JP2013113473A - Heat exchange ventilator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the relative humidity in a room not change as much as possible by performing an operation for switching to entire heat exchange ventilation without fail when the absolute humidity of outside air is not within a range of an arbitrary absolute humidity reference value.SOLUTION: A heat exchange ventilator includes a body casing 1 having an air supply air duct 6 and an exhaust air duct 7, a heat exchanger 10 which exchanges heat between an air supply flow and an exhaust flow, a bypass passage 15 which bypasses the heat exchanger, a damper 16 capable of switching an air duct, an outdoor temperature/humidity sensor 17, and a controller 18 which alternates heat exchange ventilation and normal ventilation (bypass ventilation) bypassing the heat exchanger. The controller 18 compares outdoor absolute humidity computed based upon the output signal of the outdoor temperature/humidity sensor 17 with the predetermined absolute humidity reference value, and switches the damper to the normal ventilation (bypass ventilation) when the outdoor absolute humidity is within the range of the predetermined absolute humidity reference value or to the heat exchange ventilation when the outdoor absolute humidity is not within the range of the predetermined absolute humidity reference value.

Description

  The present invention relates to a heat exchange ventilator that is mainly used in the field of ventilation and performs heat exchange through a heat exchanger while simultaneously supplying and exhausting air.

  In order to reduce the energy of the air conditioner, a box with a single inlet and outlet is provided on each of the indoor side and the outdoor side, and an air supply blower built in the inside of the box causes the outdoor inlet to Air is sucked in and air is supplied to the room from the indoor outlet through the air supply passage of the heat exchanger, and indoor air is sucked in from the indoor inlet by the exhaust blower and blown to the outdoor side through the exhaust passage of the heat exchanger. There is a heat exchange ventilator that includes an exhaust passage that exhausts air from the outlet to the outside, and a heat exchanger that is provided at an intersection of the supply passage and the exhaust passage and exchanges heat between the supply air flow and the exhaust flow. In this heat exchange ventilation device, a heat exchange ventilation mode in which heat exchange ventilation is performed and a normal ventilation mode in which ventilation is performed without heat exchange have been proposed. Furthermore, a room temperature detecting means for detecting the room temperature, an outside air temperature detecting means for detecting the outside air temperature, an air conditioner for adjusting the temperature to bring the room temperature close to the set temperature, and a heat exchange ventilator during the operation period of the air conditioner Control means for driving the supply air blower and the exhaust air blower to forcibly ventilate, and when the control means determines that heat exchange ventilation should be performed, the air conditioner started temperature adjustment After that, during the period before the room temperature becomes a value within the predetermined temperature range near the set temperature, forcible ventilation by the air supply blower and the exhaust blower is prohibited, and when it is determined that normal ventilation should be performed, There is a heat exchange ventilator having means for forcibly ventilating with an air supply blower and an exhaust blower regardless of room temperature (see, for example, Patent Document 1).

  It also detects the temperature and humidity outside the room and calculates the enthalpy of each. When cooling, it is set to normal ventilation when the enthalpy of outdoor air is smaller than the enthalpy of indoor air. There is an operation that is exchanged, and is controlled as a total heat exchange operation when the enthalpy of outdoor air is smaller than the enthalpy of room air during heating, and as a normal ventilation operation when it is large (see, for example, Patent Document 2). .

Japanese Patent No. 2647362 Japanese Patent Laid-Open No. 62-123236

  In the conventional heat exchange ventilator described in Patent Document 1, heat exchange is performed for heat exchange ventilation based on signal outputs from the room temperature detection means for detecting the room temperature and the outside air temperature detection means for detecting the outside air temperature. Control of switching between the ventilation mode and the normal ventilation mode in which ventilation is performed without heat exchange. For this reason, during cooling, if the outdoor temperature is lower than the indoor temperature, normal ventilation is performed regardless of the outdoor humidity state. For example, when the outdoor temperature is low compared to the indoor temperature, such as during rainy weather, but the relative humidity is very high, the outdoor high-humidity air is taken into the room as the supply air. Compared to heat exchange ventilation, it will be very high. Furthermore, since the room temperature is low, the cooling operation by the air conditioner cannot be performed, so that there is a problem that dehumidification cannot be performed.

