Heat exchange ventilation system

Abstract

To provide a heat exchange type ventilation device that can comprehend whether indoor has positive pressure without deteriorating air supply efficiency.SOLUTION: A heat exchange type ventilation device includes: an air-supply air channel for transporting air sucked from outdoor through an outdoor side air-supply opening into indoor through an indoor side air-supply opening; an air supplying blower for transporting air from outdoor into indoor through the air-supply air channel; an exhaust air channel for transporting air sucked from indoor through the indoor side air-supply opening to outdoor through the outdoor side air-supply opening; an exhaust blower for transporting indoor air to outdoor through the exhaust air channel; a heat exchange element; a differential pressure detection part for detecting a differential pressure of air; and a determination part. The air supplying blower is installed downstream of the heat exchange element in the air-supply air channel. The exhaust blower is installed downstream of the heat exchange element in the exhaust air channel. The determination part determines whether indoor has positive pressure on the basis of an air amount discharged from the outdoor side air-supply opening and the differential pressure detected by the differential pressure detection part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a heat exchange type ventilation device. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there has been known a heat exchange type ventilation device that exchanges heat between supplied air and exhaust air during ventilation (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-100588 A Summary of the Invention [Problem to be solved by the invention]

[0004] Some conventional heat exchange type ventilation devices are controlled so that the volume of air exhausted to the outdoors (exhaust air volume) and the volume of air supplied to the indoors (supply air volume) are the same. However, due to air leakage from gaps in the air passage in the heat exchange type ventilation device, even if the air volumes of the exhaust fan and the supply fan are the same, the exhaust air volume and the supply air volume are not the same, and the exhaust air volume may exceed the supply air volume. When the exhaust air volume exceeds the supply air volume, the indoors becomes negative pressure relative to the outdoors. When the indoors becomes negative pressure, for example, in the summer in Japan, air with high temperature and humidity from the outdoors flows into the attic through gaps in the building. The air with high temperature and humidity that flows in is present outside the duct between the room and the heat exchange type ventilation device. In addition, the indoor air with low temperature that has been cooled by the indoor air conditioner is transported to the duct between the room and the heat exchange type ventilation device by the exhaust fan of the heat exchange type ventilation device. Therefore, low temperature air exists inside the duct. The cool air inside the duct cools the duct through thermal conduction. The temperature difference between the surface of the duct and the hot and humid air outside the duct can cause condensation on the duct surface. Condensation on the duct surface can lead to the growth of mold and dust mites, so it is necessary to prevent the indoor pressure from becoming negative compared to the outdoor pressure.

[0005] For example, suppose that the intake fan is disposed upstream of the heat exchange element in the intake air duct, and the exhaust fan is disposed downstream of the heat exchange element in the exhaust air duct. In this case, the air volume of the intake fan is made larger than that of the exhaust fan, thereby making the indoor pressure positive. In other words, by comparing the air volume of the intake fan and the air volume of the exhaust fan, it is possible to know whether the indoor pressure is positive or not.

[0006] However, it is preferable that the intake fan is provided downstream of the heat exchange element in the intake air duct. The reason why it is preferable that the intake fan is provided downstream of the heat exchange element in the intake air duct, rather than upstream of the heat exchange element, is that experiments have shown that the intake fan has better intake performance (intake efficiency) relative to the power consumption when provided at a position where air is expelled rather than at a position where air is sucked in. However, if the intake fan is provided downstream of the heat exchange element in the intake air duct, as described above, the exhaust air volume and the intake air volume will not be the same due to air leakage from gaps in the air flow path in the heat exchange type ventilation device, and there is a possibility that the exhaust air volume will exceed the intake air volume, even if the air volumes of the exhaust fan and the intake fan are the same.

[0007] SUMMARY OF THE PRESENT INVETION The present invention is devised to solve the above-mentioned problems of the conventional art, and aims to provide a heat exchange type ventilation device that can determine whether or not the indoor air is at positive pressure without reducing the air supply efficiency. [Means for solving the problem]

