Ventilation system

Abstract

To prevent dew condensation in an exhaust duct and to improve energy efficiency.SOLUTION: The ventilation system 10 includes an exhaust duct 31, an air supply duct 41, a forced exhaust duct 61, an exhaust passage switching valve 91, an air supply passage switching valve 100, a differential pressure air supply member 81, an exhaust fan 111, an air supply fan 120, a forced exhaust fan 141, a temperature and humidity sensor 151, and a management device 200. The management device 200 closes the exhaust flow path and the air supply flow path and opens the forced exhaust flow path to discharge the air in the room 21 to the outside of the building 11 based on the fact that the temperature in the exhaust duct reaches near the dew point temperature. When the air in the room 21 is discharged, the outside air flows into the room 21 through the differential pressure feed member 81. Since the air supply passage is closed when the forced ventilation is performed, the air whose temperature has been adjusted by the heat exchanger 12 is prevented from being wastefully discharged to the outside. As a result, dew condensation in the exhaust duct 31 is prevented and energy efficiency is enhanced.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a ventilation system for ventilating a building. [Background technology]

[0002] Patent Document 1 discloses an air conditioning and ventilation system for use in buildings. This air conditioning and ventilation system includes an exhaust duct and an air supply duct that connect a room to the outside (outside air), a heat exchanger, and a controller. The exhaust duct and the air supply duct are provided with blower fans. Air inside the room is discharged to the outside through the exhaust duct, and outside air is introduced into the room through the air supply duct. The heat exchanger exchanges heat between the air discharged to the outside and the air flowing in from the outside.

[0003] The air conditioning and ventilation system disclosed in Patent Document 1 further includes a ventilation fan installed in a specific room, such as a bathroom or toilet, and a humidity sensor installed in the room. When the humidity sensor detects that the bathroom or toilet has been used, the ventilation fan is activated. The ventilation fan forcibly exhausts air containing a large amount of moisture from the room to the outside. While the forced exhaust is being performed, temperature-adjusted conditioned air is introduced into the room through an air supply duct, replacing the air in the room with the conditioned air. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-82652 Summary of the Invention [Problem to be solved by the invention]

[0005] In the air conditioning ventilation system disclosed in Patent Document 1, the ventilation fan is driven according to the humidity in the room (bathroom, etc.), so if the humidity in the room is low, the ventilation fan is not driven. In that case, the air in the room may be cooled as it passes through the exhaust duct, causing condensation inside the exhaust duct.

[0006] Furthermore, in the air conditioning ventilation system disclosed in Patent Document 1, the ventilation fan is driven and conditioned air is introduced into the room (bathroom, etc.), so some of the conditioned air is also expelled from the room to the outside by the ventilation fan, resulting in poor energy efficiency.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and its object is to provide a ventilation system that can prevent condensation in the exhaust duct and improve energy efficiency. [Means for solving the problem]

[0008] (1) A ventilation system according to the present invention includes an exhaust duct connecting a room of a building to the outside, an exhaust fan provided in the exhaust duct, an air supply duct connecting the room to the outside, an air supply fan provided in the air supply duct, a heat exchanger for exchanging heat between the exhaust air of the exhaust duct and the air supply to the air supply duct, a forced exhaust duct connecting the room to the outside, a forced exhaust fan provided in the forced exhaust duct, a differential pressure air supply member provided in a wall of the room, an exhaust duct valve provided in the exhaust duct, an air supply duct valve provided in the air supply duct, a forced exhaust duct valve provided in the forced exhaust duct, a sensor for detecting information related to condensation in the exhaust duct, and a controller. The controller performs a forced ventilation process that closes the exhaust duct valve and the air supply duct valve and opens the forced exhaust duct valve based on the output of the sensors.

[0009] When the controller determines, based on the sensor output, that condensation is occurring in the exhaust duct, it closes the exhaust duct valve and the intake duct valve and opens the forced exhaust duct valve. The forced exhaust fan exhausts the air inside the room to the outside through the forced exhaust duct, preventing condensation inside the exhaust duct. Because the intake duct valve is closed during forced ventilation, the air that has undergone heat exchange in the heat exchanger is prevented from being exhausted to the outside through the forced exhaust duct. As a result, energy efficiency is improved. The forced exhaust fan may be driven continuously, may be driven in conjunction with the opening and closing of the forced exhaust duct valve, or may be controlled by the controller.

[0010] (2) The sensor may be a temperature and humidity sensor provided in the exhaust duct. The controller executes a dew-point temperature acquisition process to acquire a dew-point temperature corresponding to the temperature and humidity inside the exhaust duct detected by the temperature and humidity sensor, a normal ventilation process to open the exhaust duct valve and the intake air duct valve and close the forced exhaust duct valve based on whether the temperature inside the exhaust duct detected by the temperature and humidity sensor has reached a threshold temperature corresponding to the dew-point temperature, and a forced ventilation process based on whether the temperature inside the exhaust duct has reached the threshold temperature.

[0011] A temperature and humidity sensor may be installed in an exhaust duct to manage the temperature and humidity in a room. This temperature and humidity sensor is used to determine whether condensation will occur. Specifically, condensation occurs when the temperature inside the exhaust duct reaches the dew point temperature. The controller obtains the dew point temperature from the detected temperature and humidity inside the exhaust duct and determines whether condensation will occur based on whether the temperature inside the exhaust duct has reached a threshold temperature corresponding to the dew point temperature. When the controller determines that the temperature inside the exhaust duct has reached the threshold temperature, it executes forced ventilation processing. Therefore, condensation inside the exhaust duct can be prevented without installing a new sensor to determine whether condensation will occur.

[0012] (3) The rooms may include a first room and a second room. The exhaust duct includes a first exhaust duct connecting the first room to the outside and a second exhaust duct connecting the second room to the outside. The air intake duct includes a first air intake duct connecting the first room to the outside and a second air intake duct connecting the second room to the outside. The exhaust duct valve includes a first exhaust duct valve provided in the first exhaust duct and a second exhaust duct valve provided in the second exhaust duct. The air intake duct valve includes a first air intake duct valve provided in the first air intake duct and a second air intake duct valve provided in the second air intake duct. The ventilation system according to the present invention further includes a first circulation duct connecting the first exhaust duct and the second intake duct and equipped with a first circulation fan, and a second circulation duct connecting the second exhaust duct and the first intake duct and equipped with a second circulation fan. The first exhaust duct valve is a flow path switching valve provided at a connection between the first exhaust duct and the first circulation duct. The second exhaust duct valve is a flow path switching valve provided at a connection between the second exhaust duct and the second circulation duct. The controller selectively performs a normal ventilation process using the first exhaust duct and the second exhaust duct, and a circulation ventilation process using at least one of the first circulation duct and the second circulation duct.

[0013] When the first exhaust duct valve (flow path switching valve) opens the flow path to the first exhaust duct side and the second exhaust duct valve (flow path switching valve) opens the flow path to the second exhaust duct side, only normal ventilation via the heat exchanger is performed. When the first exhaust duct valve (flow path switching valve) opens the flow path to the first circulation duct side or the second exhaust duct valve (flow path switching valve) opens the flow path to the second circulation duct side, circulatory ventilation is performed in which air from the first room flows into the second room, or air from the second room flows into the first room. In other words, the ventilation system of the present invention can selectively perform normal ventilation and circulatory ventilation. By performing circulatory ventilation, energy efficiency can be improved compared to when only normal ventilation is performed.

[0014] (4) The ventilation system according to the present invention may include a contamination detection sensor that detects a value relating to the contamination level of each room. The normal ventilation process is executed on the condition that the value detected by the contamination detection sensor is equal to or greater than a contamination threshold. The circulating ventilation process is executed on the condition that the value detected by the contamination detection sensor for at least one of the rooms is less than a contamination threshold.

[0015] If the values ​​detected by the contamination detection sensors for the multiple rooms are equal to or greater than the contamination threshold and ventilation with outside air is required, normal ventilation processing is performed. If the value detected by the contamination detection sensor for at least one of the multiple rooms is less than the contamination threshold, circulating ventilation processing is performed.

[0016] (5) The contamination detection sensor may be at least one of a temperature and humidity sensor and a carbon dioxide sensor.

[0017] The type of ventilation treatment is performed according to the humidity or carbon dioxide concentration of the air in each room.

[0018] (6) The ventilation system according to the present invention may include an outside air temperature sensor that detects an outside air temperature. The sensor includes a first temperature / humidity sensor provided in the first exhaust duct and a second temperature / humidity sensor provided in the second exhaust duct. The controller determines ventilation rates of the outside air in the first room and the second room based on the outside air temperature detected by the outside air temperature sensor, the temperature in the first exhaust duct detected by the first temperature / humidity sensor, and the temperature in the second exhaust duct detected by the second temperature / humidity sensor, and performs the normal ventilation process and the circulating ventilation process.

[0019] The greater the difference between the outside air temperature and the room temperature, the greater the energy loss, but if the difference is small, the energy loss is small even when normal ventilation is performed.Normal ventilation processing and circulation ventilation processing are performed by determining the ventilation volume with outside air based on the outside air temperature, the first detected temperature, and the second detected temperature, so energy loss can be minimized. [Effects of the Invention]

[0020] The ventilation system according to the present invention can prevent condensation in the exhaust duct and improve energy efficiency. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a schematic cross-sectional view of a building 11 in which a ventilation system 10 according to an embodiment is used. [Figure 2] FIG. 2 is a functional block diagram of the ventilation system 10 according to the embodiment. [Figure 3] Figure 3(A) is a diagram showing a control pattern determination table, Figure 3(B) is a diagram showing a drive correspondence table, Figure 3(C) is a diagram showing a ventilation volume correspondence table, and Figure 3(D) is a diagram showing a dew point temperature determination table. [Figure 4] FIG. 4 is a flowchart of the ventilation control process. [Figure 5] FIG. 5 is an explanatory diagram for explaining forced ventilation. [Figure 6] FIG. 6 is an explanatory diagram for explaining normal ventilation. [Figure 7] FIG. 7 is an explanatory diagram illustrating inter-room ventilation. [Figure 8] FIG. 8 is an explanatory diagram illustrating combined ventilation. [Figure 9] FIG. 9 is a schematic cross-sectional view of a building 11 in which a ventilation system 14 according to a modified example is used. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, an embodiment of the present invention will be described. Note that the embodiment described below is merely one example of the present invention, and it goes without saying that the embodiment of the present invention can be modified as appropriate without departing from the spirit of the present invention. Furthermore, the order of execution of each process (each step) shown in the flowchart of Figure 4 may be changed as appropriate, some may be omitted, other processes may be added, or other equivalent processes may be substituted, without departing from the spirit of the present invention.

[0023] [Outline of Ventilation System 10] As shown in FIG. 1 , the ventilation system 10 described in this embodiment is used in a building 11. The building 11 may be a private residence, an apartment building, a high-rise building, or the like. The ventilation system 10 ventilates a room in the building 11. In the following, an example will be described in which the building 11 has two rooms, a first room 21 and a second room 22, located on the same floor. However, the building 11 may have only one room, or may have three or more rooms. Furthermore, the first room 21 and the second room 22 may be located on different floors. In the following, when the first room 21 and the second room 22 are not distinguished from each other, they will be collectively referred to as room 20.

