Ventilation control interface device

Abstract

A ventilation control interface device (104) comprises: a control unit (105) that is connected to a remote controller communication line (205) that connects an indoor unit (102) of an air conditioning device and a remote controller (101) of the air conditioning device, and that controls a first ventilation device (109) and a second ventilation device (112) that perform ventilation by exhausting indoor air to the outside and supplying outside air indoors; and a remote controller communication circuit (103) that transmits and receives a signal between the control unit (105) and the remote controller (101) via the remote controller communication line (205).

Description

Ventilation Control Interface Device

[0001] The present disclosure relates to a ventilation control interface device that operates an air conditioning apparatus and a ventilation device in conjunction with each other.

[0002] When both an air conditioning apparatus and a ventilation device are installed in a space to be air-conditioned, the air conditioning efficiency can be improved by operating the air conditioning apparatus and the ventilation device in conjunction with each other. Patent Document 1 discloses a heat exchange ventilation apparatus equipped with a control unit connected to the air conditioning apparatus. The heat exchange ventilation apparatus disclosed in Patent Document 1 is capable of operating the air conditioning apparatus and the ventilation device in conjunction with each other by controlling the blower based on a signal input from the air conditioning apparatus.

[0003] Japanese Patent Application Publication No. 6-281228

[0004] When an air conditioner and a ventilation device are operated in conjunction with each other, it is necessary to set operating conditions for each of the air conditioner and the ventilation device. However, the heat exchange ventilation device disclosed in Patent Document 1 cannot share a remote controller with the air conditioner, so the user must set the operating conditions for the heat exchange ventilation device and the air conditioner in separate locations.

[0005] When operating an air conditioner and ventilation equipment in conjunction with each other, a centralized control system is sometimes adopted, in which a ventilation control interface device is connected between the indoor unit of the air conditioner and the ventilation equipment, and the operation settings of the ventilation equipment are made from the remote controller of the air conditioner. However, when using the centralized control system, both the indoor unit of the air conditioner and the multiple ventilation equipment connected to the ventilation control interface device must be compatible with the centralized control system.

[0006] The present disclosure has been made in consideration of the above, and aims to provide a ventilation control interface device that can operate the indoor unit and ventilation equipment of an air conditioning system that does not support a centralized control system in conjunction with each other, and that can set the operating conditions of each of the indoor unit and ventilation equipment from a common remote controller.

[0007] To solve the above-mentioned problems and achieve the object, a ventilation control interface device according to the present disclosure is connected to a remote controller communication line that connects an indoor unit of an air conditioner and a remote controller of the air conditioner. The ventilation control interface device includes a control unit that controls at least one ventilation device that exhausts indoor air to the outdoors and supplies outside air to the indoors to perform ventilation, and a communication circuit that transmits and receives signals between the control unit and the remote controller via the remote controller communication line.

[0008] The ventilation control interface device according to the present disclosure has the advantage that it is possible to operate the indoor unit and ventilation equipment of an air conditioning system that does not support a centralized control system in conjunction with each other, and that the operating conditions of each of the indoor unit and ventilation equipment can be set from a common remote controller.

[0009] FIG. 1 is a diagram showing the connection configuration of a ventilation control interface device according to embodiment 1; FIG. 2 is a diagram showing the connection configuration of an indoor unit, a first ventilation device, and a damper, which are objects of control by the ventilation control interface device according to embodiment 1; FIG. 3 is a diagram showing the configuration of a remote controller communication circuit of the ventilation control interface device according to embodiment 1; FIG. 4 is a diagram showing the waveform of a signal transmitted to a remote controller of the ventilation control interface device according to embodiment 1; FIG. 5 is a diagram showing the waveform of a signal received from the remote controller of the ventilation control interface device according to embodiment 1;

[0010] Hereinafter, a ventilation control interface device according to an embodiment will be described in detail with reference to the drawings.