[0008] In order to achieve this object, the heat exchange type ventilation device of the present invention comprises an intake air duct for transporting air drawn in from the outdoors through an outdoor air intake port to the indoors through an indoor air intake port, an intake air blower for transporting the outdoor air to the indoors as an intake air flow through the intake air duct, an exhaust air duct for transporting the air drawn in from the indoors through an indoor exhaust port to the outdoors through an outdoor exhaust port, an exhaust air blower for transporting the indoor air to the outdoors as an exhaust air flow through the exhaust air duct, and a heat exchange element for exchanging heat between the intake air flow and the exhaust air flow. It is downstream of the outdoor air intake in the intake air duct and upstream of the heat exchange element. Air pressure and It is downstream of the exhaust fan in the exhaust air duct and upstream of the outdoor exhaust port. The system is equipped with a differential pressure detection unit that detects the pressure difference with the air pressure, and a judgment unit that judges whether the indoor pressure is positive or not, wherein the supply air blower is provided downstream of the heat exchange element in the supply air duct, and the exhaust air blower is provided downstream of the heat exchange element in the exhaust air duct, and the judgment unit judges whether the indoor pressure is positive or not based on the volume of air exhausted from the outdoor exhaust port by the exhaust air blower and the pressure difference detected by the differential pressure detection unit, thereby achieving the desired purpose. Effect of the Invention

[0009] According to the present invention, a heat exchange type ventilation device can be provided that can determine whether or not the indoor air is at positive pressure without reducing air supply efficiency. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of a heat exchange type ventilation device according to an embodiment of the present invention. [Diagram 2] 1 is a schematic functional block diagram of a heat exchange type ventilation device according to an embodiment of the present invention. [Diagram 3] 5 is a diagram showing a data structure of an air volume table stored in a storage unit according to the embodiment of the present invention; FIG. [Figure 4] 4 is a flowchart showing control in the heat exchange type ventilation device according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The embodiments of the present invention will be described with reference to the drawings. However, the embodiments shown below are merely examples for the purpose of embodying the technical concept of the present invention, and the present invention is not limited to the following. Unless otherwise specified, numerical values, materials, shapes, relative positions, etc. described in the embodiments are merely examples and are not intended to limit the scope of the present invention.

[0012] (Embodiment) First, a heat exchange type ventilation device 1 according to an embodiment of the present invention will be described. Fig. 1 is a schematic diagram of the heat exchange type ventilation device 1. The heat exchange type ventilation device 1 is a ventilation device that supplies and exhausts air to and from an indoor space and can be installed in the ceiling space, inside a side wall, or under the floor of a building, and has a function of exchanging heat during the supply and exhaust of air.

[0013] The heat exchange type ventilation device 1 performs ventilation while exchanging heat between air exhausted from indoors to outdoors (exhaust air flow 12 described later) and air supplied from outdoors to indoors (supply air flow 11 described later). For example, the heat exchange type ventilation device 1 performs ventilation and transfers heat of the supply air flow 11 to the exhaust air flow 12 during this ventilation, thereby suppressing unnecessary inflow of heat.

[0014] Here, the exhaust air flow 12 is a flow of air discharged from indoors to outdoors. The exhaust air flow 12 is transported from indoors to the heat exchange type ventilation device 1. The exhaust air flow 12, which has been heat exchanged with the intake air flow 11 by the heat exchange type ventilation device 1, is discharged from the heat exchange type ventilation device 1 to outdoors.

[0015] The intake air flow 11 is a flow of air that is supplied from outdoors to indoors. The intake air flow 11 is transported from outdoors to the heat exchange type ventilation device 1. The intake air flow 11 that has been heat exchanged with the exhaust air flow 12 by the heat exchange type ventilation device 1 is supplied indoors.

[0016] The heat exchange type ventilation device 1 is a device that performs ventilation while exchanging heat between indoor air RA (exhaust air flow 12) and outdoor air OA (supply air flow 11).

[0017] The heat exchange type ventilation device 1 includes an inside air inlet 4, an exhaust outlet 5, an outside air inlet 7, an intake air inlet 8, a heat exchange element 2, an exhaust blower 3, an intake air blower 6, a differential pressure detection unit 13, and a control unit 14.

[0018] The inside air port 4 is an intake port for taking in indoor air RA (exhaust air flow 12) into the heat exchange type ventilation device 1. The inside air port 4 communicates with the room inside the house by connecting to a duct (not shown). The inside air port 4 constitutes a part of the exhaust air duct 9. The inside air port 4 can also be said to be an indoor exhaust port.

[0019] The exhaust port 5 is an outlet for discharging the exhaust air flow 12 from the heat exchange type ventilation device 1 to the outdoors as exhaust air EA. The exhaust port 5 may be connected to the outdoors by being connected to a duct (not shown). The exhaust port 5 constitutes a part of the exhaust air passage 9. The exhaust port 5 can also be called an outdoor exhaust port.

[0020] The outside air port 7 is an intake port for taking in outdoor air OA (supply air flow 11) into the heat exchange type ventilation device 1. The outside air port 7 may be connected to the outdoors by being connected to a duct (not shown). The outside air port 7 constitutes a part of the supply air passage 10. The outside air port 7 can also be called an outdoor side supply air port.