  On the other hand, during heating, even if the relative humidity of the outside air is very low, if the outdoor temperature is higher than the indoor temperature, normal ventilation is performed regardless of the outdoor humidity. . For this reason, for example, in the early spring, the outdoor temperature is higher than the indoor temperature, but in a situation where the relative humidity is very low, the outdoor low-humidity air is taken into the room as supply air. There was a problem that the relative humidity would be much lower than when the total heat exchange ventilation was used.

  In addition, in the conventional technique described in Patent Document 2, the temperature and humidity of the room and the outdoors are measured, the enthalpy is calculated from the measured indoor and outdoor temperature and humidity signal outputs, and the calculated room and room are calculated. In this case, if the outdoor enthalpy is lower than the indoor enthalpy during cooling, regardless of the outdoor humidity conditions, the enthalpy is compared with the indoor enthalpy. Ordinary ventilation. As a result, even if the outdoor environment is highly humid, it may be taken into the room as supply air.Therefore, the indoor relative humidity may be significantly higher than that of total heat exchange ventilation, and vice versa. For example, if the outdoor enthalpy is higher than the indoor enthalpy, normal ventilation will be performed, so even if the outdoor environment is low humidity, it may be taken in as indoor air supply. There is a problem that it falls compared with ventilation.

  The present invention has been made to solve the above-described problems. When the absolute humidity of the outside air is not within an arbitrary absolute humidity reference value, an operation for switching to total heat exchange ventilation must be performed. An object of the present invention is to provide a heat exchange ventilator that prevents relative humidity from changing as much as possible by ventilation, and can enhance comfort and energy saving.

A heat exchange ventilator according to the present invention includes a main body casing having an air supply passage for taking outdoor air into the room, an exhaust air passage for exhausting indoor air to the outside, and an air supply provided in the air supply passage. A blower, an exhaust blower provided in the exhaust air passage, a heat exchanger for exchanging heat between outdoor air flowing through the supply air passage and indoor air flowing through the exhaust air passage, and a supply air passage or an exhaust air passage A bypass passage that bypasses the heat exchanger, a damper that can switch between the supply air passage or the exhaust air passage and the bypass passage, an outdoor temperature sensor that measures outdoor temperature and humidity, and outdoor humidity A heat exchange ventilator comprising: a sensor; and a control device that switches between outdoor air and indoor air that passes through the heat exchanger and normal ventilation that does not pass through the heat exchanger (bypass ventilation). ,
The control device compares the outdoor absolute humidity calculated based on the output signals of the outdoor temperature sensor and the outdoor humidity sensor with a predetermined absolute humidity reference value,
When the outdoor absolute humidity is within the range of the specified absolute humidity reference value, switch the damper to the normal ventilation (bypass ventilation),
When the outdoor absolute humidity is not within the range of the predetermined absolute humidity reference value, the damper is switched to the heat exchange ventilation.

  According to the present invention, as a result of comparing the outdoor absolute humidity calculated based on the output signals of the outdoor temperature sensor and the outdoor humidity sensor with a predetermined absolute humidity reference value, the absolute humidity of the outdoor air is a predetermined absolute humidity reference value. If it is not within the range, the operation is switched to total heat exchange ventilation. It is possible to perform humidity exchange, and it is possible to prevent the indoor relative humidity from changing as much as possible by ventilation.

It is a perspective view which shows the internal structure of the heat exchange ventilation apparatus 100 which concerns on Embodiment 1 of this invention. It is a top view which shows the outline | summary of the internal structure of the heat exchange ventilation apparatus. It is a cross-sectional side view which shows the outline | summary of the internal structure of the heat exchange ventilation apparatus. It is an air diagram which shows an example of the upper and lower absolute humidity reference values for determining switching between normal ventilation and heat exchange ventilation. It is a flowchart which shows the process sequence in the control apparatus 18 of the heat exchange ventilation apparatus. It is a figure which shows the example of a connection of the heat exchange ventilation apparatus 100 in Embodiment 3, and the remote control 200 which operates it. It is a cross-sectional side view which shows the outline | summary of the internal structure of the heat exchange ventilation apparatus 100 in Embodiment 4. FIG. It is a figure which shows the example of the temperature map which compares the output signal of room temperature and outside temperature, and determines whether heat exchange ventilation or normal ventilation is performed. It is a flowchart which shows the process sequence in the control apparatus 18 of the heat exchange ventilation apparatus 100 in Embodiment 4. FIG.