[0011] 1 is a diagram showing the connection configuration of a ventilation control interface device according to embodiment 1. The ventilation control interface device 104 is connected to a remote controller communication line 205 that connects the indoor unit 102 of the air conditioning apparatus 20 and the remote controller 101. Therefore, the remote controller 101 can communicate with both the indoor unit 102 and the ventilation control interface device 104.

[0012] There are three types of air conditioners 20: one that receives power at the outdoor unit 201, one that receives power at the indoor unit 102, and one that receives power at both the outdoor unit 201 and the indoor unit 102. For air conditioners 20 known as package air conditioners that condition an entire house or office, the type that receives power at the outdoor unit 201 is the mainstream. Here, we will explain an example of an air conditioner 20 that receives power at the outdoor unit 201, where power supply voltage differences and earth impedance differences are likely to occur, but the air conditioner 20 may also receive power at the indoor unit 102, or may receive power separately at both the outdoor unit 201 and the indoor unit 102.

[0013] The outdoor unit 201 is supplied with commercial power and is grounded via a ground connection terminal 202. The outdoor unit 201 and the indoor unit 102 are connected by refrigerant piping (not shown) and an internal / external connection line 203. The internal / external connection line 203 connects the power supply and ground potentials between the outdoor unit 201 and the indoor unit 102.

[0014] The indoor unit 102 is connected to the remote controller 101 via a remote controller communication line 205. The ventilation control interface device 104 is also connected to the remote controller communication line 205, and the remote controller 101 is able to communicate with both the indoor unit 102 and the ventilation control interface device 104. The remote controller 101 is also equipped with a display device (not shown) and is able to display information obtained from the ventilation control interface device 104. The indoor unit 102 supplies power to part of the ventilation control interface device 104 and the remote controller 101 via the remote controller communication line 205. The power supply from the indoor unit 102 to the ventilation control interface device 104 will be described later.

[0015] The ventilation control interface device 104 is also supplied with commercial power and is connected to earth via an earth connection terminal 208 .

[0016] 2 is a diagram showing the configuration of the ventilation control interface device according to Embodiment 1. The ventilation control interface device 104 includes a remote controller communication circuit 103 that communicates with the remote controller 101, a communication terminal block 123, a power terminal block 106, a terminal block 108 to which a first ventilation device 109 is connected, a first switching circuit 110 that controls the fan speed of the first ventilation device 109 and whether or not heat exchange is performed, a terminal block 111 to which a second ventilation device 112 is connected, a second switching circuit 113 that controls the fan speed of the second ventilation device 112 and whether or not heat exchange is performed, a terminal block 114 to which a ventilation assistance device 115 is connected, a ventilation assistance device switching circuit 116 that switches the fan speed of the ventilation assistance device 115, a terminal block 117 to which a damper 118 provided for each ventilation target area is connected, and a damper opening switching circuit 119 that controls the opening and closing of the damper 118. The ventilation control interface device 104 also includes a control unit 105 that controls the remote controller communication circuit 103, the first switching circuit 110, the second switching circuit 113, the ventilation assist device switching circuit 116, and the damper opening switching circuit 119. The control unit 105 controls the first ventilation device 109 and the second ventilation device 112 to switch between operation stop and operation, switch the airflow rate, and switch whether or not to perform heat exchange ventilation based on signals received from the remote controller 101. The ventilation control interface device 104 also includes a sensor circuit 120 that acquires measurements from air quality sensors 121 provided in each ventilation target area. Examples of the air quality sensors 121 include temperature sensors, humidity sensors, and carbon dioxide sensors, but other sensors may also be used. The air quality sensor 121 may also be a combination of multiple different types of sensors. In this embodiment, the air quality sensor 121 is a temperature sensor.

[0017] A remote controller communication line 205 is connected to the remote controller communication circuit 103 via a communication terminal block 123. The remote controller communication circuit 103 is a communication circuit that transmits and receives signals between the control unit 105 and the remote controller 101 via the remote controller communication line 205.

