When a low-capacity indoor unit having a rated cooling capacity of less than 2.2 kW is installed in a space with a small floor area such as a washroom, if the refrigerant leaks from the low-capacity indoor unit and fills the small space, a risk due to the refrigerant leakage increases depending on the refrigerant charge amount. In particular, when a flammable refrigerant (including a slightly flammable refrigerant such as R32 refrigerant) is used, as the gas concentration of the refrigerant increases to some extent, a risk of ignition or the like increases accordingly.

[0006] The present disclosure proposes a low-capacity indoor unit that reduces a risk due to refrigerant leakage.

SOLUTIONS TO PROBLEMS

[0007] A low-capacity indoor unit according to the present disclosure has a rated cooling capacity of less than 2.2 kW and includes an announcement unit that announces an abnormality when the low-capacity indoor unit is connected to an outdoor unit other than a dedicated outdoor unit with which the low-capacity indoor unit is permitted to be combined.

[0008] According to the present disclosure, since the announcement unit announces an abnormality when the low-capacity indoor unit having the rated cooling capacity of less than 2.2 kW is connected to an outdoor unit other than the dedicated outdoor unit with which the low-capacity indoor unit is permitted to be combined, the low-capacity indoor unit is prevented from being connected to an outdoor unit, other than the dedicated outdoor unit, having a larger refrigerant charge amount and put into operation, thereby reducing a risk due to refrigerant leakage.

[0009] Further, in the low-capacity indoor unit according to one aspect of the present disclosure, the rated cooling capacity is equal to or less than 1.6 kW.

[0010]  According to the above-described embodiment, since the rated cooling capacity is equal to or less than 1.6 kW, the low-capacity indoor unit is suitable for air conditioning in a small space such as a washroom or a kitchen and is safer against refrigerant leakage to a small space.

[0011] Further, in the low-capacity indoor unit according to one aspect of the present disclosure, the dedicated outdoor unit is compatible with a multi-type air conditioner in which a plurality of indoor units are connectable to an outdoor unit, and the low-capacity indoor unit is operable as an indoor unit of the multi-type air conditioner and is one of the plurality of indoor units.

[0012] According to the present disclosure, it is possible to provide a multi-type air conditioner in which a plurality of indoor units including at least one low-capacity indoor unit are connected to the dedicated outdoor unit.

[0013] Further, in the low-capacity indoor unit according to one aspect of the present disclosure, the announcement unit announces an abnormality when an allowable refrigerant charge amount for an outdoor unit, which is connected to the low-capacity indoor unit, notified from the outdoor unit is greater than an allowable refrigerant charge amount calculated in advance from the rated cooling capacity.

[0014] According to the present disclosure, the announcement unit can determine whether the outdoor unit is the dedicated outdoor unit with which the low-capacity indoor unit is permitted to be combined on the basis of the allowable refrigerant charge amount for the connected outdoor unit notified from the outdoor unit.

BRIEF DESCRIPTION OF DRAWINGS

[0015] 

FIG. 1 is a structure diagram of a multi-type air conditioner including a low-capacity indoor unit according to a first embodiment of the present disclosure.

FIG. 2 is an external view of the low-capacity indoor unit viewed from obliquely below.

FIG. 3 is a block diagram of an indoor control device of the low-capacity indoor unit.

FIG. 4 is a flowchart of an operation of the indoor control device.

FIG. 5 is a block diagram of an indoor control device of a low-capacity indoor unit according to a second embodiment of the present disclosure.

FIG. 6 is a flowchart of an operation of the indoor control device.

DESCRIPTION OF EMBODIMENTS

[0016] Embodiments will be described below.

[First embodiment]

[0017] FIG. 1 is a structure diagram of a multi-type air conditioner including a low-capacity indoor unit 20C according to a first embodiment of the present disclosure.

[0018] The multi-type air conditioner according to the first embodiment includes, as shown in FIG. 1, an indoor unit 20A including an indoor heat exchanger 4A and an indoor fan 5A, an indoor unit 20B including an indoor heat exchanger 4B and an indoor fan 5B, the low-capacity indoor unit 20C including an indoor heat exchanger 4C and an indoor fan 5C, and a dedicated outdoor unit 10 connected to the indoor units 20A, 20B and the low-capacity indoor unit 20C via refrigerant pipes.

