Method for determining presence or absence, method for controlling a ventilation system, presence or absence determination system, and ventilation system

Abstract

This invention provides a method for determining the presence or absence of a person that requires less cost for equipment installation than conventional methods and can more accurately determine whether a person is present or absent. [Solution] The presence / absence determination method is a method for determining the presence or absence of a user within a facility 90, which is performed by a computer, and involves acquiring the CO2 concentration inside the facility 90 measured by a CO2 sensor 60 installed inside the facility 90 at regular intervals when ventilation is being performed inside the facility 90 by a ventilation system 100 (S101), acquiring or estimating the CO2 concentration outside the facility 90 (S102), and using the acquired CO2 concentration inside the facility 90 and the acquired or estimated CO2 concentration outside the facility 90, determining the presence or absence of a user within the facility 90 (S103).

Description

Technical Field

[0001] The present disclosure relates to a presence / absence determination method and the like.

Background Art

[0002] A whole-building air-conditioning system that air-conditions a plurality of rooms with a single air conditioner has been proposed. As such a whole-building air-conditioning system, Patent Document 1 discloses an air-conditioning control system that determines the presence / absence of people using a human presence sensor or the like and performs control in consideration of the presence / absence of people.

[0003] Further, Patent Document 2 discloses a determination method for determining the presence / absence of people using the CO2 concentration within a facility.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Human presence sensors generally use infrared or ultrasonic waves to detect people, and therefore can only detect people within a limited range. Consequently, depending on the structure or size of the facility, it may be necessary to install multiple human presence sensors. Furthermore, because human presence sensors can only detect people within a limited range, blind spots may be created depending on how the sensors are installed, potentially leading to missed detections of people. In other words, the air conditioning control system described in Patent Document 1 requires the installation of multiple human presence sensors in order to perform accurate control that takes into account the presence or absence of people, thus incurring costs for its implementation. Moreover, the air conditioning control system described in Patent Document 1 may not be able to perform accurate control that takes into account the presence or absence of people if blind spots are created depending on how the multiple human presence sensors are installed.

[0006] Furthermore, the determination method described in Patent Document 2 determines the presence or absence of people by comparing the time fluctuation of the CO2 concentration inside the facility with a threshold value. Therefore, this determination method may incorrectly determine that people are absent when the number of people inside the facility decreases (for example, when the number of people inside the facility goes from 3 to 1).

[0007] The present invention provides a method for determining the presence or absence of a person that requires less cost for introducing equipment than conventional methods and can determine the presence or absence of a person more accurately. [Means for solving the problem]

[0008] A method for determining presence or absence according to one aspect of the present invention is a method for determining the presence or absence of a user in a facility, performed by a computer, and includes acquiring the CO2 concentration inside the facility measured by a CO2 sensor installed in the facility at regular intervals when ventilation is being performed inside the facility by a ventilation system, acquiring or estimating the CO2 concentration outside the facility, and determining the presence or absence of the user in the facility using the acquired CO2 concentration inside the facility and the acquired or estimated CO2 concentration outside the facility.

[0009] A control method for a ventilation system according to one aspect of the present invention is a control method for a ventilation system using the presence / absence determination method, which is executed by a computer, wherein the ventilation system comprises an air conditioning unit, a transport device that transports air whose temperature has been adjusted by the air conditioning unit to each of a plurality of rooms in the facility, and a plurality of temperature sensors installed in each of the plurality of rooms for measuring the temperature of each of the plurality of rooms, and the control method includes, when the presence / absence determination method determines that the user is present in the room, controlling the air conditioning unit and the transport device so that the temperature measured by the temperature sensors installed in each of the plurality of rooms becomes a set temperature set by the user, and when the presence / absence determination method determines that the user is absent, stopping the air conditioning unit and the transport device, or controlling the air conditioning unit and the transport device so that the energy consumption of the air conditioning unit and the transport device becomes less than a first specified value and the temperature measured by the temperature sensors installed in each of the plurality of rooms becomes the set temperature.

[0010] A presence / absence determination system according to one aspect of the present invention comprises a CO2 sensor installed in a facility when ventilation is being performed by a ventilation system, which measures the CO2 concentration inside the facility, and a control device, wherein the control device acquires the CO2 concentration inside the facility measured by the CO2 sensor at regular intervals, acquires or estimates the CO2 concentration outside the facility, and uses the acquired CO2 concentration inside the facility and the acquired or estimated CO2 concentration outside the facility to determine whether a user is present or absent from the facility.

[0011] A ventilation system according to one aspect of the present invention comprises an occupancy determination system, an air conditioning unit, a transport device for transporting air whose temperature has been adjusted by the air conditioning unit to each of a plurality of rooms in the facility, and a plurality of temperature sensors installed in each of the plurality of rooms for measuring the temperature of each of the plurality of rooms, wherein the control device controls the air conditioning unit and the transport device so that the temperature measured by the temperature sensors installed in each of the plurality of rooms becomes a set temperature set by the user when the occupancy determination system determines that the user is in a room, and stops the air conditioning unit and the transport device when the occupancy determination system determines that the user is absent, or controls the air conditioning unit and the transport device so that the energy consumption of the air conditioning unit and the transport device becomes less than a first specified value and the temperature measured by the temperature sensors installed in each of the plurality of rooms becomes the set temperature. [Effects of the Invention]

[0012] The presence / absence determination method described herein requires less cost for equipment installation than conventional methods and can determine a person's presence or absence more accurately. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 shows the daily fluctuations in CO2 concentration and PM2.5 concentration within the facility. [Figure 2] Figure 2 is a block diagram showing the configuration of the occupancy detection system and ventilation system according to an embodiment. [Figure 3] Figure 3 is a block diagram showing the functional configuration of the occupancy detection system and ventilation system according to an embodiment. [Figure 4] Figure 4 is a flowchart showing an example of the operation of the presence / absence determination system according to the embodiment. [Figure 5] Figure 5 shows an example of fluctuations in CO2 concentration within the facility. [Figure 6] Figure 6 is a flowchart showing an example of the operation of the ventilation system according to the embodiment. [Figure 7] FIG. 7 is a block diagram showing the configuration of a ventilation system according to a first modification. [Figure 8A] FIG. 8A is a diagram showing the guideline of the control content executed by the ventilation system based on the information regarding the demand reduction request. [Figure 8B] FIG. 8B is a diagram showing the guideline of the control content executed by the ventilation system based on the information regarding the electricity charge. [Figure 9] FIG. 9 is a block diagram showing the configuration of a ventilation system according to a second modification.

BEST MODE FOR CARRYING OUT THE INVENTION

[0014] (Knowledge underlying the present disclosure) First, the inventors' points of attention will be described below.

[0015] In highly airtight and highly heat-insulated facilities that are attracting attention for energy conservation, the intake amount of air outside the facility and the discharge amount of air inside the facility are controlled by a ventilation system. In such highly airtight and highly heat-insulated facilities equipped with a ventilation system, it is considered that there may be a significant correlation between the CO2 concentration inside the facility measured by a CO2 (carbon dioxide) sensor installed inside the facility, and the number of people and the occupancy time inside the facility. Therefore, the inventors conducted an experiment to measure the fluctuations in CO2 concentration and PM2.5 concentration during absence and presence in a highly airtight and highly heat-insulated facility.

[0016] FIG. 1 is a diagram showing the daily fluctuations in CO2 concentration and PM2.5 concentration inside the facility. Specifically, FIG. 1 is a diagram showing the fluctuations in CO2 concentration and PM2.5 concentration inside the facility when two people were present in the living room on the first floor of the facility for about two hours starting from around 8:30. The facility is a two-story house. Also, the CO2 sensor for measuring the CO2 concentration and the PM2.5 sensor for measuring the PM2.5 concentration are installed in the kitchen on the first floor of the facility and in the corridor on the second floor connected to the first floor by a void.

[0017] As shown in Fig. 1, from immediately after two people entered the facility (around 8:26) until immediately before they left (around 10:21), the CO2 concentration (dotted line) measured by the CO2 sensor installed in the kitchen on the first floor and the CO2 concentration (two-dot chain line) measured by the CO2 sensor installed in the corridor on the second floor increased. On the other hand, in the same time period as above, the PM2.5 concentration (solid line) measured by the PM2.5 sensor installed in the kitchen on the first floor and the PM2.5 concentration (one-dot chain line) measured by the PM2.5 sensor installed in the corridor on the second floor showed almost no change. Also, after immediately after they left (around 10:44), the CO2 concentrations measured by the CO2 sensors installed in the kitchen on the first floor and the corridor on the second floor decreased. As described above, even in a space away from the space where people stay, since CO2 propagates smoothly, it has been demonstrated that there is a significant correlation between the CO2 concentration in the facility, the number of people in the facility, and the occupancy time.

[0018] In view of the above, the inventors have created the present disclosure.

[0019] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that each of the embodiments described below shows a specific example of the present disclosure. Therefore, the numerical values, shapes, materials, components, arrangement positions and connection forms of the components, as well as the processes (steps) and the order of the processes shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Therefore, among the components in the following embodiments, the components not described in the independent claims of the present disclosure are described as optional components.

[0020] Note that each figure is a schematic diagram and is not necessarily drawn precisely. Also, in each figure, the same reference numerals are given to substantially the same configurations, and duplicate descriptions may be omitted or simplified.

[0021] (Embodiment) [1. Configuration of Occupancy Determination System and Ventilation System] The configuration of the occupancy detection system and ventilation system according to the embodiment will be described below. Figure 2 is a block diagram showing the configuration of the occupancy detection system 10 and ventilation system 100 according to the embodiment. Figure 3 is a block diagram showing the functional configuration of the occupancy detection system 10 and ventilation system 100 according to the embodiment.

