ventilation system

Abstract

This ventilation system comprises: a ventilation fan that includes a filter for removing dust in the air blown into a room, and operates while switching between a first operation mode for operating at a relatively low air volume and a second operation mode for operating at a relatively high air volume; a carbon dioxide concentration detection unit that detects the carbon dioxide concentration inside the room; an air volume switching control unit (331) that switches the air volume of the ventilation fan on the basis of the carbon dioxide concentration inside the room detected by the carbon dioxide concentration detection unit; and a filter replacement determination unit (333) that determines a replacement period of the filter on the basis of information during a second operation mode operation time, which is the operation time of the ventilation fan in the second operation mode. The ventilation system can determine a suitable maintenance period of the filter in accordance with the usage environment of the ventilation fan, and can prompt the user about maintenance of the filter at a suitable period.

Description

[Technical Field]

[0001] The present disclosure relates to a ventilation system having a filter. [Background technology]

[0002] Conventionally, among ventilation fans that are attached to the indoor side of a building, such as a wall or ceiling, by inserting them from the indoor side, some models are equipped with filters to prevent or reduce the inflow of dust into the room or to prevent or reduce the adhesion of dust to the product.

[0003] As described in Patent Document 1, a mechanism is known for ventilation fans in which, when the operating time of the ventilation fan reaches a preset accumulated value, a display unit provided on the product body displays a message urging the user to perform maintenance on the ventilation fan. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-196770 Summary of the Invention [Problem to be solved by the invention]

[0005] However, according to the technology of Patent Document 1, a display prompting maintenance of the ventilation fan is displayed when the operating time of the ventilation fan reaches a preset cumulative value. However, depending on the environment in which the ventilation fan is used, the filter may become clogged early before the operating time of the ventilation fan reaches the preset cumulative value. If the filter becomes clogged, the ventilation air volume of the ventilation fan may decrease, which may reduce the effect of operating the ventilation fan in improving the air quality in the living space.

[0006] In a ventilation fan with variable airflow, the longer the fan is operated in a high airflow mode to improve the air quality in the living space, the earlier the filter becomes clogged. Therefore, the technology disclosed in Patent Document 1 may not be able to notify the user of the appropriate filter maintenance timing depending on the usage environment. Therefore, there is a need for a ventilation system that can determine the appropriate filter maintenance timing according to the usage environment of the ventilation fan.

[0007] The present disclosure has been made in consideration of the above, and aims to provide a ventilation system that can determine the appropriate time for filter maintenance in accordance with the usage environment of the ventilation fan. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems and achieve the object, the ventilation system according to the present disclosure includes a ventilation fan that is equipped with a filter for removing dust in the air that is blown into a room and that operates by switching between a first operation mode in which it operates at a relatively small air volume and a second operation mode in which it operates at a relatively large air volume, a carbon dioxide concentration detection unit that detects the carbon dioxide concentration in the room, an air volume switching control unit that switches the air volume of the ventilation fan based on the carbon dioxide concentration in the room detected by the carbon dioxide concentration detection unit, and information on second operation mode operation time that is the operation time of the ventilation fan in the second operation mode. and a result of comparing the result with a predetermined criterion for determining whether or not the filter needs to be replaced by comparing the result with information on the second operation mode operation time. and a filter replacement determination unit that determines when to replace the filter based on the result. [Effects of the Invention]

[0009] The ventilation system according to the present disclosure has the advantage of being able to determine the appropriate time for filter maintenance depending on the usage environment of the ventilation fan. [Brief explanation of the drawings]

[0010] [Figure 1] A block diagram showing the configuration of a ventilation system according to a first embodiment. [Figure 2] FIG. 1 is a cross-sectional view showing a configuration of a ventilation fan included in a ventilation system according to a first embodiment. [Figure 3] FIG. 1 is a block diagram showing a functional configuration of a ventilation fan included in a ventilation system according to a first embodiment. [Figure 4] FIG. 1 is a block diagram showing the functional configuration of a CO2 sensor, which is a carbon dioxide concentration detection unit included in the ventilation system according to the first embodiment. [Figure 5] FIG. 1 is a block diagram showing a functional configuration of a server included in a ventilation system according to a first embodiment. [Figure 6] FIG. 1 is a sequence diagram showing an example of an operation pattern of a ventilation fan included in the ventilation system according to the first embodiment. [Figure 7] FIG. 1 is a block diagram showing a functional configuration of a terminal device included in a ventilation system according to a first embodiment. [Figure 8] A block diagram showing the functional configuration of a ventilation system according to a first embodiment. [Figure 9] 10 is a flowchart showing an example of filter replacement determination in the ventilation system according to the first embodiment. [Figure 10] FIG. 10 is a diagram showing an example of a maintenance message displayed on a terminal device included in the ventilation system according to the first embodiment. [Figure 11] FIG. 1 is a block diagram showing another configuration example of the ventilation system according to the first embodiment. [Figure 12] FIG. 1 is a diagram showing a specific example of the configuration of a ventilation system according to a first embodiment. [Figure 13] FIG. 1 is a block diagram showing a functional configuration of a switch according to a first embodiment; [Figure 14] Sequence diagram of an example of filter replacement determination for the ventilation system equipment configuration example shown in Figure 12 [Figure 15] FIG. 1 is a block diagram showing another example of a specific device configuration of the ventilation system according to the first embodiment. [Figure 16] 1 is a flowchart showing the procedure of a method for calculating a strong operation time in a ventilation system according to a first embodiment. [Figure 17] FIG. 1 is a first characteristic diagram showing an example of a change in the high-power operation time in the ventilation system according to the first embodiment; [Figure 18]FIG. 2 is a second characteristic diagram showing an example of change in the strong operation time in the ventilation system according to the first embodiment. [Figure 19] FIG. 10 is a first characteristic diagram showing an example of change in the amount of increase per unit period of the strong operation time of the ventilation system according to the second embodiment. [Figure 20] FIG. 2 is a second characteristic diagram showing an example of change in the amount of increase per unit period of the high-power operation time of the ventilation system according to the second embodiment. [Figure 21] FIG. 1 is a diagram showing a configuration in which each function of a control unit according to a first embodiment is realized by hardware. [Figure 22] FIG. 1 is a diagram showing a configuration in which each function of a control unit according to a first embodiment is realized by software. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, a ventilation system according to an embodiment will be described in detail with reference to the drawings.

[0012] Embodiment 1 FIG. 1 is a block diagram showing the configuration of a ventilation system 100 according to a first embodiment. The ventilation system 100 according to the first embodiment includes a ventilation fan 1, a server 2, and a terminal device 3. The ventilation fan 1 and the server 2 are capable of communicating with each other. The ventilation fan 1 and the server 2 are also connected to each other so as to be able to communicate with each other via a network such as the Internet 4, which is a global information and communication network. That is, the ventilation fan 1 and the server 2 are connected to the network and are capable of sending and receiving information to and from each other.

[0013] The server 2 and the terminal device 3 are capable of communicating with each other. Furthermore, the server 2 and the terminal device 3 are connected to each other so as to be able to communicate with each other via a network such as the Internet 4. In other words, the server 2 and the terminal device 3 are connected to the network and are capable of sending and receiving information to and from each other.

[0014] Fig. 2 is a cross-sectional view showing the configuration of the ventilation fan 1 included in the ventilation system 100 according to the first embodiment. Fig. 3 is a block diagram showing the functional configuration of the ventilation fan 1 included in the ventilation system 100 according to the first embodiment.

[0015] The ventilation fan 1 is attached to the wall or ceiling of a building. Indoor On the side, Indoor As shown in Figure 2, ventilation fan 1 is attached by inserting it from the indoor side into cylindrical member 11, such as a pipe or duct, which connects the indoors and outdoors. Ventilation fan 1 comprises main body 17, which has blower 14 attached to resin main body frame 13 having cylindrical air channel 12 inserted into cylindrical member 11, decorative panel 18 which covers main body 17 from the indoor side, and filter 19 which removes dust from the air being blown.

[0016] The blower 14 is composed of an electric motor 16 and an impeller 15 connected to the drive shaft of the electric motor 16. The impeller 15 generates an airflow by rotating when driven by the electric motor 16. The electric motor 16 drives the impeller 15. The air volume of the blower 14, i.e., the air volume of the ventilation fan 1, is controlled by controlling the rotation speed of the electric motor 16.

[0017] The filter 19 reduces dust adhesion to components such as the decorative panel 18, the impeller 15, and the motor 16, and reduces dust intrusion into the room. Note that the configuration of the ventilation fan 1 and the arrangement of the filter 19 are not limited to the above example.

[0018] As shown in FIG. 3, the ventilation fan 1 includes a carbon dioxide (CO2) concentration detection unit 21, a ventilation fan storage unit 22, a ventilation fan communication unit 23, and a ventilation fan control unit 24.

[0019] The CO2 concentration detection unit 21 detects the carbon dioxide concentration in the room at a predetermined cycle. The CO2 concentration detection unit 21 transmits information on the CO2 concentration in the room, which is the detection result, to the ventilation fan control unit 24. The CO2 concentration detection unit 21 uses a CO2 sensor that detects the CO2 concentration. Hereinafter, the CO2 sensor will be referred to as the CO2 sensor 21.

[0020] Fig. 4 is a block diagram showing the functional configuration of the CO2 sensor 21, which is the CO2 concentration detection unit 21 included in the ventilation system 100 according to the first embodiment. As shown in Fig. 4, the CO2 sensor 21 includes a detection unit 211, a sensor storage unit 212, and a sensor control unit 213. The components of the CO2 sensor 21 can transmit and receive information to and from each other.

[0021] The detection unit 211 detects the CO2 concentration in the room. The detection unit 211 transmits information on the detected CO2 concentration in the room to the sensor control unit 213. The sensor storage unit 212 stores various information used to control the CO2 sensor 21 and information on the detection results in the detection unit 211.

[0022] The sensor control unit 213 controls the overall operation of the CO2 sensor 21. The sensor control unit 213 transmits information on the detection result of the detection unit 211 to the ventilation fan control unit 24. The sensor control unit 213 stores the information on the detection result of the detection unit 211 in the sensor storage unit 212.

[0023] The ventilation fan storage unit 22 stores various types of information used for operating the ventilation fan 1. The ventilation fan storage unit 22 also stores information on the CO2 concentration in the room detected by the CO2 concentration detection unit 21.

[0024] The ventilation fan communication unit 23 communicates with a server communication unit 32 (described later) of the server 2. The communication method between the ventilation fan communication unit 23 and the server communication unit 32 may be wired communication or wireless communication.

[0025] The ventilation fan control unit 24 controls the operation of the ventilation fan 1. That is, the ventilation fan control unit 24 controls the operation of the blower 14 by controlling the driving of the electric motor 16. Furthermore, the ventilation fan control unit 24 switches the air volume of the ventilation operation of the ventilation fan 1 in accordance with the control of the server 2. The ventilation fan control unit 24 controls the air volume of the blower 14, i.e., the air volume of the ventilation fan 1, by controlling the rotation speed of the electric motor 16. Furthermore, the ventilation fan control unit 24 controls the transmission of information on the detection result at the detection unit 211 transmitted from the CO2 sensor 21 to the server 2.

