Control device, control unit, and control system

Abstract

To improve a recovery amount of solar radiation heat in a double layer window, in an air supply unit for introducing outside air into an object space via an air passage in the double layer window.SOLUTION: A control device configured to control the air supply unit (U1) is configured to, when an indicator indicating a temperature of the air in the air path (P) is a first indicator, determine whether the first indicator of the first double-layer window (21) is higher than the first indicator of the second double-layer window (22) or the first indicator of the first double-layer window (21) is equal to or higher than a first value; In addition, when the first index of the second double-layer window (22) is lower than the first value, a first mode of increasing the first air volume of the first double-layer window (21) more preferentially than the second double-layer window (22) is executed.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a control device, a control unit, and a control system. [Background technology]

[0002] The ventilation system disclosed in Patent Document 1 includes multiple windows with a double-skin structure, each having an outer glass and an inner glass. The ventilation system takes in outside air that passes between the outer and inner glass through the windows facing the sun, and expels indoor air that passes between the outer and inner glass through the windows facing the other directions. Taking in outside air through the windows facing the sun allows solar heat to be obtained, reducing the load on the air conditioning system. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-148038 Summary of the Invention [Problem to be solved by the invention]

[0004] The ventilation system described in Patent Document 1 switches between windows that let outside air into the indoor space and windows that exhaust indoor air to the outside based on data calculated from the amount of solar radiation on each window surface throughout the year. However, this method of switching windows does not sufficiently recover solar heat from windows exposed to sunlight, and there is room for improvement in the method of recovering solar heat.

[0005] An object of the present disclosure is to improve the amount of solar heat recovered within a double-glazed window in an air supply unit that introduces outside air into a target space through an air passage within the double-glazed window. [Means for solving the problem]

[0006] The first aspect is a window unit (20) having a plurality of double-glazed windows (21, 22) each having an inner glass (21a) facing a target space (S) and an outer glass (21b) facing the outside of the room, wherein an air passage (P) communicating the target space (S) with the outside of the room is formed between the inner glass (21a) and the outer glass (21b); an air volume adjusting mechanism (29, 37) for adjusting a first volume of air passing through the air passage (P) of the double-layered window (21, 22); a control device for controlling an air supply unit (U1) including an air treatment device (30) that treats outside air and introduces the outside air into the target space (S) through the double-layered windows (21, 22), The window unit (20) includes a first double-layer window (21) and a second double-layer window (22), When an index indicating the temperature of the air in the air passage (P) is defined as a first index, The system has a first mode in which the first airflow rate of the first double-layer window (21) is increased preferentially over that of the second double-layer window (22) when the first index of the first double-layer window (21) is higher than the first index of the second double-layer window (22), or when the first index of the first double-layer window (21) is equal to or higher than a first value and the first index of the second double-layer window (22) is lower than the first value. It is a control device.

[0007] In the first embodiment, the first mode allows the air in the first double-layer window (21), which has a higher heat content than the second double-layer window (22), to be supplied to the air treatment unit (30). This reduces the loss of heat recovery due to solar radiation when introducing outside air through the window unit (20). For example, in winter, when the air treatment unit (30) performs heating operation, it is possible to supply relatively high-temperature outside air to the air treatment unit, thereby reducing the operating load of the air treatment unit (30).

[0008] The second aspect is the first aspect, The air conditioner has a second mode in which the first airflow rate of the second double-layer window (22) is reduced preferentially over that of the first double-layer window (21) when the first index of the first double-layer window (21) is higher than the first index of the second double-layer window (22), or when the first index of the first double-layer window (21) is equal to or higher than a first value and the first index of the second double-layer window (22) is lower than the first value.

[0009] In the second aspect, by combining the first mode and the second mode, it is possible to further reduce the operating load of the air treatment unit (30) while maintaining a constant ventilation rate for the room space (S). In other words, it is possible to reduce the operating load of the air treatment unit (30) while maintaining the designed ventilation rate.

[0010] The third aspect is the first or second aspect, When a first condition is met, the first mode is executed; The first condition is met when the total ventilation volume of the target space (S) through the window unit (20) is equal to or less than the target ventilation volume set for the target space (S), and the temperature of the air blown out by the air treatment unit (30) into the target space (S) or the temperature of the air in the target space (S) is equal to or less than the target air temperature set for the target space (S).

[0011] In the third aspect, by executing the first mode when the first condition is satisfied, the operating load on the air treatment unit (30) can be reduced and the inside air temperature of the target space (S) can be quickly brought closer to the target temperature. In addition to the above effects, by executing the first mode and the second mode, the ventilation volume of the target space (S) can be maintained at the design ventilation volume.

[0012] A fourth aspect is the first or second aspect, When a second condition is satisfied, the first mode is executed; The second condition is met when the current carbon dioxide concentration in the target space (S) is equal to or higher than the target carbon dioxide concentration set for the target space (S), and the temperature of the air blown out by the air treatment unit (30) into the target space (S) is equal to or lower than the target air temperature set for the target space (S).

[0013] In the fourth aspect, by executing the first mode when the second condition is satisfied, the operating load on the air treatment unit (30) can be reduced and the carbon dioxide concentration in the target space (S) can be kept equal to or lower than the target carbon dioxide concentration. In addition to the above effects, by executing the first mode and the second mode, the ventilation rate of the target space (S) can be maintained at the design ventilation rate.

[0014] A fifth aspect is the first or second aspect, When a third condition is met, the third mode is executed; The three conditions are met when the temperature difference between the first double-layer window (21) and the second double-layer window (22) exceeds a predetermined value. The third mode reduces the difference in air temperature between the air passage (P) of the first double-layer window (21) and the air passage (P) of the second double-layer window (22) so as to satisfy the target ventilation volume set for the target space (S).

[0015] In the fifth aspect, the air volume of each air passage (P) of the first double-layer window (21) and the second double-layer window (22) is determined so that the temperatures of the air passages (P) are the same, thereby making it possible to easily reduce the load on the air processing unit while maintaining the designed ventilation volume.

[0016] A sixth aspect is a control unit including the control device according to any one of the first to fifth aspects and a detection section (28) that detects the first index.

[0017] In a sixth aspect, a control unit can be provided that includes a control device and a detection section (28).

[0018] A seventh aspect is a control system including the control unit of the sixth aspect and the air volume adjustment mechanism (29, 37), wherein the control device (C) controls the air volume adjustment mechanism (29, 37).

[0019] In the seventh aspect, a control system including a control unit and an air volume adjustment mechanism (29, 37) can be provided. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a diagram schematically showing the configuration of a ventilation system according to this embodiment. [Figure 2] FIG. 2 is a vertical cross-sectional view of a double-layer window, schematically illustrating the configuration of the double-layer window. [Figure 3] FIG. 3 is a piping diagram of a refrigerant circuit of an air conditioner. [Figure 4] FIG. 4 is a block diagram showing the relationship between various devices in the ventilation system. [Figure 5] FIG. 5 is a flowchart showing the operation of the air supply unit. [Figure 6] FIG. 6 is a diagram schematically showing the configuration of a ventilation system according to the first modification. [Figure 7] FIG. 7 is a block diagram of the ventilation system of the first modification, which corresponds to FIG. [Figure 8] FIG. 8 is a flowchart corresponding to FIG. 5 of the first modified example. [Figure 9] FIG. 9 is a flowchart of the second modification, which corresponds to FIG. [Figure 10] FIG. 10 shows a graph for explaining how to obtain the air volume of each air passage in the operation of the air supply unit of the second modification. [Figure 11] FIG. 11 shows an example of data held by the control device in the air supply unit of the third modified example. [Figure 12] FIG. 12 is a flowchart of the third modification, which corresponds to FIG. [Figure 13]13A and 13B are graphs showing the relationship between T and Q to explain the third mode. (A) is a graph explaining the case where the third mode is not executed. (B) is a graph explaining the case where the third mode is executed. [Figure 14] FIG. 14 is a block diagram corresponding to FIG. 4, showing the configuration of a control unit according to the fourth modification. [Figure 15] FIG. 15 is a block diagram corresponding to FIG. 4, showing the configuration of a control system according to the fifth modification. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following embodiments and modifications are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or its uses. Furthermore, each configuration of each embodiment, modification, other example, etc. described below can be combined or partially substituted within the scope of the present invention.

