Patent Description:
To address environmental issues causing ozone depletion, refrigerant used in air conditioners has been changed from conventional fluorocarbons to R32 or the like. Unlike fluorocarbons, R32 is a flammable refrigerant. Leakage of R32 from an air conditioner may cause different problems from the problems that occur when a fluorocarbon leaks. Patent Literature <NUM> discloses a technology in which an air conditioner includes a refrigerant leakage detection device to warn the user if refrigerant leakage is detected. <CIT>describes a heat source unit for a refrigeration device, wherein in an outdoor unit, when the detection value of a first temperature sensor is smaller than a threshold and this is still the case after a predetermined time has elapsed, it is determined that the refrigerant has pooled below a machine chamber. It is thereby determined whether refrigerant leakage is present on the basis of the detection value of the first temperature sensor without using a gas detection sensor.

The air conditioner described in Patent Literature <NUM> can detect refrigerant leakage by operating the refrigerant leakage detection device with a storage battery even during transportation and during a non-operation period in which no air conditioning control is performed. However, depletion of the storage battery requires replacement of the storage battery, or otherwise even the normal air conditioning control operation cannot be performed. Thus, depletion of the storage battery causing the air conditioning control operation to not function may misguide the user to incorrectly think that the air conditioner has failed. This presents a problem of inconvenience to the user.

The present invention has been made in view of the foregoing, and it is an object of the present invention to provide an air conditioner capable of detecting refrigerant leakage anomalies occurring in the air conditioner during a non-operation period of air conditioning control without compromising user convenience. Solution to Problem.

To solve the problem and achieve the object described above, an air conditioner according to claim <NUM> and to claim <NUM> of the present invention includes an indoor unit, an outdoor unit, and a remote controller that instructs the indoor unit to control air conditioning. The air conditioner includes a first sensor to detect a first anomaly in the indoor unit.

Moreover, the air conditioner includes a second sensor to detect a second anomaly, the second anomaly being an anomaly other than the first anomaly. Moreover, the air conditioner includes a control unit to activate the first sensor and the second sensor during an operation period in which the air conditioner provides air conditioning control and to activate the first sensor during a non-operation period in which the air conditioner does not provide air conditioning control.

The air conditioner according to the present invention provides an advantage in that it is possible to detect an anomaly as a refrigerant leakage during a non-operation period of air conditioning control without compromising user convenience.

The air conditioner according to embodiments of the present invention will be described in detail below with reference to the drawings. These embodiments are not intended to limit the scope of this invention.

<FIG> is a diagram illustrating an example configuration of an air conditioner <NUM> according to a first embodiment of the present invention. The air conditioner <NUM> includes an indoor unit <NUM> and an outdoor unit <NUM> illustrated in <FIG>, and a remote controller (not illustrated in <FIG>) that instructs the indoor unit <NUM> to control air conditioning. The indoor unit <NUM> is, for example, a tall, floor-mounted indoor unit. Although it is assumed herein that the outdoor unit <NUM> is connected to a single indoor unit <NUM>, the air conditioner <NUM> may be configured such that the outdoor unit <NUM> is connected to a plurality of indoor units <NUM>. It is also assumed herein that the air conditioner <NUM> uses a flammable refrigerant (e.g., R32).

<FIG> is a block diagram illustrating an example configuration of the indoor unit <NUM>, the outdoor unit <NUM>, and a remote controller <NUM> constituting the air conditioner <NUM> according to the first embodiment.

The indoor unit <NUM> includes a communication unit <NUM> that communicates with the outdoor unit <NUM>; a control unit <NUM> that controls the operation of the indoor unit <NUM>; a leak sensor <NUM> that detects an anomaly relating to leakage of a refrigerant in the indoor unit <NUM>; and a sensor <NUM> that detects an anomaly other than refrigerant leakage (e.g., an anomaly of the temperature in the indoor unit <NUM>) in the indoor unit <NUM>. The leak sensor <NUM> is, for example, a gas sensor. Alternatively, the leak sensor <NUM> is, for example, a thermistor disposed, in the indoor unit <NUM>, in a pipe through which the refrigerant flows to detect refrigerant leakage by a change in the temperature of the pipe. The leak sensor <NUM> is a first sensor, and the sensor <NUM> is a second sensor. In addition, a refrigerant leakage anomaly is a first anomaly, and an anomaly that is not a refrigerant leakage anomaly, i.e., an anomaly other than the first anomaly, is a second anomaly.