  Embodiments of a heat exchange ventilator according to the present invention will be described below with reference to the drawings.

Embodiment 1 FIG.
1 is a perspective view showing an internal structure of a heat exchange ventilator 100 according to Embodiment 1 of the present invention, FIG. 2 is a plan view showing an outline of the internal structure of the heat exchange ventilator 100, and FIG. 3 is a heat exchange ventilator. It is a cross-sectional side view which shows the outline | summary of 100 internal structure. 1 to 3, solid line arrows indicate the flow of outdoor air (supply airflow), and broken line arrows indicate the flow of indoor air (exhaust flow).
The heat exchange ventilator 100 according to the first embodiment includes a main body casing 1 formed in a box shape, and the main body casing 1 has an indoor air inlet 2 and an indoor air outlet 3 on one of opposing side surfaces. It has the outdoor side inlet 4 and the outdoor side blower outlet 5 in the other side. In addition, a supply air passage 6 for taking outdoor air into the room is formed in the main body casing 1 as a passage that connects the outdoor suction port 4 and the indoor outlet 3, and exhausts the indoor air to the outside. An exhaust air passage 7 is formed as a passage communicating the indoor suction port 2 and the outdoor air outlet 5. An air supply fan 8 is provided in the air supply path 6, and an exhaust fan 9 is provided in the exhaust air path 7. Further, a heat exchanger 10 is provided for exchanging heat between the supply airflow flowing through the supply airflow path 6 and the exhaust flowflowing through the exhaust airflow path 7. As shown by arrows in FIG. 3, the air supply air flow and the exhaust air flow enter from the lower surface of the heat exchanger 10 and flow through the passages 6 a and 7 a of the heat exchanger 10 so as to cross each other. Thus, heat exchange is performed in the process of flowing through the heat exchanger 10. In addition, the heat exchanger 10 is provided so that insertion / extraction is possible from the opening part 11 provided in the other side surface of the main body casing 1. FIG. In FIGS. 1 and 2, 12 is an electric motor that rotationally drives the air supply blower 8, 13 is an electric motor that rotationally drives the exhaust air blower 9, and 14 is a blade casing of the air supply blower 8 and the exhaust air blower 9.

  Further, a bypass passage 15 that bypasses the heat exchanger 10 and bypasses the heat exchanger 10 is provided on the exhaust air passage 7 side. A bypass damper 16 is provided on the upstream side of the heat exchanger 10 in the exhaust air passage 7, and during normal ventilation without heat exchange, the exhaust air passage 7 is closed by the bypass damper 16 and the bypass passage 15 is opened. It is formed as an air passage that sucks indoor air from the indoor suction port 2 and exhausts it through the bypass passage 15 to the outside from the outdoor air outlet 5. Thereby, since heat is not exchanged from the exhaust flow to the supply airflow, it is possible to perform normal ventilation (bypass ventilation) in which supply air that is not heat-exchanged is supplied indoors. Note that the bypass passage 15 and the bypass damper 16 may be provided on either the supply air passage 6 side or the exhaust air passage 7 side. FIG. 1 shows an example in which a bypass passage 15 and a bypass damper 16 are provided on the exhaust air passage 7 side.

  Furthermore, the heat exchange ventilator 100 includes an outdoor temperature sensor and an outdoor humidity sensor 17 that measure the outdoor temperature and humidity in the vicinity of the outdoor suction port 4, and outputs of the outdoor temperature sensor and the outdoor humidity sensor 17. A control device 18 that calculates the absolute humidity of the outdoor air based on the signal is provided.

