JP7826795B2 - air conditioner - Google Patents

Description

The present invention relates to an air conditioner that removes deposits from the indoor heat exchanger in the indoor unit.

In indoor air conditioner units, dust particles and fungi such as mold that are finer than the mesh of the filter can reach the indoor heat exchanger and adhere to the fin surface of the indoor heat exchanger. In such cases, the attached particles can impede heat exchange in the indoor heat exchanger, reducing air conditioning capacity, and the proliferation of bacteria can cause unpleasant odors, reducing user comfort. To remove such attached particles, Patent Document 1 proposes an invention that uses cooling operation to cause condensation to adhere to the fin surface of the indoor heat exchanger, and then heats the condensation to sterilize the fin surface. However, the invention in Patent Document 1 assumes that the indoor air contains sufficient moisture when cooling operation is performed as a moisture attachment means. Therefore, when the room is dry, sufficient moisture cannot adhere to the fin surface, resulting in insufficient sterilization.

Patent Document 2 proposes an air conditioning system equipped with an air conditioner and a humidifier, and proposes that by increasing the humidity in the room through humidification, sufficient condensation water adheres to the fin surface of the indoor heat exchanger, allowing for cleaning.

However, in rooms that do not have a humidifier, the humidity level cannot be increased by humidification, which creates the problem of insufficient condensation adhering to the fin surface.

JP 2019-109043 A Japanese Patent Application Laid-Open No. 2021-38911

The object of the present invention is to provide an air conditioner that can effectively remove deposits from the indoor heat exchanger in the indoor unit.

One aspect of the present invention is an air conditioner that includes an indoor unit having an indoor heat exchanger and a control unit that controls the air conditioning operation of the air-conditioned space in which the indoor unit is installed. When predetermined water generation conditions are met, the control unit causes the indoor heat exchanger to function as an evaporator and performs water generation operation to cause condensation water to adhere to the indoor heat exchanger. The air conditioner has weather data acquisition means that acquires weather data for the area in which the air conditioner is installed, and the control unit determines whether the predetermined water generation conditions are met based on the weather data acquired by the weather data acquisition means.

This invention provides an air conditioner that can effectively remove deposits from the indoor heat exchanger in the indoor unit.

1 is a refrigerant circuit diagram of an air conditioner according to a first embodiment. FIG. FIG. 2 is a control block diagram of the air conditioner according to the first embodiment. FIG. 1 is a first control flow diagram of the air conditioner according to the first embodiment. FIG. 2 is a second control flow diagram of the air conditioner according to the first embodiment. FIG. 3 is a third control flow diagram of the air conditioner according to the first embodiment. FIG. 11 is a first control flow diagram of the air conditioner according to the second embodiment. FIG. 10 is a second control flow diagram of the air conditioner according to the second embodiment. FIG. 10 is a third control flow diagram of the air conditioner according to the second embodiment. FIG. 4 is a fourth control flow diagram of the air conditioner according to the second embodiment.

The air conditioner according to this embodiment will be described in detail below with reference to the drawings. Note that the present invention is not limited to this embodiment.

Figure 1 is a refrigerant circuit diagram of the air conditioner of the first embodiment. Figure 2 is a control block diagram of the air conditioner of the first embodiment.

Referring to Figure 1, an air conditioner 1 according to this embodiment will be described. Figure 1 shows a refrigerant circuit diagram of the air conditioner 1 according to this embodiment. The air conditioner 1 includes a refrigerant circuit 2 and a control unit 3, and is capable of both cooling and heating air conditioning operations. Refrigerant circulates through the refrigerant circuit 2. The air conditioner 1 is capable of both heating and cooling operations, and includes a refrigerant circuit 2 in which an indoor unit 5 located in an indoor air-conditioned space and an outdoor unit 11 located outdoors are connected via refrigerant piping. The outdoor unit 11 includes an outdoor heat exchanger 13, an outdoor blower 16 for blowing outside air to the outdoor heat exchanger 13, an accumulator 17, a compressor 12, a four-way valve 15, and an expansion valve 14. In the refrigerant circuit 2, the four-way valve 15 is located on the discharge side of the compressor 12, and the accumulator 17 is located on the suction side of the compressor 12. The outdoor blower 16 is driven by a fan motor. The indoor unit 5 has a housing 6, inside which are arranged an indoor heat exchanger 7 and an indoor blower 9 for blowing indoor air to the indoor heat exchanger 7. The indoor unit 5 also has a human presence sensor 42 that detects the presence of a person in the air-conditioned space in which the indoor unit 5 is installed. The human presence sensor 42 is, for example, an infrared sensor that detects the presence of a person by detecting human movement using infrared rays.

