JP6116296B2 - Ventilation device and air conditioning system - Google Patents

Description

  The present invention relates to a ventilation device and an air conditioning system including the ventilation device.

The law (common name: Building Management Act) on ensuring a sanitary environment in buildings stipulates that the CO ₂ concentration in the living room of a specific building be 1000 ppm or less. In order to satisfy this standard, for example, there is a method of measuring the time with a timer or the like and forcibly operating the ventilator at regular intervals, but this is a wasteful ventilation operation when there is no person in the room. For this reason, there is a demand for a ventilator that performs a ventilation operation only when ventilation is required based on the detection value of a sensor (hereinafter referred to as CO ₂ sensor) that measures the concentration of carbon dioxide (hereinafter referred to as CO ₂ ) in indoor air. It is high. In the conventional ventilator, the measurement result from the built-in CO ₂ sensor or the external CO ₂ sensor is input to the ventilator, and the ventilation air volume is automatically controlled so that the CO ₂ concentration of the indoor air does not exceed 1000 ppm. doing.

Here, in the current general CO ₂ sensor, the measurement value output fluctuates with time due to the aging of the components constituting the sensor, etc., so that a regular calibration process is required to obtain an accurate measurement value. . For this reason, a CO ₂ sensor having an automatic calibration function has been proposed. As such, for example, the minimum measured value of the CO ₂ concentration measured during the preselected measurement cycle is stored in the memory, and the minimum measured value is set to 400 ppm which is the CO ₂ concentration of fresh air as the target value. There is a technique for compensating the measurement value of the next measurement cycle based on the result of comparing the target value and the target value (see Patent Document 1).

Japanese translation of PCT publication No. 2007-502407 (pages 17 and 18)

In the ventilator described in Patent Document 1, compensation is performed by the automatic calibration function of the CO ₂ sensor so that the minimum measured value of the CO ₂ concentration during the measurement cycle approaches 400 ppm, which is the CO ₂ concentration of fresh air. . Therefore, in an environment in which the CO ₂ concentration in the indoor air during the measurement cycle drops to be regarded as equivalent to the fresh air, the error of the CO ₂ concentration of the measurement results is reduced greater than 1000ppm is CO ₂ concentration in the room air It is thought that control can be performed so that there is no.

However, the condition that the CO ₂ concentration of the room air is reduced to be considered equivalent to fresh air during the measurement cycle is not always satisfied. For example, in a normal office, the CO ₂ concentration in the room air decreases when there is no person at night or on holidays, so if the measurement cycle is set to about one week, the CO ₂ concentration as described above can be regarded as equivalent to fresh air. Time zones can be included in the measurement cycle. However, if the measurement cycle is set to about one week in an environment where the room is almost unattended, such as when monitoring is conducted 24 hours a day, the CO ₂ concentration in the indoor air is equivalent to fresh air in the measurement cycle. It is thought that it will not decrease until. Thus, the appropriate measurement cycle for calibrating the CO ₂ sensor depends on the circumstances of the environment in which the ventilation device is installed. Moreover, the influence by the structure of the building to be ventilated is also considered. For example, when the target room is highly sealed, the CO ₂ concentration in the room air may not be sufficiently reduced even if the room is unattended.

When the technique described in Patent Document 1 is applied to an environment in which the CO ₂ concentration of room air is higher than that of fresh air during the measurement cycle, erroneous compensation is performed by automatic calibration, and CO _2. The error of the density measurement result becomes large. For example, assuming that the actual minimum concentration of indoor air during the measurement cycle is 500 ppm, the measurement result when the actual CO ₂ concentration is 500 ppm is compensated so as to approach 400 ppm which is the CO ₂ concentration of fresh air. As a result, the measurement result of the compensated CO ₂ concentration becomes smaller than the actual CO ₂ concentration. When ventilator performs air volume control based on the CO ₂ concentration of the measurement result after this compensation, there is a possibility that the CO ₂ concentration in the indoor air exceeds 1000 ppm.

The present invention has been made against the background of the above-described problems. A ventilator that accurately calibrates the output of a CO ₂ sensor and keeps the CO ₂ concentration of room air below a reference value, and an air conditioner equipped with the ventilator. A system is provided.