[0022] (1) Ventilation system The ventilation system (1) shown in FIG. 1 ventilates an indoor space (S). The indoor space (S) is an example of a target space (S). The indoor space (S) may be, for example, an office or conference room in a building, a hotel guest room, or a banquet hall. The ventilation system (1) supplies outside air to the indoor space (S) based on a preset design ventilation volume, and also exhausts the indoor air to the outside. The ventilation system (1) includes an exhaust unit (U2), an air supply unit (U1), and a room temperature sensor (50).

[0023] (2) Exhaust unit The exhaust unit (U2) exhausts air from the indoor space (S) to the outside. The exhaust unit (U2) includes an exhaust duct (11) and an exhaust fan (12). The exhaust duct (11) connects the indoor space (S) to the outside. The exhaust fan (12) is disposed in the exhaust duct (11). The exhaust fan (12) transports the air in the exhaust duct (11).

[0024] (3) Air supply unit The air supply unit (U1) supplies outside air to the indoor space (S) and includes a window unit (20), a temperature sensor (28), a damper (29), an air conditioner (30), and an air supply duct (27).

[0025] (3-1) Window unit The window unit (20) has a plurality of double-layer windows (21, 22, 23). The window unit (20) of this embodiment has three double-layer windows (21, 22, 23): a first double-layer window (21), a second double-layer window (22), and a third double-layer window (23).

[0026] Each double-layer window (21, 22, 23) constitutes a window provided on a wall surface of the indoor space (S). Each double-layer window (21, 22, 23) is provided to face a different direction. In this embodiment, the first double-layer window (21) faces west, the second double-layer window (22) faces south, and the third double-layer window (23) faces east. Since each double-layer window (21, 22, 23) has the same structure, the following describes the configuration of the first double-layer window (21). In the following description, the three double-layer windows (21, 22, 23) may be referred to simply as double-layer windows (21, 22, 23) without being distinguished from one another.

[0027] The double-glazed windows (21, 22, 23) shown in Fig. 2 have an inner glass (21a) facing the interior space (S) and an outer glass (21b) facing the outside. The inner glass (21a) and the outer glass (21b) are arranged facing each other.

[0028] An air passage (P) is formed between the inner glass (21a) and the outer glass (21b). The air passage (P) is formed to extend in the vertical direction. The air passage (P) connects the interior space (S) to the outside. An air passage (P) is formed in each of the first double-layer window (21), the second double-layer window (22), and the third double-layer window (23). The air passage (P) of the first double-layer window (21) is referred to as the first air passage (P1), the air passage (P) of the second double-layer window (22) is referred to as the second air passage (P2), and the air passage (P) of the third double-layer window (23) is referred to as the third air passage (P3).

[0029] The double-layered windows (21, 22, 23) have an inlet (25) at one end of an air passage (P) and an outlet (26) at the other end of the air passage (P). The inlet (25) opens to the outside and takes in outside air into the air passage (P). The inlet (25) is provided at the bottom of the double-layered windows (21, 22, 23). The outlet (26) is provided at the top of the double-layered windows (21, 22, 23). The outlet (26) communicates with an air supply duct (27).

[0030] The air in the air passage (P) flows from the inlet (25) to the outlet (26). The inlet (25) may be provided at the lower end of the double-layered window (21, 22, 23). The outlet (26) may be provided at the upper end of the double-layered window (21, 22, 23).

[0031] (3-2) Air supply duct 1 and 2, the air supply duct (27) is connected to the double-layered windows (21, 22, 23). One end of the air supply duct (27) is connected to the outlet (26) of the air passage (P). Specifically, the air supply duct (27) has a first air supply duct (27a), a second air supply duct (27b), a third air supply duct (27c), and a fourth air supply duct (27d).

[0032] The inflow end of the first supply air duct (27a) is connected to the first double-layer window (21). The inflow end of the second supply air duct (27b) is connected to the second double-layer window (22). The inflow end of the third supply air duct (27c) is connected to the third double-layer window (23). The inflow end of the fourth supply air duct (27d) is connected to the outflow ends of the first to third supply air ducts (27a to 27c). The outflow end of the fourth supply air duct (27d) is connected to an indoor unit (30B) of the air conditioner (30) described below. In this way, the air in the first supply air duct (27a), the second supply air duct (27b), and the third supply air duct (27c) merges into the fourth supply air duct (27d). The air in the fourth supply air duct (27d) is transported to the indoor unit (30B).

[0033] (3-3) Temperature sensor The temperature sensor (28) detects the air temperature in the air passage (P) of the double-layered window (21, 22, 23). The temperature sensor (28) is an example of a detector (28) that detects a first index. The first index is an index that indicates the air temperature in the double-layered window (21, 22, 23). In the present embodiment, the first index is the air temperature in the air passage (P).

[0034] The temperature sensor (28) includes a first temperature sensor (28a), a second temperature sensor (28b), and a third temperature sensor (28c). The first temperature sensor (28a) is disposed in the first air passage (P1). The second temperature sensor (28b) is disposed in the second air passage (P2). The third temperature sensor (28c) is disposed in the third air passage (P3). In other words, the first temperature sensor (28a) detects the air temperature in the first air passage (P1). The second temperature sensor (28b) detects the air temperature in the second air passage (P2). The third temperature sensor (28c) detects the air temperature in the third air passage (P3).

[0035] (3-4) Damper The damper (29) is an air volume adjustment mechanism (29) that adjusts a first volume of air passing through the air passage (P) of the double-layered window (21, 22, 23). The damper (29) includes a first damper (29a), a second damper (29b), and a third damper (29c). The damper (29) constitutes a variable air volume (VAV).

[0036] The first damper (29a) is connected to the first air supply duct (27a). The air volume passing through the first air supply duct (27a) is adjusted by adjusting the opening of the first damper (29a). In other words, the first damper (29a) adjusts the air volume passing through the first air passage (P1) of the first double-layer window (21).

[0037] The second damper (29b) is connected to the second air supply duct (27b). The amount of air passing through the second air supply duct (27b) is adjusted by adjusting the opening of the second damper (29b). In other words, the second damper (29b) adjusts the amount of air passing through the second air passage (P2) of the second double-layer window (22).

[0038] The third damper (29c) is connected to the third air supply duct (27c). The volume of air passing through the third air supply duct (27c) is adjusted by adjusting the opening of the third damper (29c). In other words, the third damper (29c) adjusts the volume of air passing through the third air passage (P3) of the third double-layer window (23).

[0039] In this way, the amount of outside air supplied to the indoor unit (30B) can be adjusted by adjusting the opening of each damper (29). In other words, when the rotation speed of an indoor fan (37) of the indoor unit (30B), which will be described later, is constant, the amount of air supplied to the indoor space (S) can be adjusted by adjusting the opening of each damper (29).

[0040] (3-5) Air conditioning equipment As shown in FIGS. 1 and 3, the air conditioner (30) processes outside air and introduces the outside air into the indoor space (S) through the double-layered windows (21, 22, 23). In this manner, the air conditioner (30) conditions the indoor space (S). The air conditioner (30) has a refrigerant circuit (39) that performs a refrigeration cycle operation. The air conditioner (30) has an indoor unit (30B) disposed in the indoor space (S) and an outdoor unit (30A) disposed outside the room. The indoor unit (30B) and the outdoor unit (30A) are connected by a communication pipe that forms the refrigerant circuit (39). The air conditioner (30) is an example of an air processing unit (30).

[0041] (3-5-1) Outdoor unit The outdoor unit (30A) includes a compressor (31), an outdoor heat exchanger (32), an outdoor fan (33), an expansion valve (34), and a four-way selector valve (35). The compressor (31), the outdoor heat exchanger (32), the expansion valve (34), and the four-way selector valve (35) are connected to a refrigerant circuit (39).

[0042] The compressor (31) compresses the drawn refrigerant and discharges the compressed refrigerant. The compressor (31) is a rotary compressor whose operating frequency (number of rotations) is variable by an inverter device.

