Ventilation system

Abstract

Prevents condensation in exhaust ducts and improves energy efficiency. [Solution] The ventilation system 10 includes an exhaust duct 31, an intake duct 41, a forced exhaust duct 61, an exhaust flow path switching valve 91, an intake flow path switching valve 100, a differential pressure air supply member 81, an exhaust fan 111, an intake fan 120, a forced exhaust fan 141, a temperature / humidity sensor 151, and a management device 200. When the temperature inside the exhaust duct reaches near the dew point temperature, the management device 200 closes the exhaust flow path and the intake air flow path and opens the forced exhaust flow path to exhaust air from a room 21 to the outside of the building 11. When the air from the room 21 is exhausted, outside air flows into the room 21 through the differential pressure air supply member 81. When forced ventilation is performed, the intake air flow path is closed, preventing air whose temperature has been adjusted by the heat exchanger 12 from being wasted outside. As a result, condensation in the exhaust duct 31 is prevented and energy efficiency is improved.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses an air-conditioning and ventilation system used in a building. This air-conditioning and ventilation system includes an exhaust duct and an air supply duct that connect a room and the outside (outdoor air), a heat exchanger, and a controller. A blower fan is provided in the exhaust duct and the air supply duct. The air in the room is discharged to the outside through the exhaust duct, and the outside air is introduced into the room through the air supply duct. The heat exchanger performs heat exchange 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 provided in a specific room such as a bathroom or a toilet, and a humidity sensor installed in the room. When it is detected by the humidity sensor that the bathroom or toilet has been used, the ventilation fan is driven. By the ventilation fan, the air containing a large amount of moisture is forcibly discharged from the room to the outside. While forced exhaust is performed, the conditioned air whose temperature has been adjusted is introduced into the room through the air supply duct, and the air in the room is replaced with the conditioned air.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the air-conditioning and ventilation system disclosed in Patent Document 1, since the ventilation fan is driven according to the humidity of the room (such as a bathroom), the ventilation fan is not driven if the humidity of the room is low. In that case, there is a risk that the air in the room is cooled while passing through the exhaust duct and condensation occurs in the exhaust duct.

[0006] Furthermore, in the air conditioning and ventilation system disclosed in Patent Document 1, the ventilation fan is driven and adjusted air is introduced into the room (bathroom, etc.). As a result, some of the adjusted air is also discharged from the room to the outside by the ventilation fan, leading to poor energy efficiency.

[0007] This invention has been made in view of the circumstances described above, and its purpose is to provide a ventilation system that can prevent condensation in exhaust ducts and improve energy efficiency. [Means for solving the problem]

[0008] (1) The ventilation system according to the present invention comprises an exhaust duct connecting a room in a building to the outside, an exhaust fan provided in the exhaust duct, a supply air duct connecting the room to the outside, a supply air fan provided in the supply air duct, a heat exchanger that performs heat exchange between the exhaust from the exhaust duct and the supply air from the supply air duct, a forced exhaust duct connecting the room to the outside, a forced exhaust fan provided in the forced exhaust duct, a differential pressure supply air member provided in the wall of the room, an exhaust duct valve provided in the exhaust duct, a supply air duct valve provided in the supply air duct, a forced exhaust duct valve provided in the forced exhaust duct, a sensor that detects information regarding condensation in the exhaust duct, and a controller. Based on the output of the sensor, the controller performs a forced ventilation process that closes the exhaust duct valve and the supply air duct valve and opens the forced exhaust duct valve.

[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 supply duct valve and opens the forced exhaust duct valve. The forced exhaust fan expels the room air to the outside through the forced exhaust duct, preventing condensation within the exhaust duct. Since the supply duct valve is closed during forced ventilation, the air that has undergone heat exchange in the heat exchanger is prevented from being expelled to the outside through the forced exhaust duct. As a result, energy efficiency is improved. The forced exhaust fan may be driven continuously, driven in conjunction with the opening and closing of the forced exhaust duct valve, or its drive may be controlled by the controller.

[0010] (2) The sensor may be a temperature and humidity sensor installed in the exhaust duct. The controller performs a dew point temperature acquisition process to acquire the 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 supply air duct valve and close the forced exhaust duct valve based on the fact that the temperature inside the exhaust duct detected by the temperature and humidity sensor has not reached the threshold temperature corresponding to the dew point temperature; and a forced ventilation process based on the fact that the temperature inside the exhaust duct has reached the threshold temperature.

[0011] To manage the temperature and humidity of a room, temperature and humidity sensors are sometimes installed in the exhaust duct. These sensors are used to determine whether or not 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 or not condensation will occur based on whether or not the temperature inside the exhaust duct has reached a threshold temperature corresponding to the dew point temperature. If the controller determines that the temperature inside the exhaust duct has reached the threshold temperature, it executes forced ventilation. Therefore, condensation inside the exhaust duct can be prevented without installing a new sensor to determine the presence or absence of condensation.

[0012] (3) The above-mentioned room may include a first room and a second room. The above-mentioned 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 above-mentioned supply air duct includes a first supply air duct connecting the first room to the outside and a second supply air duct connecting the second room to the outside. The above-mentioned 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 above-mentioned supply air duct valve includes a first supply air duct valve provided in the first supply air duct and a second supply air duct valve provided in the second supply air duct. The ventilation system according to the present invention further comprises a first circulation duct that connects the first exhaust duct and the second supply air duct and is equipped with a first circulation fan, and a second circulation duct that connects the second exhaust duct and the first supply air duct and is equipped with a second circulation fan. The first exhaust duct valve is a flow path switching valve provided at the connection point between the first exhaust duct and the first circulation duct. The second exhaust duct valve is a flow path switching valve provided at the connection point between the second exhaust duct and the second circulation duct. The controller selectively performs normal ventilation processing using the first exhaust duct and the second exhaust duct, and circulating ventilation processing 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 a flow path to the first exhaust duct and the second exhaust duct valve (flow path switching valve) opens a flow path to the second exhaust duct, only normal ventilation via the heat exchanger is performed. When the first exhaust duct valve (flow path switching valve) opens a flow path to the first circulation duct, or when the second exhaust duct valve (flow path switching valve) opens a flow path to the second circulation duct, circulating 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 according to the present invention can selectively perform normal ventilation and circulating ventilation. By performing circulating ventilation, energy efficiency can be increased 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 related to the degree of contamination in each room. The normal ventilation process described above is performed on the condition that the value detected by the contamination detection sensor is equal to or greater than the contamination threshold. The circulating ventilation process described above is performed on the condition that the value detected by the contamination detection sensor in at least one of the multiple rooms is less than the contamination threshold.

[0015] If the contamination detection sensors in multiple rooms detect a value above the contamination threshold and ventilation with the outside air is required, normal ventilation is performed. If the contamination detection sensors in at least one of the multiple rooms detect a value below the contamination threshold, circulating ventilation is performed.

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

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

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

[0019] The greater the difference between the outside temperature and the room temperature, the greater the energy loss. When the difference is small, energy loss is small even with normal ventilation. By determining the amount of ventilation with the outside air based on the outside temperature, the first detected temperature, and the second detected temperature, and performing normal ventilation and circulating ventilation, 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 Description 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 an embodiment. [Figure 3] FIG. 3(A) is a diagram showing a control pattern determination table, FIG. 3(B) is a diagram showing a drive correspondence table, FIG. 3(C) is a diagram showing a ventilation volume correspondence table, and FIG. 3(D) is a diagram showing a dew point temperature determination table. [Figure 4] FIG. 4 is a flowchart of ventilation control processing. [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 for explaining ventilation between rooms. [Figure 8] FIG. 8 is an explanatory diagram for explaining 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 modification is used.