The indoor heat exchanger 7 includes a heat transfer tube 20 and multiple heat dissipation fins 21, which are connected to the heat transfer tube 20. The heat transfer tube 20 and heat dissipation fins 21 can be made of a metal material such as copper or aluminum. Heat exchange occurs between the indoor air and the refrigerant through the heat transfer tube 20 and the heat dissipation fins 21.

In addition, an indoor temperature sensor 29 is provided inside the indoor unit 5 to detect the temperature of the indoor air drawn into the indoor unit 5 before passing through the indoor heat exchanger 7. The accumulator 17 separates the refrigerant flowing out from the indoor heat exchanger 7 into gaseous and liquid phases so that only the gaseous phase refrigerant is drawn into the compressor 12, preventing liquid refrigerant that does not evaporate in the indoor heat exchanger 7, which functions as an evaporator during cooling operation, from being drawn into the compressor 12 and compressed.

In Figure 1, solid arrows indicate the flow of refrigerant during cooling operation, while dashed arrows indicate the flow of refrigerant during heating operation. During cooling operation, the refrigerant compressed by the compressor 12 to a high temperature and high pressure flows through the outdoor heat exchanger 13. The high temperature and high pressure refrigerant flowing through the outdoor heat exchanger 13 releases heat by exchanging heat with outside air blown by the outdoor blower 16. The refrigerant that releases heat after passing through the outdoor heat exchanger 13 is decompressed by the expansion valve 14, and the decompressed refrigerant flows through the indoor heat exchanger 7. The indoor heat exchanger 7 functions as an evaporator, and the refrigerant flowing through the indoor heat exchanger 7 exchanges heat with indoor air blown by the indoor blower 9, absorbing heat. The indoor air that has absorbed heat by the refrigerant flowing through the indoor heat exchanger 7 is cooled. The refrigerant that has absorbed heat returns to the compressor 12 via the accumulator 17 and is compressed again to a high temperature and high pressure. That is, during cooling operation, the refrigerant circuit 2 is connected so that the refrigerant flows in the following order: compressor 12, outdoor heat exchanger 13 functioning as a condenser, expansion valve 14, and indoor heat exchanger 7 functioning as an evaporator.

During cooling operation, the indoor air absorbs heat from the refrigerant flowing through the indoor heat exchanger 7 and may be cooled to below the dew point temperature. As a result, the water vapor contained in the indoor air condenses as it passes through the indoor heat exchanger 7 and adheres to the heat dissipation fins 21 and heat transfer tubes 20.

During heating operation, the four-way valve 15 allows the refrigerant to flow in the opposite direction to cooling operation. During heating operation, the refrigerant is compressed by the compressor 12 to a high temperature and high pressure and flows through the indoor heat exchanger 7. The high-temperature, high-pressure refrigerant flowing through the indoor heat exchanger 7 releases heat by exchanging heat with the indoor air blown by the indoor blower 9, and the indoor air that has exchanged heat with the high-temperature, high-pressure refrigerant is warmed. The refrigerant that has released heat after passing through the indoor heat exchanger 7 is decompressed by the expansion valve 14, and the decompressed refrigerant flows through the outdoor heat exchanger 13. The refrigerant flowing through the outdoor heat exchanger 13 exchanges heat with the outside air blown by the outdoor blower 16 and absorbs heat. The refrigerant that has absorbed heat returns to the compressor 12 via the accumulator 17 and is compressed again to a high temperature and high pressure.

Next, a control block diagram of the air conditioner according to this embodiment will be described with reference to FIG. 2. In this embodiment, the control unit 3 is described as being separate from the indoor unit 5 and the outdoor unit 11. However, the indoor unit 5 or the outdoor unit 11 may also be equipped with the control unit 3. The control unit 3 includes a cooling operation unit 35 that manages cooling operation, a heating operation unit 36 that manages heating operation, and a memory unit 41 that stores data. Since cooling and heating operations are similar to conventional operating methods, detailed descriptions are omitted. In cooling operation, the cooling operation unit 35 of the control unit 3 controls the cooling operation. The cooling operation unit 35 controls the four-way valve 15 so that the refrigerant flows in the refrigerant circuit 2 in the direction described above. The cooling operation unit 35 also controls the rotation speed of the compressor 12 so that the indoor air temperature reaches the target temperature set by the user, and controls the rotation speed of the indoor blower 9 so that the air volume reaches the set air volume set by the user. The outdoor blower 16 and expansion valve 14 are appropriately controlled so that the air conditioner 1 can perform its cooling capacity. During heating operation, the heating operation unit 36 of the control unit 3 controls the heating operation. The heating operation unit 36 controls the four-way valve 15 so that the refrigerant flows in the refrigerant circuit 2 in the direction described above. The heating operation unit 36 also controls the rotation speed of the compressor 12 so that the indoor air temperature becomes the target set temperature set by the user, and controls the rotation speed of the indoor blower 9 so that the air volume becomes the set air volume set by the user. The outdoor blower 16 and expansion valve 14 are appropriately controlled so that the air conditioner 1 can demonstrate its heating capacity.

