Ventilation system and air conditioning system equipped with the same

Abstract

This ventilation system comprises: a CO2 concentration detection device that detects the CO2 concentration within a room; a ventilation device that ventilates the room; and a ventilation control device that has a first control mode, in which the ventilation device is set to an operating state when the CO2 concentration is equal to or greater than a first threshold value lower than a ventilation reference value that is a reference value at which ventilation is required, and a second control mode, in which the ventilation device is set to an operating state when it is estimated that the CO2 concentration exceeds the ventilation reference value on the basis of the CO2 concentration and the speed at which the CO2 concentration increases. The ventilation control device performs actions in the first control mode or the second control mode on the basis of the CO2 concentration and the speed at which the CO2 concentration increases.

Description

[Technical Field]

[0001] The present disclosure relates to a ventilation system that ventilates a room based on CO2 concentration and an air conditioning system equipped with the same. [Background technology]

[0002] Conventional technology initiates ventilation when the CO2 concentration in a room is equal to or greater than a preset concentration threshold, or when the rate of increase in CO2 concentration is equal to or greater than a concentration change rate threshold (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-88320 Summary of the Invention [Problem to be solved by the invention]

[0004] In the technology of Patent Document 1, the concentration threshold is set to a ventilation standard value that requires ventilation. Therefore, ventilation is initiated only after the CO2 concentration reaches the ventilation standard value. Given that ventilation control requires maintaining the CO2 concentration in a room at or below the ventilation standard value, there is room for improvement. Furthermore, in the technology of Patent Document 1, if the CO2 concentration increases sharply due to a sudden increase in the number of people in the same room, ventilation is initiated when the rate of increase in CO2 concentration exceeds the concentration change rate threshold. Therefore, in the technology of Patent Document 1, ventilation is initiated when the rate of increase in CO2 concentration exceeds the concentration change rate threshold, even if the CO2 concentration increases temporarily but does not exceed the ventilation standard value. In other words, the technology of Patent Document 1 has the problem of unnecessary ventilation.

[0005] The present disclosure aims to solve the above-mentioned problems and to provide a ventilation system capable of performing appropriate ventilation according to the CO2 concentration in the room, and an air conditioning system equipped with the same. [Means for solving the problem]

[0006] A ventilation system according to the present disclosure includes a CO2 concentration detection device that detects a CO2 concentration in a room, a ventilation device that ventilates the room, and a ventilation control device having a first control mode that operates the ventilation device when the CO2 concentration is equal to or higher than a first concentration threshold that is lower than a ventilation reference value that is a reference value that requires ventilation, and a second control mode that operates the ventilation device when it is estimated that the CO2 concentration will exceed the ventilation reference value based on the CO2 concentration and the rate of increase of the CO2 concentration, The second control mode is CO 2 The concentration is equal to or greater than a second concentration threshold that is lower than the first concentration threshold, and CO 2 This mode puts the ventilation device into operation when the rate of change in concentration is equal to or greater than a preset concentration change rate threshold. It is something.

[0007] The air conditioning system according to the present disclosure includes the above-described ventilation system. [Effects of the Invention]

[0008] The ventilation system and air conditioning system according to the present disclosure can stably maintain the indoor CO2 concentration at or below the ventilation standard value by operating in the first control mode, compared to when the first concentration threshold is set to the ventilation standard value. Furthermore, the ventilation system can avoid unnecessary ventilation in the event of a temporary increase in the CO2 concentration that does not exceed the ventilation standard value by operating in the second control mode. In this way, the ventilation system can provide appropriate ventilation appropriate to the indoor CO2 concentration situation by using the first control mode and the second control mode. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an explanatory diagram of a usage pattern of the ventilation system according to the first embodiment. [Figure 2] 1 is a block diagram of a ventilation system according to a first embodiment. [Figure 3] 3 is a control flowchart in the ventilation system according to the first embodiment. [Figure 4]5 is a diagram showing a change in CO2 concentration and a change in the rate of change of CO2 concentration in the ventilation system according to the first embodiment. FIG. [Figure 5] FIG. 3 is a state transition diagram of a ventilation device in the ventilation system according to the first embodiment. [Figure 6] FIG. 10 is an explanatory diagram of a usage pattern of a modified example of the ventilation system according to the first embodiment. [Figure 7] FIG. 10 is a diagram showing the configuration of an air conditioning system according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Embodiment 1 1 is an explanatory diagram of a usage pattern of a ventilation system 10 according to embodiment 1. The ventilation system 10 of embodiment 1 includes a ventilation control device 1, a CO2 concentration detection device 2 that detects the CO2 concentration in a room, and a ventilation device 3 that ventilates the room in which the CO2 concentration detection device 2 is installed.

[0011] The ventilation control device 1 is a device that controls the ventilation device 3 based on the detection result of the CO2 concentration detection device 2. The CO2 concentration detection device 2 is composed of a concentration detection sensor, and is a device that detects the CO2 concentration at regular intervals (for example, every minute) and transmits the detection result to the ventilation control device 1.