[0026] In the first embodiment, the ventilation fan 1 operates in two operating modes: a weak operating mode, which is a first operating mode in which the ventilation fan 1 operates at a relatively small air volume, and a strong operating mode, which is a second operating mode in which the ventilation fan 1 operates at a relatively large air volume. That is, the ventilation fan control unit 24 controls the ventilation operation of the ventilation fan 1 in either the weak operating mode or the strong operating mode. The standard operating mode when the ventilation fan 1 is started is the weak operating mode.

[0027] The weak operation mode is an operation mode in which the ventilation fan 1 operates at the relatively smallest air volume among the multiple air volume levels at which the ventilation fan 1 can operate, that is, at the relatively smallest air volume among the multiple air volume levels at which the blower 14 can operate. The weak operation mode is an operation mode that corresponds to, for example, 24-hour ventilation.

[0028] The strong operation mode is an operation mode in which the ventilation fan 1 operates at a strong operation, which is an operation at an airflow rate that is relatively higher than the weak airflow rate among the multiple airflow rates at which the ventilation fan 1 can operate. The operating time during which the ventilation fan 1 operates in the strong operation mode, which is the second operating mode, is called the strong operation time. The strong operation time can also be said to be the second operating mode operating time.

[0029] The server 2 controls the operation of the ventilation fan 1 based on information about the CO2 concentration in the room detected by the CO2 sensor 21 and a predetermined CO2 concentration reference value (A). The server 2 also controls the terminal device 3 to display a maintenance message indicating that it is time to perform maintenance on the filter 19, based on the high-power operation time of the ventilation fan 1. The server 2 can be a cloud server or a physical server.

[0030] 5 is a block diagram showing the functional configuration of the server 2 included in the ventilation system 100 according to the first embodiment. The server 2 includes a server storage unit 31, a server communication unit 32, and a server control unit 33. The components of the server 2 can exchange information with each other.

[0031] The server storage unit 31 stores various types of information used to control the ventilation system 100.

[0032] The server communication unit 32 is capable of communicating with the ventilation fan communication unit 23 of the ventilation fan 1. The ventilation fan communication unit 23 of the ventilation fan 1 and the server communication unit 32 are capable of communicating with each other, for example, via the Internet 4. The server communication unit 32 is also capable of communicating with a terminal communication unit 44 (described later) of the terminal device 3. The terminal communication unit 44 of the terminal device 3 and the server communication unit 32 are capable of communicating with each other, for example, via the Internet 4.

[0033] The server communication unit 32 receives information such as the CO2 concentration in the room transmitted from the ventilation fan communication unit 23 of the ventilation fan 1 via the Internet 4. The server communication unit 32 transmits the received information to the server control unit 33. The server communication unit 32 also transmits information such as commands to control the operation of the ventilation fan 1 transmitted from the server control unit 33 to the ventilation fan communication unit 23 of the ventilation fan 1. The server communication unit 32 also transmits information such as maintenance messages transmitted from the server control unit 33 to the terminal communication unit 44 of the terminal device 3.

[0034] The server control unit 33 controls the overall processing of the server 2. The server control unit 33 includes an air volume switching control unit 331, a strong operation time acquisition unit 332, and a filter replacement determination unit 333.

[0035] The air volume switching control unit 331 controls the air volume of the ventilation fan 1, i.e., the air volume of the blower 14, based on information about the CO2 concentration in the room detected by the CO2 sensor 21 and a predetermined CO2 concentration reference value (A). The air volume switching control unit 331 acquires information about the CO2 concentration in the room sent from the ventilation fan control unit 24 of the ventilation fan 1.

[0036] The CO2 concentration reference value (A) is a threshold value for determining the CO2 concentration in the room, which is used to determine which operating mode of the ventilation fan 1 to use for ventilation so that comfort in the room does not deteriorate due to the CO2 concentration in the room. The CO2 concentration reference value (A) can be said to be a threshold value for determining the CO2 concentration in the room, which is used to determine whether to switch the operation of the ventilation fan 1 between multiple operating modes of the blower 14. In other words, the CO2 concentration reference value (A) is a numerical value of the CO2 concentration. The CO2 concentration reference value (A) is determined in advance and stored in the air volume switching control unit 331. The CO2 concentration reference value (A) may also be stored in the ventilation fan storage unit 22.

[0037] The ventilation fan 1 is capable of ventilation operation in two operation modes: a weak operation mode and a strong operation mode. The air volume switching control unit 331 basically controls the ventilation fan 1 in the weak operation mode, which is the first operation mode, when the CO2 concentration in the room is equal to or lower than a predetermined CO2 concentration reference value (A). Furthermore, the air volume switching control unit 331 basically controls the ventilation fan 1 in the strong operation mode, which is the second operation mode, when the CO2 concentration in the room is higher than the predetermined CO2 concentration reference value (A).

[0038] FIG. 6 is a sequence diagram showing an example of an operation pattern of the ventilation fan 1 included in the ventilation system 100 according to the first embodiment.

[0039] The air volume switching control unit 331 controls the operation of the blower 14 at low operation when the ventilation system 100 is started. After starting to control the ventilation fan 1, the air volume switching control unit 331 acquires information on the CO2 concentration in the room transmitted from the ventilation fan control unit 24 of the ventilation fan 1 and compares the acquired CO2 concentration in the room with the CO2 concentration reference value (A). If the acquired CO2 concentration in the room is higher than the CO2 concentration reference value (A), the air volume switching control unit 331 controls the operation of the blower 14 at high operation. In other words, if the acquired CO2 concentration in the room is higher than the CO2 concentration reference value (A), the air volume switching control unit 331 controls the ventilation fan control unit 24 to switch the operation mode of the blower 14 from low operation to high operation. The ventilation fan control unit 24 switches the operation mode of the blower 14 from low operation to high operation in accordance with the control of the air volume switching control unit 331.

[0040] 6, when blower 14 is being controlled in high operation, if the indoor CO2 concentration detected by CO2 sensor 21 drops below a predetermined concentration from CO2 concentration reference value (A), air volume switching control unit 331 controls ventilation fan control unit 24 to switch the operation mode of blower 14 from high operation to low operation. Ventilation fan control unit 24 switches the operation mode of blower 14 from high operation to low operation in accordance with the control of air volume switching control unit 331.

[0041] The airflow rate of the fan 14 during low operation is based on the minimum required ventilation airflow rate stipulated by the Building Standards Act. FIG. 6 shows an example in which the CO2 concentration reference value (A) is set to 1,000 ppm, and the fan 14 switches from high operation to low operation when the indoor CO2 concentration falls below the CO2 concentration reference value (A) minus 200 ppm. The above thresholds are merely examples and can be changed as needed based on the user's needs. The CO2 concentration reference value (A) can be set in the ventilation fan memory unit 22 of the ventilation fan 1, for example, from the terminal device 3 via the server 2.

[0042] The high operation time acquisition unit 332 acquires the high operation time, which is the operating time for which the ventilation fan 1 has operated in high operation. In other words, the high operation time acquisition unit 332 acquires the duration of operation in high operation mode of the ventilation fan 1. Every time the operation of the ventilation fan 1 switches from high operation to low operation, the high operation time acquisition unit 332 acquires the high operation time and sends it to the filter replacement determination unit 333.

[0043] The high operation time is the operating time of the ventilation fan 1 in high operation mode, which is the second operating mode in which the ventilation fan 1 operates at a relatively large air volume, and is also the operating time in high operation after the ventilation fan 1 has switched from low operation, so it can be said to be "ventilation air volume switching information." Furthermore, the high operation time acquisition unit 332 can be said to be the second operating mode operating time acquisition unit.

[0044] The filter replacement determination unit 333 determines the time for maintenance of the filter 19 based on the high operation time of the ventilation fan 1. The determination of the time for maintenance of the filter 19 is a determination of whether or not it is time to perform maintenance on the filter 19 to deal with clogging of the filter 19. Furthermore, when it is determined that it is time to perform maintenance on the filter 19, the filter replacement determination unit 333 displays a maintenance message on the terminal device 3 indicating that it is time to perform maintenance on the filter 19, notifying the user that it is time to perform maintenance on the filter 19 and urging the user to perform maintenance on the filter 19.

[0045] The terminal device 3 receives a control operation for the ventilation fan 1 from the user and transmits the received control operation to the server 2. That is, the terminal device 3 functions as a remote control terminal for the ventilation system 100. The terminal device 3 displays a maintenance message obtained from the server 2 to present the maintenance message to the user and prompt the user to perform maintenance on the filter 19. That is, the terminal device 3 is a device on which the user can visually recognize the maintenance message. A mobile terminal such as a smartphone can be used as the terminal device 3. The functions of the terminal device 3 can be realized, for example, by a smartphone application or a communication device connectable to the World Wide Web.

[0046] 7 is a block diagram showing the functional configuration of the terminal device 3 included in the ventilation system 100 according to the first embodiment. The terminal device 3 includes a terminal operation unit 41, a terminal display unit 42, a terminal storage unit 43, a terminal communication unit 44, and a terminal control unit 45. Information can be exchanged between the components of the terminal device 3.

[0047] The terminal operation unit 41 is an operation reception unit that receives user operations, i.e., operations from the user. The terminal operation unit 41 receives input of user operations and transmits information corresponding to the user operations to the terminal control unit 45. The terminal operation unit 41 receives various operations from the user. When the terminal operation unit 41 receives an operation by the user, it transmits operation information corresponding to the operation to the terminal control unit 45. When the terminal operation unit 41 receives a CO2 concentration reference value setting operation for setting a CO2 concentration reference value in the server 2, it transmits CO2 concentration reference value setting information corresponding to the CO2 concentration reference value setting operation to the terminal control unit 45. The terminal operation unit 41 is composed of input devices such as a keyboard, a mouse, and a touch panel display with a touch panel function, and operations on the terminal device 3 are performed by the user.

[0048] The terminal display unit 42 is a display unit that displays various types of information inside the terminal device 3. The terminal display unit 42 also displays a maintenance message obtained from the server 2 to present the maintenance message to the user and prompt the user to maintain the filter 19. The terminal display unit 42 can be considered a notification unit that notifies the user of a maintenance message that it is time to maintain the filter 19 when the filter replacement determination unit 333 determines that replacement of the filter 19 is necessary. The terminal display unit 42 can also be considered a notification unit that notifies the user of a filter replacement message that it is time to replace the filter 19 when the filter replacement determination unit 333 determines that replacement of the filter 19 is necessary.

[0049] The terminal storage unit 43 is a storage unit that stores various types of information inside the terminal device 3. The terminal storage unit 43 stores a maintenance message transmitted from the server 2.

[0050] The terminal communication unit 44 is connected to the Internet 4 and communicates with the server 2. The terminal communication unit 44 transmits various information transmitted from the server 2 to the terminal control unit 45. The terminal communication unit 44 transmits maintenance messages transmitted from the server 2 to the terminal control unit 45. The terminal communication unit 44 transmits operation information transmitted from the terminal control unit 45 to the server 2.