Modes for Carrying Out the Invention

[0022] Hereinafter, embodiments of the present invention will be described. It should be noted that the embodiments described below are merely examples of the present invention, and it is needless to say that the embodiments of the present invention can be appropriately changed without changing the gist of the present invention. In addition, the execution order of each process (each step) shown in the flowchart of FIG. 4 may be appropriately changed, some may be omitted, other processes may be added, or they may be replaced with other equivalent processes without changing the gist of the present invention.

[0023] [Overview of Ventilation System 10] As shown in Figure 1, the ventilation system 10 described in this embodiment is used in a building 11. The building 11 can be a private residence, an apartment building, a high-rise building, etc. The ventilation system 10 ventilates the rooms in the building 11. In the following description, an example will be given 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 it may have three or more rooms. Also, the first room 21 and the second room 22 may be on different floors. In the following description, when the first room 21 and the second room 22 are not distinguished, they will be collectively referred to as room 20.

[0024] Each of the 20 rooms is assigned a room ID. The ventilation system 10 identifies each of the 20 rooms individually based on 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 the building owner. Alternatively, 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 supply air members 81, 82, an exhaust flow path switching valve group 90 (see Figure 2), a supply air flow path switching valve 100, various fans, various sensors, and a control device 200.

[0027] [Various types of ducts] As shown in Figure 1, the various ducts include exhaust ducts 31, 32, supply ducts 41, 42, circulation ducts 51, 52, and forced exhaust ducts 61, 62. Each duct is installed in the ceiling space, underfloor space, etc., 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 is connected to a first opening 71 provided in the wall or ceiling of the first room 21, and the other end is connected to an opening 75 provided in the outer wall of the building 11. The first exhaust duct 31 forms (partitions) an exhaust flow path connecting 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 connecting the second room 22 to the outside through 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 is connected to a first opening 73 provided in the wall or ceiling of the first room 21, and the other end is connected to an opening 76 provided in the outer wall of the building 11. The first air supply duct 41 forms (partitions) an air supply passage connecting the first room 21 to the outside.

[0031] The second air supply duct 42 connects the second room 22 to the outside (outside air) of the building 11. Specifically, one end of the second air supply duct 42 is connected to the second opening 74 provided in the wall or ceiling of the second room 22, and the other end is connected to the first air supply duct 41. In other words, the second air supply duct 42 is connected to the outside (outside air) through the first air supply duct 41. The second air supply duct 42 forms (partitions) an air supply passage connecting the second room 22 to 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, which is connected to the first room 21, and the other end is connected to the second supply air duct 42, which 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, if 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 minimize 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, which is connected to the second room 22, and the other end is connected to the first supply air duct 41, which is connected 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, if the carbon dioxide concentration in the air of 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 minimize energy loss.

[0034] The first forced exhaust duct 61 connects the first room 21 to 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 the first exterior wall opening 65 provided in the exterior wall of the building 11. The first forced exhaust duct 61 is used for the forced exhaust of air from the first room 21. The aforementioned one end of the first forced exhaust duct 61 is connected to the first exhaust duct 31 at the connection point 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 interconnected at the same connection point.

[0035] The second forced exhaust duct 62 connects the second room 22 to the outside (outside 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 the second exterior wall opening 66 provided in the exterior wall of the building 11. The second forced exhaust duct 62 is used for the forced exhaust of air from the second room 22. The aforementioned one end of the second forced exhaust duct 62 is connected to the second exhaust duct 32 at the connection point 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 interconnected at the same connection point.

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

[0037] [Air conditioner 13] The air conditioning unit 13 comprises 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 conditioning unit 13 individually controls the room temperature of each room 20. Note that the air conditioning unit 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 supply members 81 and 82 are so-called differential pressure supply ports or differential pressure supply units. The differential pressure supply members 81 and 82 have shutters (on-off valves) that open when a pressure difference occurs between the two spaces and close when there is no pressure difference. Existing (commercially available) products are used for the differential pressure supply members 81 and 82.

[0039] The first differential pressure air supply member 81 is installed in the wall of the first room 21 that separates it from the outside. When the air pressure inside the first room 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 installed in the wall of the second room 22 that separates it from the outside. When the air pressure inside the second room 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] As shown in Figure 2, the exhaust flow path switching valve group 90 (see Figure 2) has a first exhaust flow path switching valve 91 and a second exhaust flow path switching valve 92. Each exhaust flow path switching valve 91, 92 and the supply air flow path switching valve 100 described later are each assigned a switching valve ID. The control device 200 identifies each switching valve 91, 92, and 100 individually by their switching valve IDs.

[0042] As shown in Figure 1, the first exhaust flow path switching valve 91 is installed at the connection point of the first exhaust duct 31, the first circulation duct 51, and the first forced exhaust duct 61.

[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 (commercially available) product is used for 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): the first switching position, the second switching position, the third switching position, the fourth switching position, and the fifth switching position.

[0045] The first switching position is the position in which the flow path on the first exhaust duct 31 side is opened, and the flow paths on the first forced exhaust duct 61 side and the first circulation duct 51 side are closed. The first switching position is used when ventilation through the heat exchanger 12 (hereinafter also referred to as "normal ventilation").

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

[0047] The third switching position is the 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 the position that opens the flow paths on the first exhaust duct 31 side and the first circulation duct 51 side, and closes the flow path on the first forced exhaust duct 61 side. The fourth switching position is used when performing ventilation that simultaneously performs the above-mentioned normal ventilation and the above-mentioned inter-room ventilation (hereinafter also referred to as "combined ventilation").

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

[0050] The second exhaust flow path switching valve 92 is provided at the connection point of the second exhaust duct 32, the second circulation duct 52, and the second forced exhaust duct 62.

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

[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 is the position in which the flow path on the second exhaust duct 32 side is opened and the flow paths on the second forced exhaust duct 62 side and the second circulation duct 52 side are closed. The second switching position is the position in which the flow path on the second circulation duct 52 side is opened and the flow paths on the second exhaust duct 32 side and the second forced exhaust duct 62 side are closed. The third switching position is the position in which the flow path on the second forced exhaust duct 62 side is opened and the flow paths on the second exhaust duct 32 side and the second circulation duct 52 side are closed. The fourth switching position is the position in which the flow paths on the second exhaust duct 32 side and the second circulation duct 52 side are opened and the flow path on the second forced exhaust duct 62 side is closed. The fifth switching position is the position that closes all flow paths on the second exhaust duct 32 side, the second circulation duct 52 side, and the second forced exhaust duct 62 side.

[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 supply duct valve, and a forced exhaust duct valve.

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

[0055] The air intake flow path 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 the position where the flow path on the first supply air duct 41 side is opened and the flow path on the second supply air duct 42 side is closed. The first switching position is used, for example, when ventilating the first room 21 while simultaneously performing forced ventilation of the second room 22.

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

[0058] The third switching position is the position where both the airflow paths on the first supply air duct 41 side and the second supply air duct 42 side are opened. In other words, the third switching position is the 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 the position that closes the airflow paths on both the first air supply duct 41 side and the second air supply duct 42 side. In other words, the fourth switching position is the fully closed position. The fourth switching position is used, for example, when forced ventilation is to be performed simultaneously in the first room 21 and the second room 22.