A ventilator according to the present invention is a ventilator that performs either or both of an exhaust operation for operating a blower to exhaust indoor air to the outside and an air supply operation for operating the blower to supply outdoor air to the room. A CO ₂ sensor that measures the carbon dioxide concentration in the room, and a calibration unit that calibrates the output of the CO ₂ sensor based on the measurement value of the CO ₂ sensor during a measurement period that is a periodic measurement cycle. A control means for controlling the blower and an unmanned judgment means for judging whether or not the room is unmanned, wherein the control means is determined by the unmanned judgment means to be unmanned. In addition, the forced ventilation operation is performed by operating the blower for a predetermined time , and the calibration unit is configured to perform a minimum of the carbon dioxide concentration measured by the CO ₂ sensor during the measurement period in parallel with the forced ventilation operation. Values, have rows calibration processing of the output of the CO ₂ sensor as close to the calibration reference value, the length of the measurement period, the unmanned determining means is the indoor and then unattended since it is determined that the unmanned determination It is more than the period until .

  The air conditioning system according to the present invention includes the ventilator and an air conditioner that performs air conditioning in the room to be ventilated by the ventilator.

According to the present invention, it is possible to calibrate the output of the CO ₂ sensor in accordance with the situation in the room to be ventilated subject, CO ₂ sensor can accurately detect the CO ₂ concentration in the room air. The ventilator that performs the ventilation operation according to the detected CO ₂ concentration can accurately maintain the CO ₂ concentration of the indoor air below the reference value, and reduces unnecessary ventilation operation to save energy related to the ventilation operation. be able to.

It is a figure which shows the structure of the ventilation apparatus which concerns on Embodiment 1 of this invention. It is a functional block diagram of a CO ₂ sensor according to the first embodiment of the present invention. I am a flowchart illustrating a CO ₂ calibration process of the sensor of the ventilator according to the first embodiment of the present invention. It is a figure which shows the structure of the ventilation apparatus which concerns on Embodiment 2 of this invention. It is a functional block diagram of a CO ₂ sensor according to the second embodiment of the present invention. It is a flowchart illustrating a CO ₂ calibration process of the sensor of the ventilator according to the second embodiment of the present invention. It is a figure which shows the structure of the ventilation apparatus which concerns on Embodiment 3 of this invention. It is a flowchart illustrating a CO ₂ calibration process of the sensor of the ventilator according to the third embodiment of the present invention. It is a figure which shows the structure of the ventilation apparatus which concerns on Embodiment 4 of this invention. It is a flowchart illustrating a CO ₂ calibration process of the sensor of the ventilator according to the fourth embodiment of the present invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment in which a ventilation device according to the present invention is applied to a heat exchange type ventilation device having a heat exchange element and a first type ventilation system will be described with reference to the drawings. In addition, this invention is not limited by the form of drawing shown below.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration of a ventilation device according to Embodiment 1 of the present invention. In FIG. 1, an outdoor air supply port 1, an indoor air supply port 3, an indoor exhaust port 5, and an outdoor exhaust port 6 are formed in a housing 101 of a heat exchange type ventilation device 100. An air supply fan 4 is provided in an air supply passage 102 that supplies air from the outdoor air supply port 1 (OA) through the heat exchange element 2 to the indoor air supply port 3 (SA). An exhaust fan 7 is provided in the exhaust passage 103 that exhausts air from the indoor exhaust port 5 (RA) through the heat exchange element 2 to the outdoor exhaust port 6 (EA). Note that the air supply passage 102 and the exhaust passage 103 are passages formed in the housing 101. In FIG. 1, air flowing through them is indicated by arrows for the sake of explanation.

  When the air supply fan 4 is operated, outdoor air is sucked into the housing 101 from the outdoor air supply port 1, and this outdoor air passes through the heat exchange element 2 and is sent to the air supply fan 4 for indoor air supply. The air is blown out from the mouth 3 into the room. When the exhaust fan 7 operates, room air is sucked into the housing 101 from the indoor exhaust port 5, and this indoor air passes through the heat exchange element 2 and is sent to the exhaust fan 7 to be sent to the outdoor exhaust port 6. It is blown out as exhaust from the room. The outdoor air flowing through the air supply passage 102 and the indoor air flowing through the exhaust passage 103 exchange heat in the heat exchange element 2. Thus, when performing the ventilation operation, for example, the outflow of indoor heat to the outside is suppressed in winter, and the inflow of heat from the outside into the room is suppressed in summer.