[0051] The terminal control unit 45 controls the overall processing of the terminal device 3. Furthermore, the terminal control unit 45 controls the transmission of operation information based on an operation from a user to the server 2. When the terminal control unit 45 receives CO2 concentration standard value setting information from the terminal operation unit 41, it controls the transmission of the CO2 concentration standard value setting information to the server 2 via the terminal communication unit 44. Furthermore, the terminal control unit 45 controls the display of a maintenance message acquired from the server 2 on the terminal display unit 42 based on an operation from a user. In other words, the terminal control unit 45 functions as a display control unit that controls the display of information on the terminal display unit 42.

[0052] As described above, the terminal device 3 has a CO2 concentration standard value setting function that sets a CO2 concentration standard value in the server 2. The terminal device 3 also has a CO2 concentration standard value display function that displays the CO2 concentration standard value on the terminal display unit 42. The terminal device 3 also has a CO2 concentration display function that acquires information about the CO2 concentration in the room detected by the CO2 concentration detection unit 21 from the ventilation fan 1 and displays the CO2 concentration information on the terminal display unit 42. The terminal device 3 also has a maintenance time display function that displays a maintenance message acquired from the server 2 on the terminal display unit 42 to present the maintenance message to the user.

[0053] 8 is a block diagram showing the functional configuration of the ventilation system 100 according to the first embodiment. As described above, in the ventilation system 100, information such as information on the CO2 concentration in the room detected by the CO2 concentration detection unit 21 and commands to control the operation of the ventilation fan 1 can be transmitted and received between the ventilation fan control unit 24 of the ventilation fan 1 and the server control unit 33 of the server 2. In addition, in the ventilation system 100, information such as CO2 concentration standard value setting information and maintenance messages can be transmitted and received between the terminal control unit 45 of the terminal device 3 and the server control unit 33 of the server 2.

[0054] Generally, the CO2 concentration of the outside air drawn into a room by the operation of a ventilation fan is around 400 ppm. The Building Standards Act stipulates that the indoor CO2 concentration must be kept below 1,000 ppm. Therefore, if the CO2 concentration standard value (A) is set at 1,000 ppm, ventilation fan 1 will operate at high power when the indoor CO2 concentration exceeds 1,000 ppm.

[0055] Here, the greater the volume of air passing through filter 19, the greater the amount of dust that filter 19 installed in ventilation fan 1 captures. For this reason, when ventilation fan 1 operates by switching between low and high power settings, filter 19 may become clogged earlier than when ventilation fan 1 operates only in low power mode, which may result in a decrease in ventilation air volume.

[0056] To prevent a decrease in the ventilation air volume of the ventilation fan 1, it is necessary to perform maintenance such as periodically cleaning or replacing the filter 19. If the ventilation air volume of the ventilation fan 1 decreases due to insufficient maintenance of the filter 19, the operating time of the ventilation fan 1 at high power to reduce the indoor CO2 concentration to the CO2 concentration standard value (A) tends to increase, which may lead to an increase in the running costs of the ventilation fan 1.

[0057] Furthermore, a decrease in ventilation airflow rate of the ventilation fan 1 due to insufficient maintenance of the filter 19 may lead to an increase in the operating noise of the ventilation fan 1, depending on the structure of the ventilation fan 1. Furthermore, if the indoor CO2 concentration exceeds the CO2 concentration standard value (A) and the ventilation fan 1 operates for a long time at high power until it reaches the CO2 concentration standard value (A), this means that the indoor CO2 concentration will remain higher than the ideal CO2 concentration standard value (A), which may reduce the effect of operating the ventilation fan 1 in improving the air quality in the living space.

[0058] To address these problems, the ventilation system 100 displays a maintenance message on the terminal device 3 at an appropriate time based on the high operating time of the ventilation fan 1, informing the user that it is time for maintenance of the filter 19, and prompting the user to perform maintenance on the filter 19.

[0059] Fig. 9 is a flowchart showing an example of filter replacement determination in the ventilation system 100 according to the first embodiment. The process shown in Fig. 9 is performed after the ventilation system 100 is started, that is, while the ventilation system 100 is in operation. The filter replacement determination in the ventilation system 100 is a determination of whether or not the time for maintenance of the filter 19 has come.

[0060] In step S110, the operating state of the ventilation fan 1 is acquired by the server control unit 33 of the server 2. Specifically, the filter replacement determination unit 333 of the server control unit 33 acquires information about the current operating state of the ventilation fan 1 from the ventilation fan control unit 24 of the ventilation fan 1. The ventilation fan control unit 24 transmits information about the current operating state of the ventilation fan 1 to the filter replacement determination unit 333 at a predetermined interval or in response to a request from the filter replacement determination unit 333. The information about the operating state of the ventilation fan 1 includes either operating information that the ventilation fan 1 is operating at low power or operating information that the ventilation fan 1 is operating at high power. Then, the process proceeds to step S120.

[0061] In step S120, the server control unit 33 determines whether the ventilation fan 1 is in high-power operation based on the information on the operating state of the ventilation fan 1 received from the ventilation fan 1. Specifically, the filter replacement determination unit 333 of the server control unit 33 determines whether the ventilation fan 1 is in high-power operation based on the information on the operating state of the ventilation fan 1. The filter replacement determination unit 333 determines that the ventilation fan 1 is in high-power operation when the information on the operating state of the ventilation fan 1 is operating information indicating that the ventilation fan 1 is operating in high-power operation. The filter replacement determination unit 333 determines that the ventilation fan 1 is in low-power operation, i.e., that the ventilation fan 1 is not in high-power operation, when the information on the operating state of the ventilation fan 1 is operating information indicating that the ventilation fan 1 is operating in low-power operation.

[0062] If it is determined that the ventilation fan 1 is in high-power operation, the result in step S120 is Yes, and the process proceeds to step S130. If it is determined that the ventilation fan 1 is not in high-power operation, the result in step S120 is No, and the process proceeds to step S160.

[0063] In step S130, the server control unit 33 acquires the high operation time of the most recent high operation. Specifically, the high operation time acquisition unit 332 of the server control unit 33 acquires information about the high operation time of the most recent high operation. The high operation time of the most recent high operation is the high operation time of the most recent high operation when the operation of the ventilation fan 1 was switched to low operation. The high operation time acquisition unit 332 transmits the acquired information about the most recent high operation time to the filter replacement determination unit 333. Then, the process proceeds to step S140.

[0064] In step S140, it is determined whether the high power operation time in the most recent high power operation is greater than the filter replacement control value C1 times the predetermined reference time, i.e., whether the high power operation time in the most recent high power operation is greater than the filter replacement control value C1 times the reference time.

[0065] The reference time is a reference time for the most recent high operation time in high operation, for determining whether or not filter 19 needs to be replaced based on the most recent high operation time in high operation. The reference time may be, for example, the average value of multiple high operation times over a predetermined period. The reference time may be acquired based on data on the actual operation of ventilation fan 1. Alternatively, the reference time may be acquired through simulation. The filter replacement determination unit 333 may acquire information on multiple high operation times over a predetermined period and information on the number of times that ventilation fan 1 switched from high operation to low operation over that period from the high operation time acquisition unit 332, and use the acquired information to calculate the reference time. Alternatively, the reference time may be set in the filter replacement determination unit 333 by the user from the terminal device 3.

[0066] The reference time may be obtained by other methods as long as it can be used as a criterion for determining whether or not the filter 19 needs to be replaced based on the high power operation time of the most recent high power operation.

[0067] The filter replacement control value C1 is a control value for determining how long the most recent high power operation time must be relative to a reference time before it is determined that replacement of the filter 19 is necessary. The filter replacement control value C1 is set in the filter replacement determination unit 333 by the user from the terminal device 3.

[0068] Specifically, the terminal control unit 45 of the terminal device 3 sets the filter replacement management value C1 in the server control unit 33 of the server 2 based on an instruction from the user. That is, the terminal operation unit 41 accepts a setting operation of the filter replacement management value C1 from the user to set the filter replacement management value C1. Upon accepting the setting operation of the filter replacement management value C1 by the user, the terminal operation unit 41 transmits filter replacement management value setting information, which is information corresponding to the setting operation of the filter replacement management value C1, to the terminal control unit 45. The filter replacement management value setting information includes information about the filter replacement management value C1. Upon receiving the filter replacement management value setting information from the terminal operation unit 41, the terminal control unit 45 controls transmission of the filter replacement management value setting information to the server 2 via the terminal communication unit 44.

[0069] When the server control unit 33 receives the filter replacement management value setting information via the server communication unit 32, it stores the filter replacement management value C1 in the filter replacement determination unit 333 of the server control unit 33. As a result, the filter replacement management value C1 is set in the filter replacement determination unit 333 of the server control unit 33. Note that the server control unit 33 may store the filter replacement management value C1 in the server storage unit 31. The filter replacement management value C1 is set to 2, for example. The filter replacement management value C1 can be changed as appropriate based on a user instruction.

[0070] The filter replacement determination unit 333 compares the most recent acquired high-power operation time with the reference time and determines whether the acquired high-power operation time is greater than the filter replacement management value C1 times the reference time. If the most recent acquired high-power operation time is greater than the filter replacement management value C1 times the reference time, the filter replacement determination unit 333 determines that the airflow rate of the ventilation fan 1 has decreased. If the most recent acquired high-power operation time is equal to or less than the filter replacement management value C1 times the reference time, the filter replacement determination unit 333 determines that the airflow rate of the ventilation fan 1 has not decreased. For example, the filter replacement management value C1 is set to 2. Note that the filter replacement management value C1 is not limited to 2.

[0071] If it is determined that the acquired high-power operation time is greater than the filter replacement control value C1 times the reference time, the answer is Yes in step S140 and the process proceeds to step S150. If it is determined that the acquired high-power operation time is equal to or less than the filter replacement control value C1 times the reference time, the answer is No in step S140 and the process proceeds to step S160.

[0072] In step S150, an instruction to display a maintenance message for the filter 19 is transmitted from the server control unit 33 of the server 2 to the terminal device 3. Specifically, the filter replacement determination unit 333 transmits a message display command to the terminal device 3 to instruct the terminal device 3 to display a maintenance message indicating that it is time to perform maintenance on the filter 19. Upon receiving the message display command, the terminal device 3 displays a maintenance message indicating that it is time to perform maintenance on the filter 19 on the terminal display unit 42, prompting the user to perform maintenance on the filter 19. FIG. 10 is a diagram showing an example of a maintenance message displayed on the terminal device 3 included in the ventilation system 100 according to the first embodiment. Note that the content of the maintenance message is not limited to the example of FIG. 10. Thereafter, the process proceeds to step S160.

[0073] In step S160, the acquired most recent high operation time and information on the most recent number of times the operation of the ventilation fan 1 was switched from high operation to low operation are stored in the server control unit 33. Specifically, the filter replacement determination unit 333 stores the acquired most recent high operation time and information on the most recent number of times the operation of the ventilation fan 1 was switched from high operation to low operation. Note that the filter replacement determination unit 333 may store the acquired most recent high operation time and information on the most recent number of times the operation of the ventilation fan 1 was switched from high operation to low operation in the server storage unit 31. Then, the process proceeds to step S170.