The indoor unit <NUM> further includes a storage unit <NUM> that stores control information required, for example, for the control unit <NUM> to provide air conditioning control; a display unit <NUM> that displays an anomaly and/or the like detected by the leak sensor <NUM>, the sensor <NUM>, or the like; a communication unit <NUM> that communicates with the remote controller <NUM>; and a fan <NUM> that circulates air inside the indoor unit <NUM>.

The indoor unit <NUM> may include a plurality of sensors <NUM> that each detect a different anomaly. The indoor unit <NUM> may be configured not to include the display unit <NUM>. Note that <FIG> only illustrates the components required for an operation of the first embodiment, and omits components that perform a general operation as an indoor unit component.

The outdoor unit <NUM> includes a communication unit <NUM> that communicates with the indoor unit <NUM>; a control unit <NUM> that controls the operation of the outdoor unit <NUM>; a sensor <NUM> that detects an anomaly other than refrigerant leakage (e.g., an anomaly of the temperature in the outdoor unit <NUM>) in the outdoor unit <NUM>; and a display unit <NUM> that displays an anomaly and/or the like detected by the sensor <NUM>. The sensor <NUM> is a second sensor.

The outdoor unit <NUM> may include a plurality of sensors <NUM> that each detect a different anomaly. The outdoor unit <NUM> may be configured not to include the display unit <NUM>. Note that <FIG> only illustrates the components required for an operation of the first embodiment, and omits components that perform a general operation as an outdoor unit component.

The remote controller <NUM> includes a communication unit <NUM> that communicates with the indoor unit <NUM>; and a display unit <NUM> that displays an anomaly and/or the like detected in the indoor unit <NUM> or in the outdoor unit <NUM>.

Note that <FIG> only illustrates the components required for an operation of the first embodiment, and omits components that perform a general operation as a remote controller component.

The indoor unit <NUM> and the remote controller <NUM> may be configured to be connected to each other by wire or not to be connected to each other by wire. In a case in which the indoor unit <NUM> and the remote controller <NUM> are connected to each other by wire, the communication unit <NUM> of the indoor unit <NUM> and the communication unit <NUM> of the remote controller <NUM> communicate with each other by wired communication. Otherwise, in a case in which the indoor unit <NUM> and the remote controller <NUM> are not connected to each other by wire, the communication unit <NUM> of the indoor unit <NUM> and the communication unit <NUM> of the remote controller <NUM> communicate with each other by wireless communication.

The indoor unit <NUM> and the outdoor unit <NUM> are connected to each other by wire. The control unit <NUM> of the indoor unit <NUM> exchanges control information and other information with the control unit <NUM> of the outdoor unit <NUM> via the communication unit <NUM> and the communication unit <NUM> of the outdoor unit <NUM>. The control unit <NUM> of the outdoor unit <NUM> sends information about an anomaly detected by the sensor <NUM> to the control unit <NUM> of the indoor unit <NUM> via the communication unit <NUM> and the communication unit <NUM> of the indoor unit <NUM>. The control unit <NUM> of the indoor unit <NUM> receives information about an anomaly detected by the sensor <NUM> of the outdoor unit <NUM> from the control unit <NUM> of the outdoor unit <NUM> via the communication unit <NUM> and the communication unit <NUM> of the outdoor unit <NUM>. The leak sensor <NUM>, the sensor <NUM>, and the sensor <NUM> each detect a different anomaly.

In the first embodiment, the control unit <NUM> of the indoor unit <NUM> activates all the sensors of the air conditioner <NUM>, i.e., the leak sensor <NUM> and the sensor <NUM> of the indoor unit <NUM> and the sensor <NUM> of the outdoor unit <NUM>, on the basis of the operational state of the air conditioner <NUM> during an operation period in which the air conditioner <NUM> provides air conditioning control. Since the control unit <NUM> is controlling the operation of the indoor unit <NUM>, the control unit <NUM> can recognize the operational state of the air conditioner <NUM>.