[0021] The air intake port 8 is an outlet port for discharging the intake air flow 11 as intake air SA from the heat exchange type ventilation device 1 to the indoors. The air intake port 8 communicates with the room inside the building by connecting to a duct (not shown). The air intake port 8 constitutes a part of the intake air passage 10. The air intake port 8 can also be called an indoor side air intake port.

[0022] The heat exchange element 2 is a member for performing heat exchange between the exhaust air flow 12 and the intake air flow 11. The heat exchange may be sensible heat exchange, which exchanges temperature between the exhaust air flow 12 and the intake air flow 11, or total heat exchange, which performs both sensible heat exchange and latent heat exchange, which exchanges humidity between the exhaust air flow 12 and the intake air flow 11.

[0023] The heat exchange element 2 is a total heat exchange element formed of a heat transfer paper (heat transfer plate) based on cellulose fiber. However, the material is not limited to this. For example, a moisture-permeable resin film based on polyurethane or polyethylene terephthalate, or a paper material based on cellulose fiber, ceramic fiber, or glass fiber can be used as the heat transfer plate constituting the heat exchange element 2. In addition, the heat transfer plate constituting the heat exchange element 2 can be a thin sheet with heat conductivity and a property that gas does not permeate. In this case, the heat exchange element 2 becomes a sensible heat exchange element.

[0024] The exhaust blower 3 is a blower for taking in exhaust air flow 12 from the inside air port 4 and expelling it from the exhaust port 5. The exhaust blower 3 has an exhaust fan and an exhaust motor, not shown. The exhaust fan is a centrifugal impeller such as a sirocco fan. The exhaust motor supports the exhaust fan so that it can rotate. The exhaust motor is, for example, an alternating current motor (AC motor) or a direct current motor (DC motor). The exhaust blower 3 transports indoor air to the outdoors as exhaust air flow 12 via exhaust air duct 9.

[0025] The intake air blower 6 is a blower for taking in an intake air flow 11 from the outside air port 7 and expelling it from the intake air port 8. The intake air blower has an intake air fan and an intake air motor, not shown. The intake air fan is a centrifugal impeller such as an intake air sirocco fan. The intake air motor rotatably supports the intake air fan. The intake air motor is, for example, an alternating current motor (AC motor) or a direct current motor (DC motor). The intake air blower 6 transports outdoor air to the inside of the building as an intake air flow 11 via an intake air duct 10.

[0026] In addition, inside the heat exchange type ventilation device 1, an exhaust air duct 9 that communicates the inside air port 4 and the exhaust air duct 5, and an intake air duct 10 that communicates the outside air port 7 and the intake air duct 8 are formed. The exhaust air flow 12 sucked in by the exhaust fan 3 passes through the heat exchange element 2 and the exhaust fan 3 in the exhaust air duct 9, and is discharged from the exhaust air duct 5 to the outdoors. In addition, the intake air flow 11 sucked in by the intake fan 6 passes through the heat exchange element 2 and the intake fan 6 in the intake air duct 10, and is supplied from the intake air duct 8 to the indoors. In other words, the heat exchange type ventilation device 1 is provided with the intake air duct 10 for transporting the air sucked in from the outdoors through the outside air port 7 to the indoors through the intake air duct 8. In addition, the heat exchange type ventilation device 1 is provided with the exhaust air duct 9 for transporting the air sucked in from the indoors through the inside air port 4 to the outdoors through the exhaust air duct 5.

[0027] When performing heat exchange ventilation, the heat exchange ventilation device 1 operates the exhaust fan 3 and the intake fan 6, and exchanges heat between the exhaust airflow 12 flowing through the exhaust airflow 9 and the intake airflow 11 flowing through the intake airflow 10 in the heat exchange element 2. As a result, when performing ventilation, the heat exchange ventilation device 1 transfers the heat of the intake airflow 11 taken into the room to the exhaust airflow 12 discharged to the outside, suppressing the inflow of unnecessary heat. As a result, when performing ventilation in the summer in Japan, the indoor temperature rise can be suppressed by air with a high outdoor temperature. Also, when performing ventilation, the heat exchange ventilation device 1 transfers the heat of the exhaust airflow 12 discharged to the outside to the intake airflow 11 taken into the room, suppressing the release of unnecessary heat, and recovering heat indoors. As a result, when performing ventilation in the winter in Japan, the indoor temperature drop due to air with a low outdoor temperature can be suppressed.