The control unit 3 also includes a water generation operation unit 37 that manages the operation of the water generation operation, a heating and sterilization operation unit 38 that manages the operation of the heating and sterilization operation, and an absence period prediction means 43 that predicts an absence period, which is a period during which no one is present in the room in which the indoor unit 5 is installed.

The water generating operation managed by the water generating operation unit 37 is an operation in which water vapor contained in the indoor air is converted into condensed water on the radiator fins 21 and heat transfer tubes 20. Therefore, the flow of refrigerant in the refrigerant circuit 2 is the same as in cooling operation. However, while in cooling operation the rotation speed of the compressor 12 is controlled so that the indoor air temperature reaches the target temperature set by the user, and the rotation speed of the indoor blower 9 is controlled so that the air volume reaches the set air volume set by the user, water generating operation differs from cooling operation in this respect. In water generating operation, the target temperature is set to a predetermined temperature and a predetermined fan rotation speed is set according to the room temperature so that the radiator fins 21 and heat transfer tubes 20 efficiently generate condensed water. The rotation speed of the compressor 12 is then controlled to reach the predetermined temperature, and the rotation speed of the indoor blower 9 is controlled to reach the predetermined fan rotation speed.

The water generating operation unit 37 also includes a weather data acquisition means 39 and a water generating operation determination unit 40. The weather data acquisition means 39 communicates with the outside world via a communication means (e.g., the Internet) not shown, and acquires weather data for the area in which the air conditioner 1 is installed. The acquired weather data is stored in the memory unit 41 along with time information when the weather data was acquired. The water generating operation determination unit 40 determines whether predetermined water generating conditions are met based on the weather data acquired by the weather data acquisition means 39.

The heating sterilization operation, managed by the heating sterilization operation unit 38, heats the condensation water generated on the heat radiation fins 21 and heat transfer tubes 20 during the water generation operation. By heating the condensation water, bacteria and mold adhering to the heat radiation fins 21 and heat transfer tubes 20 are sterilized using moist heat. Therefore, the heating sterilization operation is performed immediately after the water generation operation. Because the heating sterilization operation heats the condensation water generated on the heat radiation fins 21 and heat transfer tubes 20, the flow of refrigerant in the refrigerant circuit 2 is the same as in heating operation. However, in heating operation, the rotation speed of the compressor 12 is controlled so that the indoor air temperature becomes the target temperature set by the user, and the rotation speed of the indoor blower 9 is controlled so that the air volume becomes the set air volume set by the user. In this respect, the heating sterilization operation differs from the heating operation. In the case of thermal sterilization operation, a predetermined compressor rotation speed is set so that the condensation water formed on the heat radiation fins 21 and heat transfer tubes 20 is heated to an appropriate temperature, and a target heat exchange temperature, which is a target value for the temperature of the indoor heat exchanger 7 detected by a sensor (not shown), is set. Then, the rotation speed of the compressor 12 is controlled so that the predetermined compressor rotation speed is reached, and the rotation speed of the indoor blower 9 is controlled so that the temperature of the indoor heat exchanger 7 reaches the target heat exchange temperature.

The absence period prediction means 43 predicts an absence period, which is a period when no one is present in the room where the indoor unit 5 is installed. If the presence of a person is not detected in the room where the indoor unit 5 is installed as a result of detection by the human presence sensor 42, this timing is stored in the memory unit 41 as belonging to a time period when no person is detected (absence period information). The absence period prediction means 43 predicts an absence period, which is a period when no one is present in the room where the indoor unit 5 is installed, based on the absence period information stored in the memory unit 41. Furthermore, if the predicted absence period is longer than a predetermined absence period (e.g., 3 hours), the absence period prediction means 43 predicts that the user will be absent for a long period of time.