Meanwhile, during a non-operation period in which the air conditioner <NUM> does not provide air conditioning control, i.e., when the air conditioner <NUM> is in a non-operational state, the control unit <NUM> activates the leak sensor <NUM> of the indoor unit <NUM>, but does not activate the sensor <NUM> of the indoor unit <NUM> and the sensor <NUM> of the outdoor unit <NUM>. In view of an effect on the user in a case of flammable refrigerant leakage, the control unit <NUM> activates the leak sensor <NUM> even when the air conditioner <NUM> is not in operation to enable refrigerant leakage to be detected. The control unit <NUM> supplies the power that is supplied to the control unit <NUM> to the leak sensor <NUM> also during a non-operation period. This operation enables, in the air conditioner <NUM>, electrical power to be supplied to the leak sensor <NUM> to cause the leak sensor <NUM> to operate and to enable refrigerant leakage to be detected even during a non-operation period in which no air conditioning control is performed as long as electrical power is supplied to the indoor unit <NUM>.

<FIG> is a not claimed flowchart illustrating a process of detecting an anomaly that can occurr in the air conditioner <NUM>.

First, the control unit <NUM> of the indoor unit <NUM> checks whether the air conditioner <NUM> is not providing air conditioning control, i.e., the air conditioner <NUM> is in a non-operational state (step S1). If the air conditioner <NUM> is in a non-operational state (step S1: Yes), the control unit <NUM> activates the leak sensor <NUM> (step S2). The control unit <NUM> checks whether refrigerant leakage has been detected by the leak sensor <NUM> (step S3). If refrigerant leakage has been detected by the leak sensor <NUM> (step S3: Yes), the control unit <NUM> provides control to display information informing that refrigerant leakage has been detected, in any or all of the display unit <NUM> of the indoor unit <NUM>, the display unit <NUM> of the outdoor unit <NUM>, and the display unit <NUM> of the remote controller <NUM> (step S4). To prevent accumulation of the refrigerant leaked in the indoor unit <NUM>, the control unit <NUM> provides control to rotate (i.e., start) the fan <NUM> of the indoor unit <NUM> (step S5) and then terminates the process.

Returning to step S3, if there is no refrigerant leakage detected by the leak sensor <NUM> (step S3: No), the control unit <NUM> terminates the process.

Returning to step S1, if the air conditioner <NUM> is providing air conditioning control (step S1: No), the control unit <NUM> activates the leak sensor <NUM>, the sensor <NUM>, and the sensor <NUM> (step S6). The control unit <NUM> checks whether an anomaly has been detected by the leak sensor <NUM>, the sensor <NUM>, or the sensor <NUM> (step S7). If an anomaly has been detected by the leak sensor <NUM>, the sensor <NUM>, or the sensor <NUM> (step S7: Yes), the control unit <NUM> provides control to display details of the anomaly based on the sensor that has detected the anomaly, in any or all of the display unit <NUM> of the indoor unit <NUM>, the display unit <NUM> of the outdoor unit <NUM>, and the display unit <NUM> of the remote controller <NUM> (step S8). If the anomaly detected is refrigerant leakage detected by the leak sensor <NUM> (step S9: Yes) and the fan <NUM> of the indoor unit <NUM> is not in operation (step S10: Yes), then to prevent accumulation of the refrigerant leaked in the indoor unit <NUM>, the control unit <NUM> provides control to rotate (i.e., start) the fan <NUM> of the indoor unit <NUM> (step S5) and then terminates the process.

If there is no anomaly detected by the leak sensor <NUM>, the sensor <NUM>, or the sensor <NUM> (step S7: No), the control unit <NUM> terminates the process. Alternatively, if the anomaly detected is not refrigerant leakage detected by the leak sensor <NUM> (step S9: No), the control unit <NUM> terminates the process. Still alternatively, if the fan <NUM> of the indoor unit <NUM> is in operation (step S10: No), the control unit <NUM> terminates the process.

The control unit <NUM> constantly or periodically repeats the process of detecting an anomaly that may occur in the air conditioner <NUM> as illustrated in <FIG>.

Note that if the fan <NUM> is in operation, the refrigerant leaked in the indoor unit <NUM> will not accumulate in the indoor unit <NUM> even if the refrigerant leaks in the indoor unit <NUM>. Accordingly, if the fan <NUM> of the indoor unit <NUM> is in operation, the control unit <NUM> of the indoor unit <NUM> may stop supplying electrical power to the leak sensor <NUM> to inactivate the leak sensor <NUM>.