[0022] As shown in Figures 2 and 3, the presence / absence determination system 10 is a system that determines the presence or absence of a user in the facility 90 using one CO2 sensor 60. The presence / absence determination system 10 comprises a CO2 sensor 60 and a control device 80. The presence / absence determination system 10 may also be equipped with multiple CO2 sensors 60. The ventilation system 100 is a system that can ventilate the facility 90 using an outside air intake fan 30. The ventilation system 100 can also control the temperature of multiple rooms 90a to 90c in the facility 90 using one air conditioning unit 21. The ventilation system 100 can also control the humidity of multiple rooms 90a to 90c in the facility 90 using one dehumidifier 22. The number of multiple rooms is not particularly limited. The ventilation system 100 comprises the aforementioned presence / absence determination system 10 (i.e., the CO2 sensor 60 and the control device 80), a whole-house air conditioning unit 20 equipped with an indoor air intake 40, an outdoor air intake fan 30, a plurality of temperature sensors 50, and a humidity sensor 70. Each of the whole-house air conditioning unit 20, the outdoor air intake fan 30, the plurality of temperature sensors 50, the CO2 sensor 60, and the humidity sensor 70 has the function of communicating with the control device 80.

[0023] The whole-building air conditioning system 20 controls the temperature of multiple rooms 90a to 90c by adjusting the temperature of air taken in from outside the facility 90 (hereinafter also referred to as outside air) or air taken in from inside the facility 90 (hereinafter also referred to as inside air) and transporting it to each of the multiple rooms 90a to 90c. The whole-building air conditioning system 20 comprises an air conditioning unit 21, a dehumidifier 22, and a transport unit 23.

[0024] The air conditioning unit 21 is a so-called air conditioner and includes an air conditioning unit 211. The function of the dehumidifier 22, described later, may also be implemented by the air conditioning unit 21. In other words, the air conditioning unit 21 may include both an air conditioning unit 211 and a dehumidifier unit 221, described later.

[0025] The air conditioning unit 211 adjusts the temperature of the air taken in from outside the facility 90 or the air taken in from inside the facility 90, based on the control of the control device 80.

[0026] The dehumidifying device 22 is a so-called dehumidifier and includes a dehumidifying unit 221.

[0027] The dehumidification unit 221 adjusts the humidity inside the facility 90 based on the control of the control device 80. The dehumidification unit 221 is, for example, a compressor-type dehumidification unit that dehumidifies by cooling the air with a cooler and causing condensation, but it may also be a desiccant-type dehumidification unit that dehumidifies by adsorbing moist air with a hygroscopic rotor.

[0028] The conveying device 23, based on the control of the control device 80, conveys air (outside or inside) whose temperature has been adjusted by the air conditioning unit 211 to each of the multiple rooms 90a to 90c within the facility 90. The conveying device 23 comprises multiple conveying fans 23a, multiple ducts 23b, and multiple air outlets 23c. The conveying device 23 is equipped with one set of conveying fans 23a, ducts 23b, and air outlets 23c for each room.

[0029] The outside air intake fan 30 (hereinafter also referred to as the outside air intake device 30) takes in outside air from the facility 90 and transports it to the whole-house air conditioning system 20 based on the control of the control device 80. The difference between the amount of air taken in by the outside air intake fan 30 and the total amount of air sent to the multiple rooms 90a to 90c by the transport device 22 is the amount of air from inside the facility 90 (more specifically, the air in the space including the multiple rooms 90a to 90c within the facility 90) that is taken into the whole-house air conditioning system 20 through the indoor air intake 40.

[0030] One temperature sensor 50 is placed in each of the multiple rooms 90a to 90c, and measures the temperature in the room where the temperature sensor is placed. The temperature sensor 50 has a communication function and can transmit temperature data indicating the measured temperature (hereinafter also referred to as the measured temperature) to the control device 80.

[0031] The CO2 sensor 60 is installed inside the facility 90, measures the CO2 concentration inside the facility 90, and transmits the measured CO2 concentration data to the control device 80. In the example in Figure 2, the CO2 sensor 60 is shown to be installed near the indoor air intake 40, but it may be installed in other locations. The CO2 sensor 60 should be installed in a location where the air inside the facility 90 circulates, for example, it may be installed in any of the multiple rooms 90a to 90c.

[0032] The humidity sensor 70 is installed inside the facility 90, measures the humidity inside the facility 90, and transmits the humidity measurement data to the control device 80. In the example in Figure 2, the humidity sensor 70 is shown to be installed near the indoor air intake 40, but it may be installed in other locations. The humidity sensor 70 should be installed in a location where the air inside the facility 90 circulates, for example, it may be installed in any of the multiple rooms 90a to 90c.

[0033] The control device 80 is a control device that controls the whole-building air conditioning system 20 (specifically, the air conditioning unit 21, the dehumidifier 22, and the transport unit 23) and the outside air intake fan 30. The control device 80 comprises an operation reception unit 81, a control unit 82, a storage unit 83, and a communication unit 84.

[0034] The operation reception unit 81 is a user interface unit that receives operations from users of the facility 90. The operation reception unit 81 is implemented, for example, by a touch panel, but may also include hardware buttons. Although not shown in the figures, the control device 80 includes a display unit implemented by a display panel such as a liquid crystal panel or an organic EL (Electro Luminescence) panel, and the operation reception unit 81 and the display unit may constitute a GUI (Graphical User Interface).

[0035] The control unit 82 controls the whole-building air conditioning system 20 and the outside air intake fan 30 by causing the communication unit 84 to transmit control signals. The control unit 82 is implemented by, for example, a microcomputer, but may also be implemented by a processor. The control unit 82 also includes an occupancy determination unit 82a, an occupancy prediction unit 82b, and an air conditioning and air quality control unit 82c.

[0036] The presence / absence determination unit 82a determines whether a user is present or absent within the facility 90 based on the CO2 concentration within the facility 90 received by the communication unit 84. The method for determining the presence or absence of a user performed by the presence / absence determination unit 82a will be explained later in [2-1. Method for determining the presence or absence of a user].

[0037] Furthermore, the presence / absence determination unit 82a displays the determination result regarding the user's presence or absence on the display unit and presents the determination result to the user. Based on the user input received by the operation reception unit 81 regarding whether the determination result is accurate, the presence / absence determination unit 82a updates the parameters for determining the user's presence or absence. Specific examples of the parameter updates for determining the user's presence or absence performed by the presence / absence determination unit 82a will be explained later in [2-2. Specific Examples of Parameter Updates for Determining the User's Presence or Absence].

[0038] The presence / absence prediction unit 82b generates presence / absence prediction information that indicates whether or not the user will be present in the facility 90 from the present to the future, based on the presence / absence determination result of the presence / absence determination unit 82a. The method for generating presence / absence prediction information performed by the presence / absence prediction unit 82b will be described later in [2-3. Method for generating presence / absence prediction information].

[0039] The air conditioning and air quality control unit 82c controls the whole-building air conditioning system 20 based on at least one of the user presence / absence determination result obtained by the presence / absence determination unit 82a and the presence / absence prediction information obtained by the presence / absence prediction unit 82b. The air conditioning and air quality control unit 82c also controls the whole-building air conditioning system 20 based on one of the information provided by the power company regarding demand reduction requests to adjust electricity usage and information regarding electricity charges, and the user presence / absence determination result obtained by the presence / absence determination unit 82a. Specific examples of control of the whole-building air conditioning system 20 performed by the air conditioning and air quality control unit 82c will be described in detail later.

[0040] The memory unit 83 is a storage device that stores control programs and the like executed by the control unit 82. The memory unit 83 is implemented, for example, by a semiconductor memory.

[0041] The communication unit 84 is a communication module (communication circuit) that allows the control device 80 to communicate with the whole-building air conditioning system 20, the outside air intake fan 30 temperature sensor 50, the CO2 sensor 60, and the humidity sensor 70 via a local communication network. The communication performed by the communication unit 84 may be wireless communication, for example, but it may also be wired communication. There are no particular limitations on the communication standards used for communication.

[0042] Although not shown in Figure 2, a CO2 sensor different from the CO2 sensor 60 installed inside facility 90 may be installed outside facility 90 (specifically, on the outer wall of facility 90, or within the premises of facility 90, etc.). The CO2 sensor installed outside facility 90 will measure the CO2 concentration outside facility 90.

[0043] [2. Example of the operation of the presence / absence determination system] Next, an example of the operation of the presence / absence determination system 10 will be described. Figure 4 is a flowchart of an example of the operation of the presence / absence determination system 10 according to the embodiment.

[0044] First, the communication unit 84 of the control device 80 acquires the current CO2 concentration inside the facility 90 from the CO2 sensor 60 installed inside the facility 90 at regular intervals (for example, every 10 minutes) (S101). The communication unit 84 also acquires the current CO2 concentration outside the facility 90 from a CO2 sensor installed outside the facility 90 at regular intervals, or estimates the current CO2 concentration outside the facility 90 using a representative constant (S102).

[0045] The presence / absence determination unit 82a determines the presence or absence of the user using the current CO2 concentration inside the facility 90 obtained in step S101 and the current CO2 concentration outside the facility 90 obtained or estimated in step S102 (S103). The presence / absence determination unit 82a displays the obtained determination result regarding the presence or absence of the user on the display unit and presents the determination result to the user (S104).

[0046] The operation reception unit 81 receives input from the user regarding whether the judgment result presented in step S104 is accurate (S105). The presence / absence determination unit 82a updates the parameters for determining the presence or absence of the user based on the input from the user received in step S105 (S106).

[0047] The presence / absence prediction unit 82b generates presence / absence prediction information from the present to the future based on the determination result obtained by the presence / absence determination unit 82a (specifically, information regarding the user's presence / absence from the past to the present) (S107).