Next, operation | movement of the heat exchange ventilation apparatus 100 comprised as mentioned above is demonstrated.
For air conditioning ventilation using the heat exchanger 10, the bypass damper 16 closes the bypass passage 15 in advance and opens the exhaust air passage 7. Then, by starting the motors 12 and 13 of the air supply blower 8 and the exhaust blower 9, the indoor air is sucked in from the indoor side suction port 2 through the duct as indicated by the broken line arrow, and the exhaust air passage 7 and After passing through the heat exchanger 10, the exhaust air blower 9 exhausts the air from the outdoor air outlet 5 to the outside of the blowout chamber.

On the other hand, outdoor air is sucked from the outdoor suction port 4 through a duct as indicated by a solid arrow, passes through the supply air passage 6 and the heat exchanger 10, and is blown out from the indoor outlet 3 by the supply air blower 8. The air is supplied to the room via At this time, in the heat exchanger 10, heat exchange is performed between the exhaust flow and the supply air flow, and the exhaust heat is recovered to reduce the cooling / heating load.
As described above, the outdoor air is supplied to the room through the heat exchanger 10 by the supply air passage 6, and at the same time, the indoor air can be exhausted to the outside through the heat exchanger 10 by the exhaust air passage 7. Thus, heat exchange ventilation operation by simultaneous supply and exhaust can be performed while performing heat exchange between supply and exhaust.

  Here, an outdoor temperature sensor for measuring outdoor temperature and humidity and an outdoor humidity sensor 17 are installed in the vicinity of the outdoor inlet 4 as shown in FIGS. 2 and 3, and a microcomputer is installed in the heat exchange ventilator 100. A control device 18 is provided. The outdoor air temperature sensor and the outdoor humidity sensor 17 monitor the air condition of the supply air. The output signals of the outdoor temperature sensor and the outdoor humidity sensor 17 are input to the control device 18, and the absolute humidity of the outdoor air is measured based on the output signal. Perform the operation.

  Further, the upper limit absolute humidity reference value 20 and the lower limit absolute humidity reference value 21 as shown in the air diagram of FIG. 4 are input (stored) in the control device 18 in advance. Therefore, a comparison comparing the outdoor absolute humidity calculated based on the output signals of the outdoor temperature sensor and the outdoor humidity sensor 17 with any upper limit absolute humidity reference value 20 and lower limit absolute humidity reference value 21 set in advance. Means are provided in the control device 18 together with storage means.

FIG. 5 is a flowchart showing a processing procedure in the control device 18 of the heat exchange ventilator 100.
As shown in FIG. 5, when the heat exchange ventilator 100 starts operation (step S1), the calculation and determination of the absolute outdoor humidity is performed based on the outdoor temperature / humidity measurement results (step S2). Then, it is determined whether or not the calculated outside absolute humidity is within the reference value (step S3). When the outside air absolute humidity is within the range of the arbitrary upper limit side absolute humidity reference value 20 and the lower limit side absolute humidity reference value 21, normal ventilation (bypass ventilation) is permitted as shown in FIG. Step S4). In this case, the control device 18 controls switching of the air path by the bypass damper 16, closes the exhaust air path 7 on the upstream side of the heat exchanger 10 of the exhaust air path 7 and opens the bypass air path 15 side. . Therefore, the indoor air passes through the bypass passage 15 by bypassing the heat exchanger 10 from the indoor air inlet 2 of the exhaust air passage 7 so that the air flows as shown by the one-dot chain line in FIG. The air is exhausted from the outside outlet 5 to the outside of the blowing chamber. As a result, the exhaust flow is not heat-exchanged with the supply air flow, so that it is possible to switch to a normal ventilation operation in which supply air that is not heat-exchanged is supplied indoors.

  Conversely, if the outdoor absolute humidity is not within the range of the arbitrary upper limit absolute humidity reference value 20 and lower limit absolute humidity reference value 21, normal ventilation (bypass ventilation) is prohibited and the bypass damper 16 is exhausted. The bypass passage 15 side is closed on the upstream side of the heat exchanger 10 in the air passage 7 and the exhaust air passage 7 side is opened. For this reason, the indoor air passes through the heat exchanger 10 from the indoor side suction port 2 of the exhaust air passage 7 to the outside of the blowout chamber through the heat exchanger 10 so that the air flow is as shown by the solid line in FIG. Exhausted. Thus, the exhaust flow exchanges heat with the supply air flow, and performs total heat exchange ventilation in which the heat-exchanged supply air is supplied to the room (step S5).