The CO ₂ sensor 8 is a sensor that measures the CO ₂ concentration of room air, and is provided on a path through which room air exhausted from the room passes. CO ₂ sensor 8 is the measured CO ₂ concentration value (CO ₂ concentration measurement) is sent to the control circuit 10 through the communication line 9 for connecting the control circuit 10 and the CO ₂ sensor 8, the control circuit 10 It is stored and held in the CO ₂ measurement value storage means 11 provided. In the first embodiment, the CO ₂ sensor 8 is provided in the exhaust passage 103 and near the indoor exhaust port 5. However, the installation location of the CO ₂ sensor 8 is not limited to the illustrated one. For example, it can be installed in any place that comes into contact with room air, such as the vicinity of the room-side exhaust port 5 on the surface of the housing 101. Alternatively, the CO ₂ sensor 8 may be installed indoors apart from the housing 101, and the detection value of the CO ₂ sensor 8 may be input to the control circuit 10 by wired or wireless communication.

The control circuit 10 includes a CPU, a non-volatile memory and the like (both not shown), and in response to information output from the CO ₂ sensor 8 and an operation signal input from an operation device (not shown) such as a remote controller, The air supply fan 4 and the exhaust fan 7 are operated based on a control program stored in advance. The main components provided in the control circuit 10 are a CO ₂ measurement value storage unit 11, a CO ₂ sensor calibration execution instruction unit 12, an air volume control unit 13, and a clock unit 14.

The CO ₂ sensor calibration execution instructing unit 12 provided in the control circuit 10 has a function of instructing the CO ₂ sensor 8 to execute calibration via the communication line 9. When the CO ₂ sensor calibration execution instructing means 12 sends a calibration execution command to the CO ₂ sensor 8 via the communication line 9, the CO ₂ sensor 8 executes a calibration process for calibrating its own output when the command is received. To do.

The air volume control means 13 in the control circuit 10 changes the ventilation air volume of the ventilation device 100 by controlling the air supply fan 4 and the exhaust fan 7. The air volume control means 13 is an automatic control mode that adjusts the ventilation air volume based on the output of the CO ₂ sensor 8 and a manual control mode that adjusts the ventilation air volume based on an instruction from an operating device (not shown) such as a remote controller. It has at least one type of mode.

In the mode in which the ventilation air volume is automatically controlled, the air volume control means 13 outputs a CO ₂ concentration measurement value periodically output from the CO ₂ sensor 8 and held in the CO ₂ measurement value storage means 11 to a predetermined threshold value (hereinafter referred to as a “threshold value”). When approaching the (CO ₂ threshold), increase the ventilation air volume. Conversely, if the measured CO ₂ concentration is sufficiently small relative to the CO ₂ threshold, the ventilation air volume is reduced (or the ventilation is stopped). By controlling in this way, the CO ₂ concentration measurement value does not exceed a predetermined CO ₂ threshold value and works to suppress an increase in power consumption due to useless ventilation operation. Here, the predetermined CO ₂ threshold value can be set to, for example, 1000 ppm which is a legal value determined for a room of a specific building in the Building Management Law. When there is a possibility of exceeding the CO ₂ threshold due to measurement error or time required for ventilation, a value smaller than 1000 ppm may be set as the CO ₂ threshold in consideration of the margin.
In the mode in which the ventilation air volume is manually controlled without performing automatic control, the air volume control means 13 changes the ventilation air volume in accordance with an instruction from a local remote controller (not shown), for example.

  The clock means 14 in the control circuit 10 includes, for example, an oscillator that outputs a clock signal having a predetermined frequency, and hour, minute, and second counters, and counts up each counter based on the clock signal. Measure time. The control circuit 10 can acquire the current time from the clock means 14.

The diagram of the control circuit 10 shown in FIG. 1 is a block diagram conceptually showing the function of the control circuit 10, and the actual physical configuration is not necessarily configured as shown.
In addition, in the following description, the functions executed by the components other than the CO ₂ measurement value storage means 11, the CO ₂ sensor calibration execution instruction means 12, the air volume control means 13 and the clock means 14 provided in the control circuit 10 will be described. The description will be made assuming that the control circuit 10 simply executes.

FIG. 2 is a functional block diagram of the CO ₂ sensor according to Embodiment 1 of the present invention. The CO ₂ sensor 8 includes a sensor unit 81, a calibration unit 82, and a storage unit 83. The sensor unit 81 detects the CO ₂ concentration in the air by an arbitrary method, and outputs the detected information to the control circuit 10 via the communication line 9.