[0024] A room ID is assigned to each room 20. The ventilation system 10 identifies each room 20 individually by the room ID.

[0025] The ventilation system 10 may be operated and managed, for example, by a service provider that provides building management services to building owners, or the ventilation system 10 may be operated and managed directly by the owner of the building 11.

[0026] The ventilation system 10 includes various ducts, a heat exchanger 12, an air conditioning unit 13 (see Figure 2), differential pressure air supply members 81, 82, an exhaust flow path switching valve group 90 (see Figure 2), an intake flow path switching valve 100, various fans, various sensors, and a management device 200.

[0027] [Various ducts] 1, various ducts include exhaust ducts 31 and 32, supply air ducts 41 and 42, circulation ducts 51 and 52, and forced exhaust ducts 61 and 62. Each duct is installed in the ceiling space or underfloor space of the building 11.

[0028] The first exhaust duct 31 connects the first room 21 to the outside (outside air) of the building 11. Specifically, one end of the first exhaust duct 31 connects to a first opening 71 provided in a wall or ceiling of the first room 21, and the other end connects to an opening 75 provided in an outer wall of the building 11. The first exhaust duct 31 forms (partitions) an exhaust flow path that connects the first room 21 to the outside.

[0029] The second exhaust duct 32 connects the second room 22 to the outside (outside air) of the building 11. Specifically, one end of the second exhaust duct 32 is connected to a second opening 72 provided in the wall or ceiling of the second room 22, and the other end is connected to the first exhaust duct 31. The second exhaust duct 32 forms (partitions) an exhaust flow path that connects the second room 22 to the outside via the first exhaust duct 31.

[0030] The first air supply duct 41 connects the first room 21 to the outside (outside air) of the building 11. Specifically, one end of the first air supply duct 41 connects to a first opening 73 provided in a wall or ceiling of the first room 21, and the other end connects to an opening 76 provided in an outer wall of the building 11. The first air supply duct 41 forms (partitions) an air supply flow path that connects the first room 21 to the outside.

[0031] The second supply air duct 42 connects the second room 22 with the outside (outside air) of the building 11. Specifically, one end of the second supply air duct 42 is connected to a second opening 74 provided in the wall or ceiling of the second room 22, and the other end is connected to the first supply air duct 41. In other words, the second supply air duct 42 is connected to the outside (outside air) through the first supply air duct 41. The second supply air duct 42 forms (partitions) an supply air flow path that connects the second room 22 with the outside.

[0032] The first circulation duct 51 connects the first room 21 and the second room 22. Specifically, one end of the first circulation duct 51 is connected to the first exhaust duct 31 that is connected to the first room 21, and the other end is connected to the second supply duct 42 that is connected to the second room 22. The first circulation duct 51 is used to supply air from the first room 21 to the second room 22. For example, when the carbon dioxide concentration of the air in the first room 21 is low, the air in the first room 21 is used to ventilate the second room 22 without being released to the outside, in order to reduce energy loss.

[0033] The second circulation duct 52 connects the second room 22 and the first room 21. Specifically, one end of the second circulation duct 52 is connected to the second exhaust duct 32 that connects to the second room 22, and the other end is connected to the first air supply duct 41 that connects to the first room 21. The second circulation duct 52 is used to supply air from the second room 22 to the first room 21. For example, when the carbon dioxide concentration of the air in the second room 22 is low, the air in the second room 22 is used to ventilate the first room 21 without being released to the outside, in order to reduce energy loss.

[0034] The first forced exhaust duct 61 connects the first room 21 with the outside (outside air). Specifically, one end of the first forced exhaust duct 61 is connected to the first exhaust duct 31 which is connected to the first room 21, and the other end is connected to a first exterior wall opening 65 provided in the exterior wall of the building 11. The first forced exhaust duct 61 is used to forcibly exhaust air from within the first room 21. Note that the one end of the first forced exhaust duct 61 is connected to the first exhaust duct 31 at the connection position between the first exhaust duct 31 and the first circulation duct 51. In other words, the first exhaust duct 31, the first circulation duct 51, and the first forced exhaust duct 61 are connected to each other at the same connection position.

[0035] The second forced exhaust duct 62 connects the second room 22 with the outside (open air). Specifically, one end of the second forced exhaust duct 62 is connected to the second exhaust duct 32 which is connected to the second room 22, and the other end is connected to a second exterior wall opening 66 provided in the exterior wall of the building 11. The second forced exhaust duct 62 is used to forcibly exhaust air from within the second room 22. Note that the one end of the second forced exhaust duct 62 is connected to the second exhaust duct 32 at the connection position between the second exhaust duct 32 and the second circulation duct 52. In other words, the second exhaust duct 32, the second circulation duct 52, and the second forced exhaust duct 62 are connected to each other at the same connection position.

[0036] [Heat exchanger 12] The heat exchanger 12 is a device that exchanges heat between the first air flow (exhaust air) and the second air flow (supply air). An existing (commercially available) device is used for the heat exchanger 12. The end of the first exhaust duct 31 on the opening 75 side and the end of the first supply air duct 41 on the opening 76 side are connected to the heat exchanger 12. The heat exchanger 12 exchanges heat between the exhaust air discharged from the first exhaust duct 31 to the outside (outside air) and the supply air flowing into the building 11 from the first supply air duct 41. In other words, the heat exchanger 12 exchanges heat between the exhaust air discharged from the first room 21 or the second room 22 to the outside and the supply air supplied to the first room 21 or the second room 22. The operation of the heat exchanger 12 is controlled by the management device 200.

[0037] [Air conditioner 13] The air conditioner 13 includes an indoor unit and an outdoor unit. The indoor unit is installed inside the building 11. The outdoor unit is installed, for example, on the roof of the building 11. The air conditioner 13 individually controls the room temperature of each room 20. Note that the air conditioner 13 does not have to be part of the ventilation system 10, and its operation may be controlled by a control device separate from the management device 200 of the ventilation system 10.

[0038] [Differential pressure air supply members 81, 82] The differential pressure air supply members 81 and 82 are so-called differential pressure air supply ports or differential pressure air supply units. The differential pressure air supply members 81 and 82 have shutters (opening / closing valves) that open when a pressure difference occurs between the two spaces and close when there is no pressure difference. The differential pressure air supply members 81 and 82 are existing products (commercially available products).

[0039] The first differential pressure air supply member 81 is provided on one of the walls of the first chamber 21 that separates it from the outside. When the air pressure inside the first chamber 21 becomes lower than the outside air pressure, the first differential pressure air supply member 81 opens the shutter to allow air to flow in from the outside (outside air).

[0040] The second differential pressure air supply member 82 is provided on one of the walls of the second chamber 22 that separates it from the outside. When the air pressure inside the second chamber 22 becomes lower than the outside air pressure, the second differential pressure air supply member 82 opens the shutter to allow air to flow in from the outside (outside air).

[0041] [Exhaust flow path switching valve group 90] 2, the exhaust flow path switching valve group 90 (see FIG. 2) has a first exhaust flow path switching valve 91 and a second exhaust flow path switching valve 92. Each of the exhaust flow path switching valves 91, 92 and an intake flow path switching valve 100 (described later) is assigned a switching valve ID. The management device 200 individually identifies each of the switching valves 91, 92, 100 by the switching valve ID.

[0042] As shown in FIG. 1, the first exhaust flow path switching valve 91 is provided at a position where the first exhaust duct 31, the first circulation duct 51, and the first forced exhaust duct 61 are connected.

[0043] The first exhaust flow path switching valve 91 is a component that switches the flow paths by opening and closing three flow paths: the first exhaust duct 31 side, the first circulation duct 51 side, and the first forced exhaust duct 61 side. An existing product (commercially available product) is used as the first exhaust flow path switching valve 91.

[0044] The first exhaust flow path switching valve 91 can be switched to five switching positions (open / closed settings): a first switching position, a second switching position, a third switching position, a fourth switching position, and a fifth switching position.

[0045] The first switching position is a position that opens the flow path on the first exhaust duct 31 side and closes the flow paths on the first forced exhaust duct 61 side and the first circulation duct 51 side. The first switching position is used when performing ventilation through the heat exchanger 12 (hereinafter also referred to as "normal ventilation").

[0046] The second switching position is a position that opens the flow path on the first circulation duct 51 side and closes the flow paths on the first exhaust duct 31 side and the first forced exhaust duct 61 side. The second switching position is used when performing ventilation to exchange air between the first room 21 and the second room 22 (hereinafter also referred to as "inter-room ventilation").

[0047] The third switching position is a position that opens the flow path on the first forced exhaust duct 61 side and closes the flow paths on the first exhaust duct 31 side and the first circulation duct 51 side. The third switching position is used when performing ventilation using the first forced exhaust duct 61 (hereinafter also referred to as "forced ventilation").

[0048] The fourth switching position is a position in which the flow paths on the first exhaust duct 31 side and the first circulation duct 51 side are opened and the flow path on the first forced exhaust duct 61 side is closed. The fourth switching position is used when performing ventilation in which the normal ventilation and the inter-room ventilation are performed simultaneously (hereinafter also referred to as "combined ventilation").

[0049] The fifth switching position is a position where all of the flow paths on the first exhaust duct 31 side, the first circulation duct 51 side, and the first forced exhaust duct 61 side are closed. The fifth switching position is used, for example, when ventilation is not performed. However, the first exhaust flow path switching valve 91 does not necessarily have to have the fifth switching position.

[0050] The second exhaust flow path switching valve 92 is provided at a position where the second exhaust duct 32, the second circulation duct 52, and the second forced exhaust duct 62 are connected.

[0051] The second exhaust flow path switching valve 92 is a member that switches the flow paths by opening and closing three flow paths: the second exhaust duct 32 side, the second circulation duct 52 side, and the second forced exhaust duct 62 side.

[0052] The second exhaust flow path switching valve 92 has the same configuration as the first exhaust flow path switching valve 91 and can be switched to five switching positions (open / closed settings): a first switching position, a second switching position, a third switching position, a fourth switching position, and a fifth switching position. The first switching position opens the flow path on the second exhaust duct 32 side and closes the flow paths on the second forced exhaust duct 62 side and the second circulation duct 52 side. The second switching position opens the flow path on the second circulation duct 52 side and closes the flow paths on the second exhaust duct 32 side and the second forced exhaust duct 62 side. The third switching position opens the flow path on the second forced exhaust duct 62 side and closes the flow paths on the second exhaust duct 32 side and the second circulation duct 52 side. The fourth switching position opens the flow paths on the second exhaust duct 32 side and the second circulation duct 52 side and closes the flow path on the second forced exhaust duct 62 side. The fifth switching position is a position where all of the flow paths on the second exhaust duct 32 side, the second circulation duct 52 side, and the second forced exhaust duct 62 side are closed.