[0060] [Various Fans] The various fans include an exhaust fan group 110, a supply fan group 120, a circulation fan group 130, and a forced exhaust fan group 140. Each fan is assigned a fan ID. The control device 200 identifies each fan individually by its 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 of the first exhaust flow path switching valve 91 (on the heat exchanger 12 side). The first exhaust fan 111 generates an airflow from the first opening 71, which is the exhaust opening of the first room 21, to the opening 75. The first exhaust fan 111 is driven when performing the above-mentioned normal ventilation or combined ventilation through the heat exchanger 12 to 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 of the second exhaust flow path switching valve 92 (on the heat exchanger 12 side). The second exhaust fan 112 generates an airflow from the second opening 72, which is the exhaust opening of the second room 22, to the opening 75. The second exhaust fan 112 is driven when performing the above-mentioned normal ventilation or combined ventilation through the heat exchanger 12 to the second room 22.

[0064] The supply air fan 120 is installed in the first supply air duct 41. More specifically, the supply air fan 120 is installed downstream of the supply air flow path switching valve 100 (on the heat exchanger 12 side). Specifically, the supply air fan 120 is installed near the opening 76. The supply air fan 120 generates an airflow from the opening 76 toward the first opening 73, which is the supply air opening for the first room 21, and the second opening 74, which is the supply air opening for the second room 22. The supply air fan 120 is driven when performing the above-mentioned normal ventilation or combined ventilation through the heat exchanger 12 to at least one of the first room 21 or 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 from the first opening 71, which is the exhaust opening of the first room 21, to the second opening 74, which is the supply air opening of the second room 22. The first circulation fan 131 is used when performing the above-mentioned inter-room ventilation or combined ventilation.

[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 from the second opening 72, which is the exhaust opening of the second room 22, to the first opening 73, which is the supply air opening of the first room 21. The second circulation fan 132 is used when performing the above-mentioned inter-room ventilation or combined ventilation.

[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 inside the first forced exhaust duct 61. The first forced exhaust fan 141 generates an airflow from the first opening 71 for forced exhaust of the first room 21 toward the first exterior wall opening 65.

[0070] The second forced exhaust fan 142 is installed inside the second forced exhaust duct 62. The second forced exhaust fan 142 generates an airflow from the second opening 72 for forced exhaust of the second room 22 toward the second exterior 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 ambient temperature sensor 170. Each sensor is assigned a sensor ID. The control device 200 identifies each sensor individually by its 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, a supply air 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 detected values ​​indicating the temperature and humidity of the air discharged from the first room 21 into the first exhaust duct 31. There may be one or more first exhaust duct temperature and humidity sensors 151. In the example shown in Figure 1, multiple first exhaust duct temperature and humidity sensors 151 are installed inside the first exhaust duct 31 at equal intervals from each other.

[0074] The second exhaust duct temperature and humidity sensor 152 is installed inside the second exhaust duct 32. The second exhaust duct temperature and humidity sensor 152 outputs detected values ​​indicating the temperature and humidity of the air discharged from the second room 22. There may be one or more second exhaust duct temperature and humidity sensors 152. In the example shown in Figure 1, multiple second exhaust duct temperature and humidity sensors 152 are installed inside the first exhaust duct 31 at equal intervals from each other.

[0075] The air supply duct temperature and humidity sensor 153 is installed inside the first air supply duct 41. The air supply duct temperature and humidity sensor 153 outputs detected values ​​indicating the temperature and humidity of the air that has flowed into the first air supply duct 41 from the outside and has undergone heat exchange in the heat exchanger 12. There may be one or more air supply duct temperature and humidity sensors 153. For example, multiple air supply duct temperature and humidity sensors 153 are installed inside the first air supply duct 41 at equal intervals from each other.

[0076] The first circulation duct temperature and humidity sensor 154 is installed inside the first circulation duct 51. The first circulation duct temperature and humidity sensor 154 outputs detected 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 and humidity sensors 154. For example, multiple first circulation duct temperature and humidity sensors 154, spaced equally apart from each other, may be installed inside the first circulation duct 51.

[0077] The second circulation duct temperature and humidity sensor 155 is installed inside the second circulation duct 52. The second circulation duct temperature and humidity sensor 155 outputs detected 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 and humidity sensors 155. For example, multiple second circulation duct temperature and humidity sensors 155, spaced equally apart from each other, may be installed inside the second circulation duct 52.

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

[0079] The first exhaust duct CO2 sensor 161 is installed inside the first exhaust duct 31. The first exhaust duct CO2 sensor 161 outputs a detected value indicating the carbon dioxide concentration in the air discharged from the first room 21 into the first exhaust duct 31. There may be one or more first exhaust duct CO2 sensors 161. In the example shown in Figure 1, multiple first exhaust duct CO2 sensors 161 are installed inside the first exhaust duct 31 at equal intervals from each other.

[0080] The second exhaust duct CO2 sensor 162 is installed inside the second exhaust duct 32. The second exhaust duct CO2 sensor 162 outputs a detected value indicating the carbon dioxide concentration in the air discharged from the second room 22. There may be one second exhaust duct CO2 sensor 162 or multiple sensors. In the example shown in Figure 1, multiple second exhaust duct CO2 sensors 162 are installed inside the second exhaust duct 32 at equal intervals from each other.

[0081] The CO2 sensor 163 for the air supply duct is installed inside the first air supply duct 41. The CO2 sensor 163 for the air supply duct outputs a detected value indicating the carbon dioxide concentration of the air that has flowed into the first air supply duct 41 from the outside and has undergone heat exchange in the heat exchanger 12. There may be one or more CO2 sensors 163 for the air supply duct. For example, multiple CO2 sensors 163 for the air supply duct are installed inside the first air supply duct 41 at equal intervals from each other.

[0082] The first circulation duct CO2 sensor 164 is installed inside the first circulation duct 51. The first circulation duct CO2 sensor 164 outputs a detected 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, multiple first circulation duct CO2 sensors 164, spaced equally apart from each other, may be installed inside the first circulation duct 51.

[0083] The second circulation duct CO2 sensor 165 is installed inside the second circulation duct 52. The second circulation duct CO2 sensor 165 outputs a detected 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 second circulation duct CO2 sensor 165 or multiple sensors. For example, multiple second circulation duct CO2 sensors 165, spaced equally apart from each other, may be installed inside the second circulation duct 52.

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

[0085] [Management device 200] The control device 200 shown in Figure 2 is a device that controls (manages) the operation of the ventilation system 10. The control device 200 may be a personal computer or server installed in the building 11, or it may be a web server. In other words, the ventilation system 10 may be a standalone system with the control device 200 installed inside the building 11, or it may be a system where the control device 200 is installed outside the building 11 and remotely managed. For example, if the ventilation system 10 is operated and managed by the service provider mentioned above, multiple ventilation systems 10 are centrally managed by the web server (control device 200) via the internet. If the control device 200 is a web server, the control device 200 has a communication interface connected to the internet. On the other hand, the building 11 is equipped with communication devices such as a personal computer or communication modem that have a communication interface connected to the internet.

[0086] The management device 200 comprises a central processing unit (CPU) 201 and a memory 202. The CPU 201 and memory 202, or the management device 200, are examples of controllers.

[0087] Memory 202 stores the operating system OS 203, control programs 204, various tables, and various thresholds. OS 203 and control programs 204 are executed by CPU 201.