[0074] In step S170, it is determined whether or not to end the determination of the maintenance time for the filter 19. That is, it is determined whether or not to stop the ventilation operation of the ventilation fan 1. Specifically, the filter replacement determination unit 333 determines whether or not to end the determination of the maintenance time. If the filter replacement determination unit 333 has received an operation stop command, which is a command to stop the operation of the ventilation fan 1, transmitted from the terminal control unit 45 of the terminal device 3, the filter replacement determination unit 333 determines to end the determination of the maintenance time for the filter 19. If the filter replacement determination unit 333 has not received an operation stop command transmitted from the terminal control unit 45 of the terminal device 3, the filter replacement determination unit 333 determines to continue the determination of the maintenance time for the filter 19. The operation stop command is transmitted from the server 2 to the ventilation fan 1.

[0075] If it is determined that the determination of the maintenance timing of the filter 19 is to be ended, the result in step S170 is Yes, and the series of determination processes is ended by the server control unit 33. If it is determined that the determination of the maintenance timing of the filter 19 is to be continued, the result in step S170 is No, and the process returns to step S110.

[0076] Immediately after the ventilation system 100 starts operating, it is not possible to acquire information on the reference time required to determine the maintenance timing of the filter 19, and therefore it is necessary to disable for a certain period of time the above-described determination of the maintenance timing of the filter 19. Furthermore, immediately after the filter replacement of the filter 19 is performed, the filter replacement determination unit 333 performs a process to disable information on the high-power operation time acquired before the filter replacement of the filter 19, thereby preventing a maintenance message from being erroneously displayed on the terminal device 3 immediately after the filter replacement of the filter 19.

[0077] Fig. 11 is a block diagram showing another example of the configuration of the ventilation system 100 according to the first embodiment. Fig. 1 shows the configuration of the ventilation system 100 in which the CO2 sensor 21 that detects the CO2 concentration in the room is incorporated into the ventilation fan 1, but the CO2 sensor 21 may be provided outside the ventilation fan 1 as shown in Fig. 11.

[0078] In the case where the CO2 sensor 21 is not built into the ventilation fan 1 but is provided outside the ventilation fan 1, a communication device 5 is connected to the CO2 sensor 21 to enable communication between the CO2 sensor 21 and the server 2. By providing the communication device 5, even in the case where the CO2 sensor 21 is not built into the ventilation fan 1, it is possible to transmit information about the CO2 concentration in the room detected by the CO2 sensor 21 to the server 2 from the CO2 sensor 21.

[0079] FIG. 12 is a diagram illustrating a specific example of a device configuration 101 of the ventilation system 100 according to the first embodiment. FIG. 12 illustrates a configuration in which a CO2 concentration detection unit 21 that detects the CO2 concentration in a room is incorporated into the ventilation fan 1. In the example of device configuration 101 of the ventilation system 100 illustrated in FIG. 12, the ventilation fan 1 is connected to a switch 6 that has a communication function and communicates with a router 7, and communicates with the server 2 via the switch 6 and the router 7. A ventilation fan control unit 24 of the ventilation fan 1 and the switch 6 are connected by a communication line 8. The ventilation fan control unit 24 transmits information about the CO2 concentration in the room, acquired from the CO2 concentration detection unit 21, to the switch 6 via the communication line 8.

[0080] The switch 6 is an operating device for operating the ventilation system 100. The switch 6 is capable of sending and receiving information to and from the CO2 concentration detection unit 21. FIG. 13 is a block diagram showing the functional configuration of the switch 6 according to the first embodiment. The switch 6 includes a switch operating unit 51, a switch storage unit 52, a switch communication unit 53, and a switch control unit 54.

[0081] The switch operation unit 51 is an operation receiving unit that receives user operations, i.e., operations from the user, regarding operations on the ventilation system 100. The switch operation unit 51 receives input of the user operations and transmits information corresponding to the user operations to the switch control unit 54.

[0082] The switch storage unit 52 is a storage unit that stores various types of information inside the switch 6.

[0083] The switch communication unit 53 performs wireless communication with the router 7 , connects to the Internet 4 via the router 7 , and communicates with the server 2 .

[0084] The switch control unit 54 controls the overall processing of the switch 6. The switch control unit 54 controls communication with the router 7, and controls communication between the server 2 and the ventilation fan 1. The switch control unit 54 also controls the switch communication unit 53 to transmit information on the CO2 concentration in the room, which information has been transmitted from the ventilation fan control unit 24 of the ventilation fan 1, to the server 2.

[0085] Fig. 14 is a sequence diagram of an example of filter replacement determination in the device configuration example 101 of the ventilation system 100 shown in Fig. 12. Here, filter replacement determination, which is an example of filter maintenance determination, will be described.

[0086] In step S210, a CO2 concentration upper limit control value D1, which is the upper limit control value for the CO2 concentration in the room, is set. Specifically, the terminal control unit 45 of the terminal device 3 sets the CO2 concentration upper limit control value D1, which is the upper limit control value for the CO2 concentration in the room, in the server control unit 33 of the server 2 based on an instruction from the user. The CO2 concentration upper limit control value D1 corresponds to the above-mentioned CO2 concentration reference value (A).

[0087] That is, the terminal operation unit 41 receives from the user an upper limit control value setting operation for setting an upper limit control value for the indoor CO2 concentration. Upon receiving the user's upper limit control value setting operation, the terminal operation unit 41 transmits upper limit control value setting information, which is information corresponding to the upper limit control value setting operation, to the terminal control unit 45. The upper limit control value setting information includes information on the CO2 concentration upper limit control value D1. Upon receiving the upper limit control value setting information from the terminal operation unit 41, the terminal control unit 45 controls the transmission of the upper limit control value setting information to the server 2 via the terminal communication unit 44.

[0088] When the server control unit 33 receives the upper limit control value setting information via the server communication unit 32, it stores the upper limit control value setting information in the air volume switching control unit 331 of the server control unit 33. As a result, the CO2 concentration upper limit control value D1 is set in the air volume switching control unit 331 of the server control unit 33. Note that the server control unit 33 may store the upper limit control value setting information in the server storage unit 31. The CO2 concentration upper limit control value D1 is set to, for example, 1000 ppm. Thereafter, the process proceeds to step S220.

[0089] In step S220, information on the current CO2 concentration value, which is the current value of the CO2 concentration in the room where the ventilation fan 1 is installed, is transmitted from the ventilation fan 1 to the server 2. Specifically, the CO2 sensor 21 detects the CO2 concentration in the room where the ventilation fan 1 is installed at a predetermined cycle. The CO2 sensor 21 transmits the detection result, that is, the information on the CO2 concentration in the room, to the ventilation fan control unit 24 of the ventilation fan 1. The ventilation fan control unit 24 acquires the CO2 concentration information, which is the current value of the CO2 concentration in the room, from the CO2 sensor 21, and transmits the acquired latest CO2 concentration information to the server control unit 33 of the server 2 as information on the current value of the CO2 concentration. Note that the order of steps S210 and S220 may be reversed. Thereafter, the process proceeds to step S230.

[0090] In step S230, a strong operation change determination process is performed in the server control unit 33 of the server 2. The strong operation change determination process is a process for comparing the CO2 concentration upper limit management value D1 with the current CO2 concentration value to determine whether or not it is necessary to change the operation of the ventilation fan 1 from weak operation to strong operation. Specifically, the air volume switching control unit 331 of the server control unit 33 performs the strong operation change determination process.

[0091] If the current CO2 concentration value is greater than the CO2 concentration upper limit management value D1, the air volume switching control unit 331 determines that the ventilation air volume for indoor ventilation needs to be increased, and determines that the operation of the ventilation fan 1 needs to be changed from low to high. If the current CO2 concentration value is equal to or less than the CO2 concentration upper limit management value D1, the air volume switching control unit 331 determines that the ventilation air volume for indoor ventilation does not need to be increased, and determines that the operation of the ventilation fan 1 does not need to be changed from low to high. Then, the process proceeds to step S240.

[0092] In step S240, based on the determination result of the strong operation change determination process in step S230, a strong operation control command is sent from the server control unit 33 of the server 2 to the ventilation fan control unit 24 of the ventilation fan 1. The strong operation control command is a command to change the operation of the ventilation fan 1 from weak operation to strong operation. Specifically, the air volume switching control unit 331 of the server control unit 33 sends the strong operation control command to the ventilation fan control unit 24 based on the determination result of the strong operation change determination process in step S230.

[0093] That is, when it is determined in the strong operation change determination process in step S230 that the operation of the ventilation fan 1 needs to be changed from weak operation to strong operation, the air volume switching control unit 331 performs control to send a strong operation control command to the ventilation fan control unit 24 of the ventilation fan 1. The ventilation fan control unit 24 receives the strong operation control command sent from the air volume switching control unit 331. Then, the process proceeds to step S250.

[0094] On the other hand, if it is determined in the strong operation change determination process in step S230 that there is no need to change the operation of the ventilation fan 1 from weak operation to strong operation, the air volume switching control unit 331 does not send a strong operation control command to the ventilation fan control unit 24 of the ventilation fan 1. Then, the process returns to step S210.

[0095] Regarding the above-mentioned steps S210 to S240, in step S210, the CO2 concentration upper limit control value D1 may be transmitted from the terminal control unit 45 of the terminal device 3 to the ventilation fan control unit 24 of the ventilation fan 1, and steps S230 and S240 may be performed in the ventilation fan control unit 24.

[0096] In step S250, strong operation control is performed on the ventilation fan 1. Specifically, the ventilation fan control unit 24 of the ventilation fan 1 performs strong operation control to change the operation of the ventilation fan 1 from weak operation to strong operation, based on the strong operation control command received from the server control unit 33. Then, the process proceeds to step S260.

[0097] In step S260, information on the current CO2 concentration value, which is the current value of the CO2 concentration in the room where the ventilation fan 1 is installed, is transmitted from the ventilation fan 1 to the server 2. The specific processing is the same as in step S220. Then, the process proceeds to step S270.

[0098] In step S270, a process for determining whether to change to weak operation is performed by the server control unit 33 of the server 2. The process for determining whether to change to weak operation is a process for comparing the CO2 concentration lower limit control value D2, which is the lower limit control value for the CO2 concentration in the room, with the current CO2 concentration value, and determining whether or not the operation of the ventilation fan 1 needs to be changed from strong operation to weak operation.

[0099] The CO2 concentration lower limit control value D2 corresponds to the above-mentioned "concentration obtained by subtracting 200 ppm from the CO2 concentration reference value (A)." The CO2 concentration lower limit control value D2 is obtained by the air volume switching control unit 331 of the server control unit 33 performing a calculation to subtract a predetermined value from the CO2 concentration upper limit control value D1, and is stored in the air volume switching control unit 331. The CO2 concentration lower limit control value D2 is set to, for example, "CO2 concentration upper limit control value D1 - 200 ppm." Note that the CO2 concentration lower limit control value D2 may be set in step S210 in the same way as the CO2 concentration upper limit control value D1.