[0043] The outdoor heat exchanger (32) exchanges heat between the refrigerant and outdoor air. The outdoor fan (33) transports outdoor air to the outdoor heat exchanger (32).

[0044] The expansion valve (34) reduces the pressure of the refrigerant and is an electronic expansion valve whose opening is adjustable.

[0045] The four-way switching valve (35) switches the flow path of the refrigerant circuit (39). The four-way switching valve (35) switches between a first state indicated by a solid line in Fig. 3 and a second state indicated by a dashed line in Fig. 3. In the first state, the refrigeration cycle performs a cooling operation. In the second state, the refrigeration cycle performs a heating operation.

[0046] (3-5-2) Indoor unit The indoor unit (30B) includes an indoor heat exchanger (36), an indoor fan (37), and an outlet temperature sensor (38). The indoor unit (30B) blows out the air flowing in through the fourth air supply duct (27d) into the indoor space (S).

[0047] The indoor unit (30B) has an air inlet (not shown) and an air outlet (not shown). The air flowing through the fourth air supply duct (27d) is drawn into the air inlet. The air outlet blows the air into the indoor space (S). The indoor heat exchanger (36) and the indoor fan (37) are disposed in an air passage connecting the air inlet and the air outlet.

[0048] The indoor heat exchanger (36) is connected to the refrigerant circuit (39). The indoor heat exchanger (36) exchanges heat between the refrigerant and the indoor air. The indoor fan (37) transports the indoor air to the indoor heat exchanger (36). The rotation speed of the indoor fan (37) is variable.

[0049] The outlet temperature sensor (38) is provided at the outlet of the indoor unit (30B) and detects the temperature of the air blown out of the indoor unit (30B).

[0050] (3-5-3) Air conditioning control unit As shown in Fig. 4, the air conditioner (30) has an air conditioning control unit (C1). The air conditioning control unit (C1) includes an MCU (Micro Controller Unit), an electric circuit, and an electronic circuit. The MCU includes a CPU (Central Processing Unit), a memory, and a communication interface. The memory stores various programs to be executed by the CPU.

[0051] The air conditioning control unit (C1) controls the outdoor unit (30A) and the indoor unit (30B). Specifically, the air conditioning control unit (C1) controls the operation of the compressor (31), the outdoor fan (33), and the indoor fan (37), and the opening of the expansion valve (34).

[0052] (4) Room temperature sensor The room temperature sensor (50) is disposed in the room space (S) and detects the air temperature in the room space (S).

[0053] (5) Driving The air conditioner (30) performs cooling operation and heating operation. When the air conditioner (30) starts operation, at least one of the three dampers (29) opens, and outside air is drawn in through the double-glazed window (21, 22, 23) connected to the open damper (29). The drawn outside air is transported to the indoor unit (30B).

[0054] (5-1) Cooling operation In the cooling operation, the air conditioning control unit (C1) sets the four-way selector valve (35) to the first state. In the cooling operation, the operation of the compressor (31), the outdoor fan (33), and the indoor fan (37) is controlled, and the opening of the expansion valve (34) is adjusted.

[0055] During the cooling operation, the refrigerant circuit (39) performs a refrigeration cycle (cooling cycle) in which the outdoor heat exchanger (32) functions as a radiator and the indoor heat exchanger (36) functions as an evaporator.

[0056] (5-2) Heating operation In the heating operation, the air conditioning control unit (C1) sets the four-way selector valve (35) to the second state. In the heating operation, the air conditioning control unit (C1) operates the compressor (31), the outdoor fan (33), and the indoor fan (37), and adjusts the opening of the expansion valve (34).

[0057] During the heating operation, the refrigerant circuit (39) performs a refrigeration cycle (heating cycle) in which the indoor heat exchanger (36) functions as a radiator and the outdoor heat exchanger (32) functions as an evaporator.

[0058] (6) Control device The ventilation system (1) includes a control device (C) that controls the operation of the exhaust unit (U2) and the air supply unit (U1).

[0059] The control device (C) controls the operation of various devices of the air conditioner (30), the dampers (29), and the exhaust fan (12). The control device (C) receives temperature information detected by the temperature sensors (28), the discharge temperature sensor (38), and the room temperature sensor (50).

[0060] (7) Operation of the air supply unit The operation of the air supply unit (U1) performed during a period when the outdoor temperature is relatively low will be described below. The period when the outdoor temperature is relatively low is, for example, a period when the air conditioner (30) performs heating operation. In other words, the period when the outdoor temperature is relatively low is winter. The period when the outdoor temperature is relatively low is, for example, from October to March.

[0061] In this embodiment, a target temperature Tt of the air in the indoor space (S) is set. A target supply air volume Qt is set in advance for the indoor space (S). Note that, since the supply air volume and exhaust air volume for the indoor space (S) are the same, the ventilation volume for the indoor space (S) may be referred to as the supply air volume. In other words, the target supply air volume Qt is the target ventilation volume. Also, the target supply air volume Qt has the same meaning as the design ventilation volume or required ventilation volume. The design ventilation volume or required ventilation volume may be determined based on a known calculation method.

[0062] As will be described in detail later, the air supply unit (U1) executes the first mode when a first condition is met. The first condition is met when the total ventilation rate to the indoor space (S) by the window unit (20) is equal to or less than the target ventilation rate Qt set for the indoor space (S) and the temperature of the air blown out by the indoor unit (30B) to the indoor space (S) is equal to or less than the target air temperature Tt set for the indoor space (S). The operation of the air supply unit (U1) will be described with reference to FIG. 5.

[0063] In step S01, the control device (C) causes the air conditioner (30) to start a heating operation. The four-way selector valve (35) is set to the second state, and the refrigerant circuit (39) performs the second refrigeration cycle operation. At this time, the control device (C) controls the indoor fan (37) and the exhaust fan (12) to rotate at constant speeds. Hereinafter, the control device (C) controls the exhaust fan (12) so that the intake air volume and the exhaust air volume are equal to each other.

[0064] In step S02, the control device (C) adjusts the volume of air flowing through each air supply duct (27) to a preset volume. Specifically, the control device (C) controls the dampers (29a, 29b, 29c) to a preset opening degree. As a result, the outside air drawn into each double-glazed window (21, 22, 23) is supplied to the indoor unit (30B). The outside air supplied to the indoor unit (30B) is treated and then blown out into the room space (S).

[0065] Here, the volume of air blown out from the indoor unit (30B) into the indoor space (S) is the sum of the volumes of outside air drawn into the first double-layer window (21), the second double-layer window (22), and the third double-layer window (23). That is, if the volume of air flowing into the indoor unit (30B) through the first double-layer window (21) (first air volume) is Q1, the volume of air flowing into the indoor unit (30B) through the second double-layer window (22) is Q2, and the volume of air flowing into the indoor unit (30B) through the third double-layer window (23) is Q3, the total volume of air supplied to the indoor space (S) through the indoor unit (30B) is Q1 + Q2 + Q3. In the following description, the volume of air may also be referred to as the volume of air supplied.

[0066] In step S03, the control device (C) determines whether the total air supply volume (Q1+Q2+Q3) is greater than the target air supply volume Qt. If it is determined that the total air supply volume (Q1+Q2+Q3) is greater than the target air supply volume Qt (YES in step S03), the air supply volume (ventilation volume) is determined to be excessive, and step S04 is executed. If it is determined that the total air supply volume (Q1+Q2+Q3) is equal to or less than the target air supply volume Qt (NO in step S03), the air supply volume (ventilation volume) is determined to be appropriate, and step S05 is executed.

[0067] In step S04, the control device (C) reduces the opening of the dampers (29a, 29b, 29c) of the air supply ducts (27a, 27b, 27c) connected to the air passage (P1, P2, P3) having the lowest air temperature among the air passages (P) of the double-glazed windows (21, 22, 23). Thereafter, step S03 is executed again.