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

[0089] The control pattern determination table shown in Figure 3(A) is used to determine the 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 Figure 3(B) is used to determine the control values ​​of the control targets, which are the flow path switching valves 91, 92, and 100, and the fans 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 enable the appropriate type of ventilation (forced ventilation, normal ventilation, inter-room ventilation, combined ventilation) to be performed at an appropriate airflow rate (ventilation volume) according to the conditions of the first room 21 and the second room 22, and the conditions of the exhaust ducts 31 and 32. A detailed explanation follows below.

[0090] [Control Pattern Determination Table] The control pattern determination table comprises a first column labeled "Control Pattern" and two second columns labeled "First Room" and "Second Room," respectively. If the building 11 has two or more rooms 20, the control pattern determination table will have a number of second columns corresponding to the number of rooms 20.

[0091] Each field in the first column, labeled "Control Pattern," will contain a control pattern number such as "1" or "2."

[0092] Each second column has multiple sub-columns, each labeled with the item names "Contamination Level," "Status," "Ventilation Volume," "Temperature Level," "Forced Ventilation Flag," and "Normal Ventilation Flag." In other words, the various conditions of room 20 and exhaust ducts 31 and 32 are categorized (case-based) by "Contamination Level," "Status," "Ventilation Volume," "Temperature Level," "Forced Ventilation Flag," and "Normal Ventilation Flag." For example, the first room 21 has a contamination level of "4," a status of "Increasing," a ventilation volume of "3," a temperature level of "2," a forced ventilation flag of "0," and a normal ventilation flag of "1," while the second room 22 has a contamination level of "4," a status of "Increasing," a ventilation volume of "2," a temperature level of "3," a forced ventilation flag of "1," and a normal ventilation flag of "1." This represents one condition for rooms 21 and 22, and a control pattern of "1" is assigned to this condition. In other words, the control pattern determination table pre-defines and categorizes the expected conditions of the 20 rooms, and each of these categorized conditions is assigned a control pattern number as an identification number to individually identify it.

[0093] Each second column may contain only some of the subcolumns of multiple subcolumns with the item names "Contamination Level," "Status," "Ventilation Rate," "Temperature Level," "Forced Ventilation Flag," and "Normal Ventilation Flag," or it may contain subcolumns with other item names. In other words, the conditions of room 20 and exhaust ducts 31 and 32 may be classified by some of the elements of "Contamination Level," "Status," "Ventilation Rate," "Temperature Level," "Forced Ventilation Flag," and "Normal Ventilation Flag," or further classifications may be made by adding other elements.

[0094] The pollution level is registered in the field of the sub-column named "Pollution Level". For example, a standard value and a lower limit value for humidity and carbon dioxide concentration in room 20 are determined, and the pollution level is determined by the percentage tile between the standard value and the lower limit value. In other words, humidity and carbon dioxide concentration are normalized and registered in the control pattern determination table. Note that the pollution level only needs to be in two or more stages; for example, it may be normalized in three stages: "low", "medium", and "high". In the embodiment, an example in which the pollution level is normalized in five stages from "1" to "5" is described. Furthermore, the above standard value and lower limit value may be corrected (changed) according to the season or outside temperature. In addition, a normalization method other than percentage tile may be used.

[0095] The "contamination level" determines whether ventilation is necessary and the fan rotation speed level (i.e., ventilation volume). For example, if the "contamination level" is "4" or "5", ventilation is necessary and a high rotation speed level is required. Therefore, for control pattern numbers associated with "contamination levels" of "4" or "5", the switching positions of the flow path switching valves 91, 92, and 100 in the drive correspondence table (see Figure 3(B)) described later are set to normal ventilation, and the fan rotation speed level is set to a high level. In other words, the "contamination 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] The field in the sub-column named "Status" will contain one of the following: "Steady," indicating that humidity and carbon dioxide concentration have not changed; "Decreasing," indicating that they are decreasing; or "Increasing," indicating that they are increasing. Note that there should be two or more "Status" levels.

[0097] The "contamination level" and "state" indicate whether the ventilation volume is excessive or insufficient. For example, if the contamination level is "4" and the state is "increasing" or "steady," it indicates that the ventilation volume is insufficient. Conversely, if the contamination level is "4" and the state is "decreasing," it indicates that the ventilation volume is sufficient. Conversely, if the contamination level is "2" and the state is "decreasing," it indicates that the ventilation volume is excessive. Conversely, if the contamination level is "2" and the state is "steady," it indicates that the ventilation volume is neither excessive nor insufficient. In short, the "state," along with the "contamination level," is a factor that determines the fan rotation speed level.

[0098] The field in the sub-column labeled "Ventilation Volume" stores the standardized (current) ventilation volume. For example, with a contamination level of "4," a status of "Increasing," and a ventilation volume of "2," the current ventilation volume of "2" is insufficient, and ventilation needs to be increased to a level of "3" or higher. Therefore, for such situations, a control pattern number corresponding to a fan rotation speed level that results in a ventilation volume of "3" or higher is assigned. In other words, "(Current) Ventilation Volume," along with "Status" and "Contamination Level," is a factor that determines the fan rotation speed level.

[0099] The field in the sub-column named "Temperature Level" records the difference or percentage of the temperature of Room 20 relative to the outside temperature. For example, if the difference between the outside temperature and the temperature of Room 20 is less than 2°C, a temperature level of "1" is registered; if the difference is between 2°C and 4°C, a temperature level of "2" is registered; and so on, with the temperature level being determined in multiple stages from "1" to "X".

[0100] The greater the difference between the outside temperature and the temperature of room 20, the greater the energy loss when ventilating with the outside air. Conversely, the smaller the difference between the outside temperature and the temperature of room 20, the smaller the energy loss when ventilating with the outside air. For example, a temperature level of "1," indicating a small difference between the outside temperature and the temperature of room 20, corresponds to a control pattern number that performs ventilation with the outside air. Similarly, a temperature level of "X," indicating a large difference between the outside temperature and the temperature of room 20, corresponds to a control pattern number that performs inter-room ventilation or combined ventilation. In short, the "temperature level" is a factor that determines the switching position of the flow path switching valves 91, 92, and 100.

[0101] The field in the sub-column labeled "Forced Ventilation Flag" is either "1" to indicate that forced ventilation is required, or "0" to indicate that forced ventilation is not required. Whether or not forced ventilation is required is determined by 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 "1" for the Forced Ventilation Flag corresponds to the control pattern number for performing forced ventilation. In short, the "Forced Ventilation Flag" is a factor that determines the switching position of the flow path switching valves 91, 92, and 100.

[0102] The field in the sub-column named "Normal Ventilation Flag" is registered with either "1" to indicate that normal ventilation is required, or "0" to indicate that normal ventilation is not required. The normal ventilation flag of "1" is set when the pollution level, humidity, or carbon dioxide concentration in room 20 is above a threshold. The air in room 20, where the normal ventilation flag is "1", cannot be used for ventilation in other rooms. Therefore, the normal ventilation flag of "1" is associated with the control pattern number for performing normal ventilation. In other words, the "Normal Ventilation Flag" is a factor that determines the switching position of the flow path switching valves 91, 92, and 100.

[0103] If the field in the subcolumn labeled "Forced Ventilation Flag" is set to "0", and the field in the subcolumn labeled "Normal Ventilation Flag" is also set to "0", it indicates that combined ventilation or inter-room ventilation will be performed. Whether inter-room ventilation or combined ventilation is performed is determined by the "contamination level" of each room. In other words, the "Forced Ventilation Flag", "Normal Ventilation Flag", and "Contamination Level" are the elements that determine whether forced ventilation, normal ventilation, inter-room ventilation, or combined ventilation is performed, that is, the elements that determine the switching position of the flow control valves 91, 92, and 100.