[0100] Specifically, the air volume switching control unit 331 of the server control unit 33 performs a process for determining whether to change to low operation. When the current CO2 concentration value is lower than the CO2 concentration lower limit management value D2, the air volume switching control unit 331 determines that it is no longer necessary to increase the ventilation air volume for indoor ventilation, and determines to change the operation of the ventilation fan 1 from high operation to low operation. When the current CO2 concentration value is not lower than the CO2 concentration lower limit management value D2, the air volume switching control unit 331 determines that it is necessary to continue the control to increase the ventilation air volume for indoor ventilation, and determines not to change the operation of the ventilation fan 1 from high operation to low operation. Then, the process proceeds to step S280.

[0101] In step S280, based on the determination result of the low operation change determination process in step S270, a low operation control command is sent from the server control unit 33 of the server 2 to the ventilation fan control unit 24 of the ventilation fan 1. The low operation control command is a command to change the operation of the ventilation fan 1 from high operation to low operation. Specifically, the air volume switching control unit 331 of the server control unit 33 sends the low operation control command to the ventilation fan control unit 24 based on the determination result of the low operation change determination process in step S270.

[0102] That is, when it is determined in the low operation change determination process in step S270 that the operation of the ventilation fan 1 should be changed from high operation to low operation, the air volume switching control unit 331 performs control to send a low operation control command to the ventilation fan control unit 24 of the ventilation fan 1. The ventilation fan control unit 24 receives the low operation control command sent from the air volume switching control unit 331. Then, the process proceeds to step S290.

[0103] On the other hand, if it is determined in the low operation change determination process in step S270 that the operation of the ventilation fan 1 should not be changed from high operation to low operation, the air volume switching control unit 331 does not send a low operation control command to the ventilation fan control unit 24 of the ventilation fan 1. Then, the process returns to step S260.

[0104] Regarding the above-mentioned steps S260 to S280, in step S260, the CO2 concentration lower limit control value D2 may be transmitted from the air volume switching control unit 331 of the server control unit 33 of the server 2 to the ventilation fan control unit 24 of the ventilation fan 1, and steps S270 and S280 may be performed in the ventilation fan control unit 24.

[0105] In step S290, low operation control is performed on the ventilation fan 1. Specifically, the ventilation fan control unit 24 of the ventilation fan 1 performs low operation control to change the operation of the ventilation fan 1 from high operation to low operation, based on the low operation control command received from the air volume switching control unit 331. Then, the process proceeds to step S300.

[0106] In step S300, a high operation time measurement process is performed, which is a process of measuring the high operation time in order to set a reference time for the high operation time. Specifically, the high operation time acquisition unit 332 of the server control unit 33 of the server 2 performs the high operation time measurement process. The high operation time acquisition unit 332 acquires information on the operating state of the ventilation fan 1 for a predetermined period from the ventilation fan control unit 24, and acquires the high operation time for the predetermined period based on the acquired information on the operating state of the ventilation fan 1. Then, the process proceeds to step S310.

[0107] In step S310, a reference time for the high-power operation time is set in the server control unit 33 of the server 2. The reference time is the reference time for the high-power operation time described in step S140 above. Specifically, the filter replacement determination unit 333 of the server control unit 33 sets the reference time for the high-power operation time in the filter replacement determination unit 333. An example of a method for setting the reference time is as follows. First, in step S300 described above, the filter replacement determination unit 333 collects data on the high-power operation time for a certain period, for example, one month, regarding the initial operating conditions and the initial high-power operation time during the initial period when the filter 19 is not clogged. The initial period corresponds to the predetermined period described above. Then, the filter replacement determination unit 333 sets and stores the average value of the high-power operation time during the initial period as the reference time for the high-power operation time in the filter replacement determination unit 333. Then, the process proceeds to step S320.

[0108] In step S320, a filter replacement management value C2 is set in the server control unit 33 of the server 2. The filter replacement management value C2 is a management value that determines how long the high power operation time in the most recent high power operation must be relative to the reference time before it is determined that replacement of the filter 19 is necessary. The filter replacement management value C2 is set in the filter replacement determination unit 333 by the user from the terminal device 3. The method of setting the filter replacement management value C2 is the same as the method of setting the filter replacement management value C1 shown in step S140 above. setting The method is similar.

[0109] In step S330, the filter replacement determination process is determined in the server control unit 33 of the server 2. That is, whether or not replacement of the filter 19 is necessary is determined in the server control unit 33 of the server 2. Specifically, the filter replacement determination unit 333 of the server control unit 33 determines whether or not replacement of the filter 19 is necessary. The high operation time acquisition unit 332 acquires the high operation time and transmits it to the filter replacement determination unit 333 every time the operation of the ventilation fan 1 is switched from high operation to low operation.

[0110] The filter replacement determination unit 333 compares the reference high power operation time with the most recent high power operation time. The most recent high power operation time is, for example, the average high power operation time acquired over the most recent fixed period. The most recent fixed period is, for example, the most recent one month.

[0111] If the rate of increase in the most recent high-power operation time relative to the reference time exceeds the filter replacement control value C2, the filter replacement determination unit 333 determines that the airflow rate of the ventilation fan 1 has decreased and that replacement of the filter 19 is necessary. The rate of increase in the most recent high-power operation time relative to the reference time is expressed, for example, as "the most recent high-power operation time / the average high-power operation time over one month." For example, if the filter replacement control value C2=2, it is determined that replacement of the filter 19 is necessary when the most recent high-power operation time is longer than twice the initial period.

[0112] Furthermore, the above determination can be said to be made as to whether or not replacement of filter 19 is necessary when the high-power operation time is longer than a predetermined determination threshold time. Here, the determination threshold time is a threshold time that is compared with the high-power operation time to determine whether or not replacement of filter 19 is necessary based on the high-power operation time. The determination threshold time is expressed as the product of the reference time for high-power operation time and the filter replacement control value C2, i.e., "reference time for high-power operation time × filter replacement control value C2."

[0113] In step S340, based on the determination result of the filter replacement determination process in step S330, an instruction to display a filter replacement message indicating that it is time to replace the filter 19 is transmitted from the server control unit 33 of the server 2 to the terminal device 3. Specifically, based on the determination result of the filter replacement determination process in step S330, the filter replacement determination unit 333 of the server control unit 33 transmits a message display command to the terminal control unit 45 of the terminal device 3 to instruct the display of a filter replacement message indicating that it is time to replace the filter 19.

[0114] That is, if it is determined in the filter replacement determination process in step S330 that replacement of the filter 19 is necessary, the filter replacement determination unit 333 controls to send a message display command for a filter replacement message for the filter 19 to the terminal control unit 45 of the terminal device 3.

[0115] On the other hand, if it is determined in the filter replacement determination process in step S330 that replacement of the filter 19 is not necessary, the filter replacement determination unit 333 does not transmit a message display command for a filter replacement message for the filter 19 to the terminal control unit 45 of the terminal device 3. Then, the process returns to step S330.

[0116] In step S350, a filter replacement message for the filter 19 is displayed on the terminal display unit 42 of the terminal device 3. Specifically, upon receiving the message display command, the terminal control unit 45 of the terminal device 3 performs control to display a filter replacement message on the terminal display unit 42, indicating that it is time to replace the filter 19. This allows the ventilation system 100 to prompt the user to replace the filter 19.

[0117] Fig. 15 is a block diagram showing another specific equipment configuration example 102 of the ventilation system 100 according to the first embodiment. Fig. 12 shows an equipment configuration example in which a CO2 sensor 21 that detects the CO2 concentration in a room is incorporated into the ventilation fan 1, but the CO2 sensor 21 may be provided outside the ventilation fan 1 as shown in Fig. 15.

[0118] In the case where the CO2 sensor 21 is not incorporated into the ventilation fan 1 but is provided outside the ventilation fan 1, the CO2 sensor 21 is provided with a communication function or a communication device 5 as shown in Fig. 11 is connected to the CO2 sensor 21 to enable communication between the CO2 sensor 21 and the server 2. By providing the CO2 sensor 21 with a communication function or connecting the communication device 5 to the CO2 sensor 21, it is possible to transmit information about the CO2 concentration in the room detected by the CO2 sensor 21 from the CO2 sensor 21 to the server 2 even in the case where the CO2 sensor 21 is not incorporated into the ventilation fan 1.

[0119] Next, a method for calculating the strong operation time will be described in detail. Fig. 16 is a flowchart showing the steps of the method for calculating the strong operation time in the ventilation system 100 according to the first embodiment. After the ventilation system 100 is started up, the ventilation fan 1 starts operation in the weak operation mode, which is the standard operation mode.

[0120] In step S410, the operation mode value of the ventilation fan 1, which is information indicating the operation mode SM of the ventilation fan 1, is acquired by the server control unit 33 of the server 2. Specifically, the filter replacement determination unit 333 of the server control unit 33 of the server 2 acquires information on the operation mode value of the current operation of the ventilation fan 1 from the ventilation fan control unit 24 of the ventilation fan 1. Then, the process proceeds to step S420.

[0121] As described above, there are two operation modes SM of the ventilation fan 1: the weak operation mode SMW, in which the ventilation fan 1 operates at a relatively low air volume, and the strong operation mode SMS, in which the ventilation fan 1 operates at a relatively high air volume, in which the ventilation fan 1 operates at a high air volume. Here, the operation mode value of the weak operation mode SMW is defined as SMW. Also, the operation mode value of the strong operation mode SMS is defined as SMS.

[0122] In step S420, information on a current CO2 concentration value DC, which is the current value of the CO2 concentration in the room in which the ventilation fan 1 is installed, is acquired by the server control unit 33 of the server 2. Specifically, the CO2 sensor 21 detects the CO2 concentration in the room in which the ventilation fan 1 is installed at a predetermined cycle. The CO2 sensor 21 transmits the detection result, that is, information on the CO2 concentration in the room, to the ventilation fan control unit 24 of the ventilation fan 1. The ventilation fan control unit 24 acquires CO2 concentration information, which is the current value of the CO2 concentration in the room, from the CO2 sensor 21, and transmits the acquired latest CO2 concentration information as information on the current CO2 concentration value DC to the airflow volume switching control unit 331 of the server control unit 33 of the server 2. As a result, the airflow volume switching control unit 331 of the server control unit 33 acquires information on the current CO2 concentration value DC. Then, the process proceeds to step S430.

[0123] In step S430, information on the CO2 concentration upper limit control value D1, which is the upper limit control value for the indoor CO2 concentration, and information on the CO2 concentration lower limit control value D2, which is the lower limit control value for the indoor CO2 concentration, are acquired by the server control unit 33 of the server 2 as CO2 concentration reference values. Specifically, the airflow rate switching control unit 331 of the server control unit 33 of the server 2 acquires and stores the information on the CO2 concentration upper limit control value D1 and the CO2 concentration lower limit control value D2, in the same manner as in step S210 described above. Then, the process proceeds to step S440.

[0124] In step S440, strong operation change determination processing is performed by the server control unit 33 of the server 2. In this strong operation change determination processing, the contents of the operation mode value acquired in step S410 are confirmed, and the CO2 concentration upper limit management value D1 is compared with the current CO2 concentration value DC to determine whether or not it is necessary to change the operation of the ventilation fan 1 from weak operation to strong operation. That is, in the strong operation change determination processing, it is determined whether or not it is necessary to change the operation mode SM of the ventilation fan 1 to the strong operation mode SMS. Here, processing to confirm the current operation mode value is added to the strong operation change determination processing in step S230 described above.