[0012] The ventilation device 3 is a device capable of ventilating a room and is equipped with an exhaust fan that exhausts indoor air to the outside and an intake fan that draws outdoor air into the room. The configuration of the ventilation device 3 is not limited to a configuration equipped with an exhaust fan and an intake fan, and may be any device capable of ventilating a room. The ventilation device 3 also has an operation switch 3a, which the user can operate to manually switch the ventilation device 3 on and off, or the ventilation control device 1 can automatically control the operation and stopping of the ventilation device 3. The operation switch 3a is not limited to being provided on the ventilation device 3, and may be configured so that an operation unit 13 (see FIG. 2) of the ventilation control device 1, which will be described later, has the same function as the operation switch 3a.

[0013] FIG. 2 is a block diagram of a ventilation system 10 according to the first embodiment. The ventilation control device 1 includes a control unit 11, a storage unit 12, and an operation unit 13. The control unit 11 is configured with a microprocessor unit and includes a CPU, RAM, ROM, etc., and a control program, etc. is stored in the ROM. The control unit 11 controls the entire ventilation system according to the control program. The control unit 11 is not limited to a microprocessor unit. For example, the control unit 11 may be configured with updatable firmware, etc. Furthermore, the control unit 11 may be a program module that is executed by commands from a CPU, etc. (not shown).

[0014] The memory unit 12 stores various thresholds and the like, which will be described later. The memory unit 12 includes ROM, RAM, and the like. The operation unit 13 is a unit where user input is performed. The operation unit 13 is composed of, for example, at least, a button, a touch panel, or a display panel, and is a unit that accepts user instructions and outputs the content of the instructions to the control unit 11. The operation unit 13 has a setting unit 13a that sets the priority between a manual operation mode and an automatic operation mode. The manual operation mode is a mode in which the ventilation device 3 is controlled based on the operation of the operation switch 3a. The automatic operation mode is a mode in which the ventilation device 3 is controlled based on the CO2 concentration detected by the CO2 concentration detection device 2 and the rate of increase of the CO2 concentration. The ventilation control device 1 selects either the manual operation mode or the automatic operation mode according to the priority set in the setting unit 13a and controls the ventilation device 3. The operation of the ventilation system 10 will be described below assuming that the automatic operation mode is selected.

[0015] The ventilation control device 1 further includes an inter-CO2 concentration detection device communication unit 14 that communicates with the CO2 concentration detection devices 2, a ventilation device communication unit 15 that communicates with the ventilation device 3, and an external device communication unit 16 that communicates with external devices 4 such as smartphones and tablets. Communication 5a between the inter-CO2 concentration detection device communication unit 14 and the CO2 concentration detection devices 2, communication 5b between the ventilation device communication unit 15 and the ventilation device 3, and communication 5c between the external device communication unit 16 and the external device 4 are performed wirelessly or via a wired connection. The ventilation control device 1 is configured, for example, by being incorporated into a remote control or the like.

[0016] The CO2 concentration detecting device 2 includes a CO2 concentration detecting unit 22 configured with a CO2 sensor, and an inter-ventilation control device communication unit 21 that transmits the detection result detected by the CO2 concentration detecting unit 22 to the inter-CO2 concentration detecting device communication unit 14 of the ventilation control device 1. Note that while FIG. 1 shows an example in which the CO2 concentration detecting device 2 is an independent device that is installed separately from the ventilation control device 1 and the ventilation device 3, it may also be provided in the ventilation control device 1 or the ventilation device 3. The installation location of the CO2 concentration detecting device 2 is not particularly limited.

[0017] Here, ventilation control in the first embodiment will be described. In the ventilation control in the first embodiment, a first concentration threshold (e.g., 900 ppm) that is lower than a ventilation reference value (e.g., 1000 ppm), which is a reference value that requires ventilation, is set in advance. Furthermore, in the ventilation control in the first embodiment, the following two index values ​​are set in advance to avoid unnecessary ventilation in the case of a temporary increase in the CO2 concentration that does not exceed the ventilation reference value. That is, in addition to the first concentration threshold, the ventilation control device 1 is set with a second concentration threshold (e.g., 800 ppm) that is even lower than the first concentration threshold, and a concentration change rate threshold (e.g., 50 ppm / min) that is a threshold for the rate of change of the CO2 concentration.

[0018] The ventilation control device 1 has a first control mode and a second control mode. The first control mode is a mode in which the ventilation device 3 is controlled based only on the CO2 concentration. Specifically, the first control mode is a mode in which the ventilation device 3 is put into operation when the CO2 concentration is equal to or greater than a first concentration threshold. The second control mode is a mode in which the ventilation device 3 is put into operation when it is estimated, based on the CO2 concentration and the rate of increase of the CO2 concentration, that the CO2 concentration will exceed the ventilation reference value. Specifically, the second control mode is a mode in which the ventilation device 3 is put into operation when the CO2 concentration is equal to or greater than a second concentration threshold and the rate of change of the CO2 concentration is equal to or greater than a concentration change rate threshold. The ventilation control device 1 has the first control mode and the second control mode, and operates in the first control mode or the second control mode based on the detection result of the CO2 concentration detection device 2.