[0068] For example, assuming that the fully open state of the dampers (29) is 100%, the opening degree of the first damper (29a) is 45%, the opening degree of the second damper (29b) is 30%, and the opening degree of the third damper (29c) is 25%. If it is determined that the air temperature in the first air passage (P1) of the first double-layer window (21) is the lowest, the control device (C) adjusts the opening degree of the first damper (29a) to 40%. Thereafter, if it is determined again in step S04 that the target supply air flow rate Qt is greater than the supply air flow rate and if it is determined in step S05 that the air temperature in the first air passage (P1) of the first double-layer window (21) is the lowest, the control device (C) adjusts the opening degree of the first damper (29a) to 35%. In this way, the control device (C) gradually closes the dampers (29a, 29b, 29c) of the air supply ducts (27a, 27b, 27c) connected to the double-glazed windows (21, 22, 23) determined to have the lowest air temperature in the air passage (P) until it is determined that the target air supply rate Qt is equal to or less than the air supply rate. This preferentially reduces the air volume in the air passage (P) with the lowest air temperature, thereby preventing a reduction in the amount of heat recovered due to solar radiation when taking in outside air.

[0069] In step S05, the control device (C) determines whether or not the blown-out temperature Tsa, which is the temperature of the air blown out from the indoor unit (30B), is equal to or lower than the target temperature Tt. If it is determined that the blown-out temperature Tsa is equal to or lower than the target temperature Tt (YES in step S05), step S06 is executed. If it is determined that the blown-out temperature Tsa is higher than the target temperature Tt (NO in step S05), step S13 is executed.

[0070] In step S06, the control device (C) executes the first mode. In the first mode, the airflow rate (first airflow rate) of the air passages (P1, P2, P3) through which relatively high-temperature air flows among the air passages (P) of the three double-layered windows (21, 22, 23) is preferentially increased. In this embodiment, the airflow rate of the air passages (P1, P2, P3) of the double-layered windows (21, 22, 23) through which the air with the highest air temperature flows among the air passages (P1, P2, P3) of the three double-layered windows (21, 22, 23) is preferentially increased.

[0071] Specifically, in the first mode, the control device (C) preferentially increases the degree of opening of the dampers (29a, 29b, 29c) of the air supply ducts (27a, 27b, 27c) connected to the air passage (P1, P2, P3) having the highest air temperature among the air passages (P1, P2, P3) of the three double-glazed windows (21, 22, 23) over the other dampers (29a, 29b, 29c). For example, assuming that the air temperature in the first air passage (P1) is T1, the air temperature in the second air passage (P2) is T2, and the air temperature in the third air passage (P3) is T3, when the control device (C) determines that T2 is higher than T1 and T3, the control device (C) preferentially increases the degree of opening of the second damper (29b) over the first damper (29a) and the third damper (29c). In the above example, preferentially increasing the opening of the damper (29) means increasing the opening of only the second damper (29b) without changing the openings of the first damper (29a) and the third damper (29c). The opening of the damper (29) may also be controlled to increase in stages. For example, the opening of the damper (29) may be increased by 5% increments. In the above example, when the opening of the second damper (29b) is 35%, the opening of the second damper (29b) becomes 40% by executing the first mode.

[0072] In this way, the first condition is met when, in step S03, it is determined that the total air supply volume (Q1 + Q2 + Q3) is equal to or less than the target air supply volume Qt (NO in step S03), and, in step S05, it is determined that the blown-out temperature Tsa is equal to or less than the target temperature Tt (YES in step S05), and the first mode is executed.

[0073] In step S07, the control device (C) determines whether the total air supply amount (Q1+Q2+Q3) is equal to the target air supply amount Qt. If the total air supply amount (Q1+Q2+Q3) is equal to the target air supply amount Qt (YES in step S07), step S10 is executed. If the total air supply amount (Q1+Q2+Q3) is not equal to the target air supply amount Qt (NO in step S07), step S08 is executed. Note that in step S07, the determination may be YES even if the total air supply amount (Q1+Q2+Q3) is not strictly equal to the target air supply amount Qt. For example, if the total air supply amount (Q1+Q2+Q3) is within a predetermined range from the target air supply amount Qt, the determination in step S08 is YES. The predetermined range is, for example, a range of ±1 to 5% of the target air supply amount Qt.

[0074] In step S08, the control device (C) determines whether the total air supply amount (Q1+Q2+Q3) is higher than the target air supply amount Qt. If it is determined that the total air supply amount (Q1+Q2+Q3) is higher than the target air supply amount Qt (YES in step S08), step S09 is executed. If it is determined that the total air supply amount (Q1+Q2+Q3) is equal to or less than the target air supply amount Qt (NO in step S08), step S06 is executed again.

[0075] In step S09, the control device (C) executes the second mode. In the second mode, the airflow rate of the air passage (P) through which relatively low-temperature air flows, among the air passages (P) of the three double-layered windows (21, 22, 23), is preferentially reduced. In this embodiment, the airflow rate of the air passage (P) through which the lowest-temperature air flows, among the air passages (P) of the three double-layered windows (21, 22, 23), is preferentially reduced.

[0076] Specifically, in the second mode, the control device (C) preferentially reduces the opening degree of the damper (29) of the air supply duct (27) connected to the air passage (P) having the lowest air temperature among the air passages (P) of the three double-glazed windows (21, 22, 23) compared to the other dampers (29). For example, when T3 is lower than T1 and T2, the control device (C) preferentially reduces the opening degree of the third damper (29c) compared to the first damper (29a) and the second damper (29b). In the above example, preferentially reducing the opening degree of the damper (29) means reducing the opening degree of only the third damper (29c) without changing the opening degrees of the first damper (29a) and the second damper (29b). Alternatively, the opening degree of the damper (29) may be controlled to be reduced in stages. For example, the opening degree of the damper (29) may be reduced by 5% at a time. In the above example, when the opening degree of the third damper (29c) is 35%, the opening degree of the third damper (29c) becomes 30% by executing the second mode.

[0077] In step S10, the control device (C) determines whether the air temperatures in the air passages (P) connected to the dampers (29) whose opening degrees are equal to or greater than the first opening degree are the same. The first opening degree is, for example, 20%. If it is determined that the air temperatures in the air passages (P) connected to the dampers (29) whose opening degrees are equal to or greater than the first opening degree are the same (YES in step S10), step S11 is executed. If it is determined that the air temperatures in the air passages (P) connected to the dampers (29) whose opening degrees are equal to or greater than the first opening degree are not the same (NO in step S10), step S12 is executed.

[0078] In step S11, the control device (C) determines whether a predetermined time has elapsed since step S10 was executed. If it is determined that the predetermined time has elapsed (YES in step S11), step S13 is executed. If it is determined that the predetermined time has not elapsed (NO in step S11), step S11 is executed again.

[0079] In step S12, the control device (C) determines whether or not there is room to further increase the opening degree of the damper (29) connected to the air passage (P) excluding the air passage (P) with the lowest air temperature among the air passages (P) connected to the dampers (29) whose opening degree is greater than 0%. If it is determined that there is room to further increase the opening degree of the damper (29) (YES in step S12), step S05 is executed again, and the air volume distribution of each air passage (P) is readjusted. If it is determined that there is no room to further increase the opening degree of the damper (29) (NO in step S12), step S13 is executed. In this way, in step S12, it is determined whether or not the opening degree of the damper (29) can be readjusted.

[0080] In step S13, if there is a damper (29) whose opening degree is 0% (fully closed), the control device (C) sets the opening degree of the damper (29) to the first opening degree. If there is no damper (29) that is fully closed, step S13 is not executed. After execution of step S13, the control flow of the air supply unit (U1) ends. Note that step S03 may be executed again after execution of step S13.

[0081] (8) Features (8-1) Feature 1 In the air supply unit (U1) of this embodiment, the control device (C) executes a first mode in which the volume of air flowing through the air passage (P) having the highest air temperature among the air passages (P) of the three double-glazed windows (21, 22, 23) is increased preferentially over the volume of air flowing through the other air passages (P). During periods when heating operation is required (e.g., winter), the first mode is executed, thereby allowing a larger amount of outdoor air with a high heat content due to solar radiation to be taken into the air conditioner (30). This makes it possible to suppress a reduction in the amount of heat recovered when taking outdoor air into the air conditioner (30) compared to when the first mode is not executed, and to suppress an increase in the operating load of the air conditioner (30).