[0018] AC power is input to the power supply terminal block 106 from an external power supply 107. The power supply circuit 122 converts the AC power supplied from the external power supply 107 into DC power and supplies it to part of the ventilation control interface device 104. Note that the power lines connecting the power supply circuit 122 and part of the ventilation control interface device 104 are not shown in the figure.

[0019] The first switching circuit 110 changes the fan speed of the first ventilation device 109 to adjust the airflow rate by switching on and off the AC signal output to the first ventilation device 109 via the terminal block 108 using a relay, a semiconductor element, or the like. Note that the first switching circuit 110 may adjust the airflow rate by communicating with the first ventilation device 109 and causing a controller (not shown) included in the first ventilation device 109 to change the fan speed of the first ventilation device 109. Furthermore, if the first ventilation device 109 is a ventilation device capable of heat exchange ventilation, the first switching circuit 110 can switch between normal ventilation and heat exchange ventilation.

[0020] The second ventilation device 112 has a different power supply system from the first ventilation device 109 and can operate at a different fan speed from the first ventilation device 109. The second switching circuit 113 changes the fan speed of the second ventilation device 112 and adjusts the airflow by switching on and off an AC signal output to the second ventilation device 112 via the terminal block 111 using a relay, a semiconductor element, or the like. Note that the second switching circuit 113 may communicate with the second ventilation device 112 to have a control unit (not shown) change the fan speed of the second ventilation device 112 and adjust the airflow. Furthermore, if the second ventilation device 112 is a ventilation device capable of heat exchange ventilation, the second switching circuit 113 can switch between normal ventilation and heat exchange ventilation.

[0021] The ventilation assistance device 115 is a blower used as a circulation fan or a 24-hour ventilation fan. However, the ventilation assistance device 115 may also be a circulator that blows warm air stagnating at high altitudes in a space downward to reduce temperature differences within the space. The ventilation assistance device switching circuit 116 changes the fan speed of the ventilation assistance device 115 and adjusts the air volume by switching on and off the AC signal output to the ventilation assistance device 115 via the terminal block 114 using a relay, semiconductor element, or the like.

[0022] The damper 118 is used when the first ventilation device 109 or the second ventilation device 112 ventilates the ventilation target area through a duct, and is installed in a duct leading to each ventilation target area. If the damper 118 is driven by an AC motor, the amount of air sent to each ventilation target area can be adjusted for each ventilation target area by using a mechanism that adjusts the duct opening by the motor driving time after fully closing the damper 118. When the control unit 105 conditions outside air blown out from the first ventilation device 109 or the second ventilation device 112 to the indoor unit 102, the control unit 105 controls the opening of the damper 118 installed in the air path of the air conditioned by the indoor unit 102 based on a signal received from the remote controller 101.

[0023] Because power is supplied from the external power supply 107 to both the outdoor unit 201 and the ventilation control interface device 104, differences in grounding locations and power supply systems can cause a potential difference between the earth connection terminal 202 of the outdoor unit 201 and the earth connection terminal 208 of the ventilation control interface device 104. For this reason, the ventilation control interface device 104 is insulated by an isolation circuit 209 in the remote controller communication circuit 103. By insulating the remote controller communication circuit 103, communication line communication abnormalities and component failures caused by a potential difference between the earth connection terminal 202 of the outdoor unit 201 and the earth connection terminal 208 of the ventilation control interface device 104 are avoided.

[0024] Fig. 3 is a diagram showing the connection configuration of the indoor unit, first ventilation device, and damper, which are controlled by the ventilation control interface device according to embodiment 1. The ventilation control interface device 104 is not shown in Fig. 3. The indoor unit 102 and first ventilation device 109 are connected by a duct 302 that sends air. The indoor unit 102 is connected to an indoor unit indoor air intake 308 that draws in indoor air. The first ventilation device 109 is connected to a ventilation device indoor air intake 307. Note that the indoor unit 102 and the first ventilation device 109 may draw indoor air through a common air intake.