[0019] The first concentration threshold, the second concentration threshold, and the concentration change rate threshold are stored in the memory unit 12. The concentration change rate threshold is determined, for example, as in the following (1) or (2) and stored in the memory unit 12. The concentration change rate threshold may be determined by the user and input to the operation unit 13 and stored in the memory unit 12, or may be determined by the control unit 11 or the external device 4 and stored in the memory unit 12.

[0020] (1) The concentration change rate threshold is determined according to the size of the room. In this case, for example, the concentration change rate threshold corresponding to the size of the room is stored in advance in the storage unit 12, and when the user inputs the size of the room into the operation unit 13 during installation, the corresponding concentration change rate threshold is stored in the storage unit 12. (2) The concentration change rate threshold is determined based on the conditions under which the CO2 concentration previously exceeded the ventilation standard value. Specifically, for example, the concentration change rate threshold is determined as follows from previously logged CO2 concentration data. The control unit 11 or the external device 4 calculates the maximum value of the rate of change of the CO2 concentration from the time the CO2 concentration reaches or exceeds the second concentration threshold to the time it reaches the first concentration threshold, and the maximum value of the rate of change of the CO2 concentration from the time the CO2 concentration reaches or exceeds the first concentration threshold to the time it reaches the ventilation standard value. If the former is greater, the control unit 11 or the external device 4 determines the maximum value as the new concentration change rate threshold.

[0021] 3 is a control flowchart of the ventilation system 10 according to the first embodiment. When the CO2 concentration detected by the CO2 concentration detecting device 2 is equal to or greater than the first concentration threshold (step S1: YES), the ventilation control device 1 drives the ventilation device 3 to operate (step S2). This step S2 is performed when the CO2 concentration is equal to or greater than the first concentration threshold, and therefore corresponds to operation in the first control mode. When the ventilation control device 1 determines that the CO2 concentration detected by the CO2 concentration detecting device 2 is not equal to or greater than the first concentration threshold (step S1: NO), it then determines whether the CO2 concentration is equal to or greater than the second concentration threshold (step S3).

[0022] If the ventilation control device 1 determines that the CO2 concentration is not equal to or greater than the second concentration threshold (step S3: NO), it stops the ventilation device 3 (step S4). On the other hand, if the ventilation control device 1 determines in step S3 that the CO2 concentration is equal to or greater than the second concentration threshold (step S3: YES), it then determines whether the CO2 concentration change rate is equal to or greater than a preset concentration change rate threshold (step S5). The CO2 concentration change rate is, for example, the CO2 concentration change rate over the past minute, and is calculated by subtracting the CO2 concentration from one minute ago from the current CO2 concentration. The CO2 concentration change rate is calculated by the control unit 11 of the ventilation control device 1 and stored in the memory unit 12. If the ventilation control device 1 determines in step S5 that the CO2 concentration change rate is not equal to or greater than the concentration change rate threshold (step S5: NO), it stops the ventilation device 3 (step S4).

[0023] On the other hand, if the ventilation control device 1 determines in step S5 that the CO2 concentration change rate is equal to or greater than the concentration change rate threshold (step S5: YES), it puts the ventilation device 3 into operation (step S6). This step S6 is performed when the second concentration threshold≦CO2 concentration<first concentration threshold and the CO2 concentration change rate≧concentration change rate threshold, and therefore corresponds to operation in the second control mode.

[0024] The ventilation control device 1 repeatedly performs the processes of steps S1 to S6 described above at each control timing, which is, for example, one minute intervals. The "ventilation device: operating state" in step S2 and the "ventilation device: operating state" in step S6 mean that if the ventilation device was not operating at the previous control timing, the ventilation device 3 will start operating, and if the ventilation device 3 was operating at the previous control timing, the ventilation device 3 will continue operating. Furthermore, the "ventilation device: stopped state" in step S4 means that if the ventilation device 3 was operating at the previous control timing, the ventilation device 3 will stop operating, and if the ventilation device 3 was stopped at the previous control timing, the operation will continue to be stopped.

[0025] FIG. 4 is a diagram showing changes in CO2 concentration and changes in the CO2 concentration change rate in the ventilation system 10 according to the first embodiment. FIG. 4 also shows state changes between the operating state and the stopped state of the ventilation device 3. FIG. 4(a) is a graph showing changes in CO2 concentration [ppm]. FIG. 4(b) is a graph showing changes in the CO2 concentration change rate [ppm / min]. In FIG. 4(b), a positive value for the CO2 concentration change rate indicates an increase in the CO2 concentration, and a negative value for the CO2 concentration change rate indicates a decrease in the CO2 concentration. FIG. 4(c) is a timing diagram showing changes between the operating state and the stopped state of the ventilation device 3. FIG. 5 is a state transition diagram of the ventilation device 3 in the ventilation system 10 according to the first embodiment. Please refer to the description of FIG. 4 below for the state transition of the ventilation device 3 in FIG. 5 as needed.