[0125] Specifically, the air volume switching control unit 331 of the server control unit 33 performs a strong operation change determination process. The air volume switching control unit 331 determines that the operation mode SM of the ventilation fan 1 needs to be changed to the strong operation mode SMS when the following conditions are met: "The operation mode SM is the weak operation mode SMW, and the current CO2 concentration value DC is higher than the CO2 concentration upper limit management value D1." If it is determined that the operation mode SM of the ventilation fan 1 needs to be changed to the strong operation mode SMS, the air volume switching control unit 331 performs control to send a strong operation control command to the ventilation fan control unit 24 of the ventilation fan 1. The ventilation fan control unit 24 receives the strong operation control command sent from the air volume switching control unit 331.

[0126] If the condition that "the operation mode SM is the low operation mode SMW and the current CO2 concentration value DC is higher than the CO2 concentration upper limit management value D1" is not satisfied, the air volume switching control unit 331 determines that it is not necessary to change the operation mode SM of the ventilation fan 1 to the high operation mode SMS. If it is determined that it is not necessary to change the operation mode SM of the ventilation fan 1 to the high operation mode SMS, the air volume switching control unit 331 does not send a high operation control command to the ventilation fan control unit 24 of the ventilation fan 1.

[0127] If it is determined that the operation mode SM of the ventilation fan 1 needs to be changed to the strong operation mode SMS, the answer is Yes in step S440 and the process proceeds to step S450. If it is determined that the operation mode SM of the ventilation fan 1 does not need to be changed to the strong operation mode SMS, the answer is No in step S440 and the process proceeds to step S470.

[0128] In step S450, the operation of the ventilation fan 1 is changed to strong operation. That is, the operation mode SM of the ventilation fan 1 is changed to the strong operation mode SMS. Specifically, the ventilation fan control unit 24 of the ventilation fan 1 performs strong operation control to change the operation mode SM of the ventilation fan 1 from the weak operation mode SMW to the strong operation mode SMS based on the strong operation control command received from the server control unit 33. Then, the process proceeds to step S460.

[0129] In step S460, the current time, which is the time when strong operation, which is operation of the ventilation fan 1 in the strong operation mode SMS, started, is stored in the ventilation fan control unit 24 of the ventilation fan 1 as a record of information on strong operation start time TMS(N), which is information on the Nth strong operation start time TMS. The ventilation fan control unit 24 transmits the stored information on strong operation start time TMS(N) to the strong operation time acquisition unit 332 of the server control unit 33 of the server 2. The strong operation time acquisition unit 332 receives and stores the information on strong operation start time TMS(N) transmitted from the ventilation fan control unit 24.

[0130] Here, N is the number of times that the operation mode SM of the ventilation fan 1 has been changed from the weak operation mode SMW to the strong operation mode SMS after the ventilation system 100 has been started.

[0131] Furthermore, starting up the ventilation system 100 here means starting up the ventilation system 100 for the first time after the ventilation system 100 is installed, or starting up the ventilation system 100 for the first time after the filter 19 is replaced.

[0132] The strong operation start time TMS is the start time of strong operation, which is operation in the strong operation mode SMS of the ventilation fan 1. Then, the process proceeds to step S470.

[0133] In step S470, the operation mode value of the ventilation fan 1, which is information indicating the operation mode SM of the ventilation fan 1, is acquired by the server control unit 33 of the server 2. Step S470 is performed in the same manner as step S410. Thereafter, the process proceeds to step S480.

[0134] In step S480, information on the current CO2 concentration value DC, which is the current value of the CO2 concentration in the room where the ventilation fan 1 is installed, is acquired by the server control unit 33 of the server 2. Step S480 is performed in the same manner as step S420. Thereafter, the process proceeds to step S490.

[0135] In step S490, a weak operation change determination process is performed by the server control unit 33 of the server 2. In this weak operation change determination process, the contents of the operation mode value acquired in step S470 are confirmed, and the CO2 concentration lower limit management value D2 is compared with the current CO2 concentration value DC to determine whether or not it is necessary to change the operation of the ventilation fan 1 from strong operation to weak operation. That is, in the weak operation change determination process, it is determined whether or not it is necessary to change the operation mode SM of the ventilation fan 1 to the weak operation mode SMW. Here, a process of checking the current operation mode value is added to the weak operation change determination process in step S270 described above.

[0136] Specifically, the air volume switching control unit 331 of the server control unit 33 performs a process for determining whether to change to low operation. The air volume switching control unit 331 determines that the operation mode SM of the ventilation fan 1 needs to be changed to the low operation mode SMW when the following conditions are met: "The operation mode SM is the high operation mode SMS, and the current CO2 concentration value DC is lower than the CO2 concentration lower limit management value D2." When it is determined that the operation mode SM of the ventilation fan 1 needs to be changed to the low operation mode SMW, the air volume switching control unit 331 performs control to send a low operation control command to the ventilation fan control unit 24 of the ventilation fan 1. The ventilation fan control unit 24 receives the low operation control command sent from the air volume switching control unit 331.

[0137] If the condition that "the operation mode SM is the strong operation mode SMS and the current CO2 concentration value DC is lower than the CO2 concentration lower limit management value D2" is not satisfied, the air volume switching control unit 331 determines that it is not necessary to change the operation mode SM of the ventilation fan 1 to the weak operation mode SMW. If it is determined that it is not necessary to change the operation mode SM of the ventilation fan 1 to the weak operation mode SMW, the air volume switching control unit 331 does not send a weak operation control command to the ventilation fan control unit 24 of the ventilation fan 1.

[0138] If it is determined that the operation mode SM of the ventilation fan 1 needs to be changed to the low operation mode SMW, the answer is Yes in step S490, and the process proceeds to step S500. If it is determined that the operation mode SM of the ventilation fan 1 does not need to be changed to the low operation mode SMW, the answer is No in step S490, and the process proceeds to step S530.

[0139] In step S500, the operation of the ventilation fan 1 is changed to weak operation. That is, the operation mode SM of the ventilation fan 1 is changed to the weak operation mode SMW. Specifically, the ventilation fan control unit 24 of the ventilation fan 1 performs weak operation control to change the operation mode SM of the ventilation fan 1 from the strong operation mode SMS to the weak operation mode SMW, based on the weak operation mode SMW received from the server control unit 33. Then, the process proceeds to step S510.

[0140] In step S510, the current time, which is the time when weak operation, that is, operation of the ventilation fan 1 in the weak operation mode SMW, started, is stored in the ventilation fan control unit 24 of the ventilation fan 1 as a record of information on weak operation start time TMW(N), which is information on the Nth weak operation start time TMW. The ventilation fan control unit 24 transmits the stored information on weak operation start time TMW(N) to the strong operation time acquisition unit 332 of the server control unit 33 of the server 2. The strong operation time acquisition unit 332 receives and stores the information on weak operation start time TMW(N) transmitted from the ventilation fan control unit 24. Then, the process proceeds to step S520.

[0141] Here, N is the number of times that the operation mode SM of the ventilation fan 1 has been changed from the strong operation mode SMS to the weak operation mode SMW after the ventilation system 100 has been started, and is the same number of times as the N at the strong operation start time TMS(N) in step S460. Note that the time when the weak operation of the ventilation fan 1 starts can be said to be the time when the strong operation of the ventilation fan 1 ends.

[0142] In step S520, the strong operation time DT(N), which is the Nth strong operation time DT, is calculated and recorded. That is, the strong operation time DT(N) is calculated and recorded based on the information on the strong operation start time TMS(N) and the information on the weak operation start time TMW(N).

[0143] Specifically, the strong operation time acquisition unit 332 of the server control unit 33 of the server 2 calculates the strong operation time DT(N) by subtracting the information on the strong operation start time TMS(N) from the weak operation start time TMW(N) using the information on the strong operation start time TMS(N) and the information on the weak operation start time TMW(N) and the following formula (1): Then, the strong operation time acquisition unit 332 sets the Nth to the N+1th, i.e., changes N to N+1, and proceeds to step S530.

[0144] Strong operation time DT(N) = Weak operation start time TMW(N) - Strong operation start time TMS(N) (1)

[0145] In step S530, it is determined whether or not to stop the ventilation operation of the ventilation fan 1. That is, it is determined whether or not to stop the ventilation operation of the ventilation fan 1. Specifically, the filter replacement determination unit 333 of the server control unit 33 of the server 2 determines whether or not to stop the ventilation operation of the ventilation fan 1. If the filter replacement determination unit 333 has received an operation stop command, which is a command to stop the operation of the ventilation fan 1, transmitted from the terminal control unit 45 of the terminal device 3, the filter replacement determination unit 333 determines to stop the ventilation operation of the ventilation fan 1 and to end the determination of the maintenance timing of the filter 19. If the filter replacement determination unit 333 has not received an operation stop command transmitted from the terminal control unit 45 of the terminal device 3, the filter replacement determination unit 333 determines to continue the determination of the maintenance timing of the filter 19 without stopping the ventilation operation of the ventilation fan 1. The operation stop command is transmitted from the server control unit 33 of the server 2 to the ventilation fan control unit 24 of the ventilation fan 1.

[0146] If it is determined that the ventilation operation of the ventilation fan 1 is to be stopped, the result in step S530 is Yes, and the process proceeds to step S540. If it is determined that the ventilation operation of the ventilation fan 1 is to be continued, the result in step S530 is No, and the process returns to step S410.

[0147] In step S540, the ventilation operation of the ventilation fan 1 is stopped. Specifically, the ventilation fan control unit 24 of the ventilation fan 1 performs control to stop the ventilation operation of the ventilation fan 1.

[0148] Next, an example of change in the strong operation time DT in the ventilation system 100 according to the first embodiment will be described. Fig. 17 is a first characteristic diagram showing an example of change in the strong operation time DT in the ventilation system 100 according to the first embodiment. In Fig. 17, the horizontal axis shows the weak operation start time TMW(N). In Fig. 17, the time series of the weak operation start time TMW(N) is shown in monthly display, such as January, February, .... Also in Fig. 17, the vertical axis shows the strong operation time DT(N). The unit of the strong operation time DT(N) is "minutes".

[0149] FIG. 18 is a second characteristic diagram showing an example of change in the strong operation time DT in the ventilation system 100 according to the first embodiment. In FIG. 18, the horizontal axis shows the weak operation start time TMW(N). In FIG. 18, the time series of the weak operation start time TMW(N) is shown by month, such as January, February, .... Also, in FIG. 18, the vertical axis shows the average value of the strong operation time DT(N) over a predetermined unit period. In this case, the predetermined unit period is the most recent month.

[0150] 17 and 18 show the status of the same ventilation fan 1 in which a new filter 19 was started to be used in early January, the filter 19 was cleaned at the end of March, June, and September, and the filter 19 was replaced at the end of December. That is, as shown in FIGS. 17 and 18, the filter 19 was cleaned at a first timing T1 at the end of March, a second timing T2 at the end of June, and a third timing T3 at the end of September. The filter 19 was then replaced at a fourth timing T4 at the end of December.