[0082] (8-2) Feature 2 In the air supply unit (U1) of this embodiment, the control device (C) executes a second mode in which the volume of air flowing through the air passage (P) having the lowest air temperature among the air passages (P) of the three double-layered windows (21, 22, 23) is reduced preferentially compared to the volume of air flowing through the other air passages.

[0083] By thus executing the second mode in addition to the first mode, it is possible to improve the effect of suppressing an increase in the operating load of the air conditioner (30) while keeping the ventilation amount of the room space (S) constant.

[0084] (8-3) Feature 3 In the air supply unit (U1) of this embodiment, the first mode is executed when a first condition is met. The first condition is met when the total amount of air supplied to the indoor space (S) by the window unit (20) (Q1+Q2+Q3) is equal to or less than a target amount of air supplied Qt set for the indoor space (S) and the temperature of the air blown out from the indoor unit (30B) to the indoor space (S) is equal to or less than the target air temperature set for the indoor space (S).

[0085] When the first condition is satisfied, the first mode can be executed to reduce the operating load of the air conditioner (30) and to quickly bring the inside air temperature of the indoor space (S) closer to the target temperature. In addition to the above effects, the first mode and the second mode can be executed to maintain the ventilation volume of the target space (S) at the design ventilation volume.

[0086] (9) Variations A modification of the ventilation system (1) of the above embodiment will be described below. Only the configurations different from the above embodiment will be described below.

[0087] (9-1) Variation 1 The ventilation system (1) of the first modification ventilates the indoor space (S) so that the carbon dioxide (CO2) concentration in the indoor space (S) becomes the design CO2 concentration.

[0088] As shown in Figures 6 and 7, the air supply unit (U1) of Modification 1 is provided with an indoor unit (30B) for each double-layer window (21, 22, 23). Specifically, the air supply unit (U1) includes a first double-layer window (21), a second double-layer window (22), a third double-layer window (23), a first indoor unit (30B1), a second indoor unit (30B2), a third indoor unit (30B3), a first air supply duct (27a), a second air supply duct (27b), and a third air supply duct (27c). The first double-layer window (21) is connected to the first indoor unit (30B1) via the first air supply duct (27a). The second double-layer window (22) is connected to the second indoor unit (30B2) via the second air supply duct (27b). The third double-glazed window (23) is connected to the third indoor unit (30B3) via the third air supply duct (27c). In this manner, three indoor units (30B1, 30B2, 30B3) are arranged in the indoor space (S). The total amount of air supplied to the indoor space (S) is the sum of the amounts of air blown out from the indoor units (30B1, 30B2, 30B3). An outdoor unit (30A) may be connected to each of the three indoor units (30B1, 30B2, 30B3), or one outdoor unit (30A) may be connected to each of the three indoor units (30B1, 30B2, 30B3). Each of the three indoor units (30B) is provided with an outlet temperature sensor (38). Specifically, the first indoor unit (30B1) is provided with a first blow-out temperature sensor (38a), the second indoor unit (30B2) is provided with a second blow-out temperature sensor (38b), and the third indoor unit (30B3) is provided with a third blow-out temperature sensor (38c).

[0089] The air volume adjustment mechanisms (37) of Modification 1 are the indoor fans (37) of the indoor units (30B1, 30B2, 30B3). Specifically, the air volume adjustment mechanisms (37) are the first indoor fan (37a) of the first indoor unit (30B1), the second indoor fan (37b) of the second indoor unit (30B2), and the third indoor fan (37c) of the third indoor unit (30B3).

[0090] The ventilation system (1) of the first modification includes a CO2 sensor (51). The CO2 sensor (51) detects the CO2 concentration in the indoor space (S). Note that hereinafter, CO2 may also be referred to as carbon dioxide.

[0091] The operation of the air supply unit (U1) of Modification 1 will be described. In Modification 1, a target CO2 concentration Ct of the air in the indoor space (S) is set. The target CO2 concentration Ct is a design CO2 concentration. Also, a target temperature Tt of the air in the indoor space (S) is set.

[0092] Although details will be described later, the air supply unit (U1) of Modification 1 executes the first mode when a second condition is met. The second condition is met when the current CO2 concentration in the indoor space (S) is equal to or higher than the target CO2 concentration set for the indoor space (S) and the temperature of the air blown out from the indoor units (30B1, 30B2, 30B3) into the indoor space (S) is equal to or lower than the target air temperature set for the indoor space (S). The operation of the air supply unit (U1) of Modification 1 will be described below with reference to FIG. 8.

[0093] In step S21, the control device (C) causes the air conditioner (30) to start the heating operation. The four-way selector valve (35) is set to the second state, and the refrigerant circuit (39) performs the second refrigeration cycle operation. At this time, the control device (C) controls the indoor fans (37a, 37b, 37c) and the exhaust fan (12) to rotate at constant speeds. Hereinafter, the control device (C) controls the exhaust fan (12) so that the amount of intake air and the amount of exhaust air are equal to each other.

[0094] In step S22, the control device (C) adjusts the volume of air flowing through each indoor fan (37) to achieve a preset volume of air supply. Specifically, the control device (C) controls each indoor fan (37) to achieve a preset rotation speed. As a result, outside air drawn through each double-glazed window (21, 22, 23) is supplied to the indoor unit (30B). The indoor unit (30B) blows the treated outside air into the indoor space (S).

[0095] In step S23, the control device (C) determines whether the target CO2 concentration Ct is higher than the current CO2 concentration Cc in the indoor space (S). If it is determined that the target CO2 concentration Ct is higher than the current CO2 concentration Cc in the indoor space (S) (YES in step S23), the amount of supplied air is determined to be excessive, and step S24 is executed. If it is determined that the target CO2 concentration Cc is equal to or lower than the current CO2 concentration Ct in the indoor space (S) (NO in step S23), the amount of supplied air is determined to be appropriate, and step S25 is executed.

[0096] In step S24, the control device (C) reduces the rotation speed of the indoor fan (37) of the indoor unit (30B) connected to the air passage (P) having the lowest air temperature among the air passages (P) of the double-glazed windows (21, 22, 23). Thereafter, step S23 is executed again.

[0097] For example, it is assumed that the rotation speed of the indoor fan (37) can be set to five levels (the minimum rotation speed is 1 and the maximum rotation speed is 5). It is assumed that the rotation speed of the first indoor fan (37a) is 3, the rotation speed of the second indoor fan (37b) is 4, and the rotation speed of the third indoor fan (37c) is 2. When it is determined that the air temperature in the first air passage (P1) of the first double-layer window (21) is the lowest, the control device (C) adjusts the rotation speed of the first indoor fan (37a) to 2. Thereafter, when it is determined again in step S23 that the target CO2 concentration Ct is higher than the current CO2 concentration Cc in the indoor space (S) and that the air temperature in the first air passage (P1) of the first double-layer window (21) is the lowest, the control device (C) adjusts the rotation speed of the first indoor fan (37a) to 1. In this way, the indoor fan (37) of the indoor unit (30B) connected to the double-layered window (21, 22, 23) that is determined to have the lowest air temperature in the air passage (P) is gradually reduced until it is determined that the target CO2 concentration is equal to or lower than the current CO2 concentration Ct in the indoor space (S).

[0098] In step S25, the control device (C) determines whether the blown-out temperature Tsa, which is the temperature of the air blown out from the indoor units (30B1, 30B2, 30B3), is equal to or lower than the target temperature Tt. If it is determined that the blown-out temperature Tsa is equal to or lower than the target temperature Tt (YES in step S25), step S26 is executed. If it is determined that the blown-out temperature Tsa is higher than the target temperature Tt (NO in step S25), step S33 is executed. The blown-out temperature Tsa may be the average of the temperatures of the air blown out from the three indoor units (30B1, 30B2, 30B3).