[0019] The dedicated outdoor unit 10 is compatible with a multi-type air conditioner in which a plurality of indoor units are connectable to an outdoor unit, and the low-capacity indoor unit 20C is operable as an indoor unit of the multi-type air conditioner.

[0020] In FIG. 1, 1 denotes a compressor, 2 denotes a four-way switching valve having one end connected to a discharge side of the compressor 1, 3 denotes an outdoor heat exchanger having one end connected to the other end of the four-way switching valve 2, EVA, EVB, EVC denote electrically powered expansion valves each having one end connected to the other end of the outdoor heat exchanger 3, 4A, 4B, 4C denote the indoor heat exchangers each having one end connected to the other end of a corresponding one of the electrically powered expansion valves EVA, EVB, EVC, and 6 denotes an accumulator having one end connected to the other ends of the indoor heat exchangers 4A, 4B, 4C via the four-way switching valve 2 and having the other end connected to an intake side of the compressor 1. The indoor fans 5A, 5B, 5C are arranged near the indoor heat exchangers 4A, 4B, 4C, respectively.

[0021] Further, the electrically powered expansion valves EVA, EVB, EVC each have the other end connected to a corresponding one of a plurality of refrigerant pipe connection parts 7A, 7B, 7C, and the indoor heat exchangers 4A, 4B, 4C each have the one end connected to a corresponding one of the plurality of refrigerant pipe connection parts 7A, 7B, 7C via a connection pipe (refrigerant pipe). Further, the indoor heat exchangers 4A, 4B, 4C have the other ends connected to a plurality of refrigerant pipe connection parts 8A, 8B, 8C, respectively, via respective connection pipes (refrigerant pipes).

[0022] The compressor 1, the four-way switching valve 2, the outdoor heat exchanger 3, the electrically powered expansion valves EVA, EVB, EVC, the indoor heat exchangers 4A, 4B, 4C, and the accumulator 6 constitute a refrigerant circuit. This refrigerant circuit is filled with a slightly flammable R32 refrigerant.

[0023] Further, provided on the discharge side of the compressor 1 is a discharge pipe temperature sensor 11. Further, the outdoor heat exchanger 3 is provided with an outdoor heat exchanger temperature sensor 12 that detects an outdoor heat exchanger temperature, and, in the vicinity of the outdoor heat exchanger 3, an outdoor temperature sensor 13 that detects an outdoor temperature is provided.

[0024] Further, the indoor heat exchanger 4A is provided with an indoor heat exchanger temperature sensor 15A that detects an indoor heat exchanger temperature, and, in the vicinity of the indoor heat exchanger 4A, an indoor temperature sensor 16A that detects an indoor temperature is provided. Further, the indoor heat exchanger 4B is provided with an indoor heat exchanger temperature sensor 15B that detects an indoor heat exchanger temperature, and, in the vicinity of the indoor heat exchanger 4B, an indoor temperature sensor 16B that detects an indoor temperature is provided. Further, the indoor heat exchanger 4C is provided with an indoor heat exchanger temperature sensor 15C that detects an indoor heat exchanger temperature, and, in the vicinity of the indoor heat exchanger 4C, an indoor temperature sensor 16C that detects an indoor temperature is provided.

[0025] The dedicated outdoor unit 10 includes an outdoor control device 18 including a microcomputer, an input-output circuit, and the like. The outdoor control device 18 includes an operation control unit 18a that controls the compressor 1, the electrically powered expansion valves EVA, EVB, EVC, and the like, and a communication unit 18b. Further, the indoor units 20A, 20B each include an indoor control device (not shown), and the low-capacity indoor unit 20C includes an indoor control device 100 shown in FIG. 2.

[0026]  The indoor control devices of the indoor units 20A, 20B and the indoor control device 100 of the low-capacity indoor unit 20C communicate with the outdoor control device 18 of the dedicated outdoor unit 10 through a communication line (not shown) so as to cause the outdoor control device 18, the indoor control devices of the indoor units 20A, 20B, and the indoor control device 100 of the low-capacity indoor unit 20C to operate in cooperation with each other as the multi-type air conditioner.