Next, with reference to Figures 3A to 3C, the control flow for the water generating operation of the air conditioner according to the first embodiment will be described. In Figures 3A to 3C, one control flow is explained separately for each of Figures 3A to 3C. First, with reference to Figure 3A, the following description will be given. When control for the water generating operation is initiated, it is first determined whether the indoor unit 5 has stopped operating (ST1). If the indoor unit 5 is operating (No in ST1), the processing of ST1 is repeated. If the indoor unit 5 has stopped operating (Yes in ST1), it is determined whether the absence period prediction means 43 predicts that the user will be absent for a long period of time at the current time (ST2). Here, the water generating operation is an operation that causes the indoor heat exchanger 7 to function as an evaporator. Therefore, by performing the water generating operation, cool air is blown into the room in which the indoor unit 5 is installed, causing a temperature change in the room that the user does not intend. Therefore, the water generating operation is performed when no one is present in the room. Therefore, if the absence period prediction means 43 does not predict that the user will be absent for a long period of time (No in ST2), the processing returns to ST1. On the other hand, if the absence period prediction means 43 predicts that the user will be absent for a long period of time (Yes in ST2), it determines whether the water generating operation has not been performed for a predetermined period of time (ST3). In this embodiment, for example, the predetermined period is one week, preferably a period determined through experiments or the like within which deposits on the heat dissipation fins 21 and the heat transfer tubes 20 should be removed by the water generating operation and the thermal sterilization operation. If the water generating operation has been performed within the predetermined period of one week (No in ST3), it determines whether a predetermined time has elapsed since the previous acquisition of the weather data stored in the memory unit 41 (ST4). In this embodiment, for example, the predetermined time is 10 minutes, which corresponds to the interval at which the weather data is updated by the weather data provider. If the predetermined time has not elapsed since the previous acquisition of the weather data (No in ST4), the process returns to ST1. On the other hand, if the predetermined time has elapsed since the previous acquisition of the weather data (Yes in ST4), the weather data acquisition means 39 acquires weather data, including weather forecast data for the area in which the air conditioner 1 is installed, via the Internet (ST5). The weather data includes, for example, the current weather (rainy, sunny, cloudy, etc.), humidity (hereinafter, unless otherwise specified, refers to relative humidity), hourly weather, humidity, precipitation probability, and other forecasts. The acquired weather data is stored in the memory unit 41. Next, in ST5, it is determined whether or not weather data was acquired (ST6). If weather data was acquired in ST5 (Yes in ST6), the most recently acquired weather data is referenced to determine whether the current weather is rainy or the current humidity is equal to or greater than a first predetermined value, as a predetermined water production condition (ST7). That is, the latest weather data is referenced to determine whether the current weather is rainy or the current humidity is equal to or greater than a first predetermined value. In this embodiment, for example, the first predetermined value is 60%, which is a humidity that has been shown through experiments to be capable of producing a sufficient amount of condensed water during water production operation to remove deposits from the heat dissipation fins 21 and the heat transfer tubes 20. If the most recently acquired weather data indicates that the weather is not rainy and the humidity is less than the first predetermined value, i.e., the predetermined water production condition is not met (No in ST7), the process returns to ST1. On the other hand, if the most recently acquired weather data indicates that the weather is rainy or the humidity is equal to or greater than the first predetermined value, i.e., the predetermined water production condition is met (Yes in ST7), the process proceeds to ST8 in FIG. 3B. If weather data cannot be acquired in ST5 (No in ST6), the weather forecast data for the current time is referenced from the previously acquired weather data to determine whether the predetermined water production condition is that the weather is rainy or the humidity is equal to or greater than the first predetermined value (ST13). That is, the latest weather data, including the weather forecast data stored in the memory unit 41, is used to determine whether the predetermined water production condition is met. If the most recently acquired weather data indicates that the weather is not rainy and the humidity is less than the first predetermined value, i.e., the predetermined water production condition is not met (No in ST13), the process returns to ST1. On the other hand, if the previously acquired weather data indicates that the weather is rainy or equal to or greater than the first predetermined value, i.e., if the predetermined water production condition is met (Yes in ST13), the process proceeds to ST8 in Figure 3B.

Next, with reference to FIG. 3B, the following explanation will be given. In ST8, the water generating operation is started. Next, it is determined whether the end time of the water generating operation has been reached (ST9). If the end time of the water generating operation has been reached (Yes in ST9), the heat sterilization operation is then started (ST10). If the end time of the water generating operation has not been reached (No in ST9), the water generating operation continues, and the processing of ST9 is repeated. After the heat sterilization operation is started in ST10, it is next determined whether the end time of the heat sterilization operation has been reached (S11). If the end time of the heat sterilization operation has been reached (Yes in ST11), the heat sterilization operation ends, operation of the indoor unit 5 is stopped (ST12), and control of the water generating operation ends. If the end time of the heat sterilization operation has not been reached (No in ST11), the heat sterilization operation continues, and the processing of ST11 is repeated.

In this way, in this embodiment, whether or not the specified water generation conditions are met is determined based on weather data for the region in which the air conditioner 1 is installed. As a result, even in dry seasons such as winter, the water generation operation can be performed at a time when a sufficient amount of condensed water can be generated to remove deposits from the heat dissipation fins 21 and heat transfer tubes 20. Therefore, deposits on the indoor heat exchanger 7 in the indoor unit 5 can be effectively removed.