[0026] Between time t0 and time t1, the CO2 concentration is less than the second concentration threshold as shown in (a), and the ventilation device 3 is in a stopped state as shown in (c).

[0027] At time t1, as shown in (a), the CO2 concentration becomes equal to or greater than the second concentration threshold, and as shown in (b), the CO2 concentration change rate becomes equal to or greater than the concentration change rate threshold (here, 50 ppm / min), so the ventilation device 3 changes from a stopped state to an operating state (second control mode) and begins ventilating the room.

[0028] At time t2, as shown in (a), the CO2 concentration becomes equal to or greater than the first concentration threshold, and the ventilation device 3 continues to operate. Note that the operation mode has been changed from the second control mode to the first control mode.

[0029] Between time t2 and time t3, as shown in (a), the CO2 concentration is equal to or higher than the first concentration threshold, so the ventilation device 3 continues to operate (first control mode).

[0030] At time t3, the CO2 concentration falls below the first concentration threshold, as shown in (a). Therefore, at time t3, the ventilation device 3 changes from the operating state (first control mode) to the stopped state. Note that at time t3, the CO2 concentration is equal to or greater than the second concentration threshold, but the CO2 concentration change rate is less than the concentration change rate threshold. Therefore, the ventilation control device 1 does not transition from the operating state (first control mode) to the operating state (second control mode), and the ventilation device 3 remains in the stopped state. In other words, if the CO2 concentration falls below the first concentration threshold while operating in the first control mode, the ventilation device 3 changes from the operating state (first control mode) to the stopped state. When the ventilation device 3 enters the stopped state at time t3, the CO2 concentration changes from a decreasing state to an increasing state, as shown in (a).

[0031] At time t4, as shown in (a), the CO2 concentration again becomes equal to or greater than the first concentration threshold, causing the ventilation device 3 to change from the stopped state to the operating state (first control mode) as shown in (c), and start ventilating the room again, which causes the CO2 concentration to decrease.

[0032] At time t5, as shown in (a), the CO2 concentration falls below the first concentration threshold, and the ventilation device 3 changes from an operating state to a stopped state.

[0033] Here, when the CO2 concentration change rate is less than the concentration change rate threshold, the ventilation control device 1 controls the switching between the operating state and the stopped state of the ventilation device 3 (hereinafter referred to as ON / OFF) using a first concentration threshold as a judgment criterion. Specifically, this ON / OFF control corresponds to the period from time t3 to time t5 in FIG. 4. When ON / OFF control is performed using the first concentration threshold as a judgment criterion in this way, there is a possibility that the operation of the ventilation device 3 will undergo hunting, in which the ventilation device 3 repeatedly turns ON and OFF in a short period of time. For this reason, the ventilation control device 1 may perform the following control.

[0034] The ventilation control device 1 uses the second concentration threshold instead of the first concentration threshold as the threshold for determining whether to switch the ventilation device 3 from the operating state to the stopped state. Specifically, referring to the example of FIG. 4 , the ventilation control device 1 switches the ventilation device 3 from the operating state to the stopped state at time t5, for example. However, instead of switching at time t5, the ventilation device 3 is switched from the operating state to the stopped state after time t5, when the CO2 concentration falls below the second concentration threshold. The subsequent operation is the same as described above. However, even if the CO2 concentration rises above the second concentration threshold immediately after falling below the second concentration threshold due to an increase in the number of people in the room, for example, the rate of increase in CO2 is unlikely to exceed the concentration change rate threshold, given that the CO2 concentration had been on a downward trend up until that point. Therefore, the ventilation device 3 is not repeatedly turned on and off in a short period of time.

[0035] As described above, the ventilation control device 1 has a first control mode and starts ventilation when the CO2 concentration is equal to or greater than the first concentration threshold, which is lower than the ventilation reference value. Therefore, the ventilation system 10 can stably keep the CO2 concentration in the room at or below the ventilation reference value, compared to when the first concentration threshold is set to the ventilation reference value.

[0036] Furthermore, if the ventilation control device 1 only has the first control mode and does not have the second control mode, the ventilation device 3 will enter an operating state at time t2 when the CO2 concentration reaches or exceeds the first concentration threshold. When the ventilation device 3 enters an operating state at time t2, the rate of change of the CO2 concentration in the room slows down, but ventilation cannot keep up, and the CO2 concentration exceeds the ventilation standard value, as shown by dotted line A in (a).