[0099] In step S26, the control device (C) executes the first mode. In this modification, in the first mode, the control device (C) increases the rotation speed of the indoor fan (37) of the indoor unit (30B) connected to the air passage (P) having the highest air temperature among the air flowing through the air passages (P) of the three double-glazed windows (21, 22, 23) preferentially over the other indoor fans (37). For example, when T2 is higher than T1 and T3, the control device (C) controls the rotation speed of the second indoor fan (37b) to be increased preferentially over the first indoor fan (37a) and the third indoor fan (37c). Increasing the rotation speed of the indoor fan (37) preferentially means, in the above example, increasing the rotation speed of only the second indoor fan (37b) without changing the rotation speeds of the first indoor fan (37a) and the third indoor fan (37c). Alternatively, the rotation speed of the indoor fan (37) may be controlled to increase in stages. For example, the rotation speed of the indoor fan (37) may be increased by one step at a time. In the above example, when the rotation speed of the second indoor fan (37b) is 3, the rotation speed of the second indoor fan (37b) becomes 4 by executing the first mode.

[0100] In this way, the first condition is met when it is determined in step S23 that the current CO2 concentration Cc is equal to or higher than the target CO2 concentration Ct (NO in step S23) and the blown-out temperature Tsa is equal to or lower than the target temperature Tt (YES in step S25), and the first mode is executed.

[0101] In step S27, the control device (C) determines whether the target CO2 concentration Ct is equal to the current CO2 concentration Cc of the indoor space (S). If the current CO2 concentration Ct of the indoor space (S) is equal to the target CO2 concentration (YES in step S27), step S30 is executed. If the current CO2 concentration Ct of the indoor space (S) is not equal to the target CO2 concentration (NO in step S27), step S28 is executed. Note that in step S27, the determination may be YES even if the current CO2 concentration Cc of the indoor space (S) is not strictly equal to the target CO2 concentration Ct. For example, if the current CO2 concentration Cc of the indoor space (S) is within a predetermined range from the target CO2 concentration Ct, step S27 is determined to be YES. The predetermined range is, for example, a range of ±0.1 to 1% of the target CO2 concentration Ct.

[0102] In step S28, the control device (C) determines whether the current CO2 concentration Cc in the indoor space (S) is lower than the target CO2 concentration Ct. If it is determined that the current CO2 concentration Cc in the indoor space (S) is lower than the target CO2 concentration Ct (YES in step S28), step S29 is executed. If it is determined that the current CO2 concentration Cc in the indoor space (S) is equal to or higher than the target CO2 concentration Ct (NO in step S28), step S26 is executed again.

[0103] In step S29, the control device (C) executes the second mode. In the second mode, the control device (C) reduces the rotation speed of the indoor fan (37) of the indoor unit (30B) connected to the air passage (P) having the lowest air temperature among the air passages (P) of the three double-glazed windows (21, 22, 23) preferentially over the other indoor fans (37). For example, when T3 is lower than T1 and T2, the control device (C) controls the rotation speed of the third indoor fan (37c) to be reduced preferentially over the first indoor fan (37a) and the second indoor fan (37b). In the above example, reducing the rotation speed of the indoor fan (37) preferentially means reducing the rotation speed of only the third indoor fan (37c) without changing the rotation speeds of the first indoor fan (37a) and the second indoor fan (37b). Alternatively, the rotation speed of the indoor fan (37) may be controlled to be reduced in stages. For example, the rotation speed of each indoor fan (37) may be reduced one by one. In the above example, when the rotation speed of the third indoor fan (37c) is 3, the execution of the second mode causes the rotation speed of the third indoor fan (37c) to become 2. After step S29 is executed, step S27 is executed again.

[0104] In step S30, the control device (C) determines whether the temperatures of the air passages (P) connected to the indoor units (30B) in which the indoor fans (37) are rotating are all the same. If it is determined that the temperatures of the air passages (P) connected to the indoor units (30B1, 30B2, 30B3) in which the indoor fans (37) are rotating are all the same (YES in step S30), step S32 is executed. If it is determined that the temperatures of the air passages (P) connected to the indoor units (30B) in which the indoor fans (37) are not all the same (NO in step S30), step S32 is executed.

[0105] In step S31, the control device (C) determines whether a predetermined time has elapsed since step S30 was executed. If it is determined that the predetermined time has elapsed (YES in step S31), step S33 is executed. If it is determined that the predetermined time has not elapsed (NO in step S31), step S31 is executed again.

[0106] In step S32, the control device (C) determines whether or not there is room for further increasing the rotation speed of the indoor fan (37) of the indoor unit (30B) connected to the air passages (P) of the double-glazed windows (21, 22, 23) connected to the operating indoor fan (37), excluding the air passage (P) with the lowest air temperature. If it is determined that there is room for further increasing the rotation speed of the indoor fan (37) (YES in step S32), step S25 is executed again, and the air volume distribution of each air passage (P) is readjusted. If it is determined that there is no room for further increasing the rotation speed of the indoor fan (37) (NO in step S32), step S33 is executed. In this way, in step S32, it is determined whether or not the rotation speed of the indoor fan (37) can be readjusted.

[0107] In step S33, if any indoor fan (37) is stopped, the control device (C) sets the rotation speed of the indoor fan (37) to the first rotation speed. If no indoor fan (37) is stopped, step S33 is not executed. After execution of step S33, the control flow of the air supply unit (U1) ends. Note that step S03 may be executed again after execution of step S33.

[0108] In this way, in the air supply unit (U1) of Modification 1, by executing the first mode when the second condition is satisfied, the operating load of the air conditioner (30) can be reduced and the carbon dioxide concentration in the indoor space (S) can be kept below the target carbon dioxide concentration. In addition to the above effects, by executing the first mode and the second mode, the ventilation volume of the indoor space (S) can be maintained at the design ventilation volume.

[0109] (9-2) Variation 2 The operation of the air supply unit (U1) of Modification 2 differs from that of the air supply unit (U1) of the above embodiment. The air supply unit (U1) of this modification determines the volume of air circulating through each double-glazed window (21, 22, 23) based on the relationship between the temperature and volume of air in each air passage (P) in the past.

[0110] The air supply unit (U1) of the second modification operates in a third mode in addition to the first and second modes. In the third mode, the difference in air temperature between the air passages (P1, P2, P3) of the two double-glazed windows (21, 22, 23) is reduced so as to satisfy a target air supply volume set for the indoor space (S). Specifically, the third mode reduces the difference in air temperature between the first air passage (P1) and the second air passage (P2), the difference in air temperature between the second air passage (P2) and the third air passage (P3), and the difference in air temperature between the third air passage (P3) and the first air passage (P1). The third mode is executed when a third condition is met. The third condition is met when the difference in air temperature between the air passages (P) of the two double-glazed windows (21, 22, 23) exceeds a predetermined value. The operation of the air supply unit (U1) of this modification will be described below with reference to FIG. 9.

[0111] In step S41, the control device (C) causes the air conditioner (30) to start the heating operation. The four-way selector valve (35) is set to the second state, and the refrigerant circuit (39) performs the second refrigeration cycle operation. At this time, the control device (C) controls the indoor fan (37) and the exhaust fan (12) to rotate at constant speeds. Hereinafter, the control device (C) controls the exhaust fan (12) so that the amount of intake air and the amount of exhaust air are equal to each other.

[0112] In step S42, the control device (C) adjusts the volume of air flowing through the first to third air supply ducts (27a, 27b, 27c) to a preset volume. Specifically, the control device (C) controls the dampers (29a, 29b, 29c) to have preset opening degrees. As a result, outside air drawn through the double-glazed windows (21, 22, 23) is supplied to the indoor unit (30B). The indoor unit (30B) processes the supplied outside air and then blows it out into the room space (S).

[0113] In step S43, the control device (C) detects the air temperature T in each air passage (P) and stores the air temperature T and the air volume Q at the time of detecting the air temperature T. Specifically, the control device (C) stores the air temperature T1 in the first air passage (P1) and the corresponding Q1, the air temperature T2 in the second air passage (P2) and the corresponding Q2, and the air temperature T3 in the third air passage (P3) and the corresponding Q3. The air volume Q is calculated based on the opening of the damper (29).