[0104] Thus, the control pattern determination table associates the conditions of the first room 21 and the second room 22 and the exhaust ducts 31 and 32 with appropriate control patterns corresponding to those conditions. An appropriate control pattern means a control that prevents condensation in the exhaust ducts 31 and 32, maintains a low level of contamination, and minimizes energy loss. The appropriate control pattern (control value) may be determined by estimation through calculation, or by testing with actual equipment (trial and error).

[0105] [Drive compatibility table] The drive correspondence table shown in Figure 3(B) is a table that associates control pattern numbers with control values ​​for each controlled object, such as the exhaust fan group 110. In other words, the control pattern determination table identifies the control pattern number (i.e., the status of room 20, etc.), and the identified control pattern number and the drive correspondence table determine the control values ​​for the controlled objects. The control values ​​include the fan rotation speed level, the fan on / off setting, and the setting of the switching position of the flow path switching valves 91, 92, and 93.

[0106] The drive response table comprises a column with the item name "Control Pattern" and multiple columns each with the name of a controlled object, such as "First Exhaust Fan".

[0107] Each field in the column named "Control Pattern" will contain the control pattern number mentioned above.

[0108] Each field in the column labeled "First Exhaust Fan," "Second Exhaust Fan," or "Intake Fan" will contain either "Stopped" to indicate the fan is stopped, or a rotation speed level such as "1," "2," or "3" to indicate the fan's rotation speed. For example, a rotation speed level of "1" indicates the fan is rotating at a low speed, and a rotation speed level of "3" indicates the fan is rotating at a high speed. Note that there only need to be two or more rotation speed levels, and there may be five or ten levels, for example.

[0109] Each field in the column named "First Forced Exhaust Fan" or "Second Forced Exhaust Fan" will be registered with either "Stopped" to indicate the fan is stopped, or "Driven" to indicate the fan is running. Alternatively, the fan's rotation speed level may be registered instead of "Driven." In other words, the forced exhaust fan group 140 may be driven at multiple rotation speed levels.

[0110] Each field in the column labeled "First Exhaust Flow Switching Valve" or "Second Exhaust Flow Switching Valve" registers the switching settings for exhaust flow switching valves 91 and 92. The switching setting is one of the five switching positions, from the first to the fifth.

[0111] Each field in the column labeled "Air Intake Flow Switching Valve" registers the switching setting for the air intake flow switching valve 100. The switching setting is one of the four switching positions from the first to the fourth switching position.

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

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

[0114] Control pattern number "3" indicates a control pattern that performs combined ventilation for the first room 21 and the second room 22. Specifically, control pattern number "3" is a control pattern that exhausts the air in the first room 21 to the outside, mixes the air in the second room 22 with outside air, and supplies that mixture to the first room 21. Although not shown in Figure 3(B), a combined ventilation control pattern that exhausts the air in the second room 22 to the outside, mixes the air in the first room 21 with outside air, and supplies that mixture to the second room 22 is also registered in the drive correspondence table. In other words, if there are two rooms 20, there are two types of combined ventilation, excluding the difference in fan rotation speed. However, the more rooms 20 there are, the more types of combined ventilation there are.

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

[0116] 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 Figure 3(B), control pattern numbers for forced ventilation of the second room 22 and normal ventilation of the first room 21, as well as control pattern numbers for forced ventilation of both the first room 21 and the second room 22, are also registered in the drive correspondence table. In other words, if there are two rooms 20, there are three types of forced ventilation, excluding the difference in fan rotation speed. However, the number of types of forced ventilation increases as the number of rooms 20 increases.

[0117] Furthermore, although not shown in Figure 3(B), various control pattern numbers with the same settings as the switching position settings for the flow path switching valves 91, 92, and 100 in control pattern number "4," but with different fan rotation speed levels, are registered in the drive correspondence table.

[0118] Furthermore, the same control value may be registered for different control pattern numbers. For example, the same control value may be registered for multiple different control pattern numbers depending on the size of the building 11 being managed, thereby simplifying the control process.

[0119] [Ventilation volume compatible table] The ventilation rate correspondence table shown in Figure 3(C) is a table that associates control pattern numbers with the ventilation rates 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 rate of each room 20 is determined. The current ventilation rate of each room 20 is an element for determining the next control pattern. The ventilation rate correspondence table determines the ventilation rate of each room 20 according to the current control pattern number. This will be explained in detail below.

[0120] The ventilation volume table includes a column labeled "Control Pattern" and a column labeled "Ventilation Volume".

[0121] Each field in the column named "Control Pattern" will contain the control pattern number mentioned above.

[0122] The column labeled "Ventilation Rate" includes sub-columns labeled "Room 1" and "Room 2". Each field in the sub-columns labeled "Room 1" and "Room 2" registers a standardized ventilation rate level such as "0", "1", or "2". 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 room 20, a level corresponding to the proportion of outside air in that total amount, or both. Alternatively, the ventilation rate may be a value corresponding to the total amount of air supplied to room 20 and the humidity and carbon dioxide concentration detected by sensor groups 150 and 160.

[0123] There is a one-to-one correspondence between control pattern numbers and ventilation volumes. 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 Figure 3(D) is a table for determining the dew point temperature from temperature and humidity. In the dew point temperature determination table, temperature and humidity are associated with the dew point temperature. The dew point temperature inside 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 Figure 2) is a table that associates room IDs with temperature and humidity sensor IDs, CO2 sensor IDs, and fan IDs. The control device 200 uses this table to determine (identify) which room 20's temperature, humidity, and carbon dioxide concentration the detected values ​​of each sensor correspond to, and individually identifies each room 20 to drive the corresponding fan and set the switching settings for the flow path switching valves 91, 92, and 100.

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

[0127] The ventilation control process involves driving controlled devices such as the supply air fan 120 to ventilate each room 20 of the building 11. The control program 204 executes the ventilation control process in a manner that prevents condensation in the exhaust ducts 31 and 32, keeps pollution levels low, and minimizes energy loss.

[0128] The control program 204 executes ventilation control processing continuously for 24 hours, or only during a set period of time within a day, or only after a start instruction is input until a stop instruction is input.

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

[0130] The control program 204 determines the "current pollution level," "current state," and "current temperature level" based on the data stored in memory 202 and stores them in memory 202 (S12). The "current pollution level" is determined by normalizing (% tiling) the latest humidity and carbon dioxide concentration using the above reference value and lower limit. The "current state" is determined by the above time-varying data for humidity and the above period-varying data for carbon dioxide concentration. The "current temperature level" is determined by normalizing the latest temperature and the difference with the outside 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, and therefore the current control pattern is maintained. The process in step S13 prevents the flow path switching valves 91, 92, and 100 from being frequently changed in their switching positions. The determination of whether to maintain the current control pattern can 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 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] Note that the process in step S13 may be omitted. In that case, the control program 204 may periodically review (change) the control pattern at predetermined intervals of several minutes to more than ten minutes.

[0133] If the control program 204 determines to maintain the current control pattern (S13: Yes), it repeats the process from step S11 onwards without changing the control pattern. If the control program 204 determines not to maintain the current control pattern (S13: No), it obtains the latest temperature and humidity inside the exhaust ducts 31 and 32, and the dew point temperature inside the exhaust ducts 31 and 32 from the dew point temperature determination table (Figure 3(D)) (S14). The process in step S14 is an example of the 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 below a threshold temperature corresponding to the acquired dew point temperature (S15). In other words, step S15 determines 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 the dew point temperature plus a predetermined temperature such as 1°C.

