Ventilation system

Abstract

We provide ventilation systems that take into account factors other than carbon dioxide concentration. [Solution] The system comprises an exhaust fan 4 that exhausts air from an indoor space to the outdoors, a volatile organic compound concentration measuring unit 9 that measures the concentration of volatile organic compounds in the air of the space, a carbon dioxide concentration measuring unit 8 that measures the concentration of carbon dioxide in the air of the space, and a control unit that controls the exhaust fan 4. The control unit 6 comprises an airflow rate determination unit 13 that determines the exhaust airflow rate of the exhaust fan 4 based on the carbon dioxide concentration of the air of the space measured by the carbon dioxide concentration measuring unit 8, an airflow rate correction unit 15 that corrects the exhaust airflow rate determined by the airflow rate determination unit 13 based on the volatile organic compound concentration of the air of the space measured by the volatile organic compound concentration measuring unit 9, and an airflow rate control unit 16 that controls the airflow rate using the exhaust airflow rate corrected by the airflow rate correction unit 15. This solves the above problem.

Description

Technical Field

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[0001] The present invention relates to a ventilation device.

Background Art

[0002] Conventionally, a ventilation device that detects the carbon dioxide concentration and performs ventilation is known (for example, Patent Document 1).

Prior Art Document

Patent Document

[0003]

Patent Document 1

[0007] According to this disclosure, it is possible to provide a ventilation system that takes into account influences other than carbon dioxide concentration. [Brief explanation of the drawing]

[0008] [Figure 1] These are configuration diagrams and layout diagrams of the ventilation system according to this embodiment. [Figure 2] This is a schematic functional block diagram of the control unit and peripheral unit according to this embodiment. [Figure 3] This flowchart shows the control according to this embodiment. [Modes for carrying out the invention]

[0009] The embodiments for implementing this disclosure will be described below with reference to the drawings. However, the embodiments shown below are illustrative examples to embody the technical concept of this disclosure, and this disclosure is not limited to these. In particular, the materials, shapes, components, arrangement of components, and relative arrangement described in the embodiments are examples and are not intended to limit the scope of this disclosure to them alone. In addition, the same reference numerals are used for substantially identical components in each drawing, and redundant explanations are omitted or simplified.

[0010] (Embodiment) First, the ventilation device according to this embodiment will be described. The ventilation device according to this embodiment is a device capable of exhausting air from an indoor space. Figure 1 is a configuration diagram and layout diagram of the ventilation device according to this embodiment.

[0011] First, the ventilation device 100 according to this embodiment will be described. In this embodiment, the ventilation device 100 is described as a device capable of exhausting air from a predetermined indoor space. The ventilation device 100 may further have a function of supplying air to the indoor space. In this embodiment, the space inside a smoking booth is given as an example of an indoor space, but it is not limited to this. For example, the indoor space may be a living room, dining room, kitchen, bedroom, conference room, shop, living room, office, etc., or any other indoor space. Note that the space inside a smoking booth provided as a predetermined indoor space, as well as the space inside a smoking booth installed independently outdoors, are both considered indoor spaces.

[0012] The ventilation device 100 can be installed in the space above the ceiling, inside the side walls, or under the floor of a building, and ventilates the air in the indoor space of the smoking booth. In this embodiment, the ventilation device 100 is fixed to the wall separating the indoor space of the smoking booth from the space behind the side wall, and is positioned behind the wall. Inside the smoking booth, there is a table 5 or the like for placing an ashtray for disposing of cigarette butts and ash.

[0013] The ventilation device 100 comprises a housing 1, an intake port 2, an outlet port 3, an exhaust fan 4, a carbon dioxide concentration measuring unit 8, a volatile organic compound concentration measuring unit 9, a target spraying unit 10, and a control unit 6.

[0014] The enclosure 1 is roughly rectangular in shape and houses various components of the ventilation device 100.

[0015] The intake port 2 is located on the side of the housing 1 and is an opening for drawing air from the indoor space into the housing 1 through an opening in the indoor wall.