[0037] In contrast, the ventilation control device 1 of Embodiment 1 has a second control mode, and at a time t1 before time t2, it determines that the situation is such that the indoor CO2 concentration may exceed the ventilation reference value, and sets the ventilation device 3 to the operating state. As a result, the ventilation system 10 can prevent the CO2 concentration from exceeding the ventilation reference value as shown in (a).

[0038] Further, the ventilation system 10 does not simply start ventilation by setting the ventilation device 3 to the operating state when the CO2 concentration change rate becomes equal to or higher than the concentration change rate threshold, but further starts ventilation when the CO2 concentration is equal to or higher than the second concentration threshold. Therefore, the ventilation system 10 can avoid wasteful ventilation in the case of a temporary increase in the indoor CO2 concentration that does not exceed the ventilation reference value. As a result, the ventilation system 10 can suppress unnecessary changes in the room temperature and unnecessary power consumption caused by operating the ventilation device 3 at unnecessary timings.

[0039] Here, a supplement to FIG. 5 will be made. In FIG. 5, the arc-shaped arrows indicate that the "operating state (first control mode)", "operating state (second control mode)", and "stopped state" in each operating state to which this arrow is attached are continued, and the continuation conditions are described in the boxed portions. Specifically, the "operating state (first control mode)" is continued when "CO2 concentration ≥ first concentration threshold". Also, the "operating state (second control mode)" is continued when "second concentration threshold ≤ CO2 concentration < first concentration threshold, and CO2 concentration change rate ≥ concentration change rate threshold". Also, the "stopped state" is continued when "CO2 concentration < second concentration threshold, or (second concentration threshold ≤ CO2 concentration < first concentration threshold, and concentration change rate threshold < CO2 concentration change rate)".

[0040] Note that the ventilation system 10 may be modified as follows. The ventilation system 10 may appropriately combine the following modification examples.

[0041] In the above, the ventilation device 3 is assumed to have a constant ventilation volume, but it may be one in which the ventilation volume can be changed by changing the fan rotation speed. If the ventilation device 3 is one in which the ventilation volume can be changed, the operation of the ventilation system 10 may be changed as follows.

[0042] (1) The ventilation control device 1 sets the fan rotation speed to a first rotation speed in the first control mode, and to a second rotation speed lower than the first rotation speed in the second control mode. Specifically, the first rotation speed is set to, for example, the maximum rotation speed of the device. In other words, the ventilation control device 1 provides gentle ventilation when the CO2 concentration is equal to or greater than the second concentration threshold but less than the first concentration threshold, and maximizes the ventilation volume when the CO2 concentration is equal to or greater than the first concentration threshold. (2) In the case of (1) above, the ventilation control device 1 separately sets a second concentration change threshold that is faster than the concentration change rate threshold. Then, in the second control mode, when the rate of increase in the CO2 concentration is faster than the second concentration change threshold, the ventilation system 10 maximizes the ventilation volume, just as when the CO2 concentration is equal to or greater than the second concentration threshold but less than the first concentration threshold, in the same way as when the CO2 concentration is equal to or greater than the first concentration threshold.

[0043] The ventilation control device 1 may correct the default first concentration threshold and second concentration threshold that are set in advance in the storage unit 12 according to the operating conditions as follows.

[0044] (1) The ventilation control device 1 acquires the number of people in the room, and if the number of people is equal to or greater than a preset threshold, corrects the first and second concentration thresholds to lower them from the default values ​​stored in the memory unit 12 so that the ventilation device 3 starts operating sooner. Furthermore, when the number of people detected by the number of people detection device 17 falls below the threshold, the ventilation control device 1 restores the first and second concentration thresholds to their original values. The ventilation control device 1 may acquire the number of people in the room, for example, via wireless or wired communication from a human presence sensor 18 (see FIG. 6 described below) installed separately from the ventilation system 10. An example of a separate human presence sensor is a pyroelectric sensor installed in an indoor unit (not shown) that air-conditions the room. The human presence sensor 18 may alternatively be, for example, an infrared sensor installed at the entrance of the room, which counts the number of people entering and leaving the room to acquire the number of people in the room.

[0045] (2) If the CO2 increase rate reaches or exceeds a second concentration change threshold, which is faster than the concentration change rate threshold, before the CO2 concentration reaches or exceeds the second concentration threshold, the ventilation control device 1 may temporarily lower the first concentration threshold and the second concentration threshold from their default values ​​to start ventilation earlier.

[0046] (3) If the filter installed in the ventilation device 3 becomes clogged or the fan deteriorates, the ventilation volume of the ventilation device 3 will decrease even if the rotation speed remains the same. If the ventilation volume of the ventilation device 3 decreases, the CO2 concentration may exceed the ventilation standard value even if the same control is performed by the ventilation control device 1. For example, if the CO2 concentration exceeds the ventilation standard value even though the rate of increase in the CO2 concentration has not increased, or if the CO2 concentration exceeds the ventilation standard value even though there are not many people in the room, it can be assumed that the cause is a decrease in the ventilation volume.