[0135] If the control program 204 determines that the latest temperature is below the threshold temperature (S15: Yes), it stores a forced ventilation flag of "1" in memory 202, associated with the room ID of the room 20 in which the latest temperature was determined to be below the threshold temperature (S16).

[0136] If the control program 204 determines that the latest temperature in the exhaust ducts 31 and 32 is not below the threshold temperature (S15: No), it stores a forced ventilation flag of "0" in memory 202, associated with the room ID (S17).

[0137] The control program 204 stores a forced ventilation flag of "1" or "0" in memory 202 (S16, S17), and then determines whether the current contamination level stored in memory 202 in step S12 is equal to or greater than the threshold level stored in memory 202 (S18). The process in step S18 is performed for each room 20. The threshold level is, for example, "4". In other words, in step S18, it is determined whether or not ventilation with outside air is necessary. The threshold level is an example of a contamination threshold.

[0138] Alternatively, instead of step S18, it may be determined whether the latest carbon dioxide concentration in the exhaust ducts 31 and 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, the process in step S18 may be determined using a standardized pollution level or using raw data.

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

[0140] If the control program 204 determines that the current contamination level is not above the threshold level (S18: No), it stores a normal ventilation flag of "0" in memory 202, associating it with the room ID (S20).

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

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

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

[0144] Memory 202 pre-stores control pattern numbers that are executed at the start of ventilation control processing. At the start of ventilation control processing, the control program 204 drives the controlled object with control values ​​corresponding to the control pattern numbers pre-stored in memory 202.

[0145] [Forced ventilation] Figure 5 shows a state where forced ventilation is being performed in the first room 21 and normal ventilation is being performed in the second room 22.

[0146] For example, if the control program 204 obtains a control pattern number "4" with a forced ventilation flag of "1" set for the first room 21 (S16, S22), the forced ventilation shown in Figure 5 will be performed.

[0147] Forced ventilation occurs in three cases: when the forced ventilation flag of "1" is set for the first room 21 and the forced ventilation flag of "0" is set for the second room 22; when the forced ventilation flag of "1" is set for the second room 22 and the forced ventilation flag of "0" is set for the first room 21; and when the forced ventilation flag of "1" is set 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 subjected to forced ventilation.

[0148] When forced ventilation is performed in one room 20, the type of forced ventilation differs depending on whether or not the other room 20 is ventilated. Furthermore, when the other room 20 is ventilated, the type of forced ventilation also differs depending on the difference in the fan rotation speed level. In other words, there are multiple control pattern numbers other than "4" that indicate forced ventilation.

[0149] Based on the control values ​​of each controlled object associated with the control pattern number "4", the control program 204 stops the first exhaust fan 111, drives the second exhaust fan 112 and the supply fan 120 with the above drive amount, stops the circulation fans 131 and 132, drives the first forced exhaust fan 141, stops 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 flow path switching valve 100 to the second switching position.

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

[0151] Furthermore, since the air supply 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 room 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, thus preventing energy loss.

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

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

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

[0155] [Normal ventilation] Figure 6 shows the state in which normal ventilation is performed in the first room 21 and the second room 22.

[0156] For example, if the control program 204 obtains a control pattern number "1" in which a forced ventilation flag of "0" and a normal ventilation flag of "1" are set for the first room 21 and the second room 22 (S19), normal ventilation as shown in Figure 6 will be performed. Note that in addition to "1", there are several other control pattern numbers that indicate normal ventilation, which differ in the fan rotation speed level.

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

[0158] In the state shown in Figure 6, the air in the first room 21 and the second room 22 is discharged to the outside through exhaust ducts 31 and 32, and outside air that has undergone heat exchange with the air discharged to the outside via the heat exchanger 12 flows into the first room 21 and the second room 22. In other words, normal ventilation through the heat exchanger 12 is performed in the first room 21 and the second room 22.

[0159] The process in which the control program 204 drives each controlled object with the control value indicated by the control pattern number "1" associated with the normal ventilation flag "1" (S19, S23) is an example of normal ventilation processing. Normal ventilation processing is performed when the detected humidity or carbon dioxide concentration level is above the threshold level, cannot be used for ventilation of other rooms 20, and ventilation with outside air is necessary.

[0160] [Inter-room ventilation] Figure 7 shows a state where 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 where ventilation through the heat exchanger 12 is not performed. Inter-room ventilation is performed when there is a difference in the pollution levels of the two rooms 20, and the pollution levels of the two rooms 20 are relatively low. For example, if the pollution level of the first room 21 is higher than the outside air or the above standard 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, then the inter-room ventilation shown in Figure 7 will be performed.

[0161] For example, if the control program 204 obtains a control pattern number "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), then the inter-room ventilation shown in Figure 7 is performed.

[0162] In addition to "2," there are several other control pattern numbers that indicate inter-room ventilation, each with a different fan rotation speed level.

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

[0164] In the inter-room ventilation shown in Figure 7, the pollution levels (humidity, carbon dioxide concentration) of the first room 21 and the second room 22 are averaged. Furthermore, since the temperature-controlled air is not discharged to the outside, there is zero 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 controlled object 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 contamination level, according to the detected humidity or carbon dioxide concentration, is below the threshold level in all rooms 20.

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

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

[0168] Combined ventilation occurs in two cases: when the normal ventilation flag "1" is set for the first room 21 and the normal ventilation flag "0" is set for the second room 22; and when the normal ventilation flag "1" is set for the second room 22 and the normal ventilation flag "0" is set for the first room 21. In other words, the type of combined ventilation is determined by the normal ventilation flag. The type of combined ventilation is also determined by the difference in the fan rotation speed level. In short, there are multiple control pattern numbers other than "3" that indicate combined ventilation.

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

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

[0171] Furthermore, 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, energy loss in the second room 22 will be large. In that case, a control pattern will be selected in which normal ventilation is performed for the first room 21 and ventilation is stopped for the second room 22. In other words, the optimal control pattern will be selected according to the temperature level of each room 20 in order to minimize energy loss.

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

[0173] As shown in Figure 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 based on whether or not a stop instruction has been input or whether or not the termination time has arrived.

[0174] If the control program 204 determines that it will not terminate (S24: No), it will execute the processes from step S11 onwards again. If the control program 204 determines that it will terminate (S24: Yes), it will terminate the ventilation control process (end).

[0175] [Effects and Effects] In this embodiment, when it is determined that condensation is occurring in the exhaust duct 31 (S15 in Figure 4: Yes), the valve on the exhaust duct 31 side is closed, and the valve on the forced exhaust duct 61 side is opened, driving the forced exhaust fan 141. The valve on the supply air duct 41 side is also closed. The driven forced exhaust fan 141 discharges the air inside the room 21 to the outside through the forced exhaust duct 61. As a result, condensation inside the exhaust duct 31 is prevented. Also, since the valve on the supply air duct 41 side is closed during forced ventilation, the discharge of air regulated by the heat exchanger 12 to the outside through the forced exhaust duct 61 is suppressed. 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. Based on the fact that the temperature inside the exhaust duct 31 has reached a threshold temperature corresponding to the dew point temperature, the control program 204 exhausts the air inside the room 21 directly to the outside without passing through the exhaust duct 31 (see Figure 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, which is installed for temperature control and ventilation of the room 21, to determine whether or not condensation occurs in the exhaust duct 31. In other words, the ventilation system 10 can prevent condensation in the exhaust duct 31 without installing a new sensor to detect condensation separately from the temperature and humidity sensor 151.