In addition, in this embodiment, the predetermined water production condition is determined by whether the weather at the current time is rainy or the humidity at the current time is equal to or greater than a first predetermined value, but this is not limiting. For example, the condition of rainy weather at the current time may not be included, and the determination may be made only by whether the humidity at the current time is equal to or greater than a first predetermined value. Here, even if the area classification in the weather data is the same, there may be variations in humidity due to the influence of topography. On the other hand, if the area classification is the same, the weather will often be the same compared to the humidity. Therefore, by including rainy weather as a condition in addition to humidity, water production operation can be performed effectively at a time when the actual humidity is thought to be high due to rain, even if the humidity in the weather data is low.

Furthermore, considering the accuracy of weather data, it is desirable to use the most recent weather data possible, but there may be cases where communication with the outside world via the Internet becomes impossible for some reason, making it impossible to obtain weather data. Even in such cases, the inclusion of step ST6 makes it possible to use the current weather forecast data from the most recent weather data obtained previously. This allows the water generation operation to be performed at a time when a sufficient amount of condensed water can be produced to remove deposits from the heat dissipation fins 21 and heat transfer tubes 20.

Next, we will explain with reference to Figure 3C. Figure 3C shows the control flow when, in ST3, water generation operation has not been performed within the specified period of one week (Yes in ST3). When water generation operation has not been performed within the specified period of one week (Yes in ST3), it is determined whether a specified time has passed since the previous weather data was acquired (ST14). The specified time is the same as the specified time in ST4. When the specified time has not passed since the previous weather data was acquired (No in ST14), the processing returns to ST1. On the other hand, when the specified time has passed since the previous weather data was acquired (Yes in ST14), the weather data acquisition means 39 acquires weather data, including weather forecast data for the area in which the air conditioner 1 is installed, via the Internet (ST15). The acquired weather data is stored in the memory unit 41. Next, in ST15, it is determined whether weather data has been acquired (ST16). If weather data can be acquired in ST15 (Yes in ST16), the most recently acquired weather data is referenced to determine whether the current weather is rainy or the current humidity is equal to or greater than a second predetermined value, as a predetermined water production condition (ST17). Here, the second predetermined value is a value smaller than the first predetermined value in ST7 and is a humidity level that has been shown through prior experiments to be capable of producing condensation water for removing deposits from the heat dissipation fins 21 and the heat transfer tubes 20 during water production operation. In this embodiment, for example, the second predetermined value is 50%. If the most recently acquired weather data indicates that the weather is not rainy and the humidity is less than the first predetermined value, i.e., the predetermined water production condition is not met (No in ST17), the process returns to ST1. On the other hand, if the most recently acquired weather data indicates that the weather is rainy or the humidity is equal to or greater than the second predetermined value, i.e., the predetermined water production condition is met (Yes in ST17), the process proceeds to ST8 of FIG. 3B described above. If weather data could not be acquired in ST15 (No in ST16), the weather forecast data for the current time is referenced from the previously acquired weather data to determine whether the specified water production conditions, that is, the weather at the current time is rainy or the humidity at the current time is equal to or greater than a second predetermined value, are met (ST18). That is, the latest weather data stored in the memory unit 41 is used to determine whether the specified water production conditions are met. If the previously acquired weather data indicates that the weather is not rainy and the humidity is less than the second predetermined value, i.e., the specified water production conditions are not met (No in ST18), the process returns to ST1. On the other hand, if the previously acquired weather data indicates that the weather is rainy or equal to or greater than the second predetermined value, i.e., the specified water production conditions are met (Yes in ST13), the process proceeds to ST8 in FIG. 3B described above.

As described above, in this embodiment, if the water generation operation has not been performed for a predetermined period of time, the system determines whether the predetermined water generation condition is met: the weather at the current time is rainy, or the humidity at the current time is equal to or greater than a second predetermined value. In other words, the predetermined water generation condition is relaxed by setting the second predetermined value, which is lower than the first predetermined value, as the predetermined water generation condition. For example, in dry seasons such as winter, if the first predetermined value is used as the predetermined water generation condition, there is a possibility that the water generation operation will not be performed for a long period of time. However, by including step ST3, even if the water generation operation has not been performed for a long period of time, the humidity standard for performing the water generation operation can be set to a second predetermined value, which is lower than the first predetermined value, thereby preventing the water generation operation from being not performed for a long period of time. Note that in this embodiment, the system determines whether the predetermined water generation condition is met: the weather at the current time is rainy, or the humidity at the current time is equal to or greater than a second predetermined value. However, the condition of rainy weather at the current time may not be included in the determination, and the determination may be made based solely on whether the humidity at the current time is equal to or greater than the second predetermined value.