[0047] When the ventilation rate decreases due to deterioration of the ventilation device 3, the ventilation control device 1 lowers the first concentration threshold and the second concentration threshold below their default values ​​so that ventilation will begin sooner, and displays a message on the display device that ventilation is recommended. If the operation unit 13 is a display panel, the operation unit 13 may also function as the display device. The display device may also be configured with an indicator lamp such as an LED that lights up when ventilation is recommended.

[0048] Specifically, when the ventilation control device 1 detects a decrease in ventilation rate due to deterioration of the ventilation device 3, it corrects the first concentration threshold and the second concentration threshold to be lower than the default values. When the decrease in ventilation rate due to deterioration of the ventilation device 3 is resolved, the ventilation control device 1 restores the first concentration threshold and the second concentration threshold to their original values. The situation where the decrease in ventilation rate due to deterioration of the ventilation device 3 is resolved corresponds to a case where a user performs an operation to clean the filter, or a case where there is an excess of ventilation and the filter is cleaned even without a user operation.

[0049] A decrease in ventilation rate due to deterioration of the ventilation device 3 may be detected, for example, by the ventilation control device 1 accumulating the operating time of the ventilation device 3, and detecting that the accumulated operating time exceeds a preset time as a decrease in ventilation rate due to deterioration of the ventilation device 3. This is because if the ventilation device 3 has been operating for longer than the set time, it is natural that the filter will become clogged, and the intention is to assume that a decrease in ventilation rate due to clogging has occurred. Furthermore, a decrease in ventilation rate due to deterioration of the ventilation device 3 may be detected, for example, by a sensor that detects clogged filters.

[0050] The reduction amounts of the first and second density thresholds in (1), (2), and (3) above are not particularly limited and can be set arbitrarily. The reduction amounts of the first and second density thresholds may be set in advance, or may be input by the user via the operation unit 13.

[0051] In addition, there may be areas in a room where there are few people and areas where there are many people. In such cases, it is possible to perform the above control using the CO2 concentration in the areas where people are crowded. Therefore, the ventilation system 10 may have the configuration shown in Figure 6 below.

[0052] 6 is an explanatory diagram of a usage form of a modified example of the ventilation system according to Embodiment 1. The ventilation system 10 includes a plurality of CO2 concentration detecting devices 2. The CO2 concentration detecting devices 2 are installed in a dispersed manner in a room. The ventilation control device 1 identifies, from among the plurality of CO2 concentration detecting devices 2, a CO2 concentration detecting device 2 that is located near an area in the room where there are many people, and performs the above-mentioned control based on the detection result of the identified CO2 concentration detecting device 2. A human presence sensor 18 that is installed separately from the ventilation system 10 is also installed in the room.

[0053] The human presence sensor 18 is composed of a pyroelectric sensor that detects infrared rays emitted from a heat source such as a person. Although not shown, the pyroelectric sensor has a sensor unit with multiple pyroelectric elements arranged in a vertical row. The pyroelectric sensor rotates and moves the sensor unit to scan the room and detects how many people are present in which area of ​​the room. The detection results of the human presence sensor 18 are transmitted to the ventilation control device 1 via wireless or wired communication. Note that the human presence sensor 18 is not limited to a pyroelectric sensor, and any sensor that can identify the location and number of people in the room will do.

[0054] The ventilation system 10 identifies CO2 concentration detection devices 2 located near areas with a large number of people in a room, for example, as follows. The ventilation system 10 identifies the location information of each CO2 concentration detection device 2 based on the wireless strength of wireless communication 5a. The ventilation control device 1 determines the number of people around each CO2 concentration detection device 2 based on the location information of each CO2 concentration detection device 2 identified based on the wireless strength and human detection information detected by the human sensor 18. The ventilation control device 1 identifies CO2 concentration detection devices 2 located near areas with the largest number of people. The method of identifying CO2 concentration detection devices 2 located near areas with the largest number of people is not limited to the method based on wireless strength described above. For example, the location information of each CO2 concentration detection device 2 may be identified by determining the indoor location of each CO2 concentration detection device in advance and identifying the location from the identification number of the CO2 concentration detection device.

[0055] The ventilation system 10 of the first embodiment includes a CO2 concentration detection device 2 that detects the CO2 concentration in a room, and a ventilation device 3 that ventilates the room. The ventilation system 10 further includes a ventilation control device 1 that has a first control mode that operates the ventilation device 3 when the CO2 concentration is equal to or higher than a first concentration threshold that is lower than a ventilation reference value that is a reference value requiring ventilation, and a second control mode that operates the ventilation device 3 when it is estimated that the CO2 concentration will exceed a predetermined ventilation reference value based on the CO2 concentration and the rate of increase of the CO2 concentration. The ventilation control device 1 operates in the first control mode or the second control mode based on the CO2 concentration and the rate of increase of the CO2 concentration.