The hardware configuration of the indoor unit <NUM> will next be described. In the indoor unit <NUM>, the communication unit <NUM> and the communication unit <NUM> are implemented in an interface circuit capable of sending and receiving communication data. The leak sensor <NUM> and the sensor <NUM> are each implemented by a measurement device. The storage unit <NUM> is implemented by a memory. The display unit <NUM> is implemented by a light emitting diode (LED), a monitor, or the like. The fan <NUM> is implemented by a rotational fan unit and a drive unit such as a motor. The control unit <NUM> is implemented in a processing circuit. That is, the indoor unit <NUM> includes a processing circuit for activating the leak sensor <NUM>, the sensor <NUM>, and the sensor <NUM> depending on the operational state of the air conditioner <NUM>. The processing circuit may be a combination of a central processing unit (CPU) that executes a program stored in a memory and the memory or may be a dedicated hardware element.

<FIG> is a diagram illustrating an example in which the processing circuit of the indoor unit <NUM> according to the first embodiment is configured from a CPU <NUM> and a memory <NUM>. In a case in which the processing circuit is configured from the CPU <NUM> and the memory <NUM>, each function of the control unit <NUM> is implemented in software, firmware, or a combination of software and firmware. The software or firmware is described as a program or programs, and is stored in the memory <NUM>. In the processing circuit, the CPU <NUM> reads and executes a program or programs stored in the memory <NUM> to provide the functions of the control unit <NUM>. That is, the indoor unit <NUM> includes the memory <NUM> for storing the program(s) that, upon execution by the processing circuit, cause(s) the control unit <NUM> to perform steps of activating the leak sensor <NUM>, the sensor <NUM>, and the sensor <NUM> depending on the operational state of the air conditioner <NUM>. These programs may be described as causing the computer to execute the procedure and method performed by the indoor unit <NUM>. The CPU <NUM> may also be a processing device, a computing unit, a microprocessor, a microcomputer, a processor, a digital signal processor (DSP), or the like. Examples of the memory <NUM> include non-volatile or volatile semiconductor memories such as a random access memory (RAM), a read-only memory (ROM), a flash memory, an erasable programmable ROM (EPROM), and an electrically erasable programmable ROM (EEPROM); a magnetic disk, a flexible disk, an optical disk, a compact disc, a MiniDisc, and a digital versatile disc (DVD). The memory <NUM> may be the same memory as the memory for implementing the storage unit <NUM>.

<FIG> is a diagram illustrating an example in which the processing circuit of the indoor unit <NUM> according to the first embodiment is configured from a dedicated hardware element. In a case in which the processing circuit is a dedicated hardware element, a processing circuit <NUM> illustrated in <FIG> is, for example, a single circuit, a set of multiple circuits, a programmed processor, a parallel programmed processor, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or a combination thereof. The functions of the control unit <NUM> may be implemented in the processing circuit <NUM> on a per-function basis or may be implemented collectively in the processing circuit <NUM>.

The functions of the control unit <NUM> may be implemented partially in a dedicated hardware element, and partially in software or firmware. In this manner, the processing circuit can provide the functions described above in dedicated hardware, software, firmware, or a combination thereof.

As described above, according to the present embodiment, the control unit <NUM> of the indoor unit <NUM> does not activate the sensors <NUM> and <NUM>, but supplies electrical power to the leak sensor <NUM> for activation, during a non-operation period in which the air conditioner <NUM> does not provide air conditioning control. This operation enables the air conditioner <NUM> to detect refrigerant leakage even during a non-operation period. In addition, the control unit <NUM> supplies electrical power to the leak sensor <NUM> to activate the leak sensor <NUM> without using a storage battery during a non-operation period of the air conditioner <NUM>, thereby enabling leakage detection to be performed without imposing a burden on the user and thus enabling user convenience to be improved. As long as the indoor unit <NUM> is plugged into a receptacle in a usual house, the air conditioner <NUM> can detect refrigerant leakage during a non-operation period of the air conditioner <NUM>. The control unit <NUM> also provides control not to activate the sensors <NUM> and <NUM>, other than the leak sensor <NUM>, during a non-operation period of the air conditioner <NUM>. This operation enables the air conditioner <NUM> to reduce power consumption during a non-operation period as compared to when all the sensors are activated.

Although the air conditioner <NUM> is herein described as detecting continuously only refrigerant leakage during a non-operation period, the configuration is not limited thereto. In general, the air conditioner <NUM> checks the connection status between the indoor unit <NUM> and the outdoor unit <NUM> by periodic communication therebetween. Thus, the air conditioner <NUM> may also detect a communication anomaly between the indoor unit <NUM> and the outdoor unit <NUM> during a non-operation period.