[0048] Furthermore, in order for the presence / absence determination system 10 to accurately determine the presence or absence of a user with a small number of CO2 sensors 60, the CO2 sensors 60 need to be installed in locations where the air within the facility 90 is mixed without bias. For example, the CO2 sensors 60 should be installed in locations where air from within the facility 90 is taken in for air circulation, or in large rooms (such as living rooms) where there are many outlets for air that has been temperature-controlled by the air conditioning system 21.

[0049] Furthermore, in step S102, the communication unit 84 may obtain information published on the internet as the current CO2 concentration outside the facility 90.

[0050] The following sections will provide a more detailed explanation of the method used by the presence / absence determination unit 82a to determine the presence or absence of a user (S103), specific examples of the update content of the parameters for determining the presence or absence of a user (S106), and the method used by the presence / absence prediction unit 82b to generate presence / absence prediction information (S107).

[0051] [2-1. Method for determining whether a user is present or absent] First, we will explain how to determine the presence or absence of a user. First, we will explain the symbols used to determine the presence or absence of a user. Co(t) is the amount of CO2 per unit volume contained in the outside air (i.e., the air outside facility 90) at time t. Ci(t) is the amount of CO2 per unit volume contained in the inside air (i.e., the air inside facility 90) at time t, and Ci(t+1) is the amount of CO2 per unit volume contained in the inside air after a unit time has elapsed from time t. Ch is the amount of CO2 released per unit time by a person through respiration. Wo is the amount of outside air taken in per unit time by the outside air intake fan 30. Ws is the volume inside facility 90. Nh is the number of people inside facility 90. Furthermore, for the sake of simplicity, the model will be simplified in the following explanation.

[0052] When a person is present in facility 90, the amount of CO2 in facility 90 increases by Ch × Nh per unit time due to the person's respiration. On the other hand, when facility 90 is ventilated by the ventilation system 100, the ventilation system 100 takes in air from outside facility 90 and expels the same amount of air from inside facility 90 as the amount of air taken in from outside facility 90. In other words, when facility 90 is ventilated by the ventilation system 100, the amount of CO2 in facility 90 decreases by (Ci(t)-Co(t)) × Wo per unit time. Therefore, the amount of CO2 in facility 90 at time t+1, after a unit time has elapsed from time t, can be expressed by the following equation 1.

[0053] Ci(t+1)×Ws=Ci(t)×Ws-(Ci(t)-Co(t))×Wo+Ch×Nh (Formula 1)

[0054] Furthermore, by rearranging Equation 1 above, we can obtain the rate of increase in CO2 per unit time as shown in Equation 2 below.

[0055] (Ci(t+1)-Ci(t))×Ws=Ch×Nh-(Ci(t)-Co(t))×Wo (Formula 2)

[0056] Next, we will explain an example of the fluctuation of CO2 concentration inside facility 90, obtained from the model equations shown in Equation 1 or Equation 2, using Figure 5. Figure 5 is a diagram showing an example of the fluctuation of CO2 concentration inside facility 90. In Figure 5, two people enter facility 90 at time t=10, and one of the two people leaves facility 90 at time t=600, showing the fluctuation of CO2 concentration inside facility 90. In the graph shown in Figure 5, the horizontal axis is time t, and the vertical axis is the CO2 concentration (ppm) inside facility 90. Also, in Figure 5, the CO2 concentration outside facility 90 (i.e., Co(t)) is 420 ppm. Furthermore, the unit time in the following explanation is on the order of minutes (for example, 5 minutes).

[0057] As shown in Figure 5, if the situation of no people being inside facility 90 continues (as shown in Figure 5 up to t=10), the CO2 concentration inside facility 90 will approach the CO2 concentration outside facility 90 (420 ppm in Figure 5) and become constant.

[0058] When two people enter facility 90, which has been unoccupied for a long time (in Figure 5, t=10), in the period immediately following their entry (in Figure 5, from t=10 to t=150), the amount of CO2 emitted by the people per unit time (Ch × Nh) is greater than the amount of CO2 released outside facility 90 due to the intake of outside air ((Ci(t) - Co(t)) × Wo), so the CO2 concentration inside facility 90 increases rapidly. As the CO2 concentration inside facility 90 increases (in Figure 5, from t=150 to t=350), the difference between the amount of CO2 emitted by the people per unit time and the amount of CO2 released outside facility 90 due to the intake of outside air gradually approaches zero, and the rate of increase in CO2 concentration per unit time ((Ci(t+1) - Ci(t)) × Ws) decreases. Then, when the amount of CO2 emitted by a person per unit time balances the amount of CO2 released outside the facility 90 due to the intake of outside air (in Figure 5, this occurs during the period from t=350 to t=600), the CO2 concentration inside the facility 90 becomes constant (515 ppm in Figure 5).

[0059] Furthermore, in the period immediately following the departure of one of the two people in facility 90 (from t=600 to t=700 in Figure 5), the amount of CO2 released outside facility 90 due to the intake of outside air ((Ci(t)-Co(t))×Wo) is greater than the amount of CO2 released by the person per unit time (Ch×Nh), so the CO2 concentration inside facility 90 decreases rapidly. As the CO2 concentration inside facility 90 decreases (from t=700 to t=850 in Figure 5), the difference between the amount of CO2 released by the person per unit time and the amount of CO2 released outside facility 90 due to the intake of outside air gradually approaches zero, and the rate of increase in CO2 concentration per unit time ((Ci(t+1)-Ci(t))×Ws) decreases. Then, when the amount of CO2 emitted by a person per unit time balances the amount of CO2 released outside the facility 90 due to the intake of outside air (in Figure 5, during the period from t=850 to t=1000), the CO2 concentration inside the facility 90 becomes constant (468 ppm in Figure 5).

[0060] Based on the above results, when the presence / absence determination system 10 according to this embodiment determines whether a user is present or absent within the facility 90, the following two points must be considered.

[0061] The first issue is that if the presence / absence determination system 10 uses only the current CO2 concentration inside the facility 90 to determine whether a user is present or absent, it will not be able to make an accurate determination. Specifically, when a person is present in the facility 90 and then leaves the facility 90, the amount of outside air that can be taken in by the outside air intake fan 30 per unit time is limited, so the CO2 concentration will remain high for a while even after the person has left the facility 90. In such a situation, if the presence / absence determination system 10 uses only the current CO2 concentration inside the facility 90 to determine whether a user is present or absent, it will make an incorrect determination that the user is present.

[0062] The second issue is that the presence / absence determination system 10 cannot make an accurate determination of a user's presence or absence based solely on a simple increase or decrease in the CO2 concentration within the facility 90. Specifically, as shown in Figure 5 from t=350 to t=600, if a person is present in the facility 90 for a certain period of time, the CO2 concentration within the facility 90 may effectively cease to change. Also, as shown in Figure 5 from t=600 to t=700, even though people are present in the facility 90, the CO2 concentration within the facility 90 may decrease due to a decrease in the number of people present. In situations like these, if the presence / absence determination system 10 determines the user's presence or absence based solely on a simple increase or decrease in the CO2 concentration within the facility 90, it will incorrectly determine that the user is absent.

[0063] Therefore, taking the above two points into consideration, the presence / absence determination system 10 (i.e., presence / absence determination unit 82a) according to this embodiment determines the presence or absence of the user using at least the current CO2 concentration inside the facility 90, the past CO2 concentration inside the facility 90, and the current CO2 concentration outside the facility 90. Specifically, the presence / absence determination system 10 uses each acquired or estimated CO2 concentration (i.e., Ci(t), Ci(t+1), and Co(t)) as shown in Equation 1 or Equation 2 above to determine whether Nh is above a threshold (for example, 1 or more) and to determine the presence or absence of the user.

[0064] Furthermore, the presence / absence determination system 10 may determine the presence or absence of a user using a trained machine learning model. Specifically, the presence / absence determination system 10 trains a machine learning model using the historical CO2 concentration information inside the facility 90 acquired in step S101 of Figure 4 and the user input received by the operation reception unit 81 in step S105 of Figure 4, and uses the trained machine learning model to determine the presence or absence of a user. The presence / absence determination system 10 may also train the machine learning model using additional historical CO2 concentration information outside the facility 90. Then, the presence / absence determination system 10 may input the current CO2 concentration inside the facility 90, past CO2 concentrations inside the facility 90, and CO2 concentration outside the facility 90 into the trained machine learning model to determine the presence or absence of a user.

[0065] In the explanation in Figure 5, the CO2 concentration outside facility 90 was assumed to be constant (420 ppm) for the sake of clarity. However, in reality, the CO2 concentration outside facility 90 fluctuates not only depending on the region but also on a daily, seasonal, and yearly basis, and is not constant. Therefore, the presence / absence determination system 10 can improve the accuracy of its determination results by acquiring the current CO2 concentration outside facility 90 at regular intervals and determining the user's presence or absence. Furthermore, although it was explained above that the CO2 concentration outside facility 90 fluctuates, the range of fluctuation in the CO2 concentration outside facility 90 is limited to a certain extent. Therefore, instead of acquiring the current CO2 concentration outside facility 90 at regular intervals, the presence / absence determination system 10 may more easily determine the user's presence or absence by estimating a representative constant as the current CO2 concentration outside facility 90. However, if the current CO2 concentration outside facility 90 is estimated, the accuracy of determining presence or absence may decrease. Nevertheless, if facility 90 is small (Ws and Wo are small) and the amount of CO2 released by human respiration (Ch × Nh) is relatively large, this method is considered effective.

[0066] Furthermore, when the amount of outside air (Wo) taken in by the outside air intake fan 30 fluctuates due to the control device 80 controlling the outside air intake fan 30, the presence / absence determination system 10 can acquire the amount of outside air taken in and, as shown in Equation 1 or Equation 2 above, use the acquired amount of outside air and the volume of the facility 90 to further improve the accuracy of determining whether the user is present or absent.