[0028] Here, the intake fan 6 is provided downstream of the heat exchange element 2 in the intake air passage 10. Specifically, the intake fan 6 is provided downstream of the heat exchange element 2 in the intake air passage 10 and upstream of the intake port 8. The reason why the intake fan 6 is provided downstream of the heat exchange element 2 in the intake air passage 10, rather than upstream of the heat exchange element 2, is because it has been found through experiments that the intake fan 6 has better intake performance (intake efficiency) relative to power consumption when provided at a position where air is expelled, rather than at a position where air is sucked in. That is, in order to improve the intake efficiency, the intake fan 6 is provided downstream of the heat exchange element 2 in the intake air passage 10.

[0029] Moreover, the exhaust fan 3 is provided downstream of the heat exchange element 2 in the exhaust air duct 9. Specifically, the exhaust fan 3 is provided downstream of the heat exchange element 2 in the exhaust air duct 9 and upstream of the exhaust port 5. The reason why the exhaust fan 3 is provided downstream of the heat exchange element 2 in the exhaust air duct 9, rather than upstream of the heat exchange element 2, is because it has been found through experiments that the exhaust performance (exhaust efficiency) of the exhaust fan 3 relative to the power consumption is better when the exhaust fan 3 is provided at a position where air is expelled, rather than at a position where air is sucked in. That is, in order to improve exhaust efficiency, the exhaust fan 3 is provided downstream of the heat exchange element 2 in the exhaust air duct 9.

[0030] The differential pressure detection unit 13 detects the pressure difference between a first pressure P1 which is the pressure of air near the outside air port 7 and a second pressure P2 which is the pressure of air near the exhaust port 5. The vicinity of the outside air port 7 is specifically downstream of the outside air port 7 in the supply air duct 10 and upstream of the heat exchange element 2. The vicinity of the exhaust port 5 is specifically downstream of the exhaust fan 3 in the exhaust air duct 9 and upstream of the exhaust port 5. The differential pressure detection unit 13 is, for example, a micro-differential pressure sensor.

[0031] The control unit 14 is electrically connected to the exhaust fan 3, the supply fan 6, and the differential pressure detection unit 13 so as to be able to communicate with each other, and controls the heat exchange type ventilation device 1. The control content of the control unit 14 will be described later.

[0032] Next, each function of the control unit 14 according to the embodiment of the present invention will be described with reference to Fig. 2. Fig. 2 is a schematic functional block diagram of the control unit 14 and its peripheral parts.

[0033] The control unit 14 includes an air volume acquisition unit 16 , an exhaust fan control unit 21 , an intake fan control unit 19 , a memory unit 17 , an intake air volume acquisition unit 18 , and a determination unit 20 .

[0034] The air volume acquisition unit 16 acquires set air volume information input to the air volume input unit 15. The set air volume is the ventilation air volume desired by the user. The ventilation air volume desired by the user specifically refers to the supply air volume of the supply air flow 11 at the outside air port 7 desired by the user and the exhaust air volume of the exhaust air flow 12 at the exhaust port 5 desired by the user. The supply air volume of the supply air flow 11 at the outside air port 7 desired by the user and the exhaust air volume of the exhaust air flow 12 at the exhaust port 5 desired by the user are both set to the same set air volume.

[0035] The air volume input unit 15 is provided in a terminal into which the user can input set air volume information. The terminal into which the set air volume information can be input is, for example, a smartphone or a remote controller installed on an indoor wall, and is capable of communicating with the control unit 14 via wireless communication or wired communication.

[0036] The exhaust fan control unit 21 controls the air volume of the exhaust fan 3 so that the set air volume acquired by the air volume acquisition unit 16 is blown from the exhaust fan 3. The supply fan control unit 19 controls the air volume of the supply fan 6 so that the set air volume acquired by the air volume acquisition unit 16 is blown from the supply fan 6.

[0037] The memory unit 17 is a so-called memory that stores an air volume table that associates the exhaust air volume of the exhaust flow 12 at the exhaust port 5, the pressure difference between the first pressure P1 and the second pressure P2, and the supply air volume of the supply air flow 11 at the outside air port 7.