[0053] The first exhaust flow path switching valve 91 or the second exhaust flow path switching valve 92 is an example of an exhaust duct valve, an air intake duct valve, and a forced exhaust duct valve.

[0054] [Air supply flow path switching valve 100] The air intake flow path switching valve 100 is provided at the connection position between the first air intake duct 41 and the second air intake duct 42. The air intake flow path switching valve 100 is a component that switches between two flow paths by opening and closing the two flow paths, the first air intake duct 41 side and the second air intake duct 42 side. An existing product (commercially available product) is used for the air intake flow path switching valve 100. Note that if the building 11 has three or more rooms 20, multiple air intake flow path switching valves 100 may be provided. The air intake flow path switching valve 100 is an example of a first air intake duct valve and a second air intake duct valve.

[0055] The air supply passage switching valve 100 can be switched to four switching positions (open / closed settings): a first switching position, a second switching position, a third switching position, and a fourth switching position.

[0056] The first switching position is a position that opens the flow path on the side of first air supply duct 41 and closes the flow path on the side of second air supply duct 42. The first switching position is used, for example, when performing forced ventilation of second room 22 while performing ventilation of first room 21.

[0057] The second switching position is a position that opens the flow path on the second air supply duct 42 side and closes the flow path on the first air supply duct 41 side. The second switching position is used, for example, when performing forced ventilation of the first room 21 while ventilating the second room 22.

[0058] The third switching position is a position that opens both the flow paths on the first air supply duct 41 side and the second air supply duct 42 side. In other words, the third switching position is a fully open position. The first switching position is used when performing normal ventilation, inter-room ventilation, and combined ventilation of the first room 21 and the second room 22.

[0059] The fourth switching position is a position where the flow paths on the first air supply duct 41 side and the second air supply duct 42 side are closed. In other words, the fourth switching position is a fully closed position. The fourth switching position is used, for example, when forced ventilation of the first room 21 and the second room 22 is performed simultaneously.

[0060] [Various types of fans] The various fans include an exhaust fan group 110, an intake fan 120, a circulation fan group 130, and a forced exhaust fan group 140. Each fan is assigned a fan ID. The management device 200 identifies each fan individually using the fan ID.

[0061] The exhaust fan group 110 includes a first exhaust fan 111 and a second exhaust fan 112 .

[0062] The first exhaust fan 111 is installed in the first exhaust duct 31. More specifically, the first exhaust fan 111 is installed downstream (on the heat exchanger 12 side) of the first exhaust flow path switching valve 91. The first exhaust fan 111 generates an airflow from the first opening 71, which is an exhaust opening of the first room 21, toward the opening 75. The first exhaust fan 111 is driven when the above-mentioned normal ventilation or the above-mentioned combined ventilation via the heat exchanger 12 is performed on the first room 21.

[0063] The second exhaust fan 112 is installed in the second exhaust duct 32. More specifically, the second exhaust fan 112 is installed downstream (on the heat exchanger 12 side) of the second exhaust flow path switching valve 92. The second exhaust fan 112 generates an airflow from the second opening 72, which is an exhaust opening of the second room 22, toward the opening 75. The second exhaust fan 112 is driven when the above-mentioned normal ventilation or the above-mentioned combined ventilation via the heat exchanger 12 is performed on the second room 22.

[0064] The intake fan 120 is installed in the first intake duct 41. More specifically, the intake fan 120 is installed downstream (on the heat exchanger 12 side) of the intake air flow path switching valve 100. Specifically, the intake fan 120 is installed near the opening 76. The intake fan 120 generates an airflow from the opening 76 toward the first opening 73, which is an intake opening for the first room 21, and the second opening 74, which is an intake opening for the second room 22. The intake fan 120 is driven when the above-mentioned normal ventilation or the above-mentioned combined ventilation via the heat exchanger 12 is performed for at least one of the first room 21 and the second room 22.

[0065] The circulation fan group 130 includes a first circulation fan 131 and a second circulation fan 132 .

[0066] The first circulation fan 131 is installed in the first circulation duct 51. More specifically, the first circulation fan 131 is installed near the first exhaust flow path switching valve 91. The first circulation fan 131 generates an airflow that flows from the first opening 71, which is the exhaust opening of the first room 21, to the second opening 74, which is the intake opening of the second room 22. The first circulation fan 131 is used when the inter-room ventilation or the combined ventilation is performed.

[0067] The second circulation fan 132 is installed in the second circulation duct 52. More specifically, the second circulation fan 132 is installed near the second exhaust flow path switching valve 92. The second circulation fan 132 generates an airflow that flows from the second opening 72, which is the exhaust opening of the second room 22, to the first opening 73, which is the intake opening of the first room 21. The second circulation fan 132 is used when the inter-room ventilation or the combined ventilation is performed.

[0068] The forced exhaust fan group 140 includes a first forced exhaust fan 141 and a second forced exhaust fan 142 .

[0069] The first forced exhaust fan 141 is installed in the first forced exhaust duct 61. The first forced exhaust fan 141 generates an airflow from the first opening 71 for forced exhaust in the first room 21 toward the first outer wall opening 65.

[0070] The second forced exhaust fan 142 is installed in the second forced exhaust duct 62. The second forced exhaust fan 142 generates an airflow from the second opening 72 for forced exhaust in the second room 22 toward the second outer wall opening 66.

[0071] [Various sensors] The various sensors include a temperature and humidity sensor group 150, a CO2 (carbon dioxide) sensor group 160, and an outside air temperature sensor 170. Each sensor is assigned a sensor ID. The management device 200 identifies each sensor individually using the sensor ID.

[0072] The temperature and humidity sensor group 150 includes a first exhaust duct temperature and humidity sensor 151, a second exhaust duct temperature and humidity sensor 152, an intake duct temperature and humidity sensor 153, a first circulation duct temperature and humidity sensor 154, and a second circulation duct temperature and humidity sensor 155. Each sensor in the temperature and humidity sensor group 150 is an example of a contamination detection sensor.

[0073] The first exhaust duct temperature and humidity sensor 151 is installed inside the first exhaust duct 31. The first exhaust duct temperature and humidity sensor 151 outputs detection values ​​indicating the temperature and humidity of the air exhausted from the first room 21 to the first exhaust duct 31. There may be one or more first exhaust duct temperature and humidity sensors 151. In the example shown in FIG. 1, multiple first exhaust duct temperature and humidity sensors 151 are installed inside the first exhaust duct 31, spaced apart at equal intervals.

[0074] The second exhaust duct temperature / humidity sensor 152 is installed in the second exhaust duct 32. The second exhaust duct temperature / humidity sensor 152 outputs detection values ​​indicating the temperature and humidity of the air exhausted from the second room 22. There may be one or more second exhaust duct temperature / humidity sensors 152. In the example shown in Fig. 1, multiple second exhaust duct temperature / humidity sensors 152 are installed in the first exhaust duct 31, spaced apart at equal intervals.

[0075] The intake air duct temperature / humidity sensor 153 is installed inside the first intake air duct 41. The intake air duct temperature / humidity sensor 153 outputs detection values ​​indicating the temperature and humidity of air that has flowed into the first intake air duct 41 from the outside and has undergone heat exchange in the heat exchanger 12. There may be one or more intake air duct temperature / humidity sensors 153. For example, a plurality of intake air duct temperature / humidity sensors 153 are installed inside the first intake air duct 41, spaced apart at equal intervals from one another.

[0076] The first circulation duct temperature / humidity sensor 154 is installed inside the first circulation duct 51. The first circulation duct temperature / humidity sensor 154 outputs detection values ​​indicating the temperature and humidity of the air flowing from the first room 21 into the first circulation duct 51. There may be one or more first circulation duct temperature / humidity sensors 154. For example, multiple first circulation duct temperature / humidity sensors 154 are installed inside the first circulation duct 51, spaced apart at equal intervals from each other.

[0077] The second circulation duct temperature / humidity sensor 155 is installed inside the second circulation duct 52. The second circulation duct temperature / humidity sensor 155 outputs detection values ​​indicating the temperature and humidity of the air flowing from the second room 22 into the second circulation duct 52. There may be one or more second circulation duct temperature / humidity sensors 155. For example, multiple second circulation duct temperature / humidity sensors 155 are installed inside the second circulation duct 52, spaced apart at equal intervals from each other.

[0078] The CO2 sensor group 160 includes a first exhaust duct CO2 sensor 161, a second exhaust duct CO2 sensor 162, an intake duct CO2 sensor 163, a first circulation duct CO2 sensor 164, and a second circulation duct CO2 sensor 165. Each sensor in the CO2 sensor group 160 is an example of a pollution detection sensor.

[0079] The first exhaust duct CO2 sensor 161 is installed in the first exhaust duct 31. The first exhaust duct CO2 sensor 161 outputs a detection value indicating the carbon dioxide concentration in the air exhausted from the first room 21 to the first exhaust duct 31. There may be one or more first exhaust duct CO2 sensors 161. In the example shown in Fig. 1, multiple first exhaust duct CO2 sensors 161 are installed in the first exhaust duct 31, spaced apart at equal intervals.

[0080] The second exhaust duct CO2 sensor 162 is installed in the second exhaust duct 32. The second exhaust duct CO2 sensor 162 outputs a detection value indicating the carbon dioxide concentration in the air exhausted from the second room 22. There may be one or more second exhaust duct CO2 sensors 162. In the example shown in Fig. 1, multiple second exhaust duct CO2 sensors 162 are installed in the second exhaust duct 32, spaced apart at equal intervals.

[0081] The intake air duct CO2 sensor 163 is installed in the first intake air duct 41. The intake air duct CO2 sensor 163 outputs a detection value indicating the carbon dioxide concentration of air that has flowed into the first intake air duct 41 from the outside and has undergone heat exchange in the heat exchanger 12. There may be one or more intake air duct CO2 sensors 163. For example, a plurality of intake air duct CO2 sensors 163 are installed in the first intake air duct 41, spaced apart at equal intervals from one another.

[0082] The first circulation duct CO2 sensor 164 is installed in the first circulation duct 51. The first circulation duct CO2 sensor 164 outputs a detection value indicating the carbon dioxide concentration in the air flowing from the first room 21 into the first circulation duct 51. There may be one or more first circulation duct CO2 sensors 164. For example, a plurality of first circulation duct CO2 sensors 164 are installed in the first circulation duct 51, spaced apart at equal intervals from one another.

[0083] The second circulation duct CO2 sensor 165 is installed in the second circulation duct 52. The second circulation duct CO2 sensor 165 outputs a detection value indicating the carbon dioxide concentration in the air flowing from the second room 22 into the second circulation duct 52. There may be one or more second circulation duct CO2 sensors 165. For example, a plurality of second circulation duct CO2 sensors 165 are installed in the second circulation duct 52, spaced apart at equal intervals from one another.

[0084] The outside air temperature sensor 170 is installed outside the building 11. For example, the outside air temperature sensor 170 is installed near the opening 76. The outside air temperature sensor 170 outputs a detected value indicating the outside air temperature, which is the temperature outside the building 11 (outside air).