[0027] When the indoor units 20A, 20B and the low-capacity indoor unit 20C are put into cooling operation in the multi-type air conditioner, the four-way switching valve 2 is switched to a position represented by a dotted line, and then the compressor 1 is put into operation. Then, each of the electrically powered expansion valves EVA, EVB, EVC is opened to a predetermined opening degree. Then, a high-temperature and high-pressure gas refrigerant discharged from the compressor 1 exchanges heat with outdoor air in the outdoor heat exchanger 3 with the help of an outdoor fan (not shown) in operation to be condensed to a liquid refrigerant. Next, a liquid refrigerant from the indoor heat exchangers 4A, 4B, 4C is decompressed by the electrically powered expansion valves EVA, EVB, EVC, exchanges heat with indoor air in the indoor heat exchangers 4A, 4B, 4C with the help of the indoor fans 5A, 5B, 5C in operation to be evaporated to become a gas refrigerant. The gas refrigerant then returns to the intake side of the compressor 1.

[0028] Here, the indoor units 20A, 20B have a rated cooling capacity of 2.2 kW, and the low-capacity indoor unit 20C has a rated cooling capacity of 0.8 kW. That is, the low-capacity indoor unit 20C has lower capacity than the indoor units 20A, 20B.

[0029] On the other hand, when the indoor units 20A, 20B and the low-capacity indoor unit 20C are put into heating operation, the four-way switching valve 2 is switched to a position represented by a solid line, and then the compressor 1 is put into operation. Then, each of the electrically powered expansion valves EVA, EVB, EVC is opened to a predetermined opening degree. Then, a high-temperature and high-pressure gas refrigerant discharged from the compressor 1 exchanges heat with indoor air in the indoor heat exchangers 4A, 4B, 4C with the help of the indoor fans 5A, 5B, 5C in operation to be condensed to a liquid refrigerant. Next, the liquid refrigerant from the indoor heat exchangers 4A, 4B, 4C is decompressed by the electrically powered expansion valves EVA, EVB, EVC, exchanges heat with outdoor air in the outdoor heat exchanger 3 with the help of the outdoor fan (not shown) in operation to be evaporated to become a gas refrigerant. The gas refrigerant then returns to the intake side of the compressor 1.

[0030] FIG. 2 is an external view of the low-capacity indoor unit 20C viewed from obliquely below. This indoor unit is designed to be embedded in a ceiling.

[0031] As shown in FIG. 2, the low-capacity indoor unit 20C includes a casing main body 101, a panel 102 having a rectangular shape and provided below the casing main body 101, and a grille 103 detachably mounted to the panel 102.

[0032] The panel 102 has, on its one end in a longitudinal direction, a blow-out port 110 extending along a short side of the panel 102. A flap 120 is mounted to the panel 102 pivotably. In FIG. 2, the flap 120 closes the blow-out port 110.

[0033] A drain socket 107 is further provided so as to protrude from a sidewall of the casing main body 101. The drain socket 107 is connected to an external drain hose (not shown). Pipe connection parts 105, 106 are further provided so as to protrude from the sidewall of the casing main body 101. The pipe connection parts 105, 106 are each connected to a corresponding external refrigerant pipe (not shown).

[0034] Also, in FIG. 2, 108 denotes an electrical components unit, and 111 to 113 denote hanger fittings each protruding sideward from the casing main body 101.

[0035] FIG. 3 is a block diagram of the indoor control device 100 of the low-capacity indoor unit 20C.

[0036] As shown in FIG. 3, the low-capacity indoor unit 20C includes the indoor control device 100 including a microcomputer, an input-output circuit, and the like. The indoor control device 100 includes an operation control unit 100a, a communication unit 100b, a model determination unit 100c, and an announcement unit 100d.

[0037] The operation control unit 100a controls a fan motor 21 and a flap drive unit 22 on the basis of detection signals from the indoor temperature sensor 16C and the indoor heat exchanger temperature sensor 15C.

[0038] The communication unit 100b communicates with the outdoor control device 18 (shown in FIG. 1) of the dedicated outdoor unit 10 connected to the low-capacit

[0039] y indoor unit 20C via the communication unit 18b.

[0040] The model determination unit 100c determines whether a connected outdoor unit is the dedicated outdoor unit with which the low-capacity indoor unit 20C is permitted to be combined on the basis of a model ID of the outdoor unit received via the communication unit 100b.