[0067] Furthermore, if a window is open while a person is present in facility 90, the CO2 concentration inside facility 90 decreases, which may cause the presence / absence determination system 10 to incorrectly determine that the user is absent. Therefore, the presence / absence determination system 10 according to this embodiment may determine the presence or absence of a user by considering the current temperature of each of the multiple rooms 90a to 90c and the operating status of the air conditioning unit 21 (for example, the set temperature). This prevents the presence / absence determination system 10 from incorrectly determining that the user is absent. Also, if a window is open while a person is present in facility 90, the temperature of that room changes, which may cause the whole-house air conditioning unit 20 to transport more temperature-controlled air to that room, or the air conditioning effectiveness of the whole-house air conditioning unit 20 in that room may decrease, making it difficult to maintain the room temperature at the set temperature. Therefore, the occupancy determination system 10 may detect whether a window in a particular room is open based on the current temperature of each of the multiple rooms 90a to 90c and the operating status of the air conditioning unit 21, and may notify the user that the window is open if necessary.

[0068] [2-2. Specific examples of parameter updates for determining user presence or absence] Next, we will explain specific examples of parameter updates for determining the presence or absence of a user. The airtightness of facility 90, the air circulation conditions within facility 90, and the environment within facility 90, such as pets or plants present within facility 90, differ for each facility 90 in which the presence / absence determination system 10 is installed. Therefore, the impact on the CO2 concentration within facility 90 also differs for each facility 90. To improve the accuracy of determining the presence or absence of a user, the presence / absence determination system 10 updates (i.e., corrects) the parameters to suit the facility 90 in which the presence / absence determination system 10 is installed, as needed.

[0069] Specifically, the presence / absence determination system 10 (specifically, the presence / absence determination unit 82a) corrects Equation 1 or Equation 2 as shown in Equation 3 below so that the content of the user input received by the operation reception unit 81 in step S105 of Figure 4 (i.e., whether the determination result is correct or incorrect) matches the determination result regarding the user's presence or absence.

[0070] Ci(t+1)×Ws=Ci(t)×Ws-(Ci(t)-Co(t))×Wo´+Ch×Nh+V (Formula 3)

[0071] In equation 3 above, Wo' is the corrected amount of outside air taken in per unit time by the outside air intake fan 30, and V is the correction parameter.

[0072] Furthermore, when the presence / absence determination system 10 (specifically, the presence / absence determination unit 82a) uses a trained machine learning model to determine whether a user is present or absent, the machine learning model is retrained so that the content of the user input received by the operation reception unit 81 in step S105 of Figure 4 matches the determination result output by the trained machine learning model.

[0073] As described above, the presence / absence determination system 10 can make determinations suitable for the different environments of each facility 90 by updating the parameters for determining the presence or absence of the user or retraining the machine learning model based on the user's input (i.e., whether the determination result is correct or incorrect).

[0074] [2-3. Method for generating presence / absence prediction information] Next, we will explain how to generate presence / absence prediction information.

[0075] The presence / absence determination system 10 (specifically, the presence / absence prediction unit 82b) generates presence / absence prediction information from the present to the future based on the determination results obtained by the presence / absence determination unit 82a. Specifically, the presence / absence prediction unit 82b may generate presence / absence prediction information by statistically predicting the probability of whether or not a user will be present in the facility 90 at a future date and time, based on past dates and times (including, for example, the day of the week) and the determination results at those dates and times (i.e., presence / absence information).

[0076] Furthermore, the presence / absence prediction unit 82b may generate presence / absence prediction information using a trained machine learning model. For example, the presence / absence prediction unit 82b generates training data such as the date and time (including the day of the week) when a user left the facility 90 in the past, the period during which the user was absent from the facility 90, and the date and time (including the day of the week) when a user entered the facility 90, from past dates and times (including the day of the week) and the judgment result (i.e., presence / absence information) at that date and time, and uses this training data to train a machine learning model. Then, the presence / absence prediction unit 82b uses the trained machine learning model to predict the time when a user will leave the facility 90 and the time when a user will enter the facility 90 on a specific future day, and generates presence / absence prediction information.

[0077] [3. Examples of Ventilation System Operation] The following describes an example of the operation of the ventilation system 100. As described above, the ventilation system 100 according to this embodiment is equipped with an air conditioning unit 21 and a dehumidifier 22, and performs not only ventilation within the facility 90 but also temperature and humidity control within the facility 90. Generally, regarding the temperature within the facility 90, it is desired that the temperature within the facility 90 be at a comfortable level only when a user is present in the facility 90. On the other hand, regarding the humidity within the facility 90, considering the impact on the facility 90 itself and the furniture and clothing inside the facility 90, it is desired to avoid high humidity conditions within the facility 90 regardless of whether a user is present in the facility 90 or not. Therefore, the ventilation system 100 according to this embodiment utilizes the presence / absence prediction information generated by the presence / absence prediction unit 82b to perform ventilation, temperature control, and humidity control within the facility 90. Figure 6 is a flowchart showing an example of the operation of the ventilation system 100 according to this embodiment.

[0078] First, the air conditioning and air quality control unit 82c of the control device 80 determines whether or not the user is currently absent based on the determination result obtained by the presence / absence determination unit 82a (S201).

[0079] If the air conditioning and air quality control unit 82c determines that a user is currently present in the room (No in S201), it executes the process in step S204 described below. On the other hand, if the air conditioning and air quality control unit 82c determines that a user is currently absent (Yes in S201), it executes the process in the next step S202. Based on the presence / absence prediction information generated by the presence / absence prediction unit 82b and the current temperature measured by the temperature sensors 50 installed in each of the multiple rooms 90a to 90c, the air conditioning and air quality control unit 82c determines whether the predicted time from the present until the user is expected to be present in the room is longer than the time required for each of the multiple rooms 90a to 90c to reach the set temperature set for each of the multiple rooms 90a to 90c from the current temperature (S202).

[0080] If the air conditioning and air quality control unit 82c determines that the above conditions are met (Yes in S202), it controls each device (specifically, the whole-building air conditioning unit 20 and the outside air intake fan 30) according to the following policies (1a) to (1c) (S203). In policy (1a), the air conditioning and air quality control unit 82c stops the air conditioning unit 211 and the transport device 23. Alternatively, in policy (1a), the air conditioning and air quality control unit 82c controls the air conditioning unit 211 and the transport device 23 so that the energy consumption of the air conditioning unit 211 and the transport device 23 becomes less than the first specified value D1, and the temperature measured by the temperature sensors 50 installed in each of the multiple rooms 90a to 90c is the set temperature, in other words, it saves the energy consumption of the air conditioning unit 211 and the transport device 23. In policy (1b), the air conditioning and air quality control unit 82c controls the dehumidification unit 221, prioritizing the energy efficiency of dehumidification within the facility 90. Specifically, the air conditioning and air quality control unit 82c controls the dehumidifier 221 so that its energy efficiency is equal to or greater than the third specified value D3, and the humidity measured by the humidity sensor 70 installed in the facility 90 is equal to the set humidity. In policy (1c), the air conditioning and air quality control unit 82c stops the outside air intake fan 30. Alternatively, in policy (1c), the air conditioning and air quality control unit 82c controls the outside air intake fan 30 so that outside air with a value less than the second specified value D2 is taken in, in other words, the outside air intake fan 30 is saved.

[0081] On the other hand, if the air conditioning and air quality control unit 82c determines that the above conditions are not met (No in S202), it controls each device (specifically, the whole-building air conditioning unit 20 and the outside air intake fan 30) according to the following policies (2a) to (2c) (S204). In policy (2a), the air conditioning and air quality control unit 82c controls the air conditioning unit 211 and the transport device 23 so that the temperature measured by the temperature sensors 50 installed in each of the multiple rooms 90a to 90c becomes the set temperature. In policy (2b), the air conditioning and air quality control unit 82c controls the dehumidification unit 221 so that the humidity measured by the humidity sensor 70 installed in the facility 90 becomes the set humidity (i.e., dehumidification control is performed), taking into consideration the impact on the temperature control performed by the air conditioning unit 211 and the transport device 23 (specifically, policy (2a)). According to policy (2c), the air conditioning and air quality control unit 82c controls the outside air intake fan 30 so that a specified amount (second specified value D2) of outside air is taken into the facility 90.

[0082] In step S202, the time required to reach the set temperature set for each of the rooms 90a to 90c from their current temperature means the time it takes for the temperature measured by the temperature sensors 50 installed in each of the rooms 90a to 90c to stabilize near the set temperature (for example, within ±3°C of the set temperature). The air conditioning and air quality control unit 82c estimates the time required to reach the set temperature set for each of the rooms 90a to 90c from their current temperature based on the current temperature of each of the rooms 90a to 90c and the set temperature set for each of the rooms 90a to 90c.

[0083] The following sections will provide a more detailed explanation of policies (1a) to (1c) and policies (2a) to (2b) described above.

[0084] [3-1. Regarding policies (1a) to (1c)] First, let me explain policy (1a). In policy (1a), the air conditioning and air quality control unit 82c either stops the air conditioning unit 211 and the transport device 23, or saves the air conditioning unit 211 and the transport device 23. Saving the air conditioning unit 211 and the transport device 23 means, for example, that the air conditioning and air quality control unit 82c changes the set temperature set for each of the multiple rooms 90a to 90c in order to reduce the energy consumption of the air conditioning unit 211 and the transport device 23. More specifically, if the air conditioning unit 211 is operating in cooling mode, the air conditioning and air quality control unit 82c changes the set temperature to a higher temperature than the set temperature, and if the air conditioning unit 211 is operating in heating mode, the air conditioning and air quality control unit 82c changes the set temperature to a lower temperature than the set temperature. Furthermore, according to policy (1a), the air conditioning and air quality control unit 82c decides whether to stop or save the air conditioning unit 211 and the transport device 23 based on a prediction of whether the user will be absent from the facility 90 for an extended period. For example, based on the presence / absence prediction information, if the air conditioning and air quality control unit 82c predicts that the user will not be absent from the facility 90 for an extended period (e.g., less than 48 hours), it saves the air conditioning unit 211 and the transport device 23, and if it predicts that the user will be absent from the facility 90 for an extended period, it stops the air conditioning unit 211 and the transport device 23.