Next, the control flow for the water generating operation of the air conditioner according to the second embodiment will be explained with reference to Figures 4A to 4D. In Figures 4A to 4D, one control flow is explained separately for each of Figures 4A to 4D. The explanation will begin with reference to Figure 4A. Unless otherwise specified, parts with the same names as those in the first embodiment are the same as those in the first embodiment.

When control for the water generating operation is initiated, the system first determines whether the indoor unit 5 is stopped (ST51). If the indoor unit 5 is operating (No in ST1), ST1 processing is repeated. If the indoor unit 5 is stopped (Yes in ST1), the system determines whether the absence period prediction means 43 predicts that the user will be away for a long period of time at the current time (ST52). Here, the water generating operation is an operation that causes the indoor heat exchanger 7 to function as an evaporator. Therefore, performing the water generating operation causes cool air to flow into the room where the indoor unit 5 is installed, resulting in temperature changes unintended by the user. Therefore, the water generating operation is performed when no one is in the room. Therefore, if the absence period prediction means 43 does not predict that the user will be away for a long period of time (No in ST52), the system returns to ST1. On the other hand, if the absence period prediction means 43 predicts that the user will be away for a long period of time (Yes in ST52), the system determines whether the water generating operation has not been performed for a predetermined period of time (ST53). In this embodiment, the predetermined period is the same as in the first embodiment, e.g., one week. If the water generating operation has been performed within the predetermined period of one week (No in ST53), it is determined whether a predetermined time has elapsed since the previous weather data acquisition (ST54). In this embodiment, the predetermined time is the same as in the first embodiment, e.g., 10 minutes. If the predetermined time has not elapsed since the previous weather data acquisition (No in ST54), the process returns to ST51. On the other hand, if the predetermined time has elapsed since the previous weather data acquisition (Yes in ST54), the weather data acquisition means 39 acquires weather data, including weather forecast data for the area where the air conditioner 1 is installed, via the Internet (ST55). The weather data includes, for example, forecasts of the current weather (rain, sunny, cloudy, etc.) and humidity, hourly weather and humidity, and precipitation probability. The acquired weather data is stored in the memory unit 41. Next, in ST55, it is determined whether weather data was acquired (ST56). If weather data can be acquired in ST55 (Yes in ST56), the most recently acquired weather data is referenced to determine whether the current weather is rainy or the humidity is equal to or greater than a first predetermined value, as a predetermined water production condition (ST57). That is, the most recent weather data is referenced to determine whether the current weather is rainy or the humidity is equal to or greater than a first predetermined value. In this embodiment, the first predetermined value is the same as in the first embodiment, e.g., 60%. If the most recently acquired weather data indicates that the weather is not rainy and the humidity is less than the first predetermined value, i.e., the predetermined water production condition is not met (No in ST57), the process returns to ST51. On the other hand, if the most recently acquired weather data indicates that the weather is rainy or equal to or greater than the first predetermined value, i.e., the predetermined water production condition is met (Yes in ST57), the process proceeds to ST58 in FIG. 4B. If weather data could not be acquired in ST55 (No in ST56), the weather forecast data for the current time is referenced from the previously acquired weather data to determine whether the specified water production conditions are met, i.e., whether the current weather is rainy or the humidity at the current time is equal to or greater than a first predetermined value (ST63). That is, the latest weather data stored in memory unit 41 is used to determine whether the specified water production conditions are met. If the previously acquired weather data indicates that the weather is not rainy and the humidity is less than the first predetermined value, i.e., the specified water production conditions are not met (No in ST63), the process returns to ST51. On the other hand, if the previously acquired weather data indicates that the weather is rainy or equal to or greater than the first predetermined value, i.e., the specified water production conditions are met (Yes in ST63), the process proceeds to ST58 in FIG. 4B.

Next, we will explain with reference to Figure 4B. In ST58, the water generating operation is started. Next, it is determined whether the end time of the water generating operation has been reached (ST59). If the end time of the water generating operation has been reached (Yes in ST59), the heat sterilization operation is then started (ST60). If the end time of the water generating operation has not been reached (No in ST59), the water generating operation continues and the processing of ST59 is repeated. After the heat sterilization operation is started in ST60, it is next determined whether the end time of the heat sterilization operation has been reached (S61). If the end time of the heat sterilization operation has been reached (Yes in ST61), the heat sterilization operation ends, operation of the indoor unit 5 is stopped (ST62), and control related to the water generating operation ends. If the end time of the heat sterilization operation has not been reached (No in ST61), the heat sterilization operation continues and the processing of ST61 is repeated. Considering the accuracy of weather data, it is desirable to use the most recent weather data possible, but there may be cases where communication with the outside world via the Internet becomes impossible for some reason, making it impossible to obtain weather data. Even in such cases, the inclusion of step ST56 makes it possible to use the current weather forecast data from the most recent weather data obtained previously. This allows the water generating operation to be performed at a time when a sufficient amount of condensed water can be produced to remove deposits from the heat dissipation fins 21 and heat transfer tubes 20.