[0016] The air outlet 3 is located on the top surface of the housing 1. The air outlet 3 is an opening for blowing out indoor air, which has been drawn into the housing 1 from the intake port 2, to the outside of the housing 1. The air outlet 3 is connected to one end of the duct 7. The other end of the duct 7 is connected to the outdoors. In other words, the duct 7 discharges the air blown out from the air outlet 3 to the outside.

[0017] The exhaust fan 4 is a type of blower and is installed inside the housing 1. The exhaust fan 4 draws air into the housing 1 from the intake port 2 and generates an airflow that blows the drawn-in air outside through the outlet port 3 and duct 7. Specifically, as the exhaust fan 4 rotates, air from the indoor space is drawn into the housing 1 from the intake port 2 and blown out from the outlet port 3. The air blown out from the outlet port 3 is discharged outside via the duct 7. In other words, the exhaust fan 4 exhausts the air from the indoor space to the outside. The housing 1 may also be equipped with an air supply fan that supplies outdoor air to the indoor space. In other words, the ventilation device 100 may be a ventilation device capable of both supplying and exhausting air.

[0018] The carbon dioxide concentration measuring unit 8 measures the carbon dioxide concentration in the air of an indoor space. The carbon dioxide concentration measuring unit 8 is, for example, a carbon dioxide concentration sensor. Known techniques are used to measure the carbon dioxide concentration. In this embodiment, the carbon dioxide concentration measuring unit 8 is provided at the intake port 2. It is desirable that the carbon dioxide concentration measuring unit 8 be provided near the intake port 2 in order to measure the carbon dioxide concentration in the air of an indoor space. As a result, the carbon dioxide concentration measuring unit 8 measures the carbon dioxide concentration in the air of the indoor space that is taken into the housing 1 from the intake port 2. Furthermore, the carbon dioxide concentration measuring unit 8 does not have to be provided in the housing 1. For example, the carbon dioxide concentration measuring unit 8 may be provided in an indoor space, and the carbon dioxide concentration of the indoor air measured by the carbon dioxide concentration measuring unit 8 may be transmitted to the control unit 6, which will be described later, by wired communication or wireless communication. Hereinafter, carbon dioxide may be referred to as "CO2".

[0019] The volatile organic compound concentration measurement unit 9 measures the concentration of volatile organic compounds in the air of the indoor space. Volatile organic compounds are a general term for organic compounds (chemical substances) that become gases in the air, and volatile organic compounds are contained in, for example, tobacco smoke. The volatile organic compound concentration measurement unit 9 is, for example, a volatile organic compound concentration sensor. Known techniques are used for measuring the concentration of volatile organic compounds. In the present embodiment, the volatile organic compound concentration measurement unit 9 is provided at the suction port 2. The volatile organic compound concentration measurement unit 9 is preferably provided in the vicinity of the suction port 2 in order to measure the concentration of volatile organic compounds in the air of the indoor space. Thereby, the volatile organic compound concentration measurement unit 9 measures the concentration of volatile organic compounds in the air of the indoor space taken into the housing 1 from the suction port 2. Also, the volatile organic compound concentration measurement unit 9 may not be provided in the housing 1. For example, the volatile organic compound concentration measurement unit 9 may be provided in the indoor space, and the concentration of volatile organic compounds in the indoor air measured by the volatile organic compound concentration measurement unit 9 may be transmitted to the control unit 6 by wired communication or wireless communication. Hereinafter, volatile organic compounds may be referred to as "VOC". "VOC" is an abbreviation for Volatile Organic Compounds.

[0020] Note that the carbon dioxide concentration measurement unit 8 and the volatile organic compound concentration measurement unit 9 may be provided in the same device. That is, the carbon dioxide concentration measurement unit 8 and the volatile organic compound concentration measurement unit 9 may be provided in a multi-sensor having a plurality of sensor functions, and the housing 1 may be provided with the multi-sensor.