[0038] The air volume table will be described with reference to FIG. 3. FIG. 3 is a diagram showing the data structure of the air volume table stored in the storage unit 17, and is an example of the air volume table. The pressure difference in the case of a predetermined exhaust air volume and a predetermined supply air volume is measured by experiment in advance using the air volume measurement device and the differential pressure detection unit 13, and the pressure difference corresponding to the predetermined exhaust air volume and the predetermined supply air volume is stored in the air volume table as a measurement result. The air volume measurement device is a device capable of measuring air volume. In this embodiment, as an example, if the exhaust air volume is 250 [cubic meters / h] and the supply air volume is 100 [cubic meters / h], the pressure difference is A [Pa]. Also, if the exhaust air volume is 250 [cubic meters / h] and the supply air volume is 150 [cubic meters / h], the pressure difference is B [Pa]. Also, if the exhaust air volume is 250 [cubic meters / h] and the supply air volume is 200 [cubic meters / h], the pressure difference is C [Pa]. Also, if the exhaust air volume is 250 [cubic meters / h] and the supply air volume is 250 [cubic meters / h], the pressure difference is D [Pa]. Also, if the exhaust air volume is 250 [cubic meters / h] and the supply air volume is 300 [cubic meters / h], the pressure difference is E [Pa]. The pressure differences are A, B, C, D, and E in descending order. That is, the storage unit 17 stores in the air volume table the pressure differences corresponding to each supply air volume when the exhaust air volume is 250 [cubic meters / h]. The values ​​of the pressure differences in the air volume table vary depending on the size of the heat exchange type ventilation device 1, the sizes of the inside air port 4, the exhaust port 5, the outside air port 7, and the supply air port 8, the material of the heat exchange element 2, and the like.

[0039] Similarly, the storage unit 17 stores in the air volume table the pressure difference corresponding to each supply air volume when the exhaust air volume is 200 [cubic meters / h]. If the exhaust air volume is 200 [cubic meters / h] and the supply air volume is 100 [cubic meters / h], the pressure difference is F [Pa]. If the exhaust air volume is 200 [cubic meters / h] and the supply air volume is 150 [cubic meters / h], the pressure difference is G [Pa]. If the exhaust air volume is 200 [cubic meters / h] and the supply air volume is 200 [cubic meters / h], the pressure difference is H [Pa]. If the exhaust air volume is 200 [cubic meters / h] and the supply air volume is 250 [cubic meters / h], the pressure difference is I [Pa]. If the exhaust air volume is 200 [cubic meters / h] and the supply air volume is 300 [cubic meters / h], the pressure difference is J [Pa]. The pressure difference is largest in the order of F, G, H, I, and J.

[0040] Similarly, the storage unit 17 stores in the air volume table the pressure difference corresponding to each supply air volume for each exhaust air volume that can be input, with all set air volumes that can be input to the air volume input unit 15 being considered as exhaust air volumes. That is, the storage unit 17 stores a plurality of air volume tables. In addition, in the air volume table of this embodiment, the pressure difference corresponding to every 50 [cubic meters / h] of supply air volume is stored, but this is not limiting, and the pressure difference corresponding to every 10 [cubic meters / h] may be stored. The smaller the supply air volume unit, the more accurate the judgment of the judgment unit 20, which will be described later. However, the smaller the supply air volume unit, the larger the memory capacity required.

[0041] The supply airflow rate acquisition unit 18 acquires the supply airflow rate of the supply airflow 11 at the outside air port 7 based on the airflow rate exhausted from the exhaust port 5 by the exhaust fan 3, the pressure difference detected by the differential pressure detection unit 13, and the airflow rate table. The airflow rate exhausted from the exhaust port 5 by the exhaust fan 3 is the airflow rate of the exhaust fan 3. The airflow rate of the exhaust fan 3 is the set airflow rate acquired by the airflow rate acquisition unit 16. In other words, the supply airflow rate acquisition unit 18 acquires the supply airflow rate of the supply airflow 11 at the outside air port 7 from the airflow rate table stored in the memory unit 17 based on the set airflow rate acquired by the airflow rate acquisition unit 16 and the pressure difference detected by the differential pressure detection unit 13. Specifically, when the set air volume acquired by the air volume acquisition unit 16 is 250 [cubic meters / h] and the pressure difference is A [Pa], the supply air volume of the intake air flow 11 at the outdoor air outlet 7 is acquired as 100 [cubic meters / h] from the air volume table.

[0042] The determination unit 20 determines whether the indoor pressure is positive based on the intake airflow rate of the intake airflow 11 at the outdoor air inlet 7 acquired by the intake airflow rate acquisition unit 18 and the airflow rate exhausted from the exhaust port 5 by the exhaust fan 3. Specifically, the determination unit 20 determines that the indoor pressure is positive relative to the outdoor pressure if the intake airflow rate of the intake airflow 11 at the outdoor air inlet 7 acquired by the intake airflow rate acquisition unit 18 is greater than the airflow rate exhausted from the exhaust port 5 by the exhaust fan 3. In this case, the amount of air supplied to the indoor pressure is greater than the amount of air exhausted from the indoor pressure. In addition, the determination unit 20 determines that the indoor pressure is not positive relative to the outdoor pressure if the intake airflow rate of the intake airflow 11 at the outdoor air inlet 7 acquired by the intake airflow rate acquisition unit 18 is equal to or less than the airflow rate exhausted from the exhaust port 5 by the exhaust fan 3. The fact that the indoor pressure is not positive relative to the outdoor pressure means that the indoor pressure is negative or the same as the outdoor pressure. Negative pressure means that the amount of air exhausted from the room is greater than the amount of air supplied to the room. The same pressure means that the amount of air exhausted from the room is the same as the amount of air supplied to the room. This allows you to know whether the room is under positive pressure or not.