[0056] With the above configuration, the ventilation system 10 can stably maintain the indoor CO2 concentration at or below the ventilation standard value by operating in the first control mode, compared to when the first concentration threshold is set to the ventilation standard value. Furthermore, the ventilation system 10 can avoid unnecessary ventilation when a temporary increase in CO2 concentration occurs that does not exceed the ventilation standard value by operating in the second control mode. In this way, the ventilation system 10 can appropriately control the ventilation timing to provide ventilation appropriate to the indoor CO2 concentration.

[0057] The second control mode is a mode in which the ventilation device 3 is put into operation when the CO2 concentration is equal to or higher than a second concentration threshold that is lower than the first concentration threshold, and the rate of change of the CO2 concentration is equal to or higher than a predetermined concentration change rate threshold.

[0058] With the above configuration, the ventilation system 10 can avoid unnecessary ventilation when a temporary increase in CO2 concentration occurs that does not cause the CO2 concentration to exceed the ventilation standard value.

[0059] The ventilation control device 1 stops the ventilation device 3 when the CO2 concentration is below the second concentration threshold. Furthermore, the ventilation control device 1 changes the ventilation device 3 from an operating state to a stopped state when the CO2 concentration falls below the first concentration threshold while operating in the first control mode.

[0060] With the above configuration, the ventilation system 10 can avoid unnecessary ventilation when the CO2 concentration does not exceed the ventilation standard value.

[0061] The ventilation control device 1 includes an operation unit 13 through which the user inputs the concentration change rate threshold, and the concentration change rate threshold is determined by the user's input to the operation unit 13.

[0062] With the above configuration, the ventilation system 10 can set the concentration change rate threshold by inputting it to the operation unit 13 by the user.

[0063] The ventilation system 10 includes an operation switch 3a for switching between activation and deactivation of the ventilation device 3, and activation and deactivation of the ventilation device 3 can be manually switched by operating the operation switch 3a.

[0064] With the above configuration, the ventilation system 10 also allows the ventilation device 3 to be operated manually.

[0065] The ventilation system 10 includes a setting unit 13a that is operated by a user and that sets the priority between the manual operation mode and the automatic operation mode. The ventilation control device 1 controls the ventilation device 3 based on the CO2 concentration and the rate of increase in the CO2 concentration when the priority of the automatic operation mode is higher than the priority of the manual operation mode, and controls the ventilation device 3 based on the operation of the operation switch 3a when the priority of the manual operation mode is higher than the priority of the automatic operation mode.

[0066] With the above configuration, the ventilation system 10 allows the user to determine the priority between the manual operation mode and the automatic operation mode.

[0067] The ventilation control device 1 acquires the number of people in the room, and if the number of people is equal to or greater than a preset number-of-people threshold, corrects the first concentration threshold and the second concentration threshold to lower them, and if the number of people falls below the number-of-people threshold, restores the first concentration threshold and the second concentration threshold to their original values.

[0068] With the above configuration, the ventilation system 10 can quickly put the ventilation device 3 into operation when the number of people in the room is equal to or greater than the threshold number of people.

[0069] When a decrease in ventilation volume due to deterioration of the ventilation device 3 is detected, the ventilation control device 1 decreases the first concentration threshold and the second concentration threshold, and when the decrease in ventilation volume due to deterioration of the ventilation device 3 is resolved, the ventilation control device 1 restores the first concentration threshold and the second concentration threshold to their original values.

[0070] With the above configuration, the ventilation system 10 can prevent the CO2 concentration from exceeding the ventilation standard value when the ventilation device 3 deteriorates.

[0071] The ventilation system 10 includes a plurality of CO2 concentration detection devices 2, and the ventilation control device 1 identifies, from among the plurality of CO2 concentration detection devices 2, a CO2 concentration detection device 2 that is located near an area in the room where there are many people, and controls the first control mode and the second control mode based on the detection result of the identified CO2 concentration detection device 2.

[0072] With the above configuration, the ventilation system 10 can control the ventilation volume in the room based on the CO2 concentration in the area where the number of people is large.

[0073] Embodiment 2 The second embodiment relates to an air conditioning system equipped with the ventilation system 10 of the first embodiment.

[0074] Fig. 7 is a diagram showing the configuration of an air conditioning system 200 pertaining to embodiment 2. The air conditioning system 200 includes the ventilation system 10 of embodiment 1 and an air conditioner 100. The air conditioner 100 includes an indoor unit 101 and an outdoor unit 102. The indoor unit 101 and the outdoor unit 102 are connected by connecting pipes 103 and 104. The air conditioner 100 conditions the air inside the room by circulating a refrigerant between the indoor unit 101 and the outdoor unit 102 via the connecting pipes 103 and 104.

[0075] The air conditioning system 200 has a control device 1a that controls the entire air conditioning system. The control device 1a is configured to include the ventilation control device 1 of the first embodiment.