[0025] The first ventilation device 109 is equipped with a heat exchanger 306. The first ventilation device 109 is provided with a bypass air duct that can intake and exhaust air to the outdoors without passing through the heat exchanger 306 inside or outside the first ventilation device 109, and a switching device 304 can be used to switch between ventilation through the heat exchanger 306 and ventilation through the bypass air duct.

[0026] The first ventilation device 109 is connected to an outdoor intake / exhaust port 305 and can take in and exhaust air. The heat exchanger 306 has advantages when used to maintain the temperature, but in intermediate seasons or when the air conditioning device is not in use, taking in outside air may be more effective in maintaining the indoor temperature at an appropriate level.

[0027] The switching device 304 can be controlled from the remote controller 101, and by operating the remote controller 101, it is possible to switch between ventilation through the heat exchanger 306 and ventilation through the bypass air passage.

[0028] The indoor unit 102 is provided with an air outlet 309. A duct connected to the air outlet 309 branches and leads to a room exhaust outlet 311 and a room exhaust outlet 313. The duct leading to the room exhaust outlet 311 is provided with a damper 310 that switches the amount of air sent to the room exhaust outlet 311. Furthermore, the duct leading to the room exhaust outlet 313 is provided with a damper 312 that switches the amount of air sent to the room exhaust outlet 313.

[0029] 2 is installed in each room provided with room exhaust vents 311, 313. The ventilation control interface device 104 adjusts the opening and opening / closing times of the dampers 310, 312 based on the measurement results of the air quality sensor 121.

[0030] Although the example given here is one in which the two rooms in which the room exhaust ports 311 and 313 are installed are the ventilation target areas, the number of ventilation target areas may be one, or three or more. Whether the number of ventilation target areas is one or three or more, the damper 118 is installed corresponding to the ventilation target areas.

[0031] 4 is a diagram showing the configuration of a remote controller communication circuit of the ventilation control interface device according to Embodiment 1. The DC voltage conversion circuit 404 converts the DC voltage input from the indoor unit 102 and generates power for use in the circuitry of the ventilation control interface device 104 on the remote controller 101 side relative to the isolation circuit 209.

[0032] The signal for communication between the ventilation control interface device 104 and the remote controller 101 is a type in which a signal component is superimposed on a DC voltage, and transmission and reception signals are generated and received by separating the communication signal using a transformer 405.

[0033] FIG. 5 shows the waveform of a signal transmitted to the remote controller of the ventilation control interface device according to embodiment 1. For the transmission signal, a circuit that performs amplitude shift keying communication generates a carrier wave with a frequency ranging from 10 kHz to 1000 kHz. The carrier wave is a pulse that alternates between the power supply voltage and 0 V at a constant frequency. As shown in FIG. 5 , the control unit 105 outputs multiple pulses at the same cycle as the carrier wave frequency. The pulses output by the control unit 105 are isolated by a photocoupler or the like in the transmission signal isolation circuit 415, but the pulse waveform is transmitted to the sine wave generation circuit 417 unchanged. The pulses input to the sine wave generation circuit 417 are shaped into a waveform close to a sine wave without changing the frequency. The pulses shaped by the sine wave generation circuit 417 are superimposed on a DC voltage by the transformer 405 to generate a transmission signal. The transmission signal is transmitted to the remote controller 101 via the remote controller communication line 205.

[0034] 6 is a diagram showing the waveform of a signal received from the remote controller of the ventilation control interface device according to embodiment 1. The received signal received from the remote controller 101 undergoes impedance adjustment in the receiving impedance adjustment circuit 406, where the AC signal components are extracted by the transformer 405, and the impedance is adjusted to a voltage within the power supply voltage. The received signal after impedance adjustment includes a portion where there is no carrier wave. The bandpass filter 408 extracts only a certain frequency from the impedance-adjusted received signal, and converts the waveform so that it becomes high level at the carrier wave frequency. The received signal after passing through the bandpass filter 408 is insulated by a photocoupler or the like in the received signal isolation circuit 410, but the pulse waveform is sent to the control unit 105 unchanged.