[0085] Next, policy (1b) will be explained. In explaining policy (1b), we will assume that each of the air conditioning unit 21 and the dehumidifying unit 22 has a dehumidifying section 221.

[0086] In policy (1b), the air conditioning and air quality control unit 82c controls the dehumidifier unit 221 prioritizing the energy efficiency of dehumidification within the facility 90. For example, when dehumidification is performed by the air conditioning unit 21 during the cooling season when cooling operation by the air conditioning unit 211 is required, considering not only the humidity within the facility 90 but also the need to bring the temperature within the facility 90 to the set temperature, the air conditioning and air quality control unit 82c controls the airflow rate of the air conditioning unit 21 to be increased. By controlling the air conditioning unit 21 in this way, the air conditioning and air quality control unit 82c can improve the energy efficiency of temperature control within the facility 90. However, when the air conditioning and air quality control unit 82c controls the airflow rate of the air conditioning unit 21 to be increased, it becomes more difficult for the dehumidifier unit 221 of the air conditioning unit 21 to cool the air to the dew point, resulting in a decrease in the energy efficiency of dehumidification within the facility 90. Therefore, when dehumidification is performed by the air conditioning unit 21, the air conditioning and air quality control unit 82c controls the air conditioning unit 21 to reduce the airflow rate even during the cooling season, so that the dehumidification unit 221 cools the air sufficiently to dehumidify it. This allows the air conditioning and air quality control unit 82c to perform control that prioritizes energy efficiency in dehumidification within the facility 90.

[0087] Furthermore, during the heating season when heating operation by the air conditioning unit 211 is required, or during the transitional season when neither cooling nor heating operation is required, the air conditioning and air quality control unit 82c must consider the temperature drop inside the facility 90 caused by dehumidification performed by the air conditioning unit 21. Specifically, the air conditioning and air quality control unit 82c must consider the temperature drop inside the facility 90 caused by dehumidification performed by the air conditioning unit 21 so that the temperature inside the facility 90 reaches the set temperature by the expected time when users are expected to be present in the room. After considering the above, the air conditioning and air quality control unit 82c controls the whole-building air conditioning system 20 by deciding whether to perform dehumidification by the air conditioning unit 21 or by the dehumidifier 22 equipped with a reheat dehumidification function, based on the energy efficiency of dehumidification inside the facility 90.

[0088] Next, policy (1c) will be explained. In policy (1c), the air conditioning and air quality control unit 82c stops the outside air intake fan 30 or conserves its operation. The reason why the air conditioning and air quality control unit 82c controls the outside air intake fan 30 in this manner is that when temperature or humidity adjustment is required inside the facility 90, the cause is often the air outside the facility 90. In other words, the air outside the facility 90 is often at an uncomfortable temperature or humidity compared to the air inside the facility 90. Therefore, when there are no users in the facility 90, the air conditioning and air quality control unit 82c controls the outside air intake fan 30 so that outside air below the second specified value D2 is taken in, thereby reducing energy consumption in the air conditioning unit 211, the dehumidification unit 221, and the transport device 23.

[0089] [3-2. Regarding policies (2a) and (2b)] Next, policy (2a) will be explained. In policy (2a), the air conditioning and air quality control unit 82c controls the air conditioning unit 211 and the transport device 23 so that the temperature measured by the temperature sensors 50 installed in each of the multiple rooms 90a to 90c becomes the set temperature. Specifically, the air conditioning and air quality control unit 82c determines the airflow rate of the transport fans 23a connected to the multiple rooms 90a to 90c based on the difference between the temperature measured by the temperature sensors 50 installed in each of the multiple rooms 90a to 90c and the set temperature, and controls the transport device 23.

[0090] Next, policy (2b) will be explained. In policy (2b), the air conditioning and air quality control unit 82c controls the dehumidifier 221 so that the humidity measured by the humidity sensor 70 installed in the facility 90 becomes the set humidity, taking into consideration the impact on policy (2a). Specifically, the air conditioning and air quality control unit 82c determines whether dehumidification by the dehumidifier 221 is necessary based on the humidity measured by the humidity sensor 70 installed in the facility 90, and controls the dehumidifier 221.

[0091] As described above, the ventilation system 100 can reduce energy consumption in the air conditioning unit 211, the dehumidifier 221, and the transport device 23 when there are no users in the facility 90, and can maintain the humidity inside the facility 90 at an appropriate level. Furthermore, since the ventilation system 100 takes into account the expected time from the present until the user is expected to be present, it can set the temperature of each of the multiple rooms 90a to 90c to the set temperature, set the humidity inside the facility 90 to the set humidity, and fill the facility 90 with fresh air from outside before the user is present.

[0092] Therefore, with regard to the temperature inside the facility 90, the ventilation system 100 can maintain a comfortable temperature inside the facility 90, at least when a user is present in the facility 90. Furthermore, with regard to the humidity inside the facility 90, the ventilation system 100 can prevent the humidity inside the facility 90 from becoming high, regardless of whether a user is present in the facility 90 or not. This prevents the humidity inside the facility 90 from becoming high and adversely affecting the facility 90 itself, as well as the furniture and clothing inside the facility 90.

[0093] [3-3. Variations of Ventilation Systems] In the ventilation system 100 described above, an example was described in which the temperature inside the facility 90 is adjusted by one air conditioning unit 21. However, in the ventilation system according to this embodiment, the temperature inside the facility 90 may be adjusted by multiple air conditioning units. Figure 7 is a block diagram showing the configuration of the ventilation system 100a according to the first modified example.

[0094] As shown in Figure 7, the ventilation system 100a is equipped with a whole-house air conditioning system 20a instead of the whole-house air conditioning system 20. The whole-house air conditioning system 20a comprises two air conditioning units 21a and a transport device 23. The air conditioning unit 21a comprises an air conditioning unit 211 and a dehumidifying unit 221.

[0095] For example, the control device 80 of the ventilation system 100a can lower the humidity inside the facility 90 while maintaining the temperature of each of the multiple rooms 90a to 90c by controlling two air conditioning units 21a such that one air conditioning unit 21a performs dehumidification and the other air conditioning unit 21a performs heating.

[0096] Furthermore, the control device 80 of the ventilation system 100a determines the number of air conditioning units 21a to operate according to the capacity required to bring the temperature of each of the multiple rooms 90a to 90c to the set temperature (hereinafter also referred to as air conditioning capacity), or the capacity required to bring the humidity inside the facility 90 to the set humidity (hereinafter also referred to as dehumidification capacity). This allows the control device 80 to operate the air conditioning units 21a in a region where the coefficient of performance (COP) of the air conditioning units 21a is high, thereby improving the energy efficiency of the air conditioning units 21a. In other words, the control unit 82 can decide whether to operate one air conditioning unit 21a or multiple air conditioning units 21a, taking into account the air conditioning capacity, dehumidification capacity, and energy efficiency of the air conditioning units 21a.

[0097] [4. Variations in the operation of the ventilation system] The following describes variations in the operation of the ventilation system 100 described above. Specifically, the operation of the control device 80 of the ventilation system 100 when it controls each device (i.e., the whole-house air conditioning system 20 and the outside air intake fan 30) in consideration of the demand reduction request (hereinafter also referred to as "demand reduction DR") to adjust the amount of electricity used published by the power company, or dynamically fluctuating electricity rates.

[0098] In recent years, with the increasing adoption of solar and wind power generation, whose output fluctuates depending on the weather, the amount of electricity that power companies can supply has begun to fluctuate on a daily basis. As a result, power suppliers (specifically, power companies) have begun to take measures to adjust electricity usage by notifying electricity users of requests to adjust their electricity consumption as needed (i.e., upward demand response and downward demand response), or by dynamically changing electricity rates.

[0099] Therefore, the ventilation system 100 according to this embodiment may perform its operation by considering, in addition to the determination result obtained by the presence / absence determination system 10, information regarding such requests from the power company or information regarding dynamically fluctuating electricity rates. Such a ventilation system 100 can effectively adjust power consumption and reduce electricity costs while maintaining convenience and comfort when a user is present in the facility 90. The control policies of the air conditioning and air quality control unit 82c of the control device 80 will be explained below using Figures 8A and 8B.

[0100] First, we will explain the policy for the control content of the air conditioning and air quality control unit 82c in response to requests from the power company. Figure 8A is a diagram showing the policy for the control content to be performed by the ventilation system 100 based on information regarding the demand reduction request.

[0101] The air conditioning and air quality control unit 82c acquires information regarding demand reduction requests (downward demand response) via the communication unit 84 and determines whether or not a demand reduction request is in effect. Furthermore, as shown in Figure 8A, the air conditioning and air quality control unit 82c has a function to switch the control policy depending on whether or not a demand reduction request is in effect and whether or not a user is present in facility 90. Note that the policies listed in the column for "No demand reduction request (downward demand response)" are the same as the policies described in [3. Ventilation System Operation Example] above, so their explanation is omitted. Specifically, if there is no demand reduction request and a user is present in facility 90, the air conditioning and air quality control unit 82c controls each device according to the above policies (2a) to (2c). On the other hand, if there is no demand reduction request and no user is present in facility 90, the air conditioning and air quality control unit 82c controls each device according to the above policies (1a) to (1c).