Moreover, anomalies that it is anticipated will occur in the air conditioner <NUM>, i.e., anomalies that will be detected by the leak sensor <NUM> and the sensor <NUM> of the indoor unit <NUM> and the sensor <NUM> of the outdoor unit <NUM>, may each be assigned a severity, and the severity of each of the anomalies may previously be stored in the air conditioner <NUM>. The severity information may previously be set and stored in the storage unit <NUM> by the manufacturer of the air conditioner <NUM> during the initial configuration stage, and the setting or the initial configuration may be configurable by the user of the air conditioner <NUM>. The air conditioner <NUM> may be configured to activate the first sensor for detecting the first anomaly, which is a high severity anomaly having a severity higher than a predetermined severity, both during an operation period and during a non-operation period, and to activate the second sensor for detecting the second anomaly having a severity lower than the predetermined severity and lower than the severity of the first anomaly only during an operation period. For example, in the air conditioner <NUM>, the sensor <NUM> is the first sensor and the sensors <NUM> and <NUM> are each the second sensor. The air conditioner <NUM> can promptly detect an anomaly having a large effect on the user by activation of the sensor capable of detecting a high severity anomaly also during a non-operation period to detect a high severity anomaly having a large effect on the user upon occurrence regardless of whether the air conditioning control is being performed or not.

In a second embodiment, the control unit <NUM> activates the leak sensor <NUM> continuously or intermittently during a non-operation period in which the air conditioner <NUM> does not provide air conditioning control, i.e., when the air conditioner <NUM> is in a non-operational state. Differences from the first embodiment will be described below.

The configurations of the indoor unit <NUM>, the outdoor unit <NUM>, and the remote controller <NUM> are similar to those of the first embodiment. <FIG> is a diagram illustrating transition of the failure rate of a typical electrical appliance or the like. An electrical appliance or the like generally exhibits a tendency to have a higher failure rate during an initial failure period due to reasons such as a manufacturing problem attributable to assemble work, a component problem attributable to a part being used, or an installation problem attributable to installation work in the case of equipment installed in a building such as the air conditioner <NUM>. Moreover, an electrical appliance or the like degrades through continued use, and therefore exhibits a tendency to have a higher failure rate due to the life of the product itself during the aging period. In contrast, between the initial failure period and the aging period, there is a quality stabilized period in which the failure rate is low and the product quality is stable if an occurrence of an unexpected problem is not taken into consideration.

In the initial failure period after installation (i.e., start of an operation) of the air conditioner <NUM>, taking into consideration a characteristic of the failure rate of a typical electrical appliance illustrated in <FIG>, the control unit <NUM> of the indoor unit <NUM> activates the leak sensor <NUM> continuously even when the air conditioner <NUM> is not in operation.

In the quality stabilized period after the initial failure period has elapsed from the start of an operation of the air conditioner <NUM> and before the aging period, the control unit <NUM> of the indoor unit <NUM> activates the leak sensor <NUM> intermittently when the air conditioner <NUM> is not in operation. The control unit <NUM> activates the leak sensor <NUM> with a certain period, for example, at predetermined time intervals. The control unit <NUM> stops supplying electrical power to the leak sensor <NUM> during a time period in which the leak sensor <NUM> is not activated. <FIG> is a diagram illustrating a conceptual outline of the amount of power supplied to the leak sensor <NUM> from the control unit <NUM> in the second embodiment. The control unit <NUM> supplies electrical power to the leak sensor <NUM> with a predetermined period, i.e., at predetermined time intervals, to activate the leak sensor <NUM>, and supplies no electrical power to the leak sensor <NUM> in the other periods not to activate the leak sensor <NUM>. This operation enables the air conditioner <NUM> to reduce the power usage during a non-operation period of the air conditioner <NUM> as compared to the first embodiment.

Then, when the time period after the start of an operation of the air conditioner <NUM> enters the aging period, the control unit <NUM> of the indoor unit <NUM> activates the leak sensor <NUM> continuously when the air conditioner <NUM> is not in operation.