[0043] As mentioned above, negative pressure indoors can cause condensation on the surface of the duct in the Japanese summer, which can lead to the growth of mold and dust mites, so it is desirable for the indoors to be at a positive pressure relative to the outdoors.

[0044] When the determination unit 20 determines that the pressure is not positive, the supply air blower control unit 19 increases the air volume of the supply air blower 6. This makes it possible to bring the pressure inside the room closer to positive. The supply air blower control unit 19 also increases the air volume of the supply air blower 6 until the determination unit 20 determines that the pressure is positive. This makes it possible to reliably make the pressure inside the room positive.

[0045] Suppose that the intake fan 6 is disposed downstream of the outside air port 7 and upstream of the heat exchange element 2 in the intake air duct 10 in the heat exchange type ventilation device 1. In this case, the air volume of the intake fan 6 is made larger than that of the exhaust fan 3, so that the indoor pressure can be made positive. That is, by comparing the air volume of the intake fan 6 with that of the exhaust fan 3, it can be determined whether the indoor pressure is positive or not. However, as described above, it is preferable that the intake fan 6 is disposed downstream of the heat exchange element 2 in the intake air duct 10. That is, the present invention can provide a heat exchange type ventilation device that can determine whether the indoor pressure is positive or not without reducing the intake efficiency.

[0046] Each functional block of the control unit 14 can be realized in hardware terms by elements and mechanical devices such as a computer CPU (Central Processing Unit), and in software terms by a computer program, etc., but here, functional blocks realized by cooperation between them are depicted. Therefore, these functional blocks can be realized in various forms by combining hardware and software.

[0047] The operation of the heat exchange type ventilation device 1 having the above configuration will be described. Fig. 4 is a flowchart showing the control of the control unit 14 according to this embodiment. In the flowchart, numbers are assigned starting with the initial letter S. For example, S01 indicates a processing step. However, the magnitude of the numerical value indicating the processing step has no relation to the processing order.

[0048] The air volume acquisition unit 16 acquires set air volume information. The exhaust fan control unit 21 operates the exhaust fan 3 at the set air volume. Furthermore, the supply fan control unit 19 operates the supply fan 6 at the set air volume (S01). As a result, the air volume of the exhaust flow 12 at the exhaust port 5 becomes the set air volume. Furthermore, the air volume of the supply flow 11 at the supply port 8 also becomes the set air volume.

[0049] The supply air volume acquisition unit 18 acquires the pressure difference detected by the differential pressure detection unit 13 (S02). The supply air volume acquisition unit 18 acquires the supply air volume of the supply air flow 11 at the outside air port 7 based on the volume of air exhausted from the exhaust port 5 by the exhaust fan 3, the pressure difference, and the air volume table (S03).

[0050] The judgment unit 20 judges that the indoor pressure is positive relative to the outdoor pressure if the intake air volume of the intake air flow 11 at the outside air port 7 acquired by the intake air volume acquisition unit 18 is greater than the volume of air exhausted from the exhaust port 5 by the exhaust fan 3 (Yes in S04 → S05).

[0051] Furthermore, if the supply airflow rate of the supply airflow 11 at the outside air port 7 acquired by the supply airflow rate acquisition unit 18 is equal to or less than the airflow rate exhausted from the exhaust port 5 by the exhaust fan 3, the determination unit 20 determines that the indoor pressure is not positive relative to the outdoor pressure (No in S04 to S06). In this case, the supply airflow control unit 19 increases the airflow rate of the supply airflow fan 6 (S07). Then, when a certain period of time has passed and the airflow rate of the supply airflow fan 6 has stabilized, the supply airflow rate acquisition unit 18 again acquires the pressure difference detected by the differential pressure detection unit 13 (S02). If the determination unit 20 determines that the indoor pressure is not positive, the airflow rate of the supply airflow fan 6 is increased stepwise until the determination unit 20 determines that the indoor pressure is positive. This makes it possible to make the indoor pressure positive while suppressing an unnecessary increase in the airflow rate of the supply airflow fan 6.

[0052] The present invention has been described above based on the embodiments, but the present invention is not limited to the above embodiments, and it can be easily inferred that various improvements and modifications are possible within the scope of the present invention without departing from the spirit of the present invention.