Next, we will explain with reference to Figure 4C. Figure 4C shows the control flow for when, in ST53 of Figure 4A, water generation operation has not been performed within the specified period of one week (Yes in ST53). If water generation operation has not been performed within the specified period of one week (Yes in ST53), it is determined whether a specified time has passed since the previous weather data was acquired (ST64). The specified time is the same as the specified time in ST54. If the specified time has not passed since the previous weather data was acquired (No in ST64), the processing returns to ST51. On the other hand, if the specified time has passed since the previous weather data was acquired (Yes in ST64), the weather data acquisition means 39 acquires weather data, including weather forecast data for the area in which the air conditioner 1 is installed, via the Internet (ST65). The acquired weather data is stored in the memory unit 41. Next, in ST65, it is determined whether weather data was acquired (ST66). If weather data can be acquired in ST65 (Yes in ST66), the most recently acquired weather data is referenced to determine whether the specified water production conditions are met: the weather is rainy at the current time, or the humidity at the current time is equal to or greater than a first predetermined value (ST67). The first predetermined value is the same as the first predetermined value in ST57. If the most recently acquired weather data indicates that the weather is rainy or the humidity is equal to or greater than the first predetermined value, i.e., if the specified water production conditions are met (Yes in ST67), the process proceeds to ST58 shown in FIG. 4B above.

On the other hand, if the most recently acquired weather data indicates that the weather is not rainy and the humidity is less than the first predetermined value, i.e., the predetermined water production condition is not met (No in ST67), the weather forecast data is referenced from the most recently acquired weather data to determine whether there is a time during the absence period predicted by the absence period prediction means 43 at which the humidity is equal to or greater than the second predetermined value, as the predetermined water production condition (ST72). If the most recently acquired weather data indicates that there is no time during the absence period predicted by the absence period prediction means 43 at which the humidity is equal to or greater than the second predetermined value, i.e., there is no time at which the predetermined water production condition is met (No in ST72), the process returns to ST51. On the other hand, if the most recently acquired weather data indicates that there is a time during the absence period predicted by the absence period prediction means 43 at which the humidity is equal to or greater than the second predetermined value, i.e., there is a time at which the predetermined water production condition is met (Yes in ST72), the time at which the humidity is equal to or greater than the second predetermined value and is the highest is set as the time at which water production operation is possible (ST73). Next, it is determined whether the current time matches the time set in ST73 when water production operation is possible (ST74). If the current time does not match the set time when water production operation is possible (No in ST74), the process returns to ST51. On the other hand, if the current time matches the set time when water production operation is possible (Yes in ST74), the process proceeds to ST58 shown in Figure 4B described above.

Next, we will explain with reference to Figure 4D. Figure 4D shows the control flow when weather data cannot be acquired in ST65 of Figure 4C (No in ST66). If weather data cannot be acquired in ST65 (No in ST66), the weather forecast data is referenced from the previously acquired weather data to determine whether the specified water production conditions are met, that is, whether the weather at the current time is rainy or the humidity at the current time is equal to or greater than a first predetermined value (ST68). In other words, it is determined from the latest weather data stored in the memory unit 41 whether the specified water production conditions are met. If the previously acquired weather data indicates that the weather is rainy or the humidity is equal to or greater than a first predetermined value, that is, if the specified water production conditions are met (Yes in ST68), processing proceeds to ST58 shown in Figure 4B above. On the other hand, if the previously acquired weather data indicates that the weather is not rainy and the humidity is less than the first predetermined value, i.e., the predetermined water production condition is not met (No in ST68), the weather forecast data is referenced from the previously acquired weather data to determine whether there is a time during the absence period predicted by the absence period prediction means 43 when the humidity is equal to or greater than the second predetermined value, as the predetermined water production condition (ST69). If the previously acquired weather data indicates that there is no time during the absence period predicted by the absence period prediction means 43 when the humidity is equal to or greater than the second predetermined value, i.e., there is no time when the predetermined water production condition is met (No in ST69), the process returns to ST51. On the other hand, if the previously acquired weather data indicates that there is a time during the absence period predicted by the absence period prediction means 43 when the humidity is equal to or greater than the second predetermined value, i.e., there is a time when the predetermined water production condition is met (Yes in ST69), the time when the humidity is equal to or greater than the second predetermined value and is the highest is set as the time when water production operation is possible (ST70). Next, it is determined whether the current time matches the time set in ST70 when water production operation is possible (ST71). If the current time does not match the set time when water production operation is possible (No in ST71), the process returns to ST51. On the other hand, if the current time matches the set time when water production operation is possible (Yes in ST71), the process proceeds to ST58 shown in Figure 4B described above.