[0076] In the first embodiment, the ventilation system 10 is used independently, but in the second embodiment, the ventilation system 10 is incorporated into the air conditioning system 200. In this way, the ventilation system 10 may be used independently or may be incorporated into the air conditioning system 200. [Explanation of symbols]

[0077] 1 ventilation control device, 1a control device, 2 CO2 concentration detection device, 3 ventilation device, 3a operation switch, 4 external device, 5a communication between CO2 concentration detection device communication unit and CO2 concentration detection device, 5b communication between ventilation device communication unit and ventilation device, 5c communication between external device communication unit and external device, 10 ventilation system, 11 control unit, 12 memory unit, 13 operation unit, 13a setting unit, 14 communication between CO2 concentration detection devices, 15 ventilation device communication unit, 16 external device communication unit, 18 human presence sensor, 21 communication unit between ventilation control devices, 22 CO2 concentration detection unit, 100 air conditioner, 101 indoor unit, 102 outdoor unit, 103 connecting piping, 104 connecting piping, 200 air conditioning system.

Claims

1. Indoor CO ２ CO concentration detection ２ a concentration detection device; a ventilation device for ventilating the room; The CO ２ a first control mode in which the ventilation device is put into an operating state when the CO concentration is equal to or greater than a first concentration threshold value that is lower than a ventilation reference value that is a reference value that requires ventilation; ２ concentration and the CO ２ Based on the rate of increase in the concentration, ２ a second control mode that operates the ventilation device when the concentration is estimated to exceed the ventilation reference value; The second control mode is a mode in which the ventilation device is put into operation when the CO 2 concentration is equal to or higher than a second concentration threshold that is lower than the first concentration threshold and when the rate of change of the CO 2 concentration is equal to or higher than a predetermined concentration change rate threshold.

2. A CO2 concentration detection device that detects the CO2 concentration in a room; a ventilation device for ventilating the room; a ventilation control device having a first control mode in which the ventilation device is put into an operating state when the CO 2 concentration is equal to or higher than a first concentration threshold value that is lower than a ventilation reference value that is a reference value requiring ventilation, and a second control mode in which the ventilation device is put into an operating state when it is estimated that the CO 2 concentration will exceed the ventilation reference value based on the CO 2 concentration and a rate of increase of the CO 2 concentration, The ventilation control device includes: an operation in the first control mode or the second control mode is performed based on the CO 2 concentration and the rate of increase of the CO 2 concentration; a plurality of the CO 2 concentration detection devices; The ventilation control device includes: A ventilation system that identifies, from among the multiple CO2 concentration detection devices, a CO2 concentration detection device that is located near an area in the room where there are many people, and controls the first control mode and the second control mode based on the detection result of the identified CO2 concentration detection device.

3. The second control mode is ２ The concentration is equal to or greater than a second concentration threshold value that is lower than the first concentration threshold value, and ２ 3. The ventilation system according to claim 2, wherein the mode is one in which the ventilation device is put into an operating state when the rate of change of the concentration is equal to or greater than a preset threshold value of the rate of change of the concentration.

4. The ventilation control device ２ The ventilation system according to claim 1 or 3, wherein the ventilation device is stopped when the concentration is less than the second concentration threshold.

5. The ventilation control device is configured to: ２ The ventilation system according to any one of claims 1 to 3, wherein the ventilation device is changed from an operating state to a stopped state when the concentration falls below the first concentration threshold.

6. 4. The ventilation system according to claim 1, wherein the ventilation control device includes an operation unit through which a user inputs the concentration change rate threshold, and the concentration change rate threshold is determined by the user inputting the concentration change rate threshold into the operation unit.

7. A ventilation system as described in any one of claims 1 to 3, which is provided with an operation switch for switching on and off the ventilation device, and the operation switch can be operated to manually switch on and off the ventilation device.

8. a setting unit that is operated by a user and sets the priority between a manual operation mode and an automatic operation mode; The ventilation control device includes: If the priority of the automatic operation mode is higher than the priority of the manual operation mode, ２ concentration and the CO ２ controlling the ventilation device based on the rate of increase of the concentration; The ventilation system according to claim 7, wherein when the priority of the manual operation mode is higher than the priority of the automatic operation mode, the ventilation device is controlled based on the operation of the operation switch.

9. The ventilation control device includes: acquiring the number of people in the room, and if the number of people is equal to or greater than a predetermined number-of-people threshold, performing a correction to decrease the first concentration threshold and the second concentration threshold; The ventilation system according to claim 1 or 3, wherein when the number of people falls below the number of people threshold, the first concentration threshold and the second concentration threshold are restored to their original values.

10. The ventilation control device includes: When a decrease in ventilation volume due to deterioration of the ventilation device is detected, the first concentration threshold and the second concentration threshold are decreased; The ventilation system according to claim 1 or 3, wherein the first concentration threshold and the second concentration threshold are restored to their original values ​​when a decrease in ventilation volume due to deterioration of the ventilation device is resolved.

11. An air conditioning system comprising the ventilation system according to any one of claims 1 to 3.

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