[0085] [Management device 200] The management device 200 shown in FIG. 2 is a device that controls (manages) the operation of the ventilation system 10. The management device 200 may be a personal computer or a server installed in the building 11, or may be a web server. That is, the ventilation system 10 may be a standalone system in which the management device 200 is installed inside the building 11, or a system in which the management device 200 is installed outside the building 11 and remotely managed. For example, when the ventilation system 10 is operated and managed by the service provider, multiple ventilation systems 10 are centrally managed by the web server (management device 200) via the Internet. When the management device 200 is a web server, the management device 200 has a communication interface connected to the Internet. On the other hand, a communication device such as a personal computer or a communication modem having a communication interface connected to the Internet is installed in the building 11.

[0086] The management device 200 includes a CPU 201, which is a central processing unit, and a memory 202. The CPU 201 and the memory 202, or the management device 200, are an example of a controller.

[0087] The memory 202 stores an OS 203, which is an operating system, a control program 204, various tables, and various thresholds. The OS 203 and the control program 204 are executed by the CPU 201.

[0088] The various tables include a control pattern determination table, a drive correspondence table, a ventilation volume correspondence table, a dew point temperature determination table, and an ID correspondence table.

[0089] The control pattern determination table shown in Fig. 3(A) is a table for determining a control pattern number based on the conditions of the first room 21 and the second room 22 and the conditions of the exhaust ducts 31 and 32. On the other hand, the drive correspondence table shown in Fig. 3(B) is a table for determining the control values ​​of the control objects, namely the flow path switching valves 91, 92, and 100 and each fan of the fan groups 120, 130, and 140, based on the determined control pattern number. In other words, the control pattern determination table and the drive correspondence table allow the type of ventilation (forced ventilation, normal ventilation, inter-room ventilation, combined ventilation) to be performed at an appropriate airflow rate (ventilation volume) depending on the conditions of the first room 21 and the second room 22 and the conditions of the exhaust ducts 31 and 32. This will be explained in detail below.

[0090] [Control pattern determination table] The control pattern determination table has a first column with the item name "control pattern" and two second columns with the item names "first room" and "second room", respectively. If the building 11 has two or more rooms 20, the control pattern determination table will have second columns in the number corresponding to the number of rooms 20.

[0091] In each field of the first column with the item name "Control Pattern", a control pattern number such as "1", "2", etc. is registered.

[0092] Each second column has multiple subcolumns with the item names "pollution level," "state," "ventilation rate," "temperature level," "forced ventilation flag," and "normal ventilation flag," respectively. In other words, various conditions of the room 20 and the exhaust ducts 31 and 32 are classified (categorized into cases) by the "pollution level," "state," "ventilation rate," "temperature level," "forced ventilation flag," and "normal ventilation flag." For example, a pollution level of "4," a state of "increase," a ventilation rate of "3," a temperature level of "2," a forced ventilation flag of "0," and a normal ventilation flag of "1" for the first room 21, and a pollution level of "4," a state of "increase," a ventilation rate of "2," a temperature level of "3," a forced ventilation flag of "1," and a normal ventilation flag of "1" for the second room 22 indicate one condition of the rooms 21 and 22, and a control pattern of "1" is assigned to that condition. That is, in the control pattern determination table, possible situations of the room 20 are presumed and classified, and a control pattern number is assigned as an identification number for individually identifying each classified situation.

[0093] Each second column may include only some of the subcolumns with the item names "pollution level," "status," "ventilation rate," "temperature level," "forced ventilation flag," and "normal ventilation flag," or may include subcolumns with other item names. In other words, the status of room 20 and exhaust ducts 31, 32 may be classified by some of the elements "pollution level," "status," "ventilation rate," "temperature level," "forced ventilation flag," and "normal ventilation flag," or may be classified by adding other elements.

[0094] The pollution level is registered in a field of the sub-column labeled "Pollution Level." For example, reference values ​​and lower limit values ​​for humidity and carbon dioxide concentration in room 20 are determined, and the pollution level is determined by a percentage tile between the reference value and the lower limit value. That is, the humidity and carbon dioxide concentration are normalized and registered in the control pattern determination table. The pollution level may be normalized into two or more levels, for example, three levels: "low," "medium," and "high." In the embodiment, an example is described in which the pollution level is normalized into five levels from "1" to "5." The reference values ​​and lower limit values ​​may be corrected (changed) depending on the season or the outside temperature. Normalization methods other than percentage tile may also be used.

[0095] The "pollution level" determines whether ventilation is necessary and the fan rotation speed level (i.e., the ventilation volume). For example, when the "pollution level" is "4" or "5," ventilation is necessary and a high rotation speed level is required. Therefore, in the control pattern number associated with the "pollution level" of "4" or "5," the switching positions of the flow path switching valves 91, 92, and 100 are set to perform normal ventilation and the fan rotation speed level is set to be high in the drive correspondence table (see FIG. 3(B)) described below. In other words, the "pollution level" is a factor that determines the switching positions of the flow path switching valves 91, 92, and 100 and the fan rotation speed level.

[0096] In the field of the sub-column with the item name "Status", one of the following is registered: "Steady" indicating that the humidity and carbon dioxide concentration are not changing, "Decreasing" indicating that they are decreasing, or "Increasing" indicating that they are increasing. Note that the "Status" can have two or more stages.

[0097] The "pollution level" and "status" indicate whether the ventilation volume is excessive or insufficient. For example, if the pollution level is "4" and the status is "increasing" or "steady," this indicates that the ventilation volume is insufficient. If the pollution level is "4" and the status is "reducing," this indicates that the ventilation volume is sufficient. If the pollution level is "2" and the status is "reducing," this indicates that the ventilation volume is too high. If the pollution level is "2" and the status is "steady," this indicates that the ventilation volume is sufficient. In other words, the "status," together with the "pollution level," is a factor that determines the fan rotation speed level.

[0098] The sub-column field with the item name "Ventilation Volume" registers the normalized (current) ventilation volume. For example, in the case of a pollution level of "4," a state of "increase," and a ventilation volume of "2," the current ventilation volume of "2" is insufficient, so ventilation must be performed to achieve a ventilation volume of "3" or higher. Therefore, for such a situation, a control pattern number for the fan rotation speed level that will result in a ventilation volume of "3" or higher is associated. In other words, the "(current) ventilation volume," along with the "state" and "pollution level," is a factor that determines the fan rotation speed level.

[0099] In the field of the sub-column with the item name "Temperature Level," the difference amount or difference rate of the temperature of room 20 relative to the outside air temperature is registered. For example, if the difference between the outside air temperature and the temperature of room 20 is less than 2°C, a temperature level of "1" is registered, and if the difference is 2°C or more but less than 4°C, a temperature level of "2" is registered. In the same manner, the temperature level is determined in multiple stages from "1" to "X."

[0100] The greater the difference between the outside air temperature and the temperature of room 20, the greater the energy loss that occurs when ventilation with outside air is performed, and the smaller the difference between the outside air temperature and the temperature of room 20, the smaller the energy loss that occurs when ventilation with outside air is performed. For example, a temperature level of "1", which indicates a small difference between the outside air temperature and the temperature of room 20, is associated with a control pattern number that performs ventilation with outside air. Also, a temperature level of "X", which indicates a large difference between the outside air temperature and the temperature of room 20, is associated with a control pattern number that performs inter-room ventilation or combined ventilation. In other words, the "temperature level" is a factor that determines the switching position of the flow path switching valves 91, 92, and 100.

[0101] In the field of the sub-column with the item name "forced ventilation flag," "1" indicating that forced ventilation is necessary or "0" indicating that forced ventilation is not necessary is registered. Whether forced ventilation is necessary is determined based on the temperature and humidity of the exhaust ducts 31 and 32. In other words, the "forced ventilation flag" indicates the status of the exhaust ducts 31 and 32. Furthermore, a forced ventilation flag of "1" is associated with the control pattern number that performs forced ventilation. In other words, the "forced ventilation flag" is a factor that determines the switching position of the flow path switching valves 91, 92, and 100.

[0102] In the field of the subcolumn labeled "normal ventilation flag," a "1" indicating that normal ventilation is required or a "0" indicating that normal ventilation is not required is registered. A normal ventilation flag of "1" is set when the pollution level, humidity, or carbon dioxide concentration of room 20 is above a threshold. The air in room 20 with a normal ventilation flag of "1" cannot be used to ventilate other rooms. Therefore, a normal ventilation flag of "1" is associated with a control pattern number that performs normal ventilation. In other words, the "normal ventilation flag" is a factor that determines the switching position of flow path switching valves 91, 92, and 100.

[0103] When "0" is registered in the field of the sub-column labeled "Forced Ventilation Flag" and when "0" is registered in the field of the sub-column labeled "Normal Ventilation Flag," this indicates that combined ventilation or room-to-room ventilation is to be performed. Whether room-to-room ventilation or combined ventilation is to be performed is determined by the "contamination level" of each room. In other words, the "Forced Ventilation Flag," "Normal Ventilation Flag," and "Contamination Level" are factors that determine whether forced ventilation, normal ventilation, room-to-room ventilation, or combined ventilation is to be performed, i.e., they are factors that determine the switching position of the flow path switching valves 91, 92, and 100.

[0104] In this way, the control pattern determination table associates the conditions of the first room 21, the second room 22, and the exhaust ducts 31, 32 with appropriate control patterns according to the conditions. An appropriate control pattern means control that prevents condensation in the exhaust ducts 31, 32, maintains a low pollution level, and minimizes energy loss. The appropriate control pattern (control values) may be determined by estimation through calculations, or may be determined by testing using an actual device (trial and error).

[0105] [Drive compatibility table] 3(B) is a table that associates control pattern numbers with control values ​​of each control object such as the exhaust fan group 110. That is, the control pattern number (i.e., the situation of the room 20, etc.) is identified by the control pattern determination table, and the control values ​​of the control object are determined by the identified control pattern number and the drive correspondence table. The control values ​​include the rotation speed level of the fan, the on / off setting of the fan, and the switching position settings of the flow path switching valves 91, 92, and 93.

[0106] The drive correspondence table includes a column with the item name "control pattern" and a plurality of columns with the item name "first exhaust fan" and other names of objects to be controlled.

[0107] The control pattern numbers are registered in the respective fields of the column labeled "control pattern."

[0108] In each field of the column labeled "First Exhaust Fan," "Second Exhaust Fan," or "Intake Fan," a rotation speed level such as "Stopped," indicating that the fan is stopped, or "1," "2," or "3," indicating the rotation speed of the fan, is registered. For example, a rotation speed level of "1" indicates that the fan rotates at a low speed, and a rotation speed level of "3" indicates that the fan rotates at a high speed. Note that the rotation speed level may be two or more levels, and may be five or ten levels, for example.

[0109] In each field of the column with the item name "First forced exhaust fan" or "Second forced exhaust fan," "Stopped" indicating that the fan is stopped or "Driven" indicating that the fan is driven is registered. Note that instead of "Driven," the rotation speed level of the fan may be registered. In other words, the forced exhaust fan group 140 may be driven at multiple rotation speed levels.