[0114] In step S44, the control device (C) determines whether the temperature difference between the two double-layer windows (21, 22, 23) is equal to or less than a predetermined value. Specifically, the control device (C) determines whether the temperature difference between the first double-layer window (21) and the second double-layer window (22), the second double-layer window (22) and the third double-layer window (23), and the third double-layer window (23) and the first double-layer window (21) is equal to or less than a predetermined value. The predetermined value is preferably as small as possible. For example, the predetermined value is a value between 0.1°C and 1°C. If it is determined that the temperature between the two double-layer windows (21, 22, 23) is within the predetermined range (YES in step S44), step S43 is executed again. If it is determined that the temperature between the two double-layer windows (21, 22, 23) is not within the predetermined range (NO in step S44), step S45 is executed.

[0115] In step S45, the control device (C) determines whether or not two or more points of data for T and corresponding Q have been stored for each air passage (P) in step S44. If the control device (C) has two or more points of T and Q (YES in step S45), step S47 is executed. If the control device (C) does not have two or more points of T and Q (NO in step S45), step S46 is executed.

[0116] In step S46, the control device (C) executes the first mode and the second mode, after which step S44 is executed again.

[0117] In step S47, the control device (C) determines the opening degree of each damper (29) based on the air temperature T, air flow rate Q, and target air supply rate Qt stored in step S44. Specifically, as shown in FIG. 10, a straight line indicating the correlation between Q and T is created based on the multiple Qs and Ts stored for each air passage (P1, P2, P3). The required air flow rates (target Q1, target Q2, target Q3) for each air passage (P) are calculated based on the correlation between Q and T created for each air passage (P), the fact that the total air supply rate (Q1+Q2+Q3) is equal to the target air supply rate Qt, and the fact that the air temperatures in each air passage (P1, P2, P3) are equal (T1=T2=T3). The opening degree of each damper (29) is determined based on the target Q1, target Q2, and target Q3. In this way, the third mode reduces the temperature difference (T1 = T2 = T3) in the air passages (P) of the two double-paned windows (21, 22, 23) so as to satisfy the target air supply volume set for the indoor space (S) (Qt = target Q1 + target Q2 + target Q3).

[0118] In step S48, the control device (C) adjusts the opening degree of each damper (29) to the opening degree determined in step S48. After step S48 is executed, step S43 may be executed again.

[0119] In this way, even in the second modification, the target ventilation volume can be easily maintained based on past data on the temperature T and air volume Q of the air passage (P) without using a device such as an actinometer, and the operating load of the air conditioner (30) can be reduced.

[0120] (9-3) Variation 3 The operation of the air supply unit (U1) of Modification 3 differs in part from the operation of the air supply unit (U1) of Modification 2. The third mode of Modification 3 is executed based on the air temperature T and air volume Q of each air passage (P) and the outside air temperature Toa. In this modification, the ventilation system (1) has an outside air temperature sensor (not shown) that detects the outside air temperature Toa.

[0121] The control device (C) has a plurality of predetermined data. The predetermined data shown in Fig. 11 is data indicating, for each air passage (P), the relationship between the difference ΔT between the air temperature T in each air passage (P) and the outside air temperature Toa on a certain date and time, and the air volume Q. The operation of the air supply unit (U1) of this modified example will be described below with reference to Fig. 12.

[0122] In step S51, the control device (C) causes the air conditioner (30) to start the heating operation. The four-way selector valve (35) is set to the second state, and the refrigerant circuit (39) performs the second refrigeration cycle operation. At this time, the control device (C) controls the indoor fan (37) and the exhaust fan (12) to rotate at constant speeds. Hereinafter, the control device (C) controls the exhaust fan (12) so that the amount of intake air and the amount of exhaust air are equal to each other.

[0123] In step S52, the control device (C) adjusts the volume of air flowing through the first to third air supply ducts (27a, 27b, 27c) to a preset volume. Specifically, the control device (C) controls the dampers (29) to open to preset degrees. As a result, outside air drawn through the double-glazed windows (21, 22, 23) is supplied to the indoor unit (30B). The indoor unit (30B) processes the supplied outside air and then blows it out into the room space (S).

[0124] In step S53, the control device (C) determines whether the temperature difference between the two double-layer windows (21, 22, 23) is equal to or less than a predetermined value. Specifically, the control device (C) determines whether the temperature difference between the first double-layer window (21) and the second double-layer window (22), the second double-layer window (22) and the third double-layer window (23), and the third double-layer window (23) and the first double-layer window (21) is equal to or less than a predetermined value. The predetermined value is preferably as small as possible. For example, the predetermined value is a value between 0.1°C and 1°C. If it is determined that the temperature between the two double-layer windows (21, 22, 23) is within the predetermined range (YES in step S53), step S52 is executed again. If it is determined that the temperature between the two double-layer windows (21, 22, 23) is not within the predetermined range (NO in step S53), step S54 is executed.

[0125] In step S54, the control device (C) selects one piece of data from a plurality of predetermined data based on the air temperature T and air volume Q in the air passage (P) at the current outside air temperature Toa.

[0126] In step S55, the control device (C) calculates the required airflow rates (Q1, Q2, Q3) for each air passage (P) based on the data for each selected air passage (P), the fact that the total air supply rate (Q1+Q2+Q3) is equal to the target air supply rate Qt, and the fact that the air temperatures in each air passage (P) are equal (T1=T2=T3). The opening degrees of each damper (29) are determined based on the calculated required airflow rates (Q1, Q2, Q3). In this way, even in the third mode of this modified example, the temperature difference between the air passages (P) of the two double-glazed windows (21, 22, 23) is reduced so as to satisfy the target air supply rate set for the indoor space (S).

[0127] In step S56, the control device (C) adjusts the opening degree of each damper (29) to the opening degree determined in step S55. After executing step S56, step S53 may be executed again. In this case, if it is determined in step S53 that the temperature between the two double-layer windows (21, 22, 23) is within the predetermined range (YES in step S53), step S51 is executed, and if it is determined that the temperature between the two double-layer windows (21, 22, 23) is not within the predetermined range (NO in step S53), the first mode and the second mode are executed. After the first mode and the second mode are executed, step S53 is executed again.

[0128] In this modified example, by executing the third mode, it is possible to supply outside air with a relatively large amount of heat due to solar radiation to the indoor unit (30B) while satisfying the target amount of air to be supplied to the indoor space (S). This will be described with reference to FIG. 12 as an example.

[0129] As shown in Figure 12, the target air supply rate is set to 1500 CMH. When the third mode is not executed (Figure 12(A)), 500 CMH of outside air is supplied to the indoor unit (30B) through each of the double-layer windows (21, 22, 23). In this case, outside air at 16°C is drawn through the first double-layer window (21), outside air at 34°C is drawn through the second double-layer window (22), and outside air at 7°C is drawn through the third double-layer window (23), so that outside air at an average of 19°C is supplied to the indoor unit (30B).

[0130] On the other hand, when the third mode is executed (FIG. 12(B)), 500 cmH of outside air is drawn in through the first double-layered window (21), 700 cmH of outside air is drawn in through the second double-layered window (22), and 300 cmH of outside air is drawn in through the third double-layered window (23), and thus outside air at an average temperature of 28°C is supplied to the indoor unit (30B).

[0131] As described above, in the third mode, the dampers (29) are adjusted so that the temperature of the outside air supplied to the indoor unit (30B) is increased while satisfying the target air supply rate for the indoor space (S). This makes it possible to easily maintain the target ventilation rate and reduce the operating load on the air conditioner (30).

[0132] (9-4) Variation 4 As shown in FIG. 14, the fourth modification is a control unit (CU) including the control device (C) and temperature sensors (28a, 28b, 28c) in the above-described embodiment and the first to third modifications.

[0133] (9-5) Variation 5 As shown in FIG. 15, Modification 5 is a control system (CS) including the control unit (CU) of Modification 4 and the air volume adjustment mechanisms (29, 37) of the above embodiment and Modifications 1 to 3. The control device (C) controls the air volume adjustment mechanisms (29, 37). In the above embodiment and Modifications 2 and 3, the air volume adjustment mechanisms (29, 37) are dampers (29). In Modification 1, the air volume adjustment mechanisms (29, 37) are first to third indoor fans (37c).