[0102] Furthermore, if a request for demand reduction is in effect and there are users in facility 90, the air conditioning and air quality control unit 82c controls each device according to the following policies (3a) to (3c). In policy (3a), the air conditioning and air quality control unit 82c changes the set temperature of the air conditioning unit 211 to save power on the air conditioning unit 211 and the transport device 23. Specifically, if the air conditioning unit 21 is performing cooling operation, the air conditioning unit 211 and the transport device 23 are controlled to suppress power consumption by changing the set temperature of the air conditioning unit 211 to a higher temperature. Also, if the air conditioning unit 21 is performing heating operation, the air conditioning unit 211 and the transport device 23 are controlled to suppress power consumption by changing the set temperature of the air conditioning unit 211 to a lower temperature. In policy (3b), the air conditioning and air quality control unit 82c changes the set humidity of the dehumidifier unit 221 to control the dehumidifier unit 221. Specifically, the air conditioning and air quality control unit 82c controls the dehumidifier 221 to suppress power consumption by changing the set humidity of the dehumidifier 221 to a higher humidity. In policy (3c), the air conditioning and air quality control unit 82c controls the outside air intake fan 30 so that a specified amount (second specified value D2) of outside air is taken into the facility 90.

[0103] Also, when a demand response request is in progress and no user is present in the facility 90, the air conditioning and air quality control unit 82c controls each device according to the following policies (4a) to (4c). In policy (4a), the air conditioning and air quality control unit 82c stops the air conditioning unit 211 and the transport device 23. In policy (4b), the air conditioning and air quality control unit 82c prioritizes the energy efficiency of dehumidification in the facility 90 and controls the dehumidification unit 221 by changing the set humidity of the dehumidification unit 221. For example, the air conditioning and air quality control unit 82c controls the dehumidification unit 221 by changing the set temperature of the dehumidification unit 221 so that the energy efficiency in the dehumidification unit 221 is equal to or higher than the third specified value D3. In policy (4c), the air conditioning and air quality control unit 82c stops the outside air intake fan 30.

[0104] As described above, when a demand response request is in progress and a user is present in the facility 90, the ventilation system 100 can reduce the amount of power consumed by each device within a range that does not impair the convenience and comfort within the facility 90. Also, when a demand response request is in progress and no user is present in the facility 90, the ventilation system 100 can reduce more power by completely stopping the air conditioning unit 211, the transport device 23, and the outside air intake fan 30.

[0105] Next, the policy of the control content of the air conditioning and air quality control unit 82c for dynamically fluctuating electricity rates will be described. FIG. 8B is a diagram showing the policy of the control content executed by the ventilation system 100 based on information regarding the electricity rate.

[0106] The air conditioning and air quality control unit 82c acquires information regarding dynamically fluctuating electricity rates via the communication unit 84. Also, as shown in FIG. 8B, the air conditioning and air quality control unit 82c has a function of switching the policy of the control content according to which pattern among the three patterns the current electricity rate corresponds to and whether or not a user is present in the facility 90. Note that electricity rate <F0 means a situation where the electricity rate is lower than the normal electricity rate, F0 ≤ electricity rate <F1 means a situation within the range of the normal electricity rate, and F1 ≤ electricity rate means a situation where the electricity rate is higher than the normal electricity rate.

[0107] When the current electricity charge is set to a charge less than the reference value F0 (electricity charge < F0) and a user is present in the facility 90, the policy is the same as the policies (2a) to (2c) described in [3. Operation example of the ventilation system] above, so the description is omitted.

[0108] When the current electricity charge is set to a charge less than the reference value F0 and no user is present in the facility 90, the air-conditioning and air-quality control unit 82c controls each device according to the following policies (5a) to (5c). In policy (5a), the air-conditioning and air-quality control unit 82c controls the air-conditioning unit 211 and the transport device 23 so that the temperature measured by the temperature sensors 50 installed in each of the plurality of rooms 90a to 90c becomes the set temperature. In policy (5b), the air-conditioning and air-quality control unit 82c controls the dehumidifying unit 221 so that the humidity measured by the humidity sensor 70 installed in the facility 90 becomes the set humidity, taking into account the influence on policy (5a). In policy (5c), the outside air intake fan 30 is controlled so that outside air less than the second specified value D2 is taken in, that is, the outside air intake fan 30 is saved. That is, when the current electricity charge is set to a charge lower than the reference value F0, the air-conditioning and air-quality control unit 82c controls the entire building air-conditioning device 20 regarding the temperature adjustment of each of the plurality of rooms 90a to 90c and the humidity adjustment in the facility 90 in the same manner as when a user is present even when no user is present. As a result, even when a user is present in the facility 90 after the current electricity charge fluctuates to a higher electricity charge, the ventilation system 100 can reduce the amount of power consumed by each device for performing the temperature adjustment of each of the plurality of rooms 90a to 90c.

[0109] When the current electricity charge is the normal electricity charge (F0 ≤ electricity charge < F1), each policy is the same as each policy described in [3. Operation example of the ventilation system] above, so the description is omitted. Specifically, when a user is present in the facility 90, the air-conditioning and air-quality control unit 82c controls each device according to the above policies (2a) to (2c). On the other hand, when no user is present in the facility 90, the air-conditioning and air-quality control unit 82c controls each device according to the above policies (1a) to (1c).

[0110] The policies for when the current electricity rate is set at or above the standard value F1 (F1 ≤ electricity rate) are the same as the policies during the above-mentioned demand reduction request, so the explanation is omitted. Specifically, when the current electricity rate is set at or above the standard value F1 and there are users in facility 90, each device is controlled according to policies (3a) to (3c) above. Also, when the current electricity rate is set at or above the standard value F1 and there are no users in facility 90, each device is controlled according to policies (4a) to (4c) above. In this way, when the current electricity rate is set at or above the standard value F1 and there are users in facility 90, the ventilation system 100 can reduce the amount of electricity consumed by each device to the extent that it does not impair convenience and comfort within facility 90. Furthermore, when the current electricity rate is set at or above the standard value F1 and there are no users in facility 90, the ventilation system 100 can reduce even more electricity by completely stopping the air conditioning unit 211, the transport device 23, and the outside air intake fan 30.

[0111] In the above description, an example was given in which the air conditioning and air quality control unit 82c controls each device based on the determination result obtained by the occupancy determination unit 82a and one of the acquired information regarding the demand reduction request or the electricity charges. However, each device may be controlled using information other than that described above. Specifically, the air conditioning and air quality control unit 82c may control each device based on the occupancy prediction information generated by the occupancy prediction unit 82b and one of the acquired information regarding the demand reduction request or the electricity charges. For example, if the air conditioning and air quality control unit 82c predicts that, although there is currently no demand reduction request and no users are present in the facility 90, in the future (for example, a few hours later), there will be a demand reduction request and users will be present in the facility 90, then, for example, the air conditioning and air quality control unit 82c will control each device using policies (2a) to (2c) described above instead of policies (1a) to (1c) described above. This allows the ventilation system 100 to reduce the amount of electricity consumed by each device during the period when a demand reduction request is in effect.

[0112] Furthermore, the air conditioning and air quality control unit 82c may perform controls other than temperature adjustment for each of the multiple rooms 90a to 90c and humidity adjustment within the facility 90, based on the determination result obtained by the presence / absence determination unit 82a and either the acquired information regarding the demand reduction request or the information regarding electricity charges. For example, the air conditioning and air quality control unit 82c may control the on / off and brightness of lighting fixtures installed in the facility 90, the timing of water heating by the heat pump water heater, the charging and discharging timing of the EV (Electric Vehicle), or the charging and discharging timing of the storage battery.

[0113] Based on the above explanation, the control device 80 of the ventilation system 100 can reduce the amount of electricity consumed by each device (i.e., the whole-house air conditioning system 20 and the outside air intake fan 30) and the electricity charges by controlling each device based on either information regarding the demand reduction request or information regarding electricity charges, and information regarding the presence or absence of the user.

[0114] [5. Other variations] The configuration of the ventilation system according to the modified example will be described below. Figure 9 is a block diagram showing the configuration of the ventilation system 100b according to the second modified example.

[0115] As shown in Figure 9, the ventilation system 100b is equipped with a whole-house air conditioning system 20b instead of the whole-house air conditioning system 20. The whole-house air conditioning system 20b comprises an air conditioning unit 21, a dehumidifier 22, and a transport unit 24.

[0116] The conveying device 24, based on the control of the control device 80, conveys air (outside or inside) whose temperature has been adjusted by the air conditioning device 21 to each of the multiple rooms 90a to 90c. The conveying device 24 comprises a conveying fan 24a, a branching chamber 24b, multiple VAV (Variable Air Volume) dampers 24c, and multiple air outlets 24d. The conveying device 24 is equipped with one set of VAV dampers 24c and air outlets 24d for each room.

[0117] In the conveying device 24, the branching chamber 24b includes multiple air conveying paths branched to each of the multiple rooms 90a to 90c. VAV dampers 24c are provided in each of the multiple air conveying paths included in the branching chamber 24b.

[0118] Such a ventilation system 100b can perform the same operations as ventilation system 100 in the above-described example of ventilation system operation. Specifically, the control device 80 of ventilation system 100b can transport a determined amount of air to each of the multiple rooms 90a to 90c by controlling the transport fan 24a and multiple VAV dampers 24c in steps S203 and S204 of Figure 6.

[0119] [6. Effects, etc.] The above describes examples of inventions that can be obtained from the disclosures in this specification, and explains the effects and other benefits that can be obtained from such inventions.

[0120] Invention 1 is a computer-based method for determining the presence or absence of a user within a facility 90, comprising: acquiring the CO2 concentration inside the facility 90 measured by a CO2 sensor 60 installed inside the facility 90 at regular intervals while ventilation is being performed inside the facility 90 by a ventilation system 100 (S101); acquiring or estimating the CO2 concentration outside the facility 90 (S102); and determining the presence or absence of a user within the facility 90 using the acquired CO2 concentration inside the facility 90 and the acquired or estimated CO2 concentration outside the facility 90 (S103).