  According to the first embodiment, when the absolute humidity of the outside air is not within the range of the arbitrary absolute humidity reference value, the outdoor absolute humidity is changed to the total heat exchange ventilation so that the outdoor absolute humidity Under conditions that make it uncomfortable when placed in the room, humidity exchange is performed through the indoor exhaust air and the heat exchanger 10 so that the relative humidity in the room is not changed as much as possible by ventilation. For this reason, the room is highly humid during the rainy season, etc., but the temperature is low, so it cannot be dehumidified by the air conditioner, or the set temperature of the air conditioner must be further lowered to dehumidify. If the air conditioner's power consumption increases, or if it is in winter, the humidified state of the room is reduced by normal ventilation, or the humidity is reduced. It is possible to reduce problems such as extra work.

Embodiment 2. FIG.
The heat exchange ventilator in the second embodiment is the same as that in the first embodiment. Here, an absolute humidity standard, which is a criterion for determining whether to perform normal ventilation (bypass ventilation) or heat exchange ventilation, will be described.
In the Building Sanitation Law, ranges of temperatures from 17 ° C. to 28 ° C. and relative humidity from 40% to 70% are defined as standard values for efforts to maintain and manage the air environment in the building.
Therefore, in the second embodiment, the lower limit determination value and the upper limit determination value of the absolute humidity reference value that satisfies this reference value are set as follows.
Regarding the lower limit side judgment value, the absolute humidity at 40% relative humidity when considered from a temperature of 17 ° C. to 28 ° C. is 0.0047 kg / kg (DA) to 0.0095 kg / kg (DA). A lower limit determination value (lower limit absolute humidity reference value 21 in FIG. 4) of the absolute humidity reference value is set.
Regarding the upper limit side judgment value, the absolute humidity at a relative humidity of 70% when considered at a temperature of 17 ° C. to 28 ° C. is 0.0084 kg / kg (DA) to 0.0167 kg / kg (DA). An upper limit determination value (upper limit absolute humidity reference value 20 in FIG. 4) of the absolute humidity reference value is set.

Embodiment 3 FIG.
FIG. 6 is a diagram illustrating a connection example between the heat exchange ventilator 100 and the remote controller 200 for operating the heat exchange ventilator 100 according to the third embodiment.
The heat exchange ventilator 100 in the third embodiment is the same as that in the first embodiment. In the third embodiment, as shown in FIG. 6, a remote controller 200 for remotely operating the heat exchanging ventilator 100 in a wired or wireless manner is installed in the room, and the user can use the operation buttons on the remote controller 200 to perform the remote operation. The upper limit determination value and the lower limit determination value of the absolute humidity reference value may be set to an arbitrary value in the control device 18 of the heat exchange ventilator 100.

  This makes it easy to adjust the absolute humidity during ventilation in accordance with the location conditions and geographical conditions of the building. It is also possible to set the absolute humidity from outside.

Embodiment 4 FIG.
FIG. 7 is a cross-sectional side view showing an outline of the internal structure of heat exchange ventilator 100 in the fourth embodiment.
The heat exchanging ventilator 100 according to the fourth embodiment includes an indoor temperature sensor 22 that measures the temperature of the exhaust from the room in the vicinity of the indoor inlet 2. Other configurations are the same as those in the first embodiment unless otherwise specified.