[0021] The target spraying part 10 is provided near the suction port 2. The target spraying part 10 may be provided below the suction port 2, may be provided above the suction port 2, may be provided on the side part of the suction port 2, or may be provided at a position closing a part of the opening of the suction port 2. In the present embodiment, the target spraying part 10 is provided below the suction port 2. The material of the target spraying part 10 may be any material such as paper, cloth, metal, resin, etc. It is preferable that the target spraying part 10 has a mark for the user to blow the smoke of the tobacco. That is, it is a member for promoting the location where the user blows the smoke of the tobacco. For example, a mark by characters such as "Please blow the smoke of the tobacco towards here" may be indicated, a mark by a symbol for spraying such as a square may be indicated, or otherwise. Thereby, a smoker can easily blow the smoke of the tobacco onto the target spraying part 10. That is, the target spraying part 10 can prompt the smoker to blow the smoke onto the target spraying part 10. Thus, the target spraying part 10 receives the smoke blown out when the smoker smokes in the indoor space. Also, the volatile organic compound concentration measurement part 9 may be provided on the target spraying part 10. Thereby, the volatile organic compounds blown out when the smoker smokes can be detected early.

[0022] The control part 6 controls the ventilation device 100. The control part 6 is electrically communicably connected to the carbon dioxide concentration measurement part 8, the volatile organic compound concentration measurement part 9, and the exhaust fan 4, and controls the exhaust fan 4. Details of the control content of the control part 6 will be described later.

[0023] Next, each function of the control part 6 according to the present embodiment will be described with reference to FIG. 2. FIG. 2 is a schematic functional block diagram of the control part 6 and its periphery.

[0024] [[ID=​​​The carbon dioxide concentration acquisition unit 11 acquires the CO2 concentration measured by the carbon dioxide concentration measurement unit 8.

[0026] The volatile organic compound concentration acquisition unit 12 acquires the VOC concentration measured by the volatile organic compound concentration measurement unit 9.

[0027] The airflow determination unit 13 determines the exhaust airflow of the exhaust fan 4 based on the CO2 concentration of the indoor air measured by the carbon dioxide concentration measurement unit 8. In other words, the airflow determination unit 13 determines the exhaust airflow based on the CO2 concentration of the indoor air acquired by the carbon dioxide concentration acquisition unit 11. Specifically, the airflow determination unit 13 determines a larger exhaust airflow the higher the CO2 concentration acquired by the carbon dioxide concentration acquisition unit 11.

[0028] In this embodiment, as an example, the exhaust fan 4 has four adjustable airflow levels. These four levels are: zero airflow (operation stopped or airflow level 0), airflow level 1, airflow level 2, and airflow level 3. The relationship between the airflow levels is zero airflow < airflow level 1 < airflow level 2 < airflow level 3. In this embodiment, as an example, zero airflow is set to 0 CFM (Cubic Feet per Minute), airflow level 1 to 40 CFM, airflow level 2 to 70 CFM, and airflow level 3 to 100 CFM, but the airflow for each level can be set arbitrarily.

[0029] The airflow determination unit 13 determines the exhaust airflow to a higher airflow level as the CO2 concentration acquired by the carbon dioxide concentration acquisition unit 11 increases. In this embodiment, as an example, the airflow determination unit 13 determines the exhaust airflow by comparing the carbon dioxide concentration value with a first threshold and a second threshold that is greater than the first threshold. The first threshold is set to 800 ppm (parts per million), which is the carbon dioxide concentration standard value recommended by, for example, the U.S. Centers for Disease Control and Prevention and the UK Health and Safety Agency. The second threshold is set to 1000 ppm, which is the carbon dioxide concentration standard value established for the purpose of ensuring a hygienic environment in buildings such as office buildings and department stores. However, the above first and second thresholds are merely examples, and the first and second thresholds can be set arbitrarily. The airflow, first threshold, and second threshold for each airflow level are stored in the storage unit 14, which is a so-called memory.

[0030] In this embodiment, as an example, the airflow determination unit 13 determines the exhaust airflow to airflow level 1 if the CO2 concentration is above the first threshold and below the second threshold. Furthermore, the airflow determination unit 13 determines the exhaust airflow to airflow level 2 if the CO2 concentration is greater than the second threshold.

[0031] The airflow correction unit 15 corrects the exhaust airflow determined by the airflow determination unit 13 based on the VOC concentration of the indoor air measured by the volatile organic compound concentration measuring unit 9. In other words, the airflow correction unit 15 corrects the exhaust airflow determined by the airflow determination unit 13 based on the VOC concentration of the indoor air acquired by the volatile organic compound concentration acquisition unit 12. Specifically, the airflow correction unit 15 corrects the exhaust airflow determined by the airflow determination unit 13 to a larger airflow as the VOC concentration increases.