[0041] When the model determination unit 100c determines that the connected outdoor unit is not the dedicated outdoor unit with which the combination is permitted, the announcement unit 100d causes a power source lamp of a display unit 23 to blink to announce an abnormality. Here, for example, a buzzer sound may be emitted at the same time when the power source lamp blinks. Further, the means for announcing an abnormality is not limited to the power source lamp or the buzzer sound, and, for example, the abnormality may be announced by the display unit or in the form of voice output.

[0042] FIG. 4 is a flowchart of an operation of the indoor control device 100.

[0043]  First, an outdoor unit is connected to the low-capacity indoor unit 20C, and then the indoor control device 100 is put into operation on turning on the power source first.

[0044] Then, in step S1 shown in FIG. 4, a determination is made as to whether an outdoor unit is connected to the low-capacity indoor unit 20C. If it is determined that the outdoor unit is connected to the low-capacity indoor unit 20C, the process proceeds to step S2. On the other hand, when no outdoor unit is connected to the low-capacity indoor unit 20C, step S1 is repeated.

[0045] Then, in step S2, a model ID is obtained from the outdoor unit via the communication unit 100b.

[0046] Next, proceeding to step S3, the model determination unit 100c determines whether the outdoor unit thus connected is the dedicated outdoor unit with which the low-capacity indoor unit 20C is permitted to be combined on the basis of the model ID obtained from the outdoor unit.

[0047] When it is determined in step S3 that the outdoor unit is the dedicated outdoor unit, the process proceeds to step S4. On the other hand, when it is determined that the outdoor unit is not the dedicated outdoor unit, the process proceeds to step S5 to cause the announcement unit 100d to announce an abnormality, and then the process is brought to an end.

[0048] Then, in step S4, the low-capacity indoor unit 20C is put into normal operation, that is, cooling operation or heating operation in accordance with a command from a remote controller or the like.

[0049] The low-capacity indoor unit 20C configured as described above has a rated cooling capacity of less than 2.2 kW and causes the announcement unit 100d to announce an abnormality when the low-capacity indoor unit 20C is connected to an outdoor unit other than the dedicated outdoor unit 10 with which the low-capacity indoor unit 20C is permitted to be combined. This prevents the low-capacity indoor unit 20C from being connected to an outdoor unit, other than the dedicated outdoor unit 10, having a larger refrigerant charge amount and put into operation, thereby reducing a risk due to refrigerant leakage.

[0050] Here, an allowable refrigerant charge amount for the dedicated outdoor unit 10 is equal to an amount of refrigerant charged into a refrigerant circuit in the multi-type air conditioner including the dedicated outdoor unit 10 and the maximum number of indoor units each connected to the dedicated outdoor unit 10 via a corresponding pipe having a maximum allowable length.

[0051] The allowable refrigerant charge amount for the dedicated outdoor unit 10 is 1.8 kg. In this case, assuming that the installation location is a washroom or the like having a room area of 3.3 m² * a ceiling height of 2.4 m, the maximum concentration when the refrigerant has leaked is equal to or less than 0.227 kg/m³ (≈ 1.8 kg(3.3 m² * 2.4 m)).

[0052] In a multi-type air conditioner for home use, the allowable refrigerant charge amount is 4.0 kg. In this case, assuming that the installation location is a living room, a kitchen, or the like having a room area of about 7 m² * a ceiling height of 2.4 m, the maximum concentration when the refrigerant has leaked is equal to or less than 0.238 kg/m³ (≈ 4.0 kg(7 m² * 2.4 m)). However, even when the refrigerant has leaked to a small space such as a washroom (3.3 m² * 2.4 m), the maximum concentration (0.227 or less) when the refrigerant has leaked is smaller in the multi-type air conditioner including the low-capacity indoor unit 20C, and thus such a multi-type air conditioner is safer against refrigerant leakage.

[0053] Further, since the low-capacity indoor unit 20C has a rated cooling capacity of 1.6 kW (0.8 kW according to the present embodiment) or less, the low-capacity indoor unit 20C is suitable for air conditioning in a small space such as a washroom and is safer against refrigerant leakage to a small space.

[0054] Further, it is possible to provide a multi-type air conditioner in which a plurality of indoor units including at least one low-capacity indoor unit 20C are connected to the dedicated outdoor unit 10.