[0035] FIG. 7 shows the configurations of the transmission signal isolation circuit and the reception signal isolation circuit of the ventilation control interface device according to embodiment 1. The transmission signal isolation circuit 415 on the transmitting side switches the carrier signal output from the transmission port 606 of the control unit 105. The current amplified by the first transistor 605 is passed through the high-speed photocoupler 604, driving the high-speed photocoupler 604. The output of the high-speed photocoupler 604 is subjected to logic conversion by the second transistor 602 and the third transistor 603, thereby adjusting the on / off times of the waveform distorted by the high-speed photocoupler 604 and shaping the waveform. The on / off times of the waveform can be shaped by increasing the base resistance of the second transistor 602 and making the resistance between the base and the collector lower than the base resistance. Based on the signal whose waveform has been shaped by the second transistor 602 and the third transistor 603, the sine wave generation circuit 417 generates a transmission signal whose waveform resembles a sine wave.

[0036] The receiving signal isolation circuit 410 on the receiving side does not perform high-speed switching operations because the bandpass filter 408 shapes the carrier wave portion to a high level. Therefore, it is turned on and off by a normal photocoupler 608. The signal output from the bandpass filter 408 is input to the photocoupler 608 via a fourth P-channel transistor 609, driving the photocoupler 608. The signal output from the photocoupler 608 is input to the control unit 105 from the receiving port 607 of the control unit 105.

[0037] The transmission signal isolation circuit 415 and the reception signal isolation circuit 410 can be omitted if isolation is not required. A ventilation control interface device 104 including the transmission signal isolation circuit 415 and the reception signal isolation circuit 410 and a ventilation control interface device 104 omitting the transmission signal isolation circuit 415 and the reception signal isolation circuit 410 can share the same circuit configuration except for the transmission signal isolation circuit 415 and the reception signal isolation circuit 410. Therefore, even if the transmission signal isolation circuit 415 and the reception signal isolation circuit 410 are omitted, the ventilation control interface device 104 can be configured without changing the software of the control unit 105.

[0038] The remote controller 101 is not only capable of setting the temperature of the air conditioning apparatus and switching between heating and cooling, but is also capable of operating the first ventilation device 109, the second ventilation device 112, the ventilation assistance device 115, and the damper 118. When the fan speed setting operation of the first ventilation device 109, the second ventilation device 112, or the ventilation assistance device 115 is performed from the remote controller 101, the remote controller 101 outputs a communication signal to the remote controller communication line 205 to notify the ventilation control interface device 104 of the fan speed of the first ventilation device 109, the second ventilation device 112, or the ventilation assistance device 115. When the ventilation control interface device 104 receives the fan speed information, the control unit 105 controls the first switching circuit 110, the second switching circuit 113, or the ventilation assistance device switching circuit 116 to change the fan speed. Switching between the heat exchanger 306 and direct outside air intake, turning on / off 24-hour ventilation, and opening / closing the damper 118 can also be performed by operating the remote controller 101 using similar processing.

[0039] The outdoor unit 201 of the air conditioner is equipped with an outdoor air temperature sensor 201a, and some models are capable of measuring the outdoor air temperature. If the outdoor unit 201 is capable of measuring the outdoor air temperature, when taking in outdoor air, the outdoor unit 201 compares the outdoor air temperature measured by the outdoor air temperature sensor 201a with the temperature of the air drawn in through the indoor unit indoor air intake 308 measured by the air quality sensor 121, which is a temperature sensor. In cooling mode, if the outdoor air temperature is lower than the indoor air temperature, control is performed to take in outdoor air. The air quality sensor 121 can also measure the temperature of each room beyond the damper 118, and the air conditioner can adjust the temperature of each room by heating or cooling while taking in outdoor air to the target temperature. The control unit 105 displays the operating status of the first ventilation device 109, the second ventilation device 112, the ventilation auxiliary device 115, and the indoor unit 102 on the remote controller 101. The control unit 105 also causes the remote controller 101 to display the outside air temperature measured by the outside air temperature sensor 201a.