The calibration unit 82 performs a calibration process on the output of the sensor unit 81 based on an instruction from the CO ₂ sensor calibration execution instruction unit 12 of the control circuit 10. Specifically, the CO ₂ sensor 8 compares the measured CO ₂ concentration value measured at the time of receiving the calibration execution command with a reference value (hereinafter referred to as a calibration reference value) to obtain the measured CO ₂ concentration value. Calibrates its own output to match the reference value. It is assumed that the CO ₂ sensor 8 stores the calibration reference value in advance. For example, the calibration reference value, if the value indicating the CO ₂ concentration of the fresh air (e.g. 400 ppm), the CO ₂ sensor 8 executes the calibration process, the air around the CO ₂ sensor 8 at that time and fresh air A deemed calibration is performed.

The storage unit 83 stores at least a CO ₂ reference value used when the calibration unit 82 performs the calibration process.
Note that the CO ₂ sensor 8 shown in FIG. 2 is a block diagram conceptually showing the function of the CO ₂ sensor 8, and it is not always necessary that the actual physical configuration is configured as shown.

Next, the calibration process of the CO ₂ sensor 8 will be specifically described. FIG. 3 is a flowchart for explaining the calibration process of the CO ₂ sensor of the ventilation apparatus according to Embodiment 1 of the present invention.

  The control circuit 10 acquires the current time T from the clock means 14 (S1).

  Subsequently, the control circuit 10 determines whether or not the acquired current time T is within the range from the start time Ts to the end time Te of a predetermined calibration execution time (S2). If the current time T is within the range from the start time Ts to the end time Te (S2; Yes), the process proceeds to step S3. If the current time T is out of the range (S2; No), the process proceeds to step S4. Here, for example, the start time Ts is set to 11 pm and the end time Te is set to 5 am so that the room to be ventilated is likely to be unmanned, such as from midnight to early morning. In the first embodiment, it is determined (estimated) whether or not the room is unattended using the time, and the clock means 14 and the control circuit 10 determine whether or not the room is unattended. It functions as a means.

In step S3, the CO ₂ sensor calibration execution instructing unit 12 refers to the calibration execution flag F1 and determines whether the calibration processing has already been performed. When the calibration process has not been performed (S3; No), the process proceeds to step S5. When the calibration process has been performed (S3; Yes), the process returns to step S1. In the example of FIG. 3, as for the value of the calibration execution flag F1, 1 indicates that calibration has been performed, and 0 indicates that calibration processing has not been performed. The calibration completion flag F1 is stored in a storage means (not shown) provided in the control circuit 10.

  In step S4, the control circuit 10 clears the calibration execution flag F1 and returns to step S1.

In step S5, the air volume control means 13 controls the air supply fan 4 and the exhaust fan 7 to carry out forced ventilation operation with a predetermined ventilation air volume for a predetermined time. The forced ventilation operation is an operation for making the air around the CO ₂ sensor 8 equal to fresh air, and the ventilation air volume and time of the forced ventilation operation are determined in advance. When the forced ventilation operation is executed, fresh outdoor air is sucked into the ventilator 100 from the outdoor air supply port 1 and supplied from the indoor air supply port 3 to the room, and the supplied air is supplied to the indoor exhaust port. 5 is sucked into the ventilator 100 and discharged to the outside through the outdoor exhaust port 6. Thereby, the air around the CO ₂ sensor 8 installed near the indoor exhaust port 5 has a CO ₂ concentration equivalent to that of fresh air. In addition, when there is a distance between the installation position of the CO ₂ sensor 8 and the room, such as when the heat exchange type ventilation device 100 is installed behind the ceiling, the ventilation air volume of the forced ventilation operation is increased or the forced ventilation operation is performed. Make the time longer. By doing in this way, the air around the CO ₂ sensor 8 can be brought closer to fresh air. After performing the forced ventilation operation, the process proceeds to step S6.

In step S6, the CO ₂ sensor calibration execution instructing means 12 instructs the CO ₂ sensor 8 to execute calibration. The calibration means 82 of the CO ₂ sensor 8 that has received the calibration execution instruction uses the CO ₂ concentration value measured by the sensor unit 81 of the CO ₂ sensor 8 during the measurement period after the forced ventilation operation as a calibration reference value (for example, Calibration of the output is performed so that the CO ₂ concentration of fresh air is considered to be 400 ppm. When step S6 ends, the process proceeds to step S7.