[0055] According to the first embodiment, the model determination unit 100c and the announcement unit 100d are provided in the low-capacity indoor unit 20C, or alternatively, may be provided in the dedicated outdoor unit 10.

[Second embodiment]

[0056] FIG. 5 is a block diagram of an indoor control device 200 of a low-capacity indoor unit 20C according to a second embodiment of the present disclosure. The low-capacity indoor unit 20C according to the second embodiment has the same structure as the low-capacity indoor unit 20C according to the first embodiment except for the indoor control device 200.

[0057] As shown in FIG. 5, the low-capacity indoor unit 20C includes the indoor control device 200 including a microcomputer, an input-output circuit, and the like. The indoor control device 200 includes an operation control unit 200a, a communication unit 200b, an allowable refrigerant charge amount determination unit 200c, and an announcement unit 200d.

[0058] The operation control unit 200a controls the fan motor 21 and the flap drive unit 22 on the basis of detection signals from the indoor temperature sensor 16C and the indoor heat exchanger temperature sensor 15C.

[0059] The communication unit 200b communicates with the outdoor control device 18 (shown in FIG. 1) of the dedicated outdoor unit 10 connected to the low-capacity indoor unit 20C via the communication unit 18b.

[0060] The allowable refrigerant charge amount determination unit 200c determines whether an allowable refrigerant charge amount X received from an outdoor unit via the communication unit 200b is greater than an allowable refrigerant charge amount A calculated in advance from the rated cooling capacity 0.8 kW of the low-capacity indoor unit 20C.

[0061] Here, a volume of a room to which the low-capacity indoor unit 20C is applied is obtained from a floor area (3.3 m²) and ceiling height (2.4 m) of the room, for example, and then the allowable refrigerant charge amount A in which the maximum concentration in refrigerant leakage when the refrigerant has leaked to the room having the volume is equal to or less than 0.227 kg/m³ (≈ 1.8 kg(3.3 m² * 2.4 m)) is calculated in advance from the rated cooling capacity 0.8 kW of the low-capacity indoor unit 20C.

[0062] When the allowable refrigerant charge amount determination unit 200c determines that the allowable refrigerant charge amount X from a connected outdoor unit is greater than the allowable refrigerant charge amount A calculated in advance from the rated cooling capacity of the low-capacity indoor unit 20C, the announcement unit 200d causes the power source lamp of the display unit 23 to blink to announce an abnormality. Here, for example, a buzzer sound may be emitted at the same time when the power source lamp blinks. Further, the means for announcing an abnormality is not limited to the power source lamp or the buzzer sound, and, for example, the abnormality may be announced by the display unit or in the form of voice output.

[0063] FIG. 6 is a flowchart of an operation of the indoor control device 200.

[0064] First, an outdoor unit is connected to the low-capacity indoor unit 20C, and then the indoor control device 200 is put into operation on turning on the power source first.

[0065] Then, in step S11 shown in FIG. 6, a determination is made as to whether an outdoor unit is connected to the low-capacity indoor unit 20C. If it is determined that the outdoor unit is connected to the low-capacity indoor unit 20C, the process proceeds to step S12. On the other hand, when no outdoor unit is connected to the low-capacity indoor unit 20C, step S11 is repeated.

[0066] Then, in step S12, the allowable refrigerant charge amount X is obtained from the outdoor unit via the communication unit 200b.

[0067] Next, after proceeding to step S13, the allowable refrigerant charge amount determination unit 200c determines whether the allowable refrigerant charge amount X for the outdoor unit is greater than the allowable refrigerant charge amount A calculated in advance from the rated cooling capacity of the low-capacity indoor unit 20C.

[0068] When it is determined in step S13 that the allowable refrigerant charge amount X is greater than the allowable refrigerant charge amount A, the process proceeds to step S15 to cause the announcement unit 100d to announce the abnormality, and then the process is brought to an end. On the other hand, when it is determined in step S13 that the allowable refrigerant charge amount X is equal to or less than the allowable refrigerant charge amount A, the process proceeds to step S14.

[0069] Then, in step S14, the low-capacity indoor unit 20C is put into normal operation, that is, cooling operation or heating operation in accordance with a command from a remote controller or the like.