[0040] Furthermore, if the ventilation assistance equipment 115 is a circulator that circulates air within a building across multiple floors, and temperature sensors that are air quality sensors 121 are installed in rooms on each floor, the ventilation assistance equipment 115 can be operated based on the measurement values ​​of the air quality sensors 121 in each room and the target temperature, thereby controlling the target temperatures between rooms to approach each other. If the ventilation assistance equipment 115 is a 24-hour ventilation device, it may not necessarily need to be operated when the ventilation function of the first ventilation equipment 109 or the second ventilation equipment 112 is on. For this reason, linked control may be performed to stop the ventilation assistance equipment 115 when the ventilation function of the first ventilation equipment 109 or the second ventilation equipment 112 is on.

[0041] The ventilation control interface device 104 according to the first embodiment includes a control unit 105 that controls the ventilation equipment, and is connected to a remote controller communication line 205 that connects the remote controller 101 and the indoor unit 102. Therefore, the ventilation control interface device 104 according to the first embodiment can perform linked operation even if the indoor unit 102, the first ventilation equipment 109, and the second ventilation equipment 112 do not support the centralized control method.

[0042] Furthermore, because the ventilation control interface device 104 according to the first embodiment is connected to the remote controller communication line 205, the remote controller 101 can be shared by the indoor unit 102, the first ventilation device 109, and the second ventilation device 112. Therefore, a user of the ventilation control interface device 104 can use the remote controller 101 to set the operating conditions of the indoor unit 102, the first ventilation device 109, and the second ventilation device 112 by operating the remote controller 101.

[0043] Furthermore, since the ventilation control interface device 104 according to the first embodiment is capable of connecting and controlling the ventilation assisting equipment 115, the ventilation assisting equipment 115 can be operated in conjunction with the indoor unit 102, the first ventilation equipment 109, and the second ventilation equipment 112, thereby further improving the air conditioning efficiency.

[0044] Next, we will explain the hardware configuration of the control unit 105 provided in the ventilation control interface device 104. Fig. 8 is a diagram showing an example of the hardware configuration realizing the control unit provided in the ventilation control interface device according to embodiment 1. The control unit 105 is realized as a computer system by a processing circuit including a processor 91 that executes various processes, a memory 92 that serves as a main memory, and a storage device 93 that stores information.

[0045] The processor 91 may be a computing device such as an arithmetic unit, microprocessor, microcomputer, CPU (Central Processing Unit), or DSP (Digital Signal Processor). The memory 92 may be a non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), or EEPROM (Electrically Erasable Programmable Read Only Memory). The storage device 93 stores programs for setting the operation of the first ventilation device 109, the second ventilation device 112, the ventilation assist device 115, and the indoor unit 102. The processor 91 reads the programs stored in the storage device 93 into the memory 92 and executes them. The processor 91 reads the programs stored in the storage device 93 into the memory 92 and executes them, thereby realizing the functions of the control unit 105.

[0046] The configurations shown in the above embodiments are merely examples of the content, and may be combined with other known technologies, or parts of the configurations may be omitted or modified without departing from the spirit of the invention.