[0053] For example, if the intake air volume of the intake air flow 11 at the outside air port 7 acquired by the intake air volume acquisition unit 18 is smaller than the volume of air exhausted from the exhaust port 5 by the exhaust fan 3, the volume of air of the intake air fan 6 may be increased. If the intake air volume of the intake air flow 11 at the outside air port 7 acquired by the intake air volume acquisition unit 18 is the same as the volume of air exhausted from the exhaust port 5 by the exhaust fan 3, it means that the indoor pressure is not positive but is the same as the outdoor pressure. If the indoor pressure is the same as the outdoor pressure, the outdoor air does not flow into the attic or the like through gaps in the building, so the above control may be performed. This improves the degree of freedom of the control content.

[0054] In the present embodiment, the control unit 14 is disposed in the main body of the heat exchanger type ventilator 1, but is not limited thereto. For example, the control unit 14 may be provided in a terminal capable of inputting set air volume information. The terminal capable of inputting set air volume information and the heat exchanger type ventilator 1 are capable of communicating with each other by wireless communication or wired communication. This improves the degree of freedom of the configuration.

[0055] Moreover, the control unit 14 may not have the memory unit 17. In this case, the determination unit 20 determines whether the indoor pressure is positive or not based on the air volume exhausted from the exhaust port 5 by the exhaust fan 3 and the pressure difference detected by the differential pressure detection unit 13. Specifically, the determination unit 20 calculates the supply air volume of the supply air flow 11 at the outside air port 7 using a predetermined arithmetic expression from the air volume of the exhaust fan 3 exhausted from the exhaust port 5 and the pressure difference detected by the differential pressure detection unit 13, and determines whether the indoor pressure is positive or not. The arithmetic expression is, for example, an arithmetic expression of a linear function. The arithmetic expression is obtained by experimentally measuring the pressure difference in the case of a predetermined exhaust air volume and a predetermined supply air volume using an air volume measuring device and the differential pressure detection unit 13 in advance, and deriving an arithmetic expression capable of calculating the supply air volume from the exhaust air volume and the pressure difference from the measurement results. As a result, it is possible to determine whether the indoor pressure is positive or not without having the memory unit 17. However, since the calculation formula is an approximation, using the air volume table stored in storage unit 17 makes it possible to more accurately determine whether or not the indoor pressure is positive.

[0056] (Summary of the invention) The heat exchange type ventilation device according to the present invention includes an intake air duct for transporting air drawn from the outdoors through an outdoor air intake port to the indoors through an indoor air intake port, an intake air blower for transporting the outdoor air to the indoors as an intake air flow through the intake air duct, an exhaust air duct for transporting the air drawn from the indoors through an indoor exhaust port to the outdoors through an outdoor exhaust port, an exhaust air blower for transporting the indoor air to the outdoors as an exhaust air flow through the exhaust air duct, and a heat exchanger for exchanging heat between the intake air flow and the exhaust air flow. The air conditioner is provided with a heat exchange element, a differential pressure detection unit that detects the pressure difference between the air pressure near the outdoor air supply port and the air pressure near the outdoor air exhaust port, and a determination unit that determines whether the indoor pressure is positive or not, the air supply fan is provided downstream of the heat exchange element in the air supply duct, the exhaust fan is provided downstream of the heat exchange element in the exhaust air duct, and the determination unit determines whether the indoor pressure is positive or not based on the amount of air exhausted from the outdoor air exhaust port by the exhaust fan and the pressure difference detected by the differential pressure detection unit. This provides the effect of making it possible to grasp whether the indoor pressure is positive or not without reducing the air supply efficiency.

[0057] The air conditioner may further include a storage unit that stores an air volume table that associates the exhaust air volume of the exhaust flow at the outdoor exhaust port, the pressure difference between the air pressure near the outdoor air supply port and the air pressure near the outdoor exhaust port, and the supply air volume of the supply air flow at the outdoor air supply port, and a supply air volume acquisition unit that acquires the supply air volume of the supply air flow at the outdoor air supply port based on the air volume exhausted from the outdoor exhaust port by the exhaust fan, the pressure difference detected by the differential pressure detection unit, and the air volume table, and the determination unit may be configured to determine whether or not the indoor pressure is positive based on the supply air volume of the supply air flow at the outdoor air supply port acquired by the supply air volume acquisition unit and the air volume exhausted from the outdoor exhaust port by the exhaust fan. This allows the supply air volume to be acquired using the air volume table, and the supply air volume can be grasped more accurately, thereby improving the accuracy of determining whether or not the indoor pressure is positive.