[0178] In addition to normal ventilation (see Figure 6), the ventilation system 10 performs circulating ventilation using circulating ducts 51 and 52 (inter-room ventilation (see Figure 7) and combined ventilation (see Figure 8)). 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 Figure 6) when the pollution levels in both the first room 21 and the second room 22 are above the threshold level, and performs inter-room ventilation (see Figure 7) or combined ventilation (see Figure 8) when the pollution level in at least one of the first room 21 and the second room 22 is below the threshold level. Therefore, the ventilation system 10 can improve energy efficiency while maintaining a low level of air pollution in room 20.

[0180] The control pattern determination table (see Figure 3(A)) includes a field where a temperature level indicating the difference between the outside temperature and the temperature of room 20 is registered. In other words, the control pattern is determined based on the difference between the outside temperature and the temperature of room 20. For example, if the difference between the outside temperature and the temperature inside room 20 is small, energy loss is small even if normal ventilation is performed through the heat exchanger 12. In that case, normal ventilation is prioritized, and the air inside room 20 is exchanged with outside air, maintaining the humidity and carbon dioxide concentration in room 20 at low levels. If the difference between the outside temperature and the temperature inside room 20 is large, a considerable amount of energy loss occurs when normal ventilation is performed through the heat exchanger 12. In that case, inter-room ventilation or combined ventilation is prioritized over normal ventilation, reducing energy loss while maintaining the humidity and carbon dioxide concentration in room 20 at the required levels. In other words, by determining the control pattern based on the difference between the outside temperature and the temperature inside room 20, energy loss can be reduced more effectively.

[0181] [Example 1] In the embodiment, an example was 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. In the embodiment, an example was described in which flow path switching valves 91, 92, and 100 are used. In this modified example, an example is described in which the first forced exhaust duct 211 is directly connected to the first room 21 and the second forced exhaust duct 212 is directly connected to the second room 22, and various on-off valves are used instead of flow path switching valves 91, 92, and 100.

[0182] Configurations other than those described below are the same as those described in the embodiments. Configurations identical to those in the embodiments are denoted by the same reference numerals as in the embodiments.

[0183] In this modified example, the ventilation system 14 shown in Figure 9 is described. The ventilation system 14 is attached to a building 11 having multiple rooms 20. In the example shown in Figure 9, the multiple rooms 20 are the first room 21 and the second room 22.

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

[0185] The various ducts include exhaust ducts 31, 32, supply 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 through 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 through 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) to the outside.

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

[0189] The on-off valves 221, 222, and 223 are used in place of the first exhaust flow path switching valve 91. On-off valve 221 is provided in the first exhaust duct 31. On-off valve 221 opens and closes the exhaust flow path formed by the first exhaust duct 31. On-off valve 222 is provided in the first circulation duct 51. On-off valve 222 opens and closes the circulation flow path formed by the first circulation duct 51. On-off valve 223 is provided in the first forced exhaust duct 211. 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. On-off valve 231 is provided in the second exhaust duct 32. On-off valve 231 opens and closes the exhaust flow path formed by the second exhaust duct 32. On-off valve 232 is provided in the second circulation duct 52. On-off valve 232 opens and closes the circulation flow path formed by the second circulation duct 52. On-off valve 233 is provided in the second forced exhaust duct 212. 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 and 242 are provided in place of the air supply flow path switching valve 100. On-off valve 241 is provided in the first air supply duct 41. On-off valve 241 opens and closes the air supply flow path formed by the first air supply duct 41. On-off valve 242 is provided in the second air supply duct 42. On-off valve 242 opens and closes the air supply flow path formed by the second air supply duct 42.

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

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

[0194] Even if the forced exhaust passages 211 and 212 are directly connected to rooms 21 and 22, condensation in the exhaust ducts 31 and 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 still be performed.

[0196] [Other variations] In the embodiment, an example was described in which the control device 200 determines whether to perform forced ventilation, normal ventilation, inter-room ventilation, or combined ventilation, and controls the drive of controlled objects such as switching valves 91, 92, and 100. However, the control device 200 may simply determine whether or not to perform forced ventilation and control the drive of the flow path switching valves 91, 92 and forced exhaust fans 141, 142. In that case, the control processing for performing ventilation is performed by another control device. The control device 200 intercepts the ventilation control processing performed by the other control device and controls the drive of the flow path switching valves 91, 92 and forced exhaust fans 141, 142 to perform forced ventilation. Furthermore, if the control device 200 only performs forced ventilation, the number of rooms 20 that the control device 200 controls whether or not to perform forced ventilation may be one or multiple.

[0197] In the embodiment, an example was described in which the control device 200 controls the driving of both the various fans and the various switching valves. However, the various fans may be driven continuously, and the control device 200 may control only the driving 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 control device 200 may control only the driving of the switching valves 91, 92, and 93.

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

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

[0200] In the embodiment described, an example was 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 be connected at one end to the first chamber 21 and at the other end to the second chamber 22 or the second supply air duct 42. Similarly, the second circulation duct 52 may be connected at one end to the second chamber 22 and at the other end to the first chamber 21 or the first supply air duct 41.

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

[0202] In the embodiments described, the ventilation system 10 is shown to perform normal ventilation (see Figure 6), inter-room ventilation (see Figure 7), and combined ventilation (see Figure 8). However, the ventilation system 10 may perform normal ventilation (see Figure 6) and combined ventilation (see Figure 8) without performing inter-room ventilation. In other words, the ventilation system 10 may always perform a minimum amount of ventilation with the outside air.

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

[0204] In the embodiment, an example was described in which each sensor of the CO2 sensor group 160 is installed inside the duct. However, each sensor of the CO2 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 was described in which one control pattern is determined based on "contamination level," "state," "current ventilation rate," "temperature level," "forced ventilation flag," and "normal ventilation flag." However, from the "contamination level," etc., multiple control patterns capable of maintaining a low contamination level in each room 20 may be determined, and from the multiple determined control patterns, the control pattern with the lowest ventilation rate to the outside, i.e., the control pattern with the lowest energy loss, may be determined as the control pattern for ventilation.

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

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

[0208] [Note 1] Exhaust ducts that connect the rooms of a building to the outside, An exhaust fan is provided in the exhaust duct mentioned above, An air supply duct connecting the above-mentioned room to the outside, An air intake fan is installed in the above-mentioned air intake duct, A heat exchanger that performs heat exchange between the exhaust air from the exhaust duct and the supply air from the supply duct, A forced exhaust duct connecting the above room to the outside, A forced exhaust fan is installed in the forced exhaust duct mentioned above, A differential pressure air supply member installed in the wall of the above room, An exhaust duct valve is provided in the exhaust duct mentioned above, An air supply duct valve is provided in the above-mentioned air supply duct, A forced exhaust duct valve is provided in the above-mentioned forced exhaust duct, A sensor that detects information regarding condensation in the exhaust duct, It is equipped with a controller, The above controller is a ventilation system that, based on the output of the above sensor, closes the exhaust duct valve and the supply duct valve and opens the forced exhaust duct valve to perform a forced ventilation process.

[0209] [Note 2] The above sensor is a temperature and humidity sensor installed in the exhaust duct. The above controller is A dew point temperature acquisition process that acquires the dew point temperature corresponding to the temperature and humidity inside the exhaust duct detected by the above temperature and humidity sensor, Based on the temperature inside the exhaust duct detected by the temperature and humidity sensor, which has not reached the threshold temperature corresponding to the dew point temperature, the normal ventilation process involves opening the exhaust duct valve and the supply duct valve, and closing the forced exhaust duct valve. The ventilation system described in Appendix 1, which performs the forced ventilation process described above based on the fact that the temperature inside the exhaust duct described above has reached the threshold temperature described above.