In this manner, in this embodiment, if the water generating operation has not been performed for a predetermined period and there is a time during the absence period predicted by the absence period prediction means 43 when the humidity is equal to or greater than the second predetermined value, the water generating operation is performed at the time when the humidity is equal to or greater than the second predetermined value and is the highest. In other words, by using a second predetermined value lower than the first predetermined value as the predetermined water generating condition, the predetermined water generating condition is relaxed. For example, in dry seasons such as winter, if the first predetermined value is used as the predetermined water generating condition, there is a possibility that the water generating operation will not be performed for a long period of time. However, in this embodiment, even if the water generating operation has not been performed for a long period of time, the humidity standard for performing the water generating operation is set to a second predetermined value lower than the first predetermined value, and the water generating operation is performed at the time when the humidity is the highest, thereby preventing the water generating operation from not being performed for a long period of time.

In the above embodiment, the heat sterilization operation is performed after the water generation operation, but it is also possible to perform only the water generation operation without the heat sterilization operation. Even if only the water generation operation is performed, bacteria and mold adhering to the heat dissipation fins 21 and refrigerant heat transfer tubes 20 can be washed away with condensed water, but performing the heat sterilization operation after the water generation operation is more effective because it allows bacteria and mold to be sterilized by moist heat.

The above description has been given with reference to a limited number of embodiments, but the scope of the invention is not limited to these, and modifications of the embodiments based on the above disclosure will be obvious to those skilled in the art.

1...air conditioner, 2...refrigerant circuit, 3...control unit, 5...indoor unit, 6...casing, 7...indoor heat exchanger, 9...blower, 11...outdoor unit, 12...compressor, 13...outdoor heat exchanger, 14...expansion valve, 15...four-way valve, 16...outdoor blower, 17...accumulator, 20...heat transfer tube, 21...heat dissipation fin, 25...inlet temperature sensor, 26...outlet pressure sensor, 27...outlet temperature sensor, 28...humidity sensor, 29...indoor temperature sensor, 35...cooling operation unit, 36...heating operation unit, 37...water generating operation unit, 38...heating sterilization operation unit, 39...weather data acquisition means, 40...water generating operation determination unit, 41...memory unit, 42...human presence sensor, 43...absence period prediction means

Claims (7)

an indoor unit having an indoor heat exchanger;
a control unit that controls the air conditioning operation of the air-conditioned space in which the indoor unit is installed,
In an air conditioner, when a predetermined water generation condition is satisfied, the control unit causes the indoor heat exchanger to function as an evaporator and performs a water generation operation in which condensation water adheres to the indoor heat exchanger,
weather data acquisition means for acquiring weather data for the area where the air conditioner is installed;
The air conditioner, wherein the control unit determines whether the predetermined water production condition is met based on the weather data acquired by the weather data acquisition means. The air conditioner of claim 1, characterized in that the specified water production condition is that the weather data indicates rain or that humidity is equal to or greater than a first specified value. If the water generating operation has not been performed for a predetermined period of time,
3. The air conditioner according to claim 2, wherein the predetermined water production condition is that the weather data is rain or the humidity is equal to or greater than a second predetermined value lower than the first predetermined value. An air conditioner as described in any one of claims 1 to 3, characterized in that the control unit determines whether the specified water production conditions are met based on the latest weather data acquired by the weather data acquisition means. the weather data acquisition means acquires the weather data by communication with an external device at predetermined time intervals;
a storage unit for storing the acquired weather data;
An air conditioner as described in any one of claims 1 to 4, characterized in that when communication with the outside is not possible, the control unit determines whether the specified water generation conditions are met based on the latest weather data among the weather data stored in the memory unit. the indoor unit has a human presence sensor that detects the presence of a person in the air-conditioned space in which the indoor unit is installed;
an absence period prediction means for predicting an absence period of a person in the air-conditioned space using a detection result of the human presence sensor,
The air conditioner according to any one of claims 1 to 5, wherein the control unit performs the water generating operation during the absence period predicted by the absence period prediction means. The air conditioner of claim 6, wherein during the unoccupied period, the control unit performs the water generating operation at a timing when the humidity is predicted to be highest based on the weather data.