[0032] In this embodiment, as an example, the airflow correction unit 15 determines whether or not to correct the exhaust airflow and the amount of correction by comparing the VOC concentration with a third threshold and a fourth threshold that is greater than the third threshold. The third threshold is set to 35 micrograms / cubic meter, for example, as a level that is desirable to maintain in order to appropriately protect human health, based on Article 16, Paragraph 1 of the Basic Environment Law. The fourth threshold is set to 70 micrograms / cubic meter, for example, as a particulate matter concentration level at which the likelihood of health effects appearing is predicted to increase, as set by the expert meeting on fine particulate matter established by the Ministry of the Environment in 2013. However, the above third and fourth thresholds are merely examples, and the third and fourth thresholds can be set arbitrarily. The third and fourth thresholds are also stored in the storage unit 14.

[0033] In this embodiment, as an example, the airflow correction unit 15 corrects the exhaust airflow to a larger airflow than the exhaust airflow determined by the airflow determination unit 13 if the VOC concentration value is between the third threshold and the fourth threshold. Furthermore, if the VOC concentration is above the fourth threshold, the airflow correction unit 15 corrects the exhaust airflow to an even larger airflow than the corrected airflow when the VOC concentration is between the third threshold and the fourth threshold.

[0034] For example, if the exhaust airflow determined by the airflow determination unit 13 is at airflow level 1, the airflow correction unit 15 corrects the exhaust airflow to airflow level 2 if the VOC concentration is above the third threshold but below the fourth threshold, and corrects the exhaust airflow to airflow level 3 if the VOC concentration is above the fourth threshold. Also, if the exhaust airflow determined by the airflow determination unit 13 is at airflow level 2, the airflow correction unit 15 corrects the exhaust airflow to airflow level 3 if the VOC concentration is above the third threshold. The above correction amounts by the airflow correction unit 15 are merely examples and can be arbitrarily set after conducting experiments in advance.

[0035] The airflow control unit 16 controls the airflow using the exhaust airflow corrected by the airflow correction unit 15. The airflow control unit 16 performs constant airflow control in order to control the airflow using the exhaust airflow corrected by the airflow correction unit 15. Since constant airflow control is a well-known technique, a detailed explanation is omitted.

[0036] Each functional block of the control unit 6 can be implemented as hardware, such as a computer's CPU (Central Processing Unit), or as a computer program, and as software, but here, it refers to a functional block that is realized through the coordination of these components. Therefore, these functional blocks can be implemented in various forms through combinations of hardware and software.

[0037] Next, the control performed by the control unit 6 will be explained using the flowchart in Figure 3. In the flowchart, numbers are assigned starting with the letter S. For example, S1 indicates a processing step. However, the magnitude of the numerical value indicating a processing step is not related to the processing order.

[0038] First, the carbon dioxide concentration acquisition unit 11 acquires the CO2 concentration of the air in the indoor space from the carbon dioxide concentration measurement unit 8 (S1).

[0039] The airflow rate determination unit 13 determines the exhaust airflow rate based on the CO2 concentration of the indoor air acquired by the carbon dioxide concentration acquisition unit 11 (S2). At this time, the higher the CO2 concentration, the larger the exhaust airflow rate is determined, and the reason for this will be explained.

[0040] Studies have shown that as CO2 concentration increases, it can impair the decision-making and concentration of users in indoor spaces, and in the worst cases, it can lead to health problems such as headaches and difficulty breathing. Therefore, the airflow determination unit 13 determines a larger exhaust airflow when the CO2 concentration in the indoor space is high. This suppresses the rise in CO2 concentration in the indoor space, and as a result, it is possible to suppress the decline in user comfort.

[0041] Here, if the exhaust airflow is always set to airflow level 3, the rise in CO2 concentration in the indoor space can be suppressed to the greatest extent possible. However, setting the exhaust airflow to airflow level 3 at all times has the disadvantage of increasing electricity costs due to high power consumption. In addition, setting the exhaust airflow to airflow level 3 at all times may reduce user comfort due to the noise generated by operating the exhaust fan 4 at a high airflow. Therefore, it is desirable to appropriately determine the exhaust airflow according to the CO2 concentration in the indoor space. This concludes the explanation.