  In the fourth embodiment, indoor air is sensed by the indoor temperature sensor 22 to measure the indoor temperature. Then, the measurement result of the room temperature is output as an electrical signal, and the output result is input to the control device 18 of the heat exchange ventilator 100. Furthermore, the outdoor temperature sensor and the outdoor humidity sensor 17 are used to sense outdoor air, the measured outdoor temperature result is output as an electrical signal, and the output result is input to the control device 18. The control device 18 compares the output signal of the indoor temperature measurement result with the output signal of the outdoor temperature measurement result, and determines whether normal ventilation (bypass ventilation) or heat exchange ventilation is performed. And

  FIG. 8 shows the detection of the room temperature and the outside air temperature by two temperature sensors incorporated in the heat exchange ventilator 100, and compares the two output signals to perform heat exchange ventilation or normal ventilation (bypass ventilation). It is a figure which shows the example of the temperature map which determines whether it performs. For example, when the indoor temperature load is large, such as during cooling in summer, and the outside air temperature is lower than the room temperature, the cooling load can be reduced by taking in the outside air without exchanging heat. A temperature map as shown in FIG. 8 is registered in the control device 18 of the heat exchange ventilator 100 to determine whether heat exchange ventilation or normal ventilation (bypass ventilation) is performed in advance.

  In this temperature map, the horizontal axis is the room temperature, the vertical axis is the outside air temperature, and the relationship between the room temperature and the outside air temperature, the temperature range of heat exchange ventilation, the temperature range of normal ventilation (bypass ventilation), and the temperature of both A predetermined indefinite area is provided at the boundary of the range.

Next, the operation will be described with reference to FIG.
FIG. 9 is a flowchart showing a processing procedure in control device 18 of heat exchange ventilation apparatus 100 in the fourth embodiment.
The air-conditioning ventilation method using the heat exchanger 10 in the heat exchange ventilator 100 is the same as that of the first embodiment.
As shown in FIG. 9, when the heat exchanging ventilator 100 starts operation (step S11), the control device 18 sets the indoor temperature sensor 22 for measuring the indoor temperature and the outdoor temperature and humidity as the first stage. The indoor and outdoor temperatures from the outdoor temperature sensor and the outdoor humidity sensor 17 to be measured are compared (step S12), and heat exchange ventilation is performed based on the temperature information in the room and the outdoor according to the temperature map as shown in FIG. Or whether to perform normal ventilation (step S13).

Then, even if the normal ventilation is permitted in the first stage, the outdoor absolute humidity is determined in the second stage (step S14). That is, it is determined whether the outdoor absolute humidity is within the range of the arbitrary upper limit side absolute humidity reference value 20 and the lower limit side absolute humidity reference value 21 (step S15). The damper is controlled and switched to normal ventilation (step S16).
On the other hand, even if normal ventilation (bypass ventilation) is prohibited or the normal ventilation (bypass ventilation) is permitted in the first stage due to temperature conditions inside and outside the room, in the second stage, the absolute humidity outside the room Is not within the range of any absolute humidity reference value, normal ventilation is prohibited, and the damper is controlled based on the determination output signal to switch to heat exchange ventilation (step S17).

  As a result, in addition to the conventional indoor and outdoor temperature conditions, normal ventilation can reduce the air conditioning load compared to heat exchange ventilation, and switch between normal ventilation and heat exchange ventilation while observing the outdoor absolute humidity. Is possible. Therefore, it is possible to prevent the relative humidity in the room from changing as much as possible by ventilation. As in the first embodiment, the room is at high humidity during the rainy season, but the temperature is low. If it is not possible to dehumidify by the air conditioner, or if the air conditioner power consumption is increased due to the need to lower the set temperature of the air conditioner to perform dehumidification, It is possible to alleviate the problem that the humidified state of the room is reduced by the normal ventilation, or the humidifier needs to be operated extra.

Embodiment 5 FIG.
In the fifth embodiment, in the fourth embodiment, the control device 18 uses the outdoor relative humidity calculated based on the output signals of the outdoor temperature sensor and the outdoor humidity sensor 17 and an arbitrary relative humidity reference value, for example, relative humidity. With a reference value of 80%, a means for comparing with the relative humidity reference value is provided, and normal ventilation (bypass ventilation) that does not pass through the heat exchanger 10 when the outdoor relative humidity is higher than an arbitrary relative humidity reference value. It is forbidden and further added with the condition of operating with heat exchange ventilation.