[0210] [Note 3] The above-mentioned rooms include Room 1 and Room 2. The exhaust duct mentioned above is A first exhaust duct connecting the first room described above to the outside, The second room described above includes a second exhaust duct connecting the second room to the outside, The above air supply duct is A first air supply duct connecting the first room mentioned above to the outside, The second room mentioned above includes a second air supply duct connecting the second room to the outside, The above exhaust duct valve is, A first exhaust duct valve is provided in the first exhaust duct described above, The system includes a second exhaust duct valve provided in the second exhaust duct, The above air intake duct valve is, A first air supply duct valve is provided in the first air supply duct described above, The system includes a second air supply duct valve provided in the second air supply duct, The first exhaust duct and the second supply duct are connected, and a first circulation duct equipped with a first circulation fan is provided, The system further comprises a second circulation duct, which connects the second exhaust duct and the first supply air duct, and is equipped with a second circulation fan. The first exhaust duct valve described above is a flow path switching valve provided at the connection point between the first exhaust duct and the first circulation duct. The second exhaust duct valve described above is a flow path switching valve provided at the connection point between the second exhaust duct and the second circulation duct. The above controller is The ventilation system described in Appendix 1, which selectively performs a normal ventilation process using the first exhaust duct and the second exhaust duct, and a circulating ventilation process using at least one of the first circulating duct and the second circulating duct.

[0211] [Note 4] It is equipped with contamination detection sensors that detect values ​​related to the contamination level in each room. The above normal ventilation process is, This is executed on the condition that the value detected by the above contamination detection sensor is equal to or greater than the contamination threshold. The above circulating ventilation treatment is, The ventilation system described in Appendix 3 is executed on the condition that the value detected by the contamination detection sensor in at least one of the multiple rooms is below the contamination threshold.

[0212] [Note 5] The ventilation system as described in Appendix 4, wherein the above-mentioned contamination detection sensor is at least one of a temperature and humidity sensor and a carbon dioxide sensor.

[0213] [Note 6] It is equipped with an ambient temperature sensor that detects the outside temperature. The above recovery is A first temperature and humidity sensor is provided in the first exhaust duct described above, The system includes a second temperature and humidity sensor provided in the second exhaust duct, The above controller is The ventilation system described in Appendix 3, which determines the amount of ventilation between the first room and the second room and the outside air based on the outside temperature detected by the outside temperature sensor, the temperature inside the first exhaust duct detected by the first temperature and humidity sensor, and the temperature inside the second exhaust duct detected by the second temperature and humidity sensor, and then 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 rooms 21... Room 1 22...Second Room 31...First exhaust duct 32...Second exhaust duct 41...First air intake duct 42...Second air intake 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 intake flow switching valve 111...First exhaust fan 112...Second exhaust fan 120... Intake fan 131...First circulating fan 132...Second circulation fan 141...First forced exhaust fan 142...Second forced exhaust fan 151...Temperature and humidity sensor for the first exhaust duct 152...Temperature and humidity sensor for the second exhaust duct 161...CO2 sensor for the first exhaust duct 162...CO2 sensor for the second exhaust duct 170... Outside temperature sensor 200...Management device 201···CPU 202...memory 204... Control Program 221, 222, 223... Shut-off valves 231, 232, 233... Shut-off valves 241, 242... Shut-off valves

Claims

1. An exhaust duct that connects the rooms of a building to the outside, An exhaust fan is provided in the exhaust duct mentioned above, An air supply duct connecting the above-mentioned room to the outside, An air intake fan is installed in the above-mentioned air intake duct, A heat exchanger that performs heat exchange between the exhaust from the exhaust duct and the supply air from the supply duct, A forced exhaust duct connects the above-mentioned room to the outside, A forced exhaust fan is installed in the forced exhaust duct mentioned above, A differential pressure air supply member installed in the wall of the above room, An exhaust duct valve is provided in the exhaust duct mentioned above, An air supply duct valve is provided in the above-mentioned air supply duct, A forced exhaust duct valve is provided in the above-mentioned forced exhaust duct, A sensor that detects information regarding condensation in the exhaust duct, It is equipped with a controller, The above controller determines whether condensation occurs in the exhaust duct based on the output of the above sensor, and based on the determination that condensation occurs, it closes the exhaust duct valve and the supply duct valve and opens the forced exhaust duct valve to perform a forced ventilation process.

2. The above sensor is a temperature and humidity sensor installed in the exhaust duct. The above controller is A dew point temperature acquisition process that acquires the dew point temperature corresponding to the temperature and humidity inside the exhaust duct detected by the above temperature and humidity sensor, Based on the temperature inside the exhaust duct detected by the temperature and humidity sensor, which has not reached the threshold temperature corresponding to the dew point temperature, the normal ventilation process involves opening the exhaust duct valve and the supply air duct valve, and closing the forced exhaust duct valve. The ventilation system according to claim 1, wherein, based on the determination that condensation occurs because the temperature inside the exhaust duct has reached the threshold temperature, the forced ventilation process is performed.

3. The above-mentioned rooms include the first room and the second room. The exhaust duct mentioned above is A first exhaust duct connecting the first room described above to the outside, The second room described above includes a second exhaust duct connecting the second room to the outside, The above air supply duct is A first air supply duct connecting the first room described above to the outside, The second room described above includes a second air supply duct connecting the second room to the outside, The above exhaust duct valve is, A first exhaust duct valve is provided in the first exhaust duct described above, The system includes a second exhaust duct valve provided in the second exhaust duct, The above air intake duct valve is, A first air supply duct valve is provided in the first air supply duct described above, The system includes a second air supply duct valve provided in the second air supply duct, The first exhaust duct and the second supply duct are connected, and a first circulation duct equipped with a first circulation fan is provided, The system further comprises a second circulation duct, which connects the second exhaust duct and the first supply air duct, and is equipped with a second circulation fan. The first exhaust duct valve described above is a flow path switching valve provided at the connection point between the first exhaust duct and the first circulation duct. The second exhaust duct valve described above is a flow path switching valve provided at the connection point between the second exhaust duct and the second circulation duct. The above controller is The ventilation system according to claim 1, which selectively performs a normal ventilation process using the first exhaust duct and the second exhaust duct, and a circulating ventilation process using at least one of the first circulating duct and the second circulating duct.

4. It is equipped with contamination detection sensors that detect values ​​related to the contamination level in each room. The above normal ventilation process is, This is executed on the condition that the value detected by the above contamination detection sensor is equal to or greater than the contamination threshold. The above circulating ventilation treatment is, The ventilation system according to claim 3, which is performed on the condition that the value detected by the contamination detection sensor in at least one of the multiple rooms is less than the contamination threshold.

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

6. It is equipped with an ambient temperature sensor that detects the outside temperature. The above recovery is A first temperature and humidity sensor is provided in the first exhaust duct described above, The system includes a second temperature and humidity sensor provided in the second exhaust duct, The above controller is The ventilation system according to claim 3, wherein the ventilation amount between the first room and the second room and the outside air is determined based on the outside temperature detected by the outside temperature sensor, the temperature inside the first exhaust duct detected by the first temperature and humidity sensor, and the temperature inside the second exhaust duct detected by the second temperature and humidity sensor, and the normal ventilation process and the circulating ventilation process are executed.

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