[0151] As the number of times the ventilation system 100 is used and the period of use of the ventilation system 100 increases, dust adheres to the filter 19, the pressure loss of the ventilation fan 1 due to the dust adhering to the filter 19 increases, the ventilation air volume decreases, and the high-power operation time becomes longer.

[0152] The variation in the strong operation time DT of ventilation fan 1 over time varies depending on various conditions such as the installation status of ventilation fan 1, the number of people in the room where ventilation fan 1 is installed, the airflow ratio between strong and weak operation of ventilation fan 1, and the CO2 concentration in the atmosphere.

[0153] For example, consider a case where ventilation fan 1 installed in a conference room in an office building ventilates the conference room. Because the total amount of CO2 emitted from the conference room varies depending on the number of people in the room, the strong operation time DT of ventilation fan 1 varies depending on the number of people in the room. Because the number of people participating in a meeting in the conference room is variable, the strong operation time DT of ventilation fan 1 varies around the average value of the strong operation time DT, as shown in Figures 17 and 18.

[0154] As shown in Fig. 18, after maintenance of the filter 19, i.e., after cleaning of the filter 19, as the usage time of the ventilation fan 1 increases, the average value of the strong operation time DT gradually increases. In other words, the graph of the strong operation time DT over time shows a change in which the average value gradually increases while fluctuating, as shown in Fig. 18.

[0155] Next, a method for determining the maintenance timing of the filter 19 using the average value of the high-power operation time DT will be described. First, the filter replacement determination unit 333 checks the high-power operation time DT in an initial state. The initial state refers to the state immediately after the filter 19 provided in the ventilation fan 1 has been replaced with a new filter. The filter replacement determination unit 333 calculates the average value ADT of the high-power operation time in the initial state, which is the average value ADT of the high-power operation time in the initial state, and the standard deviation SDT(M1) of the high-power operation time in the initial state, based on the high-power operation time DT for a predetermined unit period in the initial state, for example, the high-power operation time DT for one month. The average value ADT(M1) of the high-power operation time DT in the initial state is set as the initial value of the average value ADT(M1) of the high-power operation time DT. The standard deviation SDT(M1) of the high-power operation time DT in the initial state is set as the initial value of the standard deviation SDT(M1) of the high-power operation time DT.

[0156] Next, the filter replacement determination unit 333 calculates the average value ADT(MN) of the strong operation time DT and the standard deviation SDT(MN) of the strong operation time DT for each month after a predetermined unit period. The average value ADT(MN) of the strong operation time DT for each month after one month has passed in the initial state is set as the average value of the strong operation time DT for the specified month.

[0157] The filter replacement determination unit 333 determines the average value ADT of the strong operation time. , place When the monthly average value ADT (MN) becomes larger than the filter replacement management value C3 times the initial average value ADT (M1), that is, when the condition of the following formula (2) is met, it is determined that the time for maintenance of filter 19 has arrived.

[0158] Average value ADT(MN)>C3 × average value ADT(M1) (2)

[0159] The filter replacement control value C3 is a control value for determining how long the average value ADT(MN) of the strong operation time in a specified month must be relative to the average value ADT(M1) of the initial strong operation time before it is determined that replacement of the filter 19 is necessary. The filter replacement control value C3 is set in the filter replacement determination unit 333 by the user from the terminal device 3. For example, if the filter replacement control value C3=2, it is determined that replacement of the filter 19 is necessary when the average value ADT(MN) of the strong operation time in a specified month is longer than twice the average value ADT(M1) of the initial strong operation time.

[0160] In this way, in the ventilation system 100, by determining when to perform maintenance on the filter 19 using the average value of the strong operation time DT, it is possible to recognize the average usage status of the ventilation fan 1 even if the strong operation time DT fluctuates due to changes in the usage status of the ventilation fan 1. This makes it possible for the ventilation system 100 to appropriately determine whether the filter 19 is clogged.

[0161] It is recommended that the filter 19 of the ventilation fan 1 be cleaned approximately once every three months and replaced approximately once a year. Filter cleaning involves removing the filter 19 and removing dust that has adhered to it with a vacuum cleaner or similar. Filter cleaning can remove large dust particles, but it cannot completely remove small dust particles. Therefore, when the filter is cleaned, the high-power operation time per unit period is temporarily shortened. However, the more frequently the filter is cleaned, the faster the ventilation airflow rate decreases, and the high-power operation time per unit period becomes longer.

[0162] That is, the rate of increase in the strong operation time per unit period from October to December is greater than the rate of increase in the strong operation time per unit period from January to March.

[0163] In the ventilation system 100 according to the first embodiment, the average value ADT(M1) of the strong operation time over one month in the initial state is about 30 minutes, and when the average value ADT(MN) of the strong operation time over a predetermined month becomes greater than twice the average value ADT(M1) of the initial value of the strong operation time, the filter replacement determination unit 333 determines that it is time to perform maintenance on the filter 19. Then, in the ventilation system 100, the average value ADT(MN) becomes longer than 60 minutes at the beginning of December, and the filter replacement determination unit 333 determines that it is time to perform maintenance on the filter 19 and displays a maintenance message on the terminal device 3 indicating that it is time to perform maintenance on the filter 19, thereby notifying the user that it is time to perform maintenance on the filter 19.

[0164] Based on the maintenance message indicating that it was time to perform maintenance on the filter 19, the user replaced the filter 19 at the end of December, completely eliminating the clogging of the filter 19. As a result, the strong operation time DT returned to the same level as the initial state, as shown in Figures 17 and 18.

[0165] As described above, the ventilation system 100 according to the first embodiment compares the high-power operation time of the ventilation fan 1 with a predetermined reference time, and when the high-power operation time satisfies a predetermined condition, controls the terminal display unit 42 of the terminal device 3 to display a maintenance message. 1 The user can be notified of the maintenance timing at an appropriate time according to the usage environment and the clogging state of the filter 19, and the user can be prompted to clean the filter 19 at an appropriate time.

[0166] That is, when the rate of increase in the most recent high-power operation time relative to the reference time exceeds the filter replacement control value C2, the filter replacement determination unit 333 determines that the airflow rate of the ventilation fan 1 has decreased and that replacement of the filter 19 is necessary. The rate of increase in the most recent high-power operation time relative to the reference time is expressed, for example, as "the most recent high-power operation time / average high-power operation time over one month." The above determination can be said to be that replacement of the filter 19 is necessary when the high-power operation time is longer than a predetermined determination threshold time.

[0167] As a result, the ventilation system 100 can prevent deterioration in the power consumption and operating noise of the ventilation fan 1 due to prolonged high-power operation caused by early clogging of the filter 19, and can appropriately maintain the indoor air quality improvement effect, thereby improving and maintaining user comfort.The user can enjoy a comfortable air quality environment by performing maintenance on the filter 19, i.e., cleaning or replacing the filter, when a maintenance message is displayed on the terminal display unit 42 of the terminal device 3 in the ventilation system 100.

[0168] Furthermore, since the ventilation system 100 does not require a dedicated detection device to detect the dirtiness of the filter 19, it is possible to inexpensively realize a ventilation system that can notify the user of maintenance times at an appropriate time depending on the clogged state of the filter 19.

[0169] Therefore, the ventilation system 100 according to the first embodiment has the advantage that it is possible to determine the appropriate maintenance timing for the filter 19 depending on the environment in which the ventilation fan 1 is used.

[0170] Embodiment 2 In the second embodiment, a case will be described in which the ventilation system 100 described above uses an increase in the high-power operation time per predetermined unit period as a means for determining when to replace the filter.

[0171] FIG. 19 is a first characteristic diagram showing an example of change in the increase per unit period of the strong operation time DT of the ventilation system 100 in the second embodiment. In FIG. 19, the horizontal axis shows the weak operation start time TMW(N). In FIG. 19, the time series of the weak operation start time TMW(N) is shown by month, such as January, February, .... In addition, in FIG. 19, the vertical axis shows the increase per unit period of the strong operation time DT(N) as a change in the strong operation time DT(N). The unit of the strong operation time DT is minutes. The increase per unit period of the strong operation time DT(N) is specifically calculated by calculating the increase per day of the strong operation time DT for the most recent month using the least squares method.

[0172] FIG. 20 is a second characteristic diagram showing an example of change in the increase per unit period of the strong operation time DT of the ventilation system 100 in the second embodiment. In FIG. 20, the horizontal axis shows the weak operation start time TMW(N). In FIG. 20, the time series of the weak operation start time TMW(N) is shown by month, such as January, February, .... Also in FIG. 20, the vertical axis shows the average value of the increase per unit period of the strong operation time DT(N) over a predetermined period. In this case, the predetermined period is the most recent month.

[0173] For example, consider a case where ventilation fan 1 installed in a conference room in an office building ventilates the conference room. Since the total amount of CO2 emitted from the conference room varies depending on the number of people in the room, the strong operation time DT of ventilation fan 1 also varies depending on the number of people in the room.

[0174] As a general trend, the strong operation time DT increases due to clogging of the filter 19. Therefore, the change in strong operation time due to clogging of the filter 19 is positive. The number of participants in a meeting varies, so if there happens to be a period of time with few meeting participants, the strong operation time DT will be small, and the change in strong operation time may become negative, as shown in Figures 19 and 20. Also, as shown in Figures 19 and 20, in July and October, immediately after the filter 19 was cleaned, the clogging of the filter 19 temporarily decreased, and the change in strong operation time became negative.

[0175] As shown in Figures 19 and 20, the rate of increase in strong operation time from October to December is greater than the rate of increase in strong operation time from January to March. As shown in Figure 19, it is difficult to understand simply by calculating the rate of increase in strong operation time, but by taking the average value over a certain period as shown in Figure 20, the clogged state of filter 19 becomes clear.

[0176] In the second embodiment, when the average value of the increase amount per unit period of the strong operation time DT over a predetermined period becomes larger than the reference increase amount of 0.4 minutes / day, the filter replacement determination unit 333 determines that it is time to perform maintenance on the filter 19. Specifically, when the average value ADT(MN) becomes approximately 0.4 minutes / day in early December, it determines that it is time to perform maintenance on the filter 19, and causes the terminal device 3 to display a maintenance message indicating that it is time to perform maintenance on the filter 19, thereby notifying the user that it is time to perform maintenance on the filter 19.

[0177] The reference increase amount is a reference value for determining whether it is time to perform maintenance on the filter 19, based on the increase amount per unit period of the strong operation time DT. The reference increase amount can be set in the filter replacement determination unit 333 from the terminal device 3 via the server 2, for example.

[0178] As described above, in the second embodiment, the filter replacement determination unit 333 determines that the filter 19 needs to be replaced when the increase per unit period of the operation time of the ventilation fan 1 in the high operation mode becomes longer than a predetermined reference increase. As a result, in the second embodiment as well, the ventilation system 100 can present the user with the maintenance timing for the filter 19 at an appropriate time corresponding to the usage environment of the ventilation fan 1 and the clogged state of the filter 19, and can prompt the user to clean the filter 19 at an appropriate time.