Information about the initial failure period, the quality stabilized period, and the aging period illustrated in <FIG> and about the cyclic period of electrical power supplied to the leak sensor <NUM> illustrated in <FIG>, i.e., information about the time periods in which the air conditioner <NUM> activates the leak sensor <NUM> during a non-operation period, is stored in the storage unit <NUM> of the indoor unit <NUM> as control information. The control unit <NUM> provides control to activate the leak sensor <NUM> continuously or intermittently as described above on the basis of the control information stored in the storage unit <NUM>.

<FIG> is a not claimed flowchart illustrating a process of detecting an anomaly that occurs in the air conditioner Z <NUM>. If the air conditioner <NUM> is in a non-operational state (step S1: Yes), the control unit <NUM> of the indoor unit <NUM> checks whether the air conditioner <NUM> is in a time period to activate the leak sensor <NUM> (step S21).

The control unit <NUM> refers to the control information stored in the storage unit <NUM>, more specifically, information about the initial failure period, the quality stabilized period, and the aging period illustrated in <FIG>, and information about the cyclic period of electrical power supplied to the leak sensor <NUM> illustrated in <FIG>. In the initial failure period, in the aging period, and in a time period in which electrical power is supplied to the leak sensor <NUM> as illustrated in <FIG> in the quality stabilized period, the control unit <NUM> determines that the air conditioner <NUM> is in a time period to activate the leak sensor <NUM>; and in a time period in which no electrical power is supplied to the leak sensor <NUM> as illustrated in <FIG> in the quality stabilized period, the control unit <NUM> determines that the air conditioner <NUM> is in a time period not to activate the leak sensor <NUM>. In a time period to activate the leak sensor <NUM> (step S21: Yes), the control unit <NUM> activates the leak sensor <NUM> (step S2). Otherwise, in a time period not to activate the leak sensor <NUM> (step S21: No), the control unit <NUM> terminates the process.

The other part of the process illustrated in <FIG> is similar to the process of the flowchart of <FIG> illustrated in relation to the first embodiment.

As described above, according to the present embodiment, the control unit <NUM> of the indoor unit <NUM> activates the leak sensor <NUM> continuously or intermittently depending on the elapsed time from the start of an operation of the air conditioner <NUM> on the basis of the control information during a non-operation period in which the air conditioner <NUM> does not provide air conditioning control. This operation enables the control unit <NUM> to activate the leak sensor <NUM> intermittently during a time period in which refrigerant leakage is less likely to be detected and to activate the leak sensor <NUM> continuously during a time period in which refrigerant leakage is more likely to be detected, thereby enabling power usage to be reduced during a non-operation period of the air conditioner <NUM> as compared to the first embodiment.

In a third embodiment, the control unit <NUM> activates the leak sensor <NUM> continuously or intermittently using a different control operation from that of the second embodiment during a non-operation period in which the air conditioner <NUM> does not provide air conditioning control, i.e., when the air conditioner <NUM> is in a non-operational state. Differences from the first and second embodiments will be described below.

The configurations of the indoor unit <NUM>, the outdoor unit <NUM>, and the remote controller <NUM> are similar to those of the first embodiment. <FIG> is a diagram illustrating a conceptual outline of transition of the result of measurement of a refrigerant leakage amount, obtained by the leak sensor <NUM> of the indoor unit <NUM> in the third embodiment. The leak sensor <NUM> measures the refrigerant leakage amount upon detection of the refrigerant leakage.

<FIG> illustrates a second threshold. The second threshold is used such that the control unit <NUM> determines that refrigerant leaks when the refrigerant leakage amount measured by the leak sensor <NUM> exceeds the second threshold.

<FIG> also illustrates a first threshold. The first threshold is lower than the second threshold and is used in control such that the control unit <NUM> switches the operational method of the leak sensor <NUM> when the refrigerant leakage amount measured by the leak sensor <NUM> exceeds the first threshold.

If the refrigerant leakage amount measured by the leak sensor <NUM> is at or below the first threshold, it is unlikely that the refrigerant leakage amount will exceed the second threshold within a short time period. Thus, the control unit <NUM> makes the next measurement of the refrigerant leakage amount after a certain interval, i.e., intermittently. The time interval for intermittent operation may be the same as the time interval of the second embodiment.

In contrast, if the refrigerant leakage amount detected by the leak sensor <NUM> exceeds the first threshold, the refrigerant leakage amount may thereafter exceed the second threshold. Thus, the control unit <NUM> makes the next measurement of the refrigerant leakage amount without any interval, i.e., continuously.