[0134] (10) Other embodiments In the above embodiment and each modification, the control device (C) may control only the air supply unit (U1). That is, the control device (C) may not control the exhaust unit (U2). In this case, the exhaust unit (U2) is controlled by a separate control unit, and the control device (C) communicates with that control unit. Furthermore, the control device (C) does not have to be integrated with the air conditioning control unit (C1), and does not have to control the air conditioner (30). In this case, the control device (C) communicates with the air conditioning control unit (C1).

[0135] The first mode may be executed when the difference in air temperature between the air passages (P) of the two double-layered windows (21, 22, 23) is equal to or greater than a predetermined value. Similarly, the second mode may be executed when the difference in air temperature between the air passages (P) of the two double-layered windows (21, 22, 23) is equal to or greater than a predetermined value.

[0136] The first mode may be a mode in which the double-layer windows (21, 22, 23) among the three double-layer windows (21, 22, 23) whose first index is equal to or greater than a first value are preferentially increased in first airflow rate over the double-layer windows (21, 22, 23) whose first index is lower than the first value. That is, when the first index is air temperature, the first airflow rate of the double-layer windows (21, 22, 23) whose air temperature is equal to or greater than a predetermined air temperature (first value) is preferentially increased over the first airflow rate of the double-layer windows (21, 22, 23) whose air temperature is lower than the predetermined air temperature (first value). The first value is a value that is set arbitrarily. When the first index is air temperature, the first value also indicates the air temperature.

[0137] The second mode may be a mode in which the first airflow rate is reduced preferentially for double-layer windows (21, 22, 23) among the three double-layer windows (21, 22, 23) whose first index is equal to or greater than a first value, and for double-layer windows (21, 22, 23) whose first index is lower than the first value. That is, when the first index is air temperature, the first airflow rate is reduced preferentially for double-layer windows (21, 22, 23) whose air temperature is lower than a predetermined air temperature (first value) compared to the first airflow rate for double-layer windows (21, 22, 23) whose air temperature is equal to or greater than a predetermined air temperature (first value). The first value is a value that is set arbitrarily. When the first index is air temperature, the first value also indicates the air temperature.

[0138] The window unit (20) may have two double-layer windows (21, 22, 23), or may have four or more double-layer windows (21, 22, 23). When the window unit (20) has two double-layer windows (a first double-layer window (21) and a second double-layer window (22)), the first mode increases the first airflow rate of the first double-layer window (21) preferentially over that of the second double-layer window (22) when the first index of the first double-layer window (21) is higher than the first index of the second double-layer window (22), or when the first index of the first double-layer window (21) is equal to or greater than a first value and the first index of the second double-layer window (22) is lower than the first value. In addition, in the second mode, when the first index of the first double-layer window (21) is higher than the first index of the second double-layer window (22), or when the first index of the first double-layer window (21) is equal to or greater than the first value and the first index of the second double-layer window (22) is lower than the first value, the first airflow rate of the second double-layer window (22) is reduced preferentially over that of the first double-layer window (21).

[0139] The first index may be any index that indicates the air temperature in the air passage (P) and is not limited to the temperature in the air passage (P) itself. The first index may be a temperature that correlates with the air temperature in the air passage (P). For example, the first index may be the temperature in the air supply duct (27) connected to each of the double-glazed windows (21, 22, 23). In this case, the temperature sensor (28) is disposed in the air supply duct (27).

[0140] The outside air may be the air outside the indoor space (S).

[0141] The indoor unit (30B) may have a humidifier (not shown) for humidifying the blown air. In this case, the temperature of the blown air may be calculated by subtracting a predetermined constant, which takes into account the humidification of the air, from the temperature of the intake air drawn into the indoor unit (30B). The temperature of the intake air may be a value detected by the temperature sensor (28).

[0142] In the above-described modified examples 2 and 3, the first mode does not have to be executed. In other words, in the above-described modified examples 2 or 3, only the third mode may be executed.

[0143] In the above embodiment and Modification 1, the temperature of the blown air may be room temperature. Specifically, in the operation of the air supply unit (U1) in the above embodiment, the control device (C) may determine in step S05 whether the room temperature is equal to or lower than the target temperature Tt. Also, in the operation of the air supply unit (U1) in Modification 1, the control device (C) may determine in step S25 whether the room temperature is equal to or lower than the target temperature Tt.

[0144] Although the embodiments and modifications have been described above, it will be understood that various modifications in form and detail are possible without departing from the spirit and scope of the claims. Furthermore, the above embodiments and modifications may be combined or substituted as appropriate as long as the functionality of the subject matter of this disclosure is not impaired. The terms "first," "second," etc., described above, are used to distinguish the terms to which these terms are attached, and do not limit the number or order of the terms. [Industrial Applicability]

[0145] As described above, the present disclosure is useful for control devices, control units, and control systems. [Explanation of symbols]

[0146] 20 Window Unit 21 First double-decker window 21, 22, 23 Double-glazed windows 21a Inner glass 21b Outer glass 22 Second double-decker window 28 Temperature sensor (detection part) 29,37 Air volume adjustment mechanism 30 Air conditioning equipment (air processing unit) C Control device P Air passage S. Indoor space (target space) U Air supply unit

Claims

1. a window unit (20) including a plurality of double-layered windows (21, 22, 23) each having an inner glass (21a) facing a target space (S) and an outer glass (21b) facing the outside of the room, wherein an air passage (P) communicating the target space (S) with the outside of the room is formed between the inner glass (21a) and the outer glass (21b); an air volume adjustment mechanism (29, 37) that adjusts a first volume of air passing through the air passage (P) of the double-layer window (21, 22, 23); a control device for controlling an air supply unit (U1) including an air treatment device (30) that treats outside air and introduces it into the target space (S) through the double-layered windows (21, 22, 23), The window unit (20) includes a first double-layer window (21) and a second double-layer window (22), When an index indicating the temperature of the air in the air passage (P) is defined as a first index, a first mode in which the first airflow rate of the first double-layer window (21) is increased preferentially over that of the second double-layer window (22) when the first index of the first double-layer window (21) is higher than the first index of the second double-layer window (22), or when the first index of the first double-layer window (21) is equal to or higher than a first value and the first index of the second double-layer window (22) is lower than the first value; Control device.

2. a second mode in which the first airflow rate of the second double-layer window (22) is reduced preferentially over that of the first double-layer window (21) when the first index of the first double-layer window (21) is higher than the first index of the second double-layer window (22), or when the first index of the first double-layer window (21) is equal to or higher than a first value and the first index of the second double-layer window (22) is lower than the first value; The control device according to claim 1 .

3. When a first condition is met, the first mode is executed; The first condition is met when the total ventilation volume of the target space (S) through the window unit (20) is equal to or less than a target ventilation volume set for the target space (S), and the temperature of the air blown out by the air treatment unit (30) into the target space (S) or the temperature of the air in the target space (S) is equal to or less than a target air temperature set for the target space (S). The control device according to claim 1 or 2.

4. When a second condition is met, the first mode is executed; The second condition is met when the current carbon dioxide concentration in the target space (S) is equal to or higher than a target carbon dioxide concentration set for the target space (S), and the temperature of the air blown out from the air treatment unit (30) into the target space (S) is equal to or lower than the target air temperature set for the target space (S). The control device according to claim 1 or 2.

5. When a third condition is met, a third mode is executed; the third condition is satisfied when a temperature difference between the first double-layer window (21) and the second double-layer window (22) exceeds a predetermined value; the third mode reduces the difference in air temperature between the air passage (P) of the first double-layer window (21) and the air passage (P) of the second double-layer window (22) so as to satisfy a target ventilation volume set for the target space (S); The control device according to claim 1 or 2.

6. A control unit comprising: the control device according to claim 1 or 2; and a detection section (28) that detects the first indicator.

7. A control system comprising: the control unit according to claim 6; and the air volume adjustment mechanism (29, 37), wherein the control device (C) controls the air volume adjustment mechanism (29, 37).

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