[0179] In the above-described second embodiment, similarly to the first embodiment, the ventilation system 100 has the advantage of being able to determine the appropriate maintenance timing for the filter 19 depending on the usage environment of the ventilation fan 1.

[0180] Embodiment 3 In the ventilation system 100, a large change in the strong operation time DT is observed due to the replacement of the filter 19, so conversely, it is also possible to estimate the completion time of filter maintenance of the filter 19 from the change in the strong operation time DT. That is, in the ventilation system 100, it is possible to determine the completion of filter replacement based on the ventilation airflow rate switching information.

[0181] As described above, the strong operation time DT is the operating time of the ventilation fan 1 in strong operation after switching from weak operation, and can therefore be said to be "ventilation air volume switching information."

[0182] For example, let ADT(X) be the average value of the strong operation time DT over the most recent month. Let SDT(X) be the variance value of the strong operation time DT over the most recent month. The filter replacement determination unit 333 can determine that maintenance of the filter 19 through filter replacement is complete when the strong operation time DT(X+1) becomes smaller than the range of variation, that is, when the condition of the following formula (3) is satisfied. "X" indicates a specific month within the most recent month. "X+1" indicates a specific month within the month following the specific month within the most recent month.

[0183] Strong operation time DT(X+1) <ADT(X)-3×SDT(X) ···(3)

[0184] In the above formula (3), the standard of variation is set to 3σ, but the standard of variation may be set to, for example, 2σ or 1σ.

[0185] To further improve the accuracy of determining whether filter replacement of the filter 19 is complete based on the strong operation time DT, the filter replacement determination unit 333 may determine that filter replacement of the filter 19 is complete when the strong operation time DT(X) decreases beyond the range of variation multiple times in a row, such as strong operation time DT(X+1), strong operation time DT(X+2), strong operation time DT(X+3), ... Strong operation time DT(X+2) indicates the strong operation time DT for the specific two-month period following the most recent specific month. Strong operation time DT(X+3) indicates the strong operation time DT for the specific three-month period following the most recent specific month.

[0186] When the filter replacement determination unit 333 determines that the filter replacement of the filter 19 has been completed, that is, that the maintenance of the filter 19 has been completed by the filter replacement, the filter replacement determination unit 333 stops the control for displaying a maintenance message on the terminal device 3 indicating that it is time to perform maintenance on the filter 19. 19 Furthermore, when the filter replacement determination unit 333 determines that the maintenance of the filter 19 by filter replacement has been completed, the filter replacement determination unit 333 may display a maintenance completion message on the terminal device 3 indicating that the maintenance of the filter 19 by filter replacement has been completed, thereby notifying the user that the maintenance of the filter 19 by filter replacement has been completed.

[0187] That is, based on the average value ADT(X) of the strong operation time DT for a predetermined period, the variance value SDT(X) of the strong operation time DT for a predetermined period, and the strong operation time DT(X+1) for the period immediately after the predetermined period, the filter replacement determination unit 333 can determine that maintenance of the filter 19 by filter replacement has been completed when the strong operation time DT(X+1) for the period immediately after the predetermined period satisfies the above formula (3) and the strong operation time DT(X+1) for the period immediately after the predetermined period has become smaller than the range of variation in the strong operation time DT(X).

[0188] Therefore, it can be said that the filter replacement determination unit 333 has the function of a filter replacement completion determination unit that determines the completion of replacement of the filter 19 based on the ventilation air volume switching information.

[0189] In addition, in the ventilation system 100, as another example of determining whether the filter replacement of the filter 19 has been completed, the following method may be used.

[0190] The filter replacement determination unit 333 compares the strong operation time DT(X+1) with the initial value of the average value ADT(M1) of the strong operation time DT and the initial value of the standard deviation SDT(M1) of the strong operation time DT, and determines that the filter 19 has returned to its initial state, i.e., the state it was in immediately after the filter 19 was replaced with a new filter, when the condition of the following formula (4) is satisfied.

[0191] Average value ADT(M1) - Standard deviation SDT(M1) < Strong operation time DT(X+1) < Average value ADT(M1) + Standard deviation SDT(M1) (4)

[0192] That is, the filter replacement determination unit 333 can determine that maintenance of the filter 19 by filter replacement has been completed when the strong operation time DT falls within the range of variation in the initial situation.

[0193] In order to further improve the accuracy of determining whether filter replacement of filter 19 is complete based on strong operation time DT, filter replacement determination unit 333 may determine that filter replacement of filter 19 is complete when strong operation time DT(X) satisfies the condition of formula (4) above multiple times in succession, such as strong operation time DT(X+1), strong operation time DT(X+2), strong operation time DT(X+3), ...

[0194] As described above, in the third embodiment, the ventilation system 100 can estimate the completion time of the filter maintenance of the filter 19 from the strong operation time DT.

[0195] Next, the hardware configuration of each of the control units 80 according to the first embodiment will be described. The control unit 80 according to the first embodiment corresponds to the ventilation fan control unit 24 of the ventilation fan 1, the sensor control unit 213 of the CO2 concentration detection unit 21, the server control unit 33 of the server 2, the terminal control unit 45 of the terminal device 3, and the switch control unit 54 of the switch 6 according to the first embodiment. Each function of the control unit 80 according to the first embodiment is realized by a processing circuit. The processing circuit may be dedicated hardware, or may be a processing unit that executes a program stored in a storage device.

[0196] When the processing circuit is dedicated hardware, the processing circuit may be a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an application specific integrated circuit, a field programmable gate array, or a combination thereof. Figure 21 is a diagram showing a configuration in which each function of the control unit 80 according to the first embodiment is realized by hardware. The processing circuit 81 incorporates a logic circuit 81a that realizes the functions of the control unit 80.

[0197] When the processing circuit 81 is a processing device, the functions of the control unit 80 are realized by software, firmware, or a combination of software and firmware.

[0198] FIG. 22 is a diagram illustrating a configuration in which each function of the control unit 80 according to the first embodiment is implemented by software. The processing circuit 81 includes a processor 811 that executes a program 81b, a random access memory 812 that the processor 811 uses as a work area, and a storage device 813 that stores the program 81b. The processor 811 loads the program 81b stored in the storage device 813 onto the random access memory 812 and executes it, thereby realizing the functions of the control unit 80. The software or firmware is written in a programming language and stored in the storage device 813. The processor 811 may be, but is not limited to, a central processing unit. The storage device 813 may be a semiconductor memory such as a random access memory (RAM), a read-only memory (ROM), a flash memory, an erasable programmable read-only memory (EPROM), or an electrically erasable programmable read-only memory (EEPROM). The semiconductor memory may be a non-volatile memory or a volatile memory. In addition to semiconductor memory, a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, or a DVD (Digital Versatile Disc) can be applied to the storage device 813. The processor 811 may output data such as a calculation result to the storage device 813 for storage, or may store the data in an auxiliary storage device (not shown) via the random access memory 812. By integrating the processor 811, the random access memory 812, and the storage device 813 on one chip, the functions of the control unit 80 can be realized by a microcomputer.

[0199] The processing circuit 81 realizes the functions of the control unit 80 by reading and executing the program 81b stored in the storage device 813. It can also be said that the program 81b causes the computer to execute the procedures and methods for realizing the functions of the control unit 80.

[0200] The processing circuit 81 may be configured so that some of the functions of the control unit 80 are realized by dedicated hardware, and some of the functions of the control unit 80 are realized by software or firmware.

[0201] In this way, the processing circuitry 81 can realize each of the above-described functions by hardware, software, firmware, or a combination of these.

[0202] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention. [Explanation of symbols]

[0203] 1 ventilation fan, 2 server, 3 terminal device, 4 Internet, 5 communication device, 6 switch, 7 router, 8 communication line, 11 tubular member, 12 wind tunnel, 13 main body frame, 14 blower, 15 impeller, 16 electric motor, 17 main body, 18 design panel, 19 filter, 21 carbon dioxide concentration detection unit, 22 ventilation fan memory unit, 23 ventilation fan communication unit, 24 ventilation fan control unit, 31 server memory unit, 32 server communication unit, 33 server control unit, 41 terminal operation unit, 42 terminal display unit, 43 terminal memory unit, 44 terminal communication unit, 45 terminal control unit, 51 switch operation unit, 52 switch memory unit, 53 switch communication unit, 54 switch control unit, 80 control unit, 81 processing circuit, 81a logic circuit, 81b program, 100 ventilation system, 101 equipment configuration example, 211 Detection unit, 212 sensor memory unit, 213 sensor control unit, 331 airflow volume switching control unit, 332 strong operation time acquisition unit, 333 filter replacement determination unit, 811 processor, 812 random access memory, 813 storage device, DC CO2 concentration current value, DT strong operation time, SM operation mode, SMS strong operation mode, SMW weak operation mode, TMS strong operation start time, TMW weak operation start time.

Claims

1. a ventilation fan that is equipped with a filter that removes dust from the air that is blown into the room and that operates by switching between a first operation mode in which it operates at a relatively small air volume and a second operation mode in which it operates at a relatively large air volume; a carbon dioxide concentration detection unit that detects the carbon dioxide concentration in the room; an air volume switching control unit that switches the air volume of the ventilation fan based on the carbon dioxide concentration in the room detected by the carbon dioxide concentration detection unit; a filter replacement determination unit that determines when to replace the filter based on a result of comparing information on a second operation mode operation time, which is an operation time of the ventilation fan in the second operation mode, with a predetermined criterion for determining whether or not replacement of the filter is necessary by comparing the information on the second operation mode operation time with the information on the second operation mode operation time; A ventilation system comprising:

2. The ventilation fan operates in the first operation mode when the carbon dioxide concentration in the room is equal to or lower than a predetermined carbon dioxide concentration standard value, and operates in the second operation mode when the carbon dioxide concentration in the room is higher than the predetermined carbon dioxide concentration standard value, a second operation mode operation time acquisition unit that acquires the second operation mode operation time, the filter replacement determination unit determines that replacement of the filter is necessary when the second operation mode operation time becomes longer than a predetermined determination threshold time; The ventilation system according to claim 1 .

3. The ventilation fan operates in the first operation mode when the carbon dioxide concentration in the room is equal to or lower than a predetermined carbon dioxide concentration standard value, and operates in the second operation mode when the carbon dioxide concentration in the room is higher than the predetermined carbon dioxide concentration standard value, a second operation mode operation time acquisition unit that acquires the second operation mode operation time, the filter replacement determination unit determines that replacement of the filter is necessary when an increase in the second operation mode operation time per unit period becomes longer than a predetermined reference increase. The ventilation system according to claim 1 .

4. a notification unit that notifies a user of a filter replacement message indicating that it is time to replace the filter when the filter replacement determination unit determines that the filter needs to be replaced; 3. The ventilation system according to claim 2,

5. a filter replacement completion determination unit that determines completion of replacement of the filter when the second operation mode operation time in a period immediately after a predetermined period becomes smaller than an average value of the second operation mode operation time in the predetermined period exceeding a variation in the second operation mode operation time in the predetermined period; 5. A ventilation system according to claim 1, wherein:

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