[0110] In each field of the column labeled "First Exhaust Flow Switching Valve" or "Second Exhaust Flow Switching Valve," the switching setting of the exhaust flow switching valves 91, 92 is registered. The switching setting is one of the first to fifth switching positions.

[0111] Each field in the column labeled "Air Supply Flow Channel Switching Valve" registers the switching setting of the air supply flow channel switching valve 100. The switching setting is one of the first to fourth switching positions.

[0112] In the example shown in Fig. 3(B), the control pattern number "1" indicates a control pattern for performing normal ventilation on the first room 21 and the second room 22. Although not shown in Fig. 3(B), various control pattern numbers that have the same settings as the switching positions of the flow path switching valves 91, 92, and 100 for the control pattern number "1" but different fan rotation speed levels are registered in the drive correspondence table.

[0113] The control pattern number "2" indicates a control pattern for performing inter-room ventilation for the first room 21 and the second room 22. Although not shown in Fig. 3(B) , various control pattern numbers that have the same settings as the switching positions of the flow path switching valves 91, 92, and 100 for the control pattern number "2" but different fan rotation speed levels are registered in the drive correspondence table.

[0114] The control pattern number "3" indicates a control pattern for performing combined ventilation on the first room 21 and the second room 22. Specifically, the control pattern number "3" is a control pattern for discharging the air in the first room 21 to the outside, mixing the air in the second room 22 with outside air, and supplying the mixed air to the first room 21. Although not shown in FIG. 3(B), the drive correspondence table also registers a control pattern for combined ventilation for discharging the air in the second room 22 to the outside, mixing the air in the first room 21 with outside air, and supplying the mixed air to the second room 22. In other words, if there are two rooms 20, excluding differences in the fan rotation speeds, there are two types of combined ventilation. However, the more rooms 20 there are, the more types of combined ventilation there are.

[0115] Also, although not shown in Figure 3(B), various control pattern numbers that have the same settings as the switching positions of the flow path switching valves 91, 92, and 100 for control pattern number "3" but different fan rotation speed levels are registered in the drive correspondence table.

[0116] The control pattern number "4" indicates a control pattern in which forced ventilation is performed on the first room 21 and normal ventilation is performed on the second room 22. Although not shown in FIG. 3(B), the drive correspondence table also registers control pattern numbers in which forced ventilation is performed on the second room 22 and normal ventilation is performed on the first room 21, and control pattern numbers in which forced ventilation is performed on the first room 21 and the second room 22. In other words, if there are two rooms 20, excluding differences in the fan rotation speeds, there are three types of forced ventilation. However, the more rooms 20 there are, the more types of forced ventilation there are.

[0117] Although not shown in FIG. 3(B), various control pattern numbers having the same settings as the switching positions of the flow path switching valves 91, 92, and 100 in the control pattern number "4" but different fan rotation speed levels are registered in the drive correspondence table.

[0118] The same control value may be registered for different control pattern numbers. For example, the same control value may be registered for a plurality of different control pattern numbers depending on the size of the building 11 to be managed, thereby simplifying the control.

[0119] [Ventilation volume table] The ventilation volume correspondence table shown in FIG. 3(C) is a table that associates control pattern numbers with the ventilation volumes of each room 20. To explain in more detail, once the control pattern number is determined, the control value is determined. Once the control value is determined, the ventilation volume of each room 20 is determined. The current ventilation volume of each room 20 is an element for determining the next control pattern. The ventilation volume correspondence table determines the ventilation volume of each room 20 according to the current control pattern number. This will be explained in detail below.

[0120] The ventilation volume correspondence table includes a column with the item name "control pattern" and a column with the item name "ventilation volume."

[0121] The control pattern numbers are registered in the respective fields of the column labeled "control pattern."

[0122] The column with the item name "Ventilation Rate" includes sub-columns with the item names "First Room" and "Second Room." A standardized ventilation rate level, such as "0," "1," or "2," is registered in each field of the sub-columns with the item names "First Room" and "Second Room." The ventilation rate level may be three levels, or four or more levels. The ventilation rate may be a level corresponding to the total amount of air supplied to the room 20, or a level corresponding to the proportion of outside air in the total amount, or both. Alternatively, the ventilation rate may be a value corresponding to the total amount of air supplied to the room 20 and the humidity and carbon dioxide concentration detected by the sensor groups 150 and 160.

[0123] There is a one-to-one correspondence between the control pattern number and the ventilation volume. In other words, determining the control pattern number is equivalent to determining the ventilation volume. Note that different control patterns may result in the same ventilation volume.

[0124] [Dew point temperature determination table] The dew-point temperature determination table shown in Fig. 3(D) is a table for determining the dew-point temperature from the temperature and humidity. In the dew-point temperature determination table, the temperature and humidity are associated with the dew-point temperature. The dew-point temperature in the exhaust ducts 31 and 32 is determined (specified) based on the temperature and humidity measured by the temperature and humidity sensor group 150 and the dew-point temperature determination table.

[0125] The ID correspondence table (see FIG. 2) is a table that associates room IDs, temperature and humidity sensor IDs, CO2 sensor IDs, and fan IDs. The management device 200 uses this table to determine (specify) the temperature, humidity, and carbon dioxide concentration of each room 20 that the detected values ​​of each sensor correspond to, and then identifies each room 20 to drive the corresponding fan and switch the flow path switching valves 91, 92, and 100.

[0126] [Ventilation control processing] The control program 204 of the management device 200 causes the CPU 201 to execute the ventilation control process shown in Fig. 4. In the following, the process that the control program 204 causes the CPU 201 to execute will be simply described as the process executed by the control program 204.

[0127] The ventilation control process is a process for driving controlled objects such as the air supply fan 120 to ventilate each room 20 of the building 11. The control program 204 executes the ventilation control process so as to prevent condensation in the exhaust ducts 31 and 32, keep the pollution level low, and minimize energy loss.

[0128] The control program 204 executes the ventilation control process continuously for 24 hours, or only during a set time period in one day, or only after a start instruction is input and until an end instruction is input.

[0129] First, the control program 204 acquires the temperature and humidity, carbon dioxide concentration, and outdoor air temperature detected by the temperature and humidity sensor group 150, the CO2 sensor group 160, and the outdoor air temperature sensor 170, and stores them in the memory 202 (S11). The process of step S11 is repeatedly executed at a predetermined sampling period. That is, the memory 202 stores data on changes over time in the temperature and humidity in the exhaust ducts 31, 32, the supply air ducts 41, 42, and the circulation ducts 51, 52, data on changes over time in the carbon dioxide concentration, and data on changes over time in the outdoor air temperature. The data on the temperature and humidity, the carbon dioxide concentration, and the outdoor air temperature over time is stored, for example, in an Excel spreadsheet.

[0130] The control program 204 determines the "current pollution level," "current status," and "current temperature level" based on the above data stored in the memory 202, and stores them in the memory 202 (S12). The "current pollution level" is determined by normalizing (percentile) the latest humidity and carbon dioxide concentration using the reference value and lower limit value. The "current status" is determined by the above time change data of humidity and the above period change data of carbon dioxide concentration. The "current temperature level" is determined by normalizing the difference between the latest temperature and the outside air temperature.

[0131] The control program 204 determines whether to maintain the current control pattern (S13). For example, if there is no risk of condensation, the pollution level is low, and the condition is stable, there is no need to change the control pattern, so the current control pattern is maintained. The processing of step S13 prevents the flow path switching valves 91, 92, and 100 from being frequently changed in switching position. The determination of whether to maintain the current control pattern may be made by any method. For example, the control program 204 determines whether to maintain the current control pattern based on the "current pollution level," "current condition," and "current temperature level" stored in the memory 202 in step S12, as well as the time-varying data of temperature and humidity and the time-varying data of carbon dioxide concentration.

[0132] The process of step S13 may be omitted. In this case, the control program 204 may periodically review (change) the control pattern at predetermined intervals of several minutes to several tens of minutes.

[0133] If the control program 204 determines to maintain the current control pattern (S13: Yes), it executes the processes from step S11 onwards again without changing the control pattern. If the control program 204 determines not to maintain the current control pattern (S13: No), it acquires the dew-point temperatures in the exhaust ducts 31, 32 from the latest temperature and humidity in the exhaust ducts 31, 32 and the dew-point temperature determination table (FIG. 3(D)) (S14). The process of step S14 is an example of a dew-point temperature acquisition process.

[0134] The control program 204 determines whether the latest temperature in the first exhaust duct 31 and the latest temperature in the second exhaust duct 32 are equal to or lower than a threshold temperature corresponding to the acquired dew-point temperature (S15). That is, in step S15, it is determined whether there is a risk of condensation occurring in the first exhaust duct 31 and the second exhaust duct 32. The threshold temperature corresponding to the dew-point temperature is a value obtained by adding a predetermined temperature, such as 1°C, to the dew-point temperature.

[0135] When the control program 204 determines that the latest temperature is equal to or lower than the threshold temperature (S15: Yes), it stores a forced ventilation flag of "1" in the memory 202 in association with the room ID of the room 20 in which it has determined that the latest temperature is equal to or lower than the threshold temperature (S16).

[0136] When the control program 204 determines that the latest temperature in the exhaust ducts 31, 32 is not equal to or lower than the threshold temperature (S15: No), it stores a forced ventilation flag of "0" in the memory 202 in association with the room ID (S17).

[0137] After storing a forced ventilation flag of "1" or "0" in the memory 202 (S16, S17), the control program 204 determines whether the current contamination level stored in the memory 202 in step S12 is equal to or higher than a threshold level stored in the memory 202 (S18). The processing of step S18 is performed for each room 20. The threshold level is, for example, "4." That is, in step S18, it is determined whether ventilation with outside air is necessary. The threshold level is an example of a contamination threshold.

[0138] Instead of step S18, it may be determined whether the latest carbon dioxide concentration in the exhaust ducts 31, 32 is equal to or greater than a threshold concentration (e.g., 700 ppm) pre-stored in memory 202, and whether the latest humidity is equal to or greater than a threshold humidity pre-stored in memory 202. In other words, in the processing of step S18, the determination may be made based on a standardized pollution level or raw data.

[0139] When the control program 204 determines that the current contamination level is equal to or higher than the threshold level (S18: Yes), it stores a normal ventilation flag of "1" in the memory 202 in association with the room ID of the determined room 20 (S19).

[0140] When the control program 204 determines that the current contamination level is not equal to or higher than the threshold level (S18: No), it stores a normal ventilation flag of "0" in the memory 202 in association with the room ID (S20).

[0141] After executing the process of step S19 or step S20, the control program 204 acquires the "current ventilation volume" (S21) based on the current control pattern number stored in the memory 202 and the ventilation volume correspondence table (see FIG. 3(C)). Specifically, the control program 204 reads out the "current control pattern number" determined in step S22 and stored in the memory 202, reads out the ventilation volume corresponding to the read control pattern number from the ventilation volume correspondence table, and stores it in the memory 202 as the current ventilation volume.