  In step S7, the control circuit 10 sets a value in the calibration completion flag F1, and returns to step S1. By determining whether or not the calibration is performed using the calibration completed flag F1, the calibration is performed only once when the time is within the range of the calibration execution time from the start time Ts to the end time Te. The

Such processing from step S1 to step S7 is repeatedly executed, and the forced ventilation operation is periodically executed, and the CO ₂ is measured based on the measured value of the CO ₂ sensor 8 during the measurement period provided after each forced ventilation operation. Calibration of the output of the _two sensors 8 is also periodically executed.

By performing the control in the above steps S1 to S7, the forced ventilation operation is performed in a state in which it is determined that there is no person based on the time, and the air around the CO ₂ sensor 8 is measured as being in a state very close to fresh air. Calibration of the output of the CO ₂ sensor 8 can be performed based on the CO ₂ concentration measured during the period. Thus, even without an automatic calibration function CO ₂ sensor 8, CO ₂ sensor 8 becomes possible to detect the CO ₂ concentration with high accuracy. Since the CO ₂ sensor 8 can detect the CO ₂ concentration with high accuracy, the reliability of the ventilation operation of the ventilation device 100 that executes the ventilation operation according to the detected CO ₂ concentration is increased, and the CO ₂ concentration of the indoor air is a reference value. The following can be accurately maintained. Moreover, useless ventilation operation can be reduced and the energy concerning ventilation operation can be saved.

In step S4 in FIG. 3, the calibration execution flag F1 is cleared. However, this may not be performed, and the calibration execution flag F1 may be cleared once in a separately defined period (for example, one week). . In this case, the calibration process of the output of the CO ₂ sensor 8 is performed once in a separately determined period instead of once a day.

The clock means 14 may have a calendar function that can refer to not only the time but also the date (including year, month, day, day of the week, and holiday information). In this case, instead of determining the time range in step S2 of FIG. 3, it is determined whether or not the place to be ventilated is a holiday by determining whether or not the place to be ventilated is a holiday. Thus, the CO ₂ sensor 8 can be calibrated. Further, the CO ₂ sensor 8 may be calibrated either at midnight on weekdays, during the daytime on holidays, or both by determining whether or not the place to be ventilated is unmanned by the combination of time and day of the week.

In the first embodiment, the heat exchange type ventilator 100 including the heat exchange element 2 has been described as an example. However, the present invention is not limited to this, and the present invention may be applied to a ventilator such as a ventilator without a heat exchange function. It is possible to calibrate the CO ₂ sensor 8 in the same manner. The same applies to the embodiments described later.

Embodiment 2. FIG.
In the first embodiment, the CO ₂ sensor calibration execution instructing means 12 of the control circuit 10 is configured to instruct the CO ₂ sensor 8 to execute calibration. However, the CO ₂ sensor is provided with an automatic calibration function. May be. Hereinafter, such an embodiment will be described. FIG. 4 is a diagram showing a configuration of a ventilation device according to Embodiment 2 of the present invention. The same elements as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted, focusing on differences from the first embodiment.

As shown in FIG. 4, the control circuit 10A of the present embodiment does not include the CO ₂ sensor calibration execution instructing unit 12 shown in the first embodiment. Further, in the present embodiment, CO ₂ sensor 8A are provided in place of the CO ₂ sensor 8 shown in the first embodiment. The CO ₂ sensor 8A is provided on a path through which room air exhausted from the room passes and is connected to the control circuit 10A through the communication line 9, but is similar to the first embodiment, but has an automatic calibration function. It differs in that it has. Other configurations are the same as those in the first embodiment.

FIG. 5 is a functional block diagram of the CO ₂ sensor according to Embodiment 2 of the present invention. In addition to the function of the CO ₂ sensor 8 described in the first embodiment, the CO ₂ sensor 8A has a function of automatically executing a calibration process regardless of an instruction from the control circuit 10. Specifically, the CO ₂ sensor 8A includes a clock unit 84 in addition to the sensor unit 81, the calibration unit 82A, and the storage unit 83. The clock means 84 includes an oscillator that outputs a clock signal having a predetermined