[0070] According to the low-capacity indoor unit 20C configured as described above, making the allowable refrigerant charge amount X for the dedicated outdoor unit 10 less than the allowable refrigerant charge amount A calculated in advance from the rated cooling capacity of the low-capacity indoor unit 20C prevents, when the low-capacity indoor unit 20C is connected to the dedicated outdoor unit 10, the announcement unit 200d from announcing an abnormality. However, when an outdoor unit other than the dedicated outdoor unit 10 is connected, the allowable refrigerant charge amount X for the outdoor unit notified is greater than the allowable refrigerant charge amount A calculated in advance from the rated cooling capacity, which causes the announcement unit 200d to announce an abnormality.

[0071] According to the second embodiment, the allowable refrigerant charge amount determination unit 200c is provided in the low-capacity indoor unit 20C, or alternatively, may be provided in the dedicated outdoor unit 10.

[0072] According to the first and second embodiments, a determination is made as to whether the connected outdoor unit is the dedicated outdoor unit 10 on the basis of the model ID obtained from the outdoor unit, and a determination is made as to whether the allowable refrigerant charge amount X from the outdoor unit is greater than the allowable refrigerant charge amount A calculated in advance from the rated cooling capacity of the low-capacity indoor unit 20C, but the means for determining whether the connected outdoor unit is the dedicated outdoor unit with which the low-capacity indoor unit 20C is permitted to be combined is not limited to the above-described means.

[0073] Further, according to the first and second embodiments, a description has been given of the multi-type air conditioner including the dedicated outdoor unit 10 and the plurality of indoor units (including the low-capacity indoor unit 20C) connected to the dedicated outdoor unit 10, but the present disclosure may be applied to an air conditioner in which the dedicated outdoor unit and the low-capacity indoor unit are connected to each other on a one-to-one basis.

[0074] The foregoing description concerns specific embodiments of the present disclosure; however, the present disclosure is not limited to the first and second embodiments, and various modifications and variations may be made within the scope of the present disclosure.

REFERENCE SIGNS LIST

[0075] 

1 compressor

2 four-way switching valve

3 outdoor heat exchanger

4A, 4B, 4C indoor heat exchanger

5A, 5B, 5C indoor fan

6 accumulator

7A, 7B, 7C refrigerant pipe connection part

8A, 8B, 8C refrigerant pipe connection part

10 dedicated outdoor unit

11 discharge pipe temperature sensor

12 outdoor heat exchanger temperature sensor

13 outdoor temperature sensor

15A, 15B, 15C indoor heat exchanger temperature sensor

16A, 16B, 16C indoor temperature sensor

18 outdoor control device

18a operation control unit

18b communication unit

20A, 20B indoor unit

20C low-capacity indoor unit

100 indoor control device

100a operation control unit

100b communication unit

100c model determination unit

100d announcement unit

200 indoor control device

200a operation control unit

200b communication unit

200c allowable refrigerant charge amount determination unit

200d announcement unit

EVA, EVB, EVC electrically powered expansion valve

Claims

1. A low-capacity indoor unit (20C) having a rated cooling capacity of less than 2.2 kW, the low-capacity indoor unit (20C) comprising
an announcement unit (100d, 200d) that announces an abnormality when the low-capacity indoor unit (20C) is connected to an outdoor unit other than a dedicated outdoor unit (10) with which the low-capacity indoor unit (20C) is permitted to be combined.

2. The low-capacity indoor unit (20C) according to claim 1, wherein
the rated cooling capacity is equal to or less than 1.6 kW.

3. The low-capacity indoor unit (20C) according to claim 1 or 2, wherein
the dedicated outdoor unit (10) is compatible with a multi-type air conditioner in which a plurality of indoor units (20A, 20B, 20C) are connectable to an outdoor unit, and
the low-capacity indoor unit (20C) is operable as an indoor unit of the multi-type air conditioner and is one of the plurality of indoor units (20A, 20B, 20C).

4. The low-capacity indoor unit (20C) according to any one of claims 1 to 3, wherein
the announcement unit (200d) announces an abnormality when an allowable refrigerant charge amount for an outdoor unit, which is connected to the low-capacity indoor unit (20C), notified from the outdoor unit is greater than an allowable refrigerant charge amount calculated in advance from the rated cooling capacity.

Drawing