[0142] The control program 204 determines a control pattern number based on the "current pollution level," "current state," "current temperature level," "forced ventilation flag of 0 or 1," "normal ventilation flag of 0 or 1," and "current ventilation volume" stored in the memory 202 in steps S12, S16, S17, S19, S20, and S22, as well as the control pattern determination table (see FIG. 3(A)) (S22). Specifically, the control program 204 reads out the control pattern numbers corresponding to the "current pollution level," "current state," "current temperature level," forced ventilation flag, normal ventilation flag, and "current ventilation volume" from the control pattern determination table (see FIG. 3(A)). The control program 204 updates the "current control pattern number" stored in the memory 202 with the read control pattern number (S22).

[0143] Based on the updated control pattern number and the drive correspondence table (see FIG. 3(B)), the control program 204 acquires control values ​​that are set values ​​for the switching positions of the exhaust flow path switching valves 91, 92, the switching position of the intake air flow path switching valve 100, the drive amount of the exhaust fans 111, 112, the drive amount of the intake air fan 120, the drive amount of the circulation fans 131, 132, and whether to drive or stop the forced exhaust fans 141, 142 (S23).The control program 204 controls the drive of each control object, such as the exhaust flow path switching valves 91, 92, based on the acquired control values ​​(S23).

[0144] The memory 202 pre-stores a control pattern number to be executed at the start of the ventilation control process. At the start of the ventilation control process, the control program 204 drives the controlled object with a control value corresponding to the control pattern number pre-stored in the memory 202.

[0145] [Forced ventilation] FIG. 5 shows a state in which forced ventilation is performed on the first room 21 and normal ventilation is performed on the second room 22.

[0146] For example, when the control program 204 acquires a control pattern number of "4" with a forced ventilation flag of "1" set for the first room 21 (S16, S22), the forced ventilation shown in FIG. 5 is performed.

[0147] Forced ventilation is performed in three cases: when the forced ventilation flag is set to "1" for the first room 21 and the forced ventilation flag is set to "0" for the second room 22; when the forced ventilation flag is set to "1" for the second room 22 and the forced ventilation flag is set to "0" for the first room 21; and when the forced ventilation flag is set to "1" for both the first room 21 and the second room 22. In other words, the forced ventilation flag determines whether or not forced ventilation is performed and which rooms are to be forced ventilated.

[0148] When forced ventilation is performed on one room 20, the type of forced ventilation is determined by whether or not ventilation is performed on the other room 20. When ventilation is performed on the other room 20, the type of forced ventilation is also determined by the difference in the fan rotation speed level. In other words, there are multiple control pattern numbers indicating forced ventilation in addition to "4."

[0149] Based on the control values ​​of each control object associated with the control pattern number "4", the control program 204 stops the operation of the first exhaust fan 111, drives the second exhaust fan 112 and the supply air fan 120 at the above-mentioned drive amounts, stops the operation of the circulation fans 131 and 132, drives the first forced exhaust fan 141, stops the operation of the second forced exhaust fan 142, sets the first exhaust flow path switching valve 91 to the third switching position, sets the second exhaust flow path switching valve 92 to the first switching position, and sets the supply air flow path switching valve 100 to the second switching position.

[0150] By switching the first exhaust flow path switching valve 91 to the third switching position, the air in the first room 21 flows only into the first forced exhaust duct 61, and does not flow into the first exhaust duct 31. As a result, condensation is prevented from occurring in the first exhaust duct 31.

[0151] Furthermore, because the air intake flow path switching valve 100 is in the second switching position, the air that has undergone heat exchange in the heat exchanger 12 does not flow into the first chamber 21. In other words, the air that has undergone heat exchange in the heat exchanger 12 is prevented from being discharged to the outside through the first forced exhaust duct 61, which would result in energy loss.

[0152] As the air in the first chamber 21 is exhausted from the first forced exhaust duct 61 and the inflow of air into the first chamber 21 from the first air supply duct 41 is stopped, the air pressure in the first chamber 21 drops and becomes lower than the outside air pressure. This opens the first differential pressure air supply member 81 and outside air flows into the first chamber 21 through the first differential pressure air supply member 81. In other words, the air in the first chamber 21 is exchanged (ventilated) with outside air.

[0153] When the control program 204 stores the forced ventilation flag of "1" in the memory 202 (S16), the control program 204 may maintain the forced ventilation flag at "1" for a predetermined period of time, such as 3 or 5 minutes, regardless of the detection values ​​of the sensors, thereby maintaining the forced ventilation state of the target room 20. In this case, after the predetermined period has elapsed, the control program 204 skips the process of step S13, which determines whether or not to maintain the control pattern, and determines a new control pattern number (S22).

[0154] The process (S16, S23) in which the control program 204 drives each control object with a control value associated with a control pattern number such as "4" associated with a forced ventilation flag of "1" is an example of forced ventilation processing.

[0155] [Normal ventilation] FIG. 6 shows a state in which the first room 21 and the second room 22 are normally ventilated.

[0156] For example, when the control program 204 acquires a control pattern number of "1" in which the forced ventilation flag is set to "0" and the normal ventilation flag is set to "1" for the first room 21 and the second room 22 (S19), normal ventilation is performed as shown in Fig. 6. Note that, in addition to the control pattern number "1" indicating normal ventilation, there are a plurality of other control pattern numbers which have different fan rotation speed levels.

[0157] Based on the control values ​​of each control object associated with the control pattern number "1", the control program 204 drives the exhaust fans 111, 112 and the supply air fan 120 at the above-mentioned drive amount, stops the circulation fans 131, 132 and the forced exhaust fans 141, 142, sets both exhaust flow path switching valves 91, 92 to the first switching position, and sets the supply air flow path switching valve 100 to the third switching position.

[0158] 6, the air in the first room 21 and the second room 22 is discharged to the outside through the exhaust ducts 31 and 32, and the outside air that has exchanged heat with the air discharged to the outside through the heat exchanger 12 is then flowed into the first room 21 and the second room 22. In other words, normal ventilation is performed in the first room 21 and the second room 22 through the heat exchanger 12.

[0159] The process (S19, S23) in which the control program 204 drives each control target with the control value indicated by the control pattern number "1" associated with the normal ventilation flag "1" is an example of normal ventilation process. The normal ventilation process is executed when the pollution level according to the detected humidity or carbon dioxide concentration is equal to or higher than the threshold level, the room cannot be used for ventilation of other rooms 20, and ventilation with outside air is required.

[0160] [Ventilation between rooms] FIG. 7 shows a state in which inter-room ventilation, which is ventilation between the first room 21 and the second room 22, is performed. In other words, it shows a state in which ventilation through the heat exchanger 12 is not performed. Inter-room ventilation is performed when there is a difference in pollution levels between the two rooms 20 and the pollution levels of the two rooms 20 are relatively low. For example, when the pollution level of the first room 21 is higher than that of outside air or the above-mentioned reference value but lower than the threshold level, and the pollution level of the second room 22 is lower than the pollution level of the first room 21, the inter-room ventilation shown in FIG. 7 is performed.

[0161] For example, when the control program 204 acquires a control pattern number of "2" in which a forced ventilation flag of "0" and a normal ventilation flag of "0" are set for the first room 21 and the second room 22 (S17, S20), the inter-room ventilation shown in FIG. 7 is performed.

[0162] In addition to the control pattern number "2" indicating inter-room ventilation, there are a number of other control pattern numbers with different fan rotation speed levels.

[0163] Based on the control values ​​of each control object associated with the control pattern number "2", the control program 204 stops the exhaust fans 111, 112, the supply air fan 120, and the forced exhaust fans 141, 142, drives the circulation fans 131, 132 at the above-mentioned drive amount, sets both exhaust flow path switching valves 91, 92 to the second switching position, and sets the supply air flow path switching valve 100 to the third switching position.

[0164] 7, the pollution levels (humidity, carbon dioxide concentration) of the first room 21 and the second room 22 are averaged. In addition, since the temperature-adjusted air is not discharged to the outside, there is no energy loss due to ventilation with the outside air.

[0165] The inter-room ventilation process (S21, S23) in which the control program 204 drives each control target with a control value associated with a control pattern number indicating inter-room ventilation, such as "2," is an example of a circulating ventilation process. The inter-room ventilation process is executed when the pollution level corresponding to the detected humidity or carbon dioxide concentration is below the threshold level in all rooms 20.

[0166] [Combined ventilation] FIG. 8 shows a state in which combined ventilation is performed, which is both inter-room ventilation, which is ventilation between the first room 21 and the second room 22, and normal ventilation, which is ventilation between the first room 21 and the second room 22 and the outside air.

[0167] For example, if the control program 204 acquires a control pattern number of "3" in which a forced ventilation flag of "0" is set for the first room 21 and the second room 22, a normal ventilation flag of "1" is set for one of the rooms 20, the first room 21, and a normal ventilation flag of "0" is set for the other room 20, the second room 22 (S22), the combined ventilation shown in Figure 8 is performed.

[0168] Combined ventilation is performed in two ways: when the normal ventilation flag of "1" is set for the first room 21 and the normal ventilation flag of "0" is set for the second room 22; or when the normal ventilation flag of "1" is set for the second room 22 and the normal ventilation flag of "0" is set for the first room 21. In other words, the normal ventilation flag determines what type of combined ventilation is performed. The type of combined ventilation also differs depending on the fan rotation speed level. In other words, there are multiple control pattern numbers indicating combined ventilation, in addition to "3."

[0169] Based on the control values ​​of each control object associated with the control pattern number "3", the control program 204 drives the first exhaust fan 111, the supply air fan 120, and the second circulation fan 132 at the above-mentioned drive amount, stops the drive of the second exhaust fan 112, the first circulation fan 131, and the forced exhaust fans 141, 142, sets the first exhaust flow path switching valve 91 to the first switching position, sets the second exhaust flow path switching valve 92 to the fourth switching position, and sets the supply air flow path switching valve 100 to the third switching position.

[0170] In the combined ventilation shown in Figure 8, the air in the first room 21, which has a high pollution level, is all discharged to the outside, whereas the air in the second room 22, which has a low pollution level, is not discharged to the outside but is used to ventilate the first room 21. Therefore, energy loss is reduced compared to when the air in the second room 22 is not used.

[0171] If the temperature level (temperature difference with the outside air) of the first room 21 is low and the temperature level of the second room 22 is high, the energy loss in the second room 22 will be large. In this case, a control pattern is selected in which normal ventilation is performed for the first room 21 and ventilation is stopped for the second room 22. In other words, an optimal control pattern is selected according to the temperature level of each room 20 so as to minimize the energy loss.

[0172] The combined ventilation process (S23) in which the control program 204 drives each control object with a control value associated with a control pattern number indicating combined ventilation, such as "3," is an example of a circulation ventilation process. The combined ventilation process is executed when the pollution level corresponding to the detected humidity or carbon dioxide concentration is below a threshold level in at least one room 20.

[0173] 4, the control program 204 determines whether or not to terminate the ventilation control process (S24). For example, the control program 204 determines whether or not to terminate the ventilation control process depending on whether or not a stop command has been input or whether or not the end time has arrived.