Even after the refrigerant leakage amount has exceeded the first threshold and the control unit <NUM> has continuously measured the refrigerant leakage amount, if the refrigerant leakage amount falls below the first threshold, then the control unit <NUM> may thereafter make the next measurement of the refrigerant leakage amount again after a certain interval, i.e., intermittently.

Information about the first threshold and the second threshold illustrated in <FIG>, i.e., information about the time periods in which the air conditioner <NUM> activates the leak sensor <NUM> during a non-operation period, is stored in the storage unit <NUM> of the indoor unit <NUM> as control information. The control unit <NUM> provides control to activate the leak sensor <NUM> continuously or intermittently as described above on the basis of the control information stored in the storage unit <NUM>.

<FIG> is a flowchart illustrating a process of detecting an anomaly that occurs in the air conditioner <NUM>, in the air conditioner <NUM> according to the third embodiment. If there is no refrigerant leakage detected by the leak sensor <NUM> (step S3: No), the control unit <NUM> checks whether the refrigerant leakage amount measured by the leak sensor <NUM> has exceeded the first threshold (step S31).

If the refrigerant leakage amount measured by the leak sensor <NUM> has exceeded the first threshold (step S31: Yes), the control unit <NUM> activates the leak sensor <NUM> continuously (step S32). That is, the control unit <NUM> makes the next measurement of the refrigerant leakage amount without any interval, i.e., continuously.

If the refrigerant leakage amount measured by the leak sensor <NUM> is at or below the first threshold (step S31: No), the control unit <NUM> activates the leak sensor <NUM> intermittently (step S33). That is, the control unit <NUM> makes the next measurement of the refrigerant leakage amount after a certain interval, i.e., intermittently.

The other part of the process illustrated in <FIG> is similar to the process of the flowchart of <FIG> illustrated in relation to the second embodiment.

As described above, according to the present embodiment, the control unit <NUM> of the indoor unit <NUM> activates the leak sensor <NUM> continuously or intermittently depending on the refrigerant leakage amount of the previous measurement by the leak sensor <NUM> on the basis of the control information during a non-operation period in which the air conditioner <NUM> does not provide air conditioning control. This operation enables the control unit <NUM> to activate the leak sensor <NUM> intermittently during a time period in which refrigerant leakage is less likely to be detected and to activate the leak sensor <NUM> continuously during a time period in which refrigerant leakage is more likely to be detected, thereby enabling power usage to be reduced during a non-operation period of the air conditioner <NUM> similarly to the second embodiment.

The configurations described in the foregoing embodiments are merely examples of various aspects of the present invention. These configurations may be combined with a known other technology, and moreover, a part of such configurations may be omitted and/or modified without departing from the scope of the present invention which is solely defined by the appended claims.

Claim 1:
An air conditioner (<NUM>) including an indoor unit (<NUM>), an outdoor unit (<NUM>), and a remote controller (<NUM>) configured to instruct the indoor unit (<NUM>) to control air conditioning, the air conditioner (<NUM>) comprising:
a first sensor (<NUM>) configured to detect a first anomaly in the indoor unit (<NUM>), the first anomaly being an anomaly relating to leakage of a refrigerant;
a second sensor (<NUM>, <NUM>) configured to detect a second anomaly, the second anomaly being an anomaly other than the first anomaly;
a control unit (<NUM>) configured to activate the first sensor (<NUM>) and the second sensor (<NUM>, <NUM>) during an operation period in which the air conditioner (<NUM>) provides air conditioning control and to activate the first sensor (<NUM>) during a non-operation period in which the air conditioner (<NUM>) does not provide air conditioning control; and
a storage unit (<NUM>) configured to store control information including information for a time period in which the air conditioner (<NUM>) activates the first sensor (<NUM>) during a non-operation period, wherein,
if the air conditioner (<NUM>) is not in operation, the control unit (<NUM>) refers to the control information, and activates the first sensor (<NUM>) continuously when a refrigerant leakage amount of a previous measurement by the first sensor (<NUM>) does not exceed a second threshold, which is a threshold for determining that the refrigerant leaks, but exceeds a first threshold, which is lower than the second threshold, and activates the first sensor (<NUM>) intermittently when the refrigerant leakage amount of the previous measurement by the first sensor (<NUM>) does not exceed the first threshold.