[0042] Next, the volatile organic compound concentration acquisition unit 12 acquires the VOC concentration of the indoor air from the volatile organic compound concentration measurement unit 9 (S3).

[0043] The airflow correction unit 15 corrects the exhaust airflow determined by the airflow determination unit 13 based on the VOC concentration of the indoor air acquired by the volatile organic compound concentration acquisition unit 12 (S4). At this time, the higher the VOC concentration, the greater the airflow determined by the airflow determination unit 13 is corrected to. The reason for this will be explained below.

[0044] The air exhaled by smokers after they smoke contains many VOCs. VOCs are a factor in harming human health. Therefore, controlling the exhaust airflow based solely on CO2 concentration may exacerbate the health risks caused by VOCs. For example, immediately after a smoker enters an indoor smoking booth, the CO2 concentration is likely to be low. In other words, the exhaust airflow is likely to be small in this state. After the smoker enters, the VOC concentration in the indoor space increases significantly due to the smoker's smoking, but the CO2 concentration does not increase rapidly. This means that the exhaust airflow may remain small even when there are concerns about health risks from VOCs, which is a drawback of determining the exhaust airflow based solely on CO2 concentration. Smokers are likely to start smoking immediately after entering a smoking booth, so it is preferable to control the exhaust airflow considering not only the CO2 concentration but also the VOC concentration. Furthermore, it is preferable for the airflow correction unit 15 to correct the exhaust airflow determined by the airflow determination unit 13 to a larger airflow as the VOC concentration increases. This allows for efficient discharge of VOCs from the indoor space and suppresses health risks to humans. Furthermore, it can reduce health risks to people even when smokers start smoking immediately after entering a smoking booth.

[0045] Furthermore, if the VOC concentration is below the third threshold, the airflow correction unit 15 does not correct the exhaust airflow determined by the airflow determination unit 13. In other words, step S4 is skipped.

[0046] The airflow control unit 16 performs airflow control using the exhaust airflow corrected by the airflow correction unit 15 (S5).

[0047] By implementing the above control measures, appropriate control can be carried out that takes into account the smoking behavior of smokers. This can reduce the health damage caused by VOCs to people. In addition, it can reduce the health damage to people when smokers start smoking immediately after entering a smoking booth (indoor space).

[0048] Furthermore, as mentioned above, the system is equipped with a target spraying unit 10 that receives smoke emitted when a smoker smokes in an indoor space, and a volatile organic compound concentration measuring unit 9 is provided on the target spraying unit 10. This allows for early detection of VOCs caused by a smoker's smoking, further suppressing health damage to people caused by VOCs. Without the target spraying unit 10, early detection of smoking when a smoker enters an indoor space may not be possible, and it may not be possible to expel the VOCs generated by smoking promptly, potentially leading to greater health damage.

[0049] Although the present invention has been described above based on embodiments, it can be easily inferred that the present invention is not limited in any way to the above embodiments, and that various improvements and modifications are possible without departing from the spirit of the present invention.

[0050] As can be seen from the above embodiment, the control unit prioritizes CO2 concentration over VOC concentration when determining the exhaust airflow rate. When the CO2 concentration in an indoor space is high, it can potentially cause serious harm such as respiratory distress, so it is desirable to prioritize CO2 concentration over VOC concentration when determining the exhaust airflow rate. This allows for control that takes into account the degree of adverse impact on human health. As a result, it is possible to suppress serious health damage to people.

[0051] (Summary of the invention) The ventilation device according to this disclosure comprises an exhaust fan that exhausts air from an indoor space to the outdoors, a volatile organic compound concentration measuring unit that measures the concentration of volatile organic compounds in the air of the space, a carbon dioxide concentration measuring unit that measures the concentration of carbon dioxide in the air of the space, and a control unit that controls the exhaust fan. The control unit comprises an airflow determination unit that determines the exhaust airflow of the exhaust fan based on the carbon dioxide concentration of the air of the space measured by the carbon dioxide concentration measuring unit, an airflow correction unit that corrects the exhaust airflow determined by the airflow determination unit based on the volatile organic compound concentration of the air of the space measured by the volatile organic compound concentration measuring unit, and an airflow control unit that controls the airflow using the exhaust airflow corrected by the airflow correction unit.