[0174] If the control program 204 determines not to end (S24: No), it executes the processes from step S11 onwards again. If the control program 204 determines to end (S24: Yes), it ends the ventilation control process (END).

[0175] [Action and effect] In this embodiment, when it is determined that condensation will occur in exhaust duct 31 (S15 in FIG. 4: Yes), the valve on the exhaust duct 31 side is closed, and the valve on the forced exhaust duct 61 side is opened, and the forced exhaust fan 141 is driven. In addition, the valve on the supply air duct 41 side is closed. The driven forced exhaust fan 141 exhausts the air inside room 21 to the outside through forced exhaust duct 61. As a result, condensation is prevented inside exhaust duct 31. Furthermore, because the valve on the supply air duct 41 side is closed during forced ventilation, the air conditioned by heat exchanger 12 is prevented from being exhausted to the outside through forced exhaust duct 61. As a result, energy loss is reduced and energy efficiency is improved.

[0176] When the temperature inside the exhaust duct 31 reaches the dew point temperature, condensation occurs inside the exhaust duct 31. When the temperature inside the exhaust duct 31 reaches a threshold temperature corresponding to the dew point temperature, the control program 204 directly exhausts the air inside the room 21 to the outside without passing through the exhaust duct 31 (see FIG. 5). Therefore, the ventilation system 10 can perform forced ventilation before condensation occurs inside the exhaust duct 31.

[0177] Furthermore, the ventilation system 10 uses a temperature and humidity sensor 151 provided for adjusting the temperature and ventilating the room 21 to determine whether condensation will occur in the exhaust duct 31. In other words, the ventilation system 10 can prevent condensation in the exhaust duct 31 without providing a new sensor for detecting condensation in addition to the temperature and humidity sensor 151.

[0178] The ventilation system 10 performs normal ventilation (see FIG. 6) as well as circulation ventilation (room-to-room ventilation (see FIG. 7) and combined ventilation (see FIG. 8)) using circulation ducts 51 and 52. Therefore, energy loss can be reduced compared to when only normal ventilation is performed. As a result, the ventilation system 10 can improve energy efficiency.

[0179] The ventilation system 10 performs normal ventilation (see FIG. 6) when the pollution levels of both the first room 21 and the second room 22 are equal to or higher than a threshold level, and performs inter-room ventilation (see FIG. 7) or combined ventilation (see FIG. 8) when the pollution levels of at least one of the first room 21 and the second room 22 are lower than the threshold level. Therefore, the ventilation system 10 can improve energy efficiency while maintaining a low pollution level of the air in the room 20.

[0180] The control pattern determination table (see FIG. 3(A)) has a field for registering a temperature level indicating the difference between the outside air temperature and the temperature of the room 20. That is, the control pattern is determined based on the difference between the outside air temperature and the temperature of the room 20. For example, when the difference between the outside air temperature and the temperature inside the room 20 is small, energy loss is small even when normal ventilation is performed through the heat exchanger 12. In this case, normal ventilation is performed preferentially, and the air inside the room 20 is exchanged with outside air, maintaining the humidity and carbon dioxide concentration of the room 20 at low levels. When the difference between the outside air temperature and the temperature inside the room 20 is large, performing normal ventilation through the heat exchanger 12 results in a significant energy loss. In this case, inter-room ventilation or combined ventilation is performed preferentially over normal ventilation, reducing energy loss while maintaining the humidity and carbon dioxide concentration of the room 20 at required levels. That is, by determining the control pattern based also on the difference between the outside air temperature and the temperature inside the room 20, energy loss can be more effectively reduced.

[0181] [Variation 1] In the embodiment, an example has been described in which the first forced exhaust duct 61 is connected to the first exhaust duct 31, and the second forced exhaust duct 62 is connected to the second exhaust duct 32. Also, in the embodiment, an example has been described in which the flow path switching valves 91, 92, and 100 are used. In this modified example, an example will be described in which the first forced exhaust duct 211 is directly connected to the first chamber 21, and the second forced exhaust duct 212 is directly connected to the second chamber 22, and various on-off valves are used instead of the flow path switching valves 91, 92, and 100.

[0182] The configurations other than those described below are the same as those described in the embodiment, and the same components as those in the embodiment are denoted by the same reference numerals as those in the embodiment.

[0183] In this modification, a ventilation system 14 shown in Fig. 9 will be described. The ventilation system 14 is attached to a building 11 having a plurality of rooms 20. In the example shown in Fig. 9, the plurality of rooms 20 are a first room 21 and a second room 22.

[0184] The ventilation system 14 includes various ducts, differential pressure air supply members 81, 82, a heat exchanger 12, an air conditioning unit 13 (see Figure 2), various on-off valves, a group of fans 110, 120, 130, 140 (see Figure 2), a group of sensors 150, 160 (see Figure 2), an outside air temperature sensor 170, and a management device 200 (see Figure 2).

[0185] The various ducts include exhaust ducts 31, 32, intake ducts 41, 42, circulation ducts 51, 52, a first forced exhaust duct 211, and a second forced exhaust duct 212.

[0186] One end of the first forced exhaust duct 211 is connected to the wall of the first room 21, and the other end is inserted into an opening 213 provided in the outer wall of the building 11. In other words, the first forced exhaust duct 211 connects the space inside the first room 21 (indoors) with the outside.

[0187] One end of the second forced exhaust duct 212 is connected to the wall of the second room 22, and the other end is inserted into an opening 214 provided in the outer wall of the building 11. In other words, the second forced exhaust duct 212 connects the space inside the second room 22 (indoors) with the outside.

[0188] The various on-off valves include on-off valves 221, 222, and 223, on-off valves 231, 232, and 233, and on-off valves 241 and 242.

[0189] The on-off valves 221, 222, and 223 are used in place of the first exhaust flow path switching valve 91. The on-off valve 221 is provided in the first exhaust duct 31. The on-off valve 221 opens and closes the exhaust flow path formed by the first exhaust duct 31. The on-off valve 222 is provided in the first circulation duct 51. The on-off valve 222 opens and closes the circulation flow path formed by the first circulation duct 51. The on-off valve 223 is provided in the first forced exhaust duct 211. The on-off valve 223 opens and closes the forced exhaust flow path formed by the first forced exhaust duct 211.

[0190] The on-off valves 231, 232, and 233 are used in place of the second exhaust flow path switching valve 92. The on-off valve 231 is provided in the second exhaust duct 32. The on-off valve 231 opens and closes the exhaust flow path formed by the second exhaust duct 32. The on-off valve 232 is provided in the second circulation duct 52. The on-off valve 232 opens and closes the circulation flow path formed by the second circulation duct 52. The on-off valve 233 is provided in the second forced exhaust duct 212. The on-off valve 233 opens and closes the forced exhaust flow path formed by the second forced exhaust duct 212.

[0191] The on-off valves 241, 242 are provided in place of the air intake flow path switching valve 100. The on-off valve 241 is provided in the first air intake duct 41. The on-off valve 241 opens and closes the air intake flow path formed by the first air intake duct 41. The on-off valve 242 is provided in the second air intake duct 42. The on-off valve 242 opens and closes the air intake flow path formed by the second air intake duct 42.

[0192] The memory 202 of the management device 200 stores a drive correspondence table similar to the drive correspondence table shown in Fig. 3B. In this drive correspondence table, "open" or "closed" indicating the open / closed state of the on-off valves 221, 222, 223, 231, 232, 233, 241, 242 is registered instead of the switching positions of the flow path switching valves 91, 92, 100.

[0193] The control program 204 controls the opening and closing of the on-off valves 221, 222, 223, 231, 232, 233, 241, and 242 in accordance with "open" or "close" registered in the drive correspondence table.

[0194] Even if the forced exhaust flow paths 211, 212 are directly connected to the rooms 21, 22, condensation in the exhaust ducts 31, 32 can be prevented.

[0195] Furthermore, even if the on-off valves 221, 222, 223, 231, 232, 233, 241, and 242 are used instead of the flow path switching valves 91, 92, and 100, forced ventilation, normal ventilation, inter-room ventilation, and combined ventilation can be performed.

[0196] [Other variations] In the embodiment, an example has been described in which the management device 200 determines whether to perform forced ventilation, normal ventilation, room-to-room ventilation, or combined ventilation, and controls the operation of control targets such as the switching valves 91, 92, and 100. However, the management device 200 may simply determine whether to perform forced ventilation and control the operation of the flow path switching valves 91 and 92 and the forced exhaust fans 141 and 142. In this case, the control process for performing ventilation is performed by another management device. The management device 200 interrupts the ventilation control process performed by the other management device and controls the operation of the flow path switching valves 91 and 92 and the forced exhaust fans 141 and 142 to perform forced ventilation. Furthermore, when the management device 200 only performs forced ventilation, the number of rooms 20 for which the management device 200 manages whether to perform forced ventilation may be one or more.

[0197] In the embodiment, an example has been described in which the management device 200 controls the operation of both the various fans and the various switching valves. However, the various fans may be constantly driven, and the management device 200 may only control the operation of the various switching valves. Alternatively, the various fans may be driven in conjunction with the switching positions of the flow path switching valves 91, 92, and 100, and the management device 200 may only control the operation of the switching valves 91, 92, and 93.

[0198] In the embodiment, an example has been described in which the temperature and humidity sensor group 150 is used. However, instead of the temperature and humidity sensor group 150, or together with the temperature and humidity sensor group 150, a dew condensation sensor that detects dew condensation may be provided in the exhaust ducts 31, 32.

[0199] In the embodiment, an example has been described in which the first exhaust duct 31 and the second exhaust duct 32 are connected to each other, and the first supply air duct 41 and the second supply air duct 42 are connected to each other. However, the first exhaust duct 31 and the second exhaust duct 32 may be provided independently without being connected to each other, and similarly, the first supply air duct 41 and the second supply air duct 42 may be provided independently without being connected to each other. However, by connecting the first exhaust duct 31 and the second exhaust duct 32 together and connecting the first supply air duct 41 and the second supply air duct 42 together, the number of heat exchangers 12 used can be reduced.

[0200] In the embodiment, an example has been described in which the first circulation duct 51 is connected to the first exhaust duct 31 and the first supply air duct 41, and the second circulation duct 52 is connected to the second exhaust duct 32 and the first supply air duct 41. However, the first circulation duct 51 may have one end connected to the first room 21 and the other end connected to the second room 22 or the second supply air duct 42. Similarly, the second circulation duct 52 may have one end connected to the second room 22 and the other end connected to the first room 21 or the first supply air duct 41.

[0201] In the embodiment, an example has been described in which the forced ventilation flag is set to "1" when the temperature in the exhaust ducts 31, 32 reaches a threshold temperature corresponding to the dew point temperature. However, the forced ventilation flag may also be set to "1" when the temperature in the circulation ducts 51, 52 reaches the threshold temperature. This makes it possible to prevent condensation from occurring in the circulation ducts 51, 52 as well.