[0121] This method for determining presence or absence can improve the accuracy of the determination by acquiring the CO2 concentration inside and outside the facility 90 at regular intervals to determine the presence or absence of a user. Furthermore, instead of acquiring the CO2 concentration outside the facility 90 at regular intervals, the method can more easily determine the presence or absence of a user by estimating the CO2 concentration outside the facility 90. Additionally, the method can determine the presence or absence of a user by using at least one CO2 sensor 60 installed inside the facility 90, i.e., by using a smaller number of CO2 sensors 60. Therefore, this method provides a method for determining the presence or absence of a person that requires less cost for equipment installation than conventional methods and can more accurately determine the presence or absence of a person.

[0122] Invention 2 is a method for determining presence or absence of a user, which further includes presenting the user with the determination result regarding the user's presence or absence (S104), receiving input from the user regarding whether the determination result is accurate or not (S105), and updating the parameters for determining the user's presence or absence based on the input received from the user (S106), as described in Invention 1.

[0123] This method of determining presence or absence can be adapted to the different environments of each facility 90 by updating the parameters used to determine the user's presence or absence based on the user's input (i.e., whether the determination result is correct or incorrect).

[0124] Invention 3 is a method for determining presence or absence of a user according to Invention 1 or 2, wherein the ventilation system 100 is equipped with an outside air intake device 30 that takes in outside air from outside the facility 90 into the facility 90, and the method for determining presence or absence of a user further uses the amount of outside air taken in by the outside air intake device 30 and the volume of the facility 90 when determining the presence or absence of a user.

[0125] This method for determining presence or absence can improve the accuracy of determining the presence or absence of a user by acquiring the amount of outside air taken in by the outside air intake device 30 when the amount of outside air taken in fluctuates, and by using the acquired amount of outside air and the volume of the facility 90.

[0126] Invention 4 is a presence / absence determination method according to any of Inventions 1 to 3, which generates presence / absence prediction information (S107) that indicates whether or not the user will be present in the facility 90 from the present to the future, based on the determination result regarding the presence or absence of the user.

[0127] This method for determining whether a user is present or absent can generate prediction information about the user's future schedule, based on the results of the determination of the user's presence or absence.

[0128] Invention 5 is a control method for a ventilation system 100 that is performed by a computer and uses one of the presence / absence determination methods of Inventions 1 to 4, wherein the ventilation system 100 comprises an air conditioning unit 211, a transport device 23 that transports air whose temperature has been adjusted by the air conditioning unit 211 to each of the multiple rooms 90a to 90c of the facility 90, and a plurality of temperature sensors 50 installed in each of the multiple rooms 90a to 90c to measure the temperature of each of the multiple rooms 90a to 90c, and in the control method, if the presence / absence determination method determines that a user is present in the room, the temperature sensors installed in each of the multiple rooms 90a to 90c This is a control method for a ventilation system 100, which includes controlling the air conditioning unit 211 and the transport device 23 so that the temperature measured by the sensor 50 becomes the set temperature set by the user (S204), and if the presence / absence determination method determines that the user is absent, stopping the air conditioning unit 211 and the transport device 23, or controlling the air conditioning unit 211 and the transport device 23 so that the energy consumption of the air conditioning unit 211 and the transport device 23 becomes less than the first specified value D1 and the temperature measured by the temperature sensors 50 installed in each of the multiple rooms 90a to 90c becomes the set temperature (S203).

[0129] This control method for the ventilation system 100 can reduce energy consumption in the air conditioning unit 211 and the transport device 23 when there are no users in the facility 90. Furthermore, since the control method for the ventilation system 100 takes into account the estimated time from the present until the user is expected to be present, the measured temperatures in each of the multiple rooms 90a to 90c can be brought to the set temperature before the user arrives.

[0130] Invention 6 is a control method for the ventilation system 100 of Invention 5, wherein the ventilation system 100 is equipped with an outside air intake device 30 that takes in outside air from outside the facility 90 into the facility 90, and the control method is as follows: when it is determined by the presence / absence determination method that a user is present in the room, the outside air intake device 30 is controlled so that outside air with a second specified value D2 is taken in (S204), and when it is determined by the presence / absence determination method that a user is absent, the outside air intake device 30 is stopped, or the outside air intake device 30 is controlled so that outside air with a value less than the second specified value D2 is taken in (S203).

[0131] The control method for such a ventilation system 100 takes into account the expected time from the present until the user is expected to be present in the room, so that the room can be filled with fresh air from outside the room before the user is present.

[0132] Invention 7 is a control method for the ventilation system 100 of Invention 5 or 6, comprising a dehumidifier 221 that adjusts the humidity inside the facility 90 to a preset humidity, and a humidity sensor 70 installed inside the facility 90 that measures the humidity inside the facility 90, and in the control method, if it is determined by the presence / absence determination method that a user is present in the room, the dehumidifier 221 is controlled so that the humidity measured by the humidity sensor 70 installed inside the facility 90 becomes the preset humidity, taking into consideration the impact on the temperature adjustment of the air performed by the air conditioning unit 211 (S204), and if it is determined by the presence / absence determination method that a user is absent, the dehumidifier 221 is controlled so that the energy efficiency of the dehumidifier 221 becomes 3 or more than the third specified value D3, and the humidity measured by the humidity sensor 70 installed inside the facility 90 becomes the preset humidity (S203).

[0133] This control method for the ventilation system 100 can reduce energy consumption in the dehumidifier 221 when there are no users in the facility 90, and can maintain an appropriate humidity level inside the facility 90. Furthermore, since the control method for the ventilation system 100 takes into account the expected time from the present until the user is expected to be present, the humidity inside the facility 90 can be set to the desired humidity level before the user arrives. As a result, the control method for the ventilation system 100 can prevent the humidity inside the facility 90 from becoming too high, which would adversely affect the facility 90 itself, as well as the furniture and clothing inside it.

[0134] Invention 8 is a control method for the ventilation system 100a of Invention 7, wherein the ventilation system 100a has a plurality of air conditioning units 21a each comprising an air conditioning unit 211 and a dehumidifying unit 221, and the control method is as follows: When it is determined by the presence / absence determination method that a user is present in the room, some of the air conditioning units 21a among the plurality of air conditioning units 21a are controlled so that the humidity inside the facility 90 is adjusted to a set range, and the remaining air conditioning units 21a among the plurality of air conditioning units 21a are controlled so that the temperature measured by temperature sensors 50 installed in each of the plurality of rooms 90a to 90c becomes the set temperature; When it is determined by the presence / absence determination method that a user is absent, an air conditioning unit 21a to be operated is determined from the plurality of air conditioning units 21a based on the current humidity measured by the humidity sensor 70 and the set range, and the determined air conditioning unit 21a is controlled so that the humidity measured by the humidity sensor 70 installed in the facility becomes the set humidity.

[0135] The control method for such a ventilation system 100a determines the number of air conditioning units 21a to operate according to the capacity required to bring the temperature of each of the multiple rooms 90a to 90c to a set temperature, or the capacity required to bring the humidity within the facility 90 to a set humidity. As a result, the control method for the ventilation system 100a can operate the air conditioning units 21a in a region where the coefficient of performance of the air conditioning units 21a is high, thereby improving the energy efficiency of the air conditioning units 21a.

[0136] Invention 9 is a control method for a ventilation system 100 according to any of Inventions 5 to 7, wherein the control method acquires information regarding a request for demand reduction to adjust electricity usage published by a power company, or information regarding dynamically fluctuating electricity rates, and controls the ventilation system 100 based on one of the acquired information regarding the request for demand reduction or the electricity rate, and information regarding the presence or absence of the user.

[0137] This control method for the ventilation system 100 can reduce the amount of electricity consumed by each device and the electricity charges by controlling the ventilation system 100 based on either information regarding demand reduction requests or information regarding electricity charges, and information regarding the presence or absence of users.

[0138] Invention 10 is a presence / absence determination system 10 comprising a CO2 sensor 60 installed inside the facility 90 when ventilation is being performed inside the facility 90 by a ventilation system 100, which measures the CO2 concentration inside the facility 90, and a control device 80, wherein the control device 80 acquires the CO2 concentration inside the facility 90 measured by the CO2 sensor 60 at regular intervals, acquires or estimates the CO2 concentration outside the facility 90, and uses the acquired CO2 concentration inside the facility 90 and the acquired or estimated CO2 concentration outside the facility 90 to determine whether or not a user is using the facility 90.

[0139] Such a presence / absence determination system 10 can improve the accuracy of its determination results by acquiring the CO2 concentration inside and outside the facility 90 at regular intervals to determine the presence or absence of a user. Furthermore, instead of acquiring the CO2 concentration outside the facility 90 at regular intervals, the presence / absence determination system 10 can more easily determine the presence or absence of a user by estimating the CO2 concentration outside the facility 90. Additionally, the presence / absence determination system 10 can determine the presence or absence of a user by using at least one CO2 sensor 60 installed inside the facility 90, that is, by using a smaller number of CO2 sensors 60. Therefore, the presence / absence determination system 10 provides a presence / absence determination method that requires less cost for equipment installation than conventional methods and can more accurately determine the presence or absence of a person.

[0140] Invention 11 comprises the presence / absence determination system 10 described in Invention 10, an air conditioning unit 211, a transport device 23 that transports air whose temperature has been adjusted by the air conditioning unit 211 to each of the multiple rooms 90a to 90c of the facility 90, and a plurality of temperature sensors 50 installed in each of the multiple rooms 90a to 90c to measure the temperature of each of the multiple rooms 90a to 90c, and the control device 80 determines that a user is present in the room by the presence / absence determination method, and measures the temperature measured by the temperature sensors 50 installed in each of the multiple rooms 90a to 90c. The ventilation system 100 controls the air conditioning unit 211 and the transport device 23 so that the temperature reached is the set temperature set by the user, and if the presence / absence determination method determines that the user is absent, the air conditioning unit 211 and the transport device 23 are stopped, or the air conditioning unit 211 and the transport device 23 are controlled so that the energy consumption of the air conditioning unit 211 and the transport device 23 becomes less than the first specified value D1 and the temperature measured by the temperature sensors 50 installed in each of the multiple rooms 90a to 90c is the set temperature.