  This prevents high-humidity outside air from being supplied to the heat exchanger 10, so that high-humidity air such as mist can be prevented from being condensed in the heat exchanger 10 provided inside the main body casing 2 and becoming condensed water. In addition, it is possible to prevent the heat exchanger 10 from being deteriorated due to condensation.

  DESCRIPTION OF SYMBOLS 1 Main body casing, 2 indoor side inlet, 3 indoor side outlet, 4 outdoor side inlet, 5 outdoor side outlet, 6 supply air path, 7 exhaust air path, 8 supply air fan, 9 exhaust air fan, 10 heat exchange , 11 opening, 12, 13 motor, 14 blade casing, 15 bypass passage, 16 bypass damper, 17 outdoor temperature sensor and outdoor humidity sensor, 18 control device, 20 upper limit side absolute humidity reference value, 21 lower limit side absolute humidity reference Value, 22 indoor temperature sensor, 100 heat exchange ventilator, 200 remote control.

Claims (5)

A main body casing having an air supply passage for taking outdoor air into the room, and an exhaust air passage for exhausting indoor air to the outside;
An air supply fan provided in the air supply path;
An exhaust blower provided in the exhaust air passage;
A heat exchanger for exchanging heat between outdoor air flowing through the supply air passage and indoor air flowing through the exhaust air passage;
A bypass passage connected to the supply air passage or the exhaust air passage and bypassing the heat exchanger;
A damper capable of switching the air path between the supply air path or the exhaust air path and the bypass passage;
An outdoor temperature sensor and an outdoor humidity sensor for measuring outdoor temperature and humidity;
A control device that switches between outdoor and indoor air through heat exchange ventilation through the heat exchanger and normal ventilation (bypass ventilation) not through the heat exchanger, and a heat exchange ventilator comprising:
The control device compares the outdoor absolute humidity calculated based on the output signals of the outdoor temperature sensor and the outdoor humidity sensor with a predetermined absolute humidity reference value,
When the outdoor absolute humidity is within the range of the specified absolute humidity reference value, switch the damper to the normal ventilation (bypass ventilation),
When the outdoor absolute humidity is not within the range of the predetermined absolute humidity reference value, the damper is switched to the heat exchange ventilation.
A heat exchange ventilator characterized by that. Set the lower limit judgment value of the absolute humidity reference value between 0.0047 kg / kg (DA) and 0.0095 kg / kg (DA),
The heat exchange ventilator according to claim 1, wherein the upper limit determination value of the absolute humidity reference value is set between 0.0084 kg / kg (DA) and 0.0167 kg / kg (DA). It has an indoor temperature sensor that measures the indoor temperature,
The controller is
Output the output signal of the outdoor temperature sensor and the indoor temperature sensor according to the determination output signal based on the absolute humidity,
In the first stage, the indoor temperature information by the indoor temperature sensor is compared with the outdoor temperature information by the outdoor temperature sensor,
In accordance with a temperature map registered in advance in the control device from the outdoor temperature information and the indoor temperature information, the primary determination of whether to perform the normal ventilation (bypass ventilation) or the heat exchange ventilation,
When normal ventilation (bypass ventilation) is permitted in the primary judgment, and in the second stage, if the outdoor absolute humidity is within the range of the specified absolute humidity reference value, the judgment output signal On the basis of the normal ventilation (bypass ventilation),
3. The heat exchange ventilation according to claim 1, wherein when the outdoor absolute humidity is not within a range of a predetermined absolute humidity reference value, the heat exchange ventilation is switched based on the determination output signal. apparatus. The control device compares the outdoor relative humidity calculated based on the output signals of the outdoor temperature sensor and the outdoor humidity sensor with a predetermined relative humidity reference value,
When outdoor relative humidity is higher than a predetermined relative humidity reference value, normal ventilation that does not pass through the heat exchanger (bypass ventilation) is prohibited, and operation is performed with heat exchange ventilation. The heat exchange ventilator according to any one of 3 above.   The heat exchange ventilator according to any one of claims 1 to 4, further comprising means by which a user can arbitrarily set a lower limit side determination value and an upper limit side determination value of the absolute humidity reference value. .

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