[0052] This allows for control that takes into account factors other than carbon dioxide concentration. In other words, it allows for control that takes into account smoking by smokers. Therefore, it can suppress health damage to humans caused by volatile organic compounds.

[0053] Furthermore, the airflow determination unit may set the exhaust airflow to a larger volume as the carbon dioxide concentration increases.

[0054] This allows for the suppression of rising indoor carbon dioxide concentrations with appropriate ventilation. As a result, a decrease in user comfort can be minimized. Furthermore, unnecessary power consumption can be reduced.

[0055] Furthermore, the airflow correction unit may correct the exhaust airflow determined by the airflow determination unit to an airflow that is larger as the concentration of volatile organic compounds increases.

[0056] This helps to reduce the health risks to humans caused by volatile organic compounds (VOCs). For example, when a smoker enters an indoor space and immediately starts smoking, VOCs can be properly released, thus mitigating health risks to humans while considering smoking. Furthermore, it reduces unnecessary power consumption.

[0057] Furthermore, the device may be equipped with a target spraying section that receives smoke emitted when a smoker smokes in the space, and a volatile organic compound concentration measuring section may be provided in the target spraying section.

[0058] This technology allows for early detection of VOCs (volatile organic compounds) emitted by smokers, further reducing the health risks to humans caused by VOCs. Furthermore, it enables early detection of VOCs emitted by smokers, such as when a smoker smokes immediately upon entering an indoor space, further reducing the health risks to humans caused by VOCs.

[0059] Furthermore, the indoor space may also be the space inside a smoking booth.

[0060] This allows for optimal control to minimize health risks to people when smoking occurs in a smoking booth. In other words, it can minimize health risks to people when smoking occurs in a smoking booth. [Industrial applicability]

[0061] This invention is useful for ventilation systems and the like that equipped with an exhaust fan. [Explanation of Symbols]

[0062] 1 cabinet 2. Inlet 3 Air outlet 4 Exhaust Fans 5 tables 6 Control Unit 7 ducts 8. Carbon dioxide concentration measurement unit 9. Volatile Organic Compound Concentration Measurement Unit 10 Target spraying area 11. Carbon dioxide concentration acquisition unit 12. Volatile Organic Compound Concentration Acquisition Unit 13. Airflow determination unit 14 Storage section 15. Airflow correction unit 16 Airflow control unit 100 Ventilation system

Claims

1. An exhaust fan that exhausts the air from an indoor space to the outside, A volatile organic compound concentration measuring unit for measuring the concentration of volatile organic compounds in the air of the aforementioned space, A carbon dioxide concentration measuring unit for measuring the carbon dioxide concentration of the air in the aforementioned space, The system comprises a control unit for controlling the exhaust fan, The control unit, An airflow determination unit that determines the exhaust airflow rate of the exhaust fan based on the carbon dioxide concentration of the air in the space measured by the carbon dioxide concentration measuring unit, Based on the volatile organic compound concentration of the air in the space measured by the volatile organic compound concentration measuring unit, the airflow rate correction unit corrects the exhaust airflow rate determined by the airflow rate determination unit from the determined exhaust airflow rate. A ventilation device comprising: an airflow control unit that performs airflow control using the exhaust airflow corrected by the airflow correction unit; and an airflow control unit that performs airflow control using the corrected exhaust airflow.

2. The aforementioned airflow determination unit is The ventilation device according to claim 1, wherein the exhaust air volume is determined to be larger as the carbon dioxide concentration increases.

3. The aforementioned airflow correction unit is The ventilation device according to claim 1 or 2, wherein the exhaust air volume determined by the air volume determination unit is corrected to an air volume that increases as the concentration of the volatile organic compound increases.

4. The ventilation device according to claim 1, comprising a target spraying section for receiving smoke blown out when a smoker smokes in the aforementioned space, and the target spraying section being provided with the volatile organic compound concentration measuring section.

5. The ventilation device according to claim 1, wherein the indoor space is the space inside a smoking booth.

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