[0058] The determination unit may be configured to determine that the pressure is positive if the intake air volume of the intake air flow at the outdoor intake port acquired by the intake air volume acquisition unit is greater than the volume of air exhausted from the outdoor exhaust port by the exhaust fan, and to determine that the pressure is not positive if the intake air volume of the intake air flow at the outdoor intake port acquired by the intake air volume acquisition unit is equal to or less than the volume of air exhausted from the outdoor exhaust port by the exhaust fan. This provides the effect of making it possible to grasp whether the indoor pressure is positive or not.

[0059] The system may further include an intake air blower control unit that increases the air volume of the intake air blower when the determination unit determines that the pressure is not positive. This makes it possible to increase the air volume of the intake air blower when it is determined that the pressure inside the room is not positive, thereby achieving the effect of bringing the pressure inside the room closer to positive.

[0060] The intake air blower control unit may be configured to increase the air volume of the intake air blower until the determining unit determines that the pressure is positive. This makes it possible to continue increasing the air volume of the intake air blower when it is determined that the pressure inside the room is not positive, thereby providing the effect of reliably making the pressure inside the room positive. [Industrial Applicability]

[0061] The present invention is useful as a heat exchange type ventilation device used for ventilating a building. [Explanation of symbols]

[0062] 1. Heat exchange type ventilation system 2 Heat exchange element 3 Exhaust fan 4 Inner air vent 5. Exhaust port 6. Air supply fan 7. Outside air vent 8 Air supply port 9 Exhaust duct 10 Air supply duct 11 Intake air flow 12 Exhaust flow 13 Differential pressure detection section 14 Control section 15 Air volume input section 16 Air volume acquisition section 17 Memory section 18 Intake air volume acquisition unit 19 Air supply fan control section 20 Judgment section 21 Exhaust fan control section

Claims

1. an air intake duct for transporting air drawn in from the outdoors through the outdoor air intake port to the indoors through the indoor air intake port; an intake air blower that transports the outdoor air to the indoors as an intake air flow through the intake air duct; an exhaust duct for transporting air drawn from the indoors through an indoor exhaust port to the outdoors through an outdoor exhaust port; an exhaust fan that transports the indoor air to the outdoors as an exhaust flow through the exhaust air duct; a heat exchange element for exchanging heat between the intake air flow and the exhaust air flow; a differential pressure detection unit that detects a pressure difference between an air pressure downstream of the outdoor air intake port and upstream of the heat exchange element in the intake air duct and an air pressure downstream of the exhaust fan and upstream of the outdoor exhaust port in the exhaust air duct; A determination unit that determines whether the indoor pressure is positive or not, The intake air blower is a heat exchange element provided downstream of the heat exchange element in the air supply passage; The exhaust fan is a heat exchange element provided downstream of the heat exchange element in the exhaust air duct; The determination unit is A heat exchange type ventilation device that determines whether the indoor pressure is positive or not based on the volume of air exhausted from the outdoor exhaust port by the exhaust fan and the pressure difference detected by the differential pressure detection unit.

2. a storage unit that stores an air volume table that associates an exhaust air volume of the exhaust flow at the outdoor exhaust port, a pressure difference between an air pressure near the outdoor intake port and an air pressure near the outdoor exhaust port, and an intake air volume of the intake air flow at the outdoor intake port; a supply air volume acquisition unit that acquires a supply air volume of the supply air flow at the outdoor air supply port based on the volume of air exhausted from the outdoor exhaust port by the exhaust fan, the pressure difference detected by the differential pressure detection unit, and the air volume table, The determination unit is 2. A heat exchange type ventilation device as described in claim 1, wherein the supply air volume acquisition unit determines whether the indoor air is at positive pressure based on the supply air volume of the supply air flow at the outdoor supply air port acquired by the supply air volume acquisition unit and the volume of air exhausted from the outdoor exhaust port by the exhaust fan.

3. The determination unit is if the intake air volume of the intake air flow at the outdoor intake port acquired by the intake air volume acquisition unit is greater than the volume of air exhausted from the outdoor exhaust port by the exhaust fan, it is determined that the pressure is positive; A heat exchange type ventilation device as described in claim 2, wherein if the intake air volume acquisition unit acquires an intake air volume of the intake air flow at the outdoor intake port that is less than the volume of air exhausted from the outdoor exhaust port by the exhaust fan, it is determined that the pressure is not positive.

4. 4. The heat exchange type ventilation device according to claim 1, further comprising an intake air blower control section which increases an air volume of the intake air blower when the determination section determines that the pressure is not positive.

5. The intake air blower control unit is 5. A heat exchange type ventilation system according to claim 4, wherein the air volume of said supply air blower is increased until said determining section determines that the pressure is positive.

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