[0202] In the embodiment, an example has been described in which the ventilation system 10 performs normal ventilation (see FIG. 6), inter-room ventilation (see FIG. 7), and combined ventilation (see FIG. 8). However, the ventilation system 10 may perform normal ventilation (see FIG. 6) and combined ventilation (see FIG. 8), and not perform inter-room ventilation. In other words, the ventilation system 10 may always perform ventilation with a minimum amount of outside air.

[0203] In the embodiment, an example has been described in which both the temperature and humidity sensor group 150 and the CO2 sensor group 160 are provided as pollution detection sensors. However, only one of the temperature and humidity sensor group 150 and the CO2 sensor group 160 may be provided as the pollution detection sensor. Alternatively, a sensor other than the temperature and humidity sensor group 150 and the CO2 sensor group 160, such as a dust sensor that detects fine particles such as pollen or yellow sand, or a gas sensor that detects other gases such as CO, may be provided as the pollution detection sensor.

[0204] In the embodiment, an example has been described in which each sensor of the CO sensor group 160 is installed inside a duct. However, each sensor of the CO sensor group 160 may be installed inside the room 20 in addition to or instead of inside the duct.

[0205] In the embodiment, an example has been described in which one control pattern is determined based on the "pollution level," "status," "current ventilation rate," "temperature level," "forced ventilation flag," and "normal ventilation flag." However, a plurality of control patterns capable of maintaining a low pollution level in each room 20 may be determined based on the "pollution level" etc., and the control pattern with the lowest ventilation rate with the outside, i.e., the control pattern with the lowest energy loss, may be determined as the control pattern for ventilation from the plurality of determined control patterns.

[0206] In the embodiment, an example has been described in which the control value of each control object is determined using the control pattern determination table and the drive correspondence table (see FIG. 3). However, instead of the control pattern determination table and the drive correspondence table, the control value may be determined using a function. The memory 202 stores a function instead of the control pattern determination table and the drive correspondence table. The function takes the "pollution level," "state," "ventilation volume," "temperature level," "forced ventilation flag," and "normal ventilation flag" as arguments, and outputs the control value of each control object as a return value.

[0207] In the embodiment, an example has been described in which differential pressure air supply members 81, 82 that operate (open and close) due to a pressure difference without the need for a power supply are provided in each room 20. However, instead of the differential pressure air supply members 81, 82, an on-off valve whose opening and closing is controlled by the management device 200 may be provided in each room 20. In that case, the on-off valve is opened when the forced exhaust fan group 140 is driven, and is closed at other times.

[0208] [Appendix 1] an exhaust duct connecting a room in the building to the outside; an exhaust fan provided in the exhaust duct; an air supply duct connecting the room to the outside; an air supply fan provided in the air supply duct; a heat exchanger that exchanges heat between the exhaust air from the exhaust duct and the intake air from the intake duct; a forced exhaust duct connecting the room to the outside; a forced exhaust fan provided in the forced exhaust duct; a differential pressure air supply member provided on a wall of the room; an exhaust duct valve provided in the exhaust duct; an air intake duct valve provided in the air intake duct; a forced exhaust duct valve provided in the forced exhaust duct; a sensor for detecting information regarding condensation in the exhaust duct; a controller; and The controller performs a forced ventilation process based on the output of the sensor by closing the exhaust duct valve and the intake duct valve and opening the forced exhaust duct valve.

[0209] [Appendix 2] the sensor is a temperature and humidity sensor provided in the exhaust duct, The above controller is a dew-point temperature acquisition process for acquiring a dew-point temperature according to the temperature and humidity in the exhaust duct detected by the temperature and humidity sensor; a normal ventilation process in which, based on the temperature in the exhaust duct detected by the temperature and humidity sensor not reaching a threshold temperature corresponding to the dew point temperature, the exhaust duct valve and the intake air duct valve are opened and the forced exhaust duct valve is closed; The ventilation system of claim 1, wherein the forced ventilation process is performed based on the temperature inside the exhaust duct reaching the threshold temperature.

[0210] [Appendix 3] The rooms include a first room and a second room, The exhaust duct is a first exhaust duct connecting the first room to the outside; a second exhaust duct connecting the second room with the outside, The above air supply duct is a first air supply duct connecting the first room to the outside; a second air supply duct connecting the second room with the outside, The exhaust duct valve is a first exhaust duct valve provided in the first exhaust duct; a second exhaust duct valve provided in the second exhaust duct, The air intake duct valve is a first air intake duct valve provided in the first air intake duct; a second air intake duct valve provided in the second air intake duct, a first circulation duct that connects the first exhaust duct and the second intake duct and that is provided with a first circulation fan; a second circulation duct that connects the second exhaust duct and the first intake duct and is provided with a second circulation fan, the first exhaust duct valve is a flow path switching valve provided at a connection portion between the first exhaust duct and the first circulation duct, the second exhaust duct valve is a flow path switching valve provided at a connection portion between the second exhaust duct and the second circulation duct, The above controller is A ventilation system as described in Appendix 1, which selectively performs a normal ventilation process using the first exhaust duct and the second exhaust duct, and a circulation ventilation process using at least one of the first circulation duct and the second circulation duct.

[0211] [Appendix 4] It is equipped with a pollution detection sensor that detects the pollution level in each room. The above normal ventilation process is This is executed on the condition that the value detected by the contamination detection sensor is equal to or greater than the contamination threshold value, The above-mentioned circulation ventilation process is A ventilation system as described in Appendix 3, which is executed on the condition that the value detected by the contamination detection sensor for at least one of the multiple rooms is less than the contamination threshold.

[0212] [Appendix 5] 5. The ventilation system according to claim 4, wherein the pollution detection sensor is at least one of a temperature and humidity sensor and a carbon dioxide sensor.

[0213] [Appendix 6] It is equipped with an outside temperature sensor that detects the outside temperature. The sensor is a first temperature and humidity sensor provided in the first exhaust duct; a second temperature and humidity sensor provided in the second exhaust duct, The above controller is The ventilation system described in Appendix 3 determines the ventilation volume of the outside air in the first room and the second room based on the outside air temperature detected by the outside air temperature sensor, the temperature in the first exhaust duct detected by the first temperature and humidity sensor, and the temperature in the second exhaust duct detected by the second temperature and humidity sensor, and performs the normal ventilation process and the circulating ventilation process. [Explanation of symbols]

[0214] 10. Ventilation system 11. Building 12...heat exchanger 13...Air conditioner 20...room 21. Room 1 22. Second Room 31 First exhaust duct 32 Second exhaust duct 41 First air supply duct 42 Second air supply duct 51 First circulation duct 52 Second circulation duct 61 First forced exhaust duct 62 Second forced exhaust duct 81... First differential pressure air supply member 82... Second differential pressure air supply member 91 First exhaust flow path switching valve 92 Second exhaust flow path switching valve 100···Air supply flow path switching valve 111···First exhaust fan 112 Second Exhaust Fan 120···Air intake fan 131 First circulation fan 132 Second Circulation Fan 141···First forced exhaust fan 142 Second forced exhaust fan 151···Temperature and humidity sensor for first exhaust duct 152...Temperature and humidity sensor for second exhaust duct 161....CO2 sensor for first exhaust duct 162....CO2 sensor for second exhaust duct 170 Outside air temperature sensor 200...Management device 201 CPU 202 Memory 204 Control Program 221, 222, 223...Shut-off valve 231, 232, 233...Shut-off valve 241, 242...Shut-off valve

Claims

1. an exhaust duct connecting a room in the building to the outside; an exhaust fan provided in the exhaust duct; an air supply duct connecting the room to the outside; an air supply fan provided in the air supply duct; a heat exchanger that exchanges heat between the exhaust air from the exhaust duct and the intake air from the intake duct; a forced exhaust duct connecting the room to the outside; a forced exhaust fan provided in the forced exhaust duct; a differential pressure air supply member provided on a wall of the room; an exhaust duct valve provided in the exhaust duct; an air intake duct valve provided in the air intake duct; a forced exhaust duct valve provided in the forced exhaust duct; a sensor for detecting information regarding condensation in the exhaust duct; a controller; and The controller performs a forced ventilation process based on the output of the sensor by closing the exhaust duct valve and the intake duct valve and opening the forced exhaust duct valve.

2. the sensor is a temperature and humidity sensor provided in the exhaust duct, The above controller is a dew-point temperature acquisition process for acquiring a dew-point temperature according to the temperature and humidity in the exhaust duct detected by the temperature and humidity sensor; a normal ventilation process in which, based on the temperature in the exhaust duct detected by the temperature and humidity sensor not reaching a threshold temperature corresponding to the dew point temperature, the exhaust duct valve and the intake air duct valve are opened and the forced exhaust duct valve is closed; The ventilation system according to claim 1 , wherein the forced ventilation process is executed when the temperature inside the exhaust duct reaches the threshold temperature.

3. The rooms include a first room and a second room, The exhaust duct is a first exhaust duct connecting the first room to the outside; a second exhaust duct connecting the second room with the outside, The above air supply duct is a first air supply duct connecting the first room to the outside; a second air supply duct connecting the second room with the outside, The exhaust duct valve is a first exhaust duct valve provided in the first exhaust duct; a second exhaust duct valve provided in the second exhaust duct, The air intake duct valve is a first air intake duct valve provided in the first air intake duct; a second air intake duct valve provided in the second air intake duct, a first circulation duct connecting the first exhaust duct and the second intake duct and including a first circulation fan; a second circulation duct that connects the second exhaust duct and the first intake duct and is provided with a second circulation fan, the first exhaust duct valve is a flow path switching valve provided at a connection portion between the first exhaust duct and the first circulation duct, the second exhaust duct valve is a flow path switching valve provided at a connection portion between the second exhaust duct and the second circulation duct, The above controller is The ventilation system of claim 1, wherein a normal ventilation process using the first exhaust duct and the second exhaust duct and a circulation ventilation process using at least one of the first circulation duct and the second circulation duct are selectively performed.

4. It is equipped with a pollution detection sensor that detects the pollution level in each room. The above normal ventilation process is This is executed on the condition that the value detected by the contamination detection sensor is equal to or greater than the contamination threshold value, The above-mentioned circulation ventilation process is The ventilation system according to claim 3, wherein the ventilation system is executed on the condition that a value detected by the contamination detection sensor in at least one of the plurality of rooms is less than a contamination threshold value.

5. 5. The ventilation system according to claim 4, wherein the contamination detection sensor is at least one of a temperature and humidity sensor and a carbon dioxide sensor.

6. It is equipped with an outside temperature sensor that detects the outside temperature. The sensor is a first temperature and humidity sensor provided in the first exhaust duct; a second temperature and humidity sensor provided in the second exhaust duct, The above controller is 4. The ventilation system according to claim 3, wherein the ventilation volume of the outside air in the first room and the second room is determined based on the outside air temperature detected by the outside air temperature sensor, the temperature in the first exhaust duct detected by the first temperature and humidity sensor, and the temperature in the second exhaust duct detected by the second temperature and humidity sensor, and the normal ventilation process and the circulating ventilation process are performed.

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