[0047] 20 Air conditioning apparatus, 91 Processor, 92 Memory, 93 Storage device, 101 Remote controller, 102 Indoor unit, 103 Remote controller communication circuit, 104 Ventilation control interface device, 105 Control unit, 106 Power supply terminal block, 107 External power supply, 108, 111, 114, 117 Terminal block, 109 First ventilation device, 110 First switching circuit, 112 Second ventilation device, 113 Second switching circuit, 115 Ventilation auxiliary device, 116 Ventilation auxiliary device switching circuit, 118, 310, 312 Damper, 119 Damper opening switching circuit, 120 Sensor circuit, 121 Air quality sensor, 122 Power supply circuit, 123 Communication terminal block, 201 Outdoor unit, 201a Outdoor air temperature sensor, 202, 208 Earth connection terminal, 203 Indoor / outdoor connection line, 205 Remote controller communication line, 209: isolation circuit, 302: duct, 304: switching device, 305: intake / exhaust port, 306: heat exchanger, 307: ventilation equipment indoor air intake port, 308: indoor unit indoor air intake port, 309: air outlet, 311, 313: room exhaust port, 404: DC voltage conversion circuit, 405: transformer, 406: receiving impedance adjustment circuit, 408: bandpass filter, 410: receiving signal isolation circuit, 415: transmitting signal isolation circuit, 417: sine wave generation circuit, 602: second transistor, 603: third transistor, 604: high-speed photocoupler, 605: first transistor, 606: transmitting port, 607: receiving port, 608: photocoupler, 609: fourth transistor.

Claims

1. It is connected to the remote controller communication line that connects the indoor unit of the air conditioner and the remote controller of the air conditioner, The system comprises a control unit that controls at least one ventilation device that exhausts indoor air to the outside and supplies outside air to the inside for ventilation, and a communication circuit that transmits and receives signals between the control unit and the remote controller via the remote controller communication line. The communication circuit is a ventilation control interface device that includes an isolation circuit that electrically isolates the remote controller communication line from the control unit.

2. The ventilation control interface device according to claim 1, wherein the control unit causes the ventilation equipment to switch between operation and stop, switch airflow, and switch whether or not to perform heat exchange ventilation, based on the signal received from the remote controller.

3. The ventilation control interface device according to claim 1, wherein when the control unit conditioned the outside air blown out from the ventilation equipment into the indoor unit, the control unit controls the opening degree of a damper installed in the airflow path of the air after it has been conditioned by the indoor unit based on the signal received from the remote controller.

4. The damper is driven by an AC motor, The ventilation control interface device according to claim 3, wherein the control unit controls the opening degree of the damper based on the driving time of the AC motor from the fully closed state of the damper.

5. The communication circuit includes a sine wave generation circuit that brings the pulse output by the control unit closer to a sine wave, and a bandpass filter that shapes the signal received from the remote controller into a pulse in which the portion including the carrier wave is high level and the portion not including the carrier wave is low level. The ventilation control interface device according to claim 1, wherein the isolation circuit includes a transmit signal isolation circuit provided between the sine wave generation circuit and the control unit, and a receive signal isolation circuit provided between the bandpass filter and the control unit.

6. The ventilation control interface device according to claim 5, wherein the transmission signal isolation circuit comprises a first transistor that amplifies the current of a pulse output by the control unit, a high-speed photocoupler driven by the pulse whose current has been amplified by the first transistor, and a second transistor and a third transistor that shape the pulse output from the high-speed photocoupler.

7. The ventilation control interface device according to claim 3, wherein the control unit, when the air conditioner is in cooling operation, blows the outside air out to the indoor unit if the outside air temperature measured by the outside air temperature sensor provided on the outdoor unit of the air conditioner is lower than the indoor temperature measured by the temperature sensor that measures the indoor temperature.

8. A temperature sensor is installed in each room on multiple floors of the building to measure the indoor temperature, and a circulator is connected to it to circulate the air inside the building across the multiple floors. The ventilation control interface device according to claim 3, wherein the control unit controls the circulator so that the temperature of each room on the plurality of levels approaches a target value based on the measurement results of the temperature sensor.

9. A 24-hour ventilation system is connected. The ventilation control interface device according to claim 3, wherein the control unit stops the 24-hour ventilation device when it is conditioned by the outside air taken in from the outside air intake into the indoor unit.

10. The ventilation control interface device according to any one of claims 1 to 9, wherein the control unit displays the operating status of the ventilation equipment and the indoor unit on the remote controller.