[0141] Such a ventilation system 100 can reduce energy consumption in the air conditioning unit 211 and the transport device 23 when there are no users in the facility 90. Furthermore, since the ventilation system 100 takes into account the estimated time from the present until the user is expected to be present, it can bring the measured temperatures of each of the multiple rooms 90a to 90c to the set temperature before the user arrives.

[0142] (Other embodiments) The above-described methods for determining presence or absence and controlling ventilation systems, etc., relating to one or more embodiments, have been explained based on the above embodiments. However, this disclosure is not limited to the above embodiments. Within the scope of one or more embodiments, various modifications that a person skilled in the art could conceive of may be applied to the above embodiments, or forms constructed by combining components from different embodiments may also be included within the scope of one or more embodiments.

[0143] For example, in the above embodiment, a process executed by one processing unit may be executed by another processing unit. Furthermore, the order of multiple processes may be changed, or multiple processes may be executed in parallel.

[0144] Furthermore, the communication method between devices in the above embodiment is not particularly limited. In addition, relay devices (not shown) may be involved in the communication between devices.

[0145] Furthermore, the order of processing described in the flowchart of the above embodiment is just one example. The order of multiple processing steps may be changed, and multiple processing steps may be executed in parallel.

[0146] Furthermore, although the presence / absence determination system was implemented by multiple devices in the above embodiment, it may also be implemented as a single device. The presence / absence determination system may be implemented as a single device corresponding to a control device, or as a single device corresponding to a server device. Also, when the presence / absence determination system is implemented by multiple devices, the components of the presence / absence determination system may be distributed among the multiple devices in any way. The same applies to the ventilation system as well.

[0147] Furthermore, in the above embodiment, each component may be implemented by hardware. For example, each component may be a circuit (or integrated circuit). These circuits may form a single circuit as a whole, or they may be separate circuits. Also, each of these circuits may be a general-purpose circuit or a dedicated circuit.

[0148] Furthermore, some or all of the functions of the occupancy determination system and ventilation system according to the above embodiment may be realized by a processor such as a CPU executing a program.

[0149] Some or all of the components constituting each of the above devices may consist of detachable IC cards or standalone modules attached to each device. The IC card or module is a computer system composed of a microprocessor, ROM, RAM, etc. The IC card or module may include a highly functional LSI. The microprocessor operates according to a computer program, thereby enabling the IC card or module to achieve its function. The IC card or module may also be tamper-resistant.

[0150] Furthermore, the general or specific embodiments of this disclosure may be implemented as a system, apparatus, method, integrated circuit, computer program, or recording medium such as a computer-readable CD-ROM. They may also be implemented in any combination of systems, apparatus, methods, integrated circuits, computer programs, and recording media.

[0151] For example, the invention may be implemented as a method for determining presence or absence, or as a method for controlling a ventilation system, which is executed by a computer. Alternatively, it may be implemented as a program for causing a computer to execute such a method for determining presence or absence, or as a control method. Furthermore, the invention may be implemented as a computer-readable non-temporary recording medium on which such a program is stored. The invention may also be a program product containing such a program. [Explanation of symbols]

[0152] 10. Presence / Absence Determination System 21, 21a Air conditioner 211 Air Conditioning Department 221 Dehumidification section 23, 24 Conveyor equipment 30. Outdoor air intake fan (outdoor air intake device) 50 Temperature Sensors 60 CO2 sensors 70 Humidity Sensor 80 Control device 90 facilities Rooms 90a, 90b, and 90c 100 Ventilation System D1 First specified value D2 Second specified value D3 Third specified value

Claims

1. A method for determining the presence or absence of a user within a facility, which is performed by a computer, When ventilation is being performed within the facility by the ventilation system, CO2 installed within the facility ２ The sensor measures CO2 within the facility. ２ The concentration is acquired at regular intervals. CO2 outside the aforementioned facility ２ Obtain or estimate the concentration, CO acquired within the aforementioned facility ２ The concentration and the CO2 obtained or estimated from outside the facility. ２ This includes determining the presence or absence of the user within the facility using the concentration, Presence / absence determination method.

2. The aforementioned method for determining presence or absence further includes: The determination result regarding the presence or absence of the user is presented to the user, and input from the user regarding whether the determination result is accurate is received. Based on the input received from the user, the parameters for determining the presence or absence of the user are updated. The method for determining presence or absence according to claim 1.

3. The ventilation system includes an outside air intake device that brings outside air into the facility, In the aforementioned method for determining presence or absence of the user, the amount of air taken in from outside the facility by the outside air intake device and the volume of the facility are used in determining the presence or absence of the user. The method for determining presence or absence according to claim 1.

4. The presence / absence determination method generates presence / absence prediction information that indicates whether the user will be present in the facility from the present to the future, based on the determination result regarding the user's presence or absence. The method for determining presence or absence according to claim 1.

5. A method for controlling the ventilation system using the presence / absence determination method described in claim 1, which is performed by a computer, The aforementioned ventilation system Air conditioning unit, A conveying device that transports air whose temperature has been adjusted by the aforementioned air conditioning unit to each of the multiple rooms in the facility, Each of the aforementioned rooms is equipped with a plurality of temperature sensors that measure the temperature of each of the aforementioned rooms, In the aforementioned control method, If the presence / absence determination method determines that the user is present in the room, the air conditioning unit and the transport device are controlled so that the temperature measured by the temperature sensors installed in each of the multiple rooms reaches the set temperature set by the user. If the presence / absence determination method determines that the user is absent, the air conditioning unit and the transport device are stopped, or the air conditioning unit and the transport device are controlled so that the energy consumption of the air conditioning unit and the transport device becomes less than a first specified value, and the temperature measured by the temperature sensors installed in each of the multiple rooms becomes the set temperature. A method for controlling a ventilation system.

6. The ventilation system includes an outside air intake device that brings outside air into the facility, In the aforementioned control method, If the presence / absence determination method determines that the user is present in the room, the outside air intake device is controlled so that a second specified amount of outside air is taken in. If the presence / absence determination method determines that the user is absent, the outside air intake device is stopped, or the outside air intake device is controlled so that outside air below the second specified value is taken in. A method for controlling a ventilation system according to claim 5.

7. The aforementioned ventilation system A dehumidifier that adjusts the humidity inside the facility to a pre-set humidity level, The facility is equipped with a humidity sensor installed within the facility to measure the humidity within the facility, In the aforementioned control method, If the presence / absence determination method determines that the user is present in the room, the dehumidifier is controlled so that the humidity measured by the humidity sensor installed in the facility becomes the set humidity, taking into consideration the impact on the temperature control of the air by the air conditioning unit. If the presence / absence determination method determines that the user is absent, the dehumidifier is controlled so that the energy efficiency of the dehumidifier is equal to or greater than the third specified value, and the humidity measured by the humidity sensor installed in the facility is equal to the set humidity. A method for controlling a ventilation system according to claim 5.

8. The ventilation system comprises multiple air conditioning units, each having an air conditioning unit and a dehumidifying unit. In the aforementioned control method, If the presence / absence determination method determines that the user is present in the room, some of the air conditioning units among the multiple air conditioning units are controlled so that the humidity in the facility is adjusted to within the set range, and the remaining air conditioning units among the multiple air conditioning units are controlled so that the temperature measured by the temperature sensors installed in each of the multiple rooms reaches the set temperature. If the presence / absence determination method determines that the user is absent, the system determines which air conditioning unit to operate from the multiple air conditioning units based on the current humidity measured by the humidity sensor and the set range, and controls the air conditioning unit that was determined to operate so that the humidity measured by the humidity sensor installed in the facility becomes the set humidity. A method for controlling a ventilation system according to claim 7.

9. In the aforementioned control method, We obtain information on demand reduction requests to adjust electricity usage published by power companies, or information on dynamically fluctuating electricity rates. Based on the acquired information regarding the demand reduction request and the electricity charges, and the information regarding the user's presence or absence, the ventilation system is controlled. A method for controlling a ventilation system according to any one of claims 5 to 7.

10. When ventilation is being performed within the facility by the ventilation system, the CO2 in the facility is installed within the facility. ２ CO2 concentration measurement ２ Sensors and, Equipped with a control device, The control device is The aforesaid CO ２ CO within the facility measured by the sensor ２ The concentration is acquired at regular intervals, CO2 outside the aforementioned facility ２ Obtain or estimate the concentration, CO acquired within the aforementioned facility ２ The concentration and the CO2 obtained or estimated from outside the facility. ２ Using the concentration, the presence or absence of a user using the facility is determined. Presence / absence determination system.

11. The presence / absence determination system according to claim 10, Air conditioning unit, A conveying device that transports air whose temperature has been adjusted by the aforementioned air conditioning unit to each of the multiple rooms in the facility, Each of the aforementioned rooms is equipped with a plurality of temperature sensors that measure the temperature of each of the aforementioned rooms, The control device is If the presence / absence determination system determines that the user is present in the room, the air conditioning unit and the transport device are controlled so that the temperature measured by the temperature sensors installed in each of the multiple rooms reaches the set temperature set by the user. If the presence / absence determination system determines that the user is absent, the air conditioning unit and the transport device are stopped, or the air conditioning unit and the transport device are controlled so that the energy consumption of the air conditioning unit and the transport device becomes less than a first specified value, and the temperature measured by the temperature sensors installed in each of the multiple rooms becomes the set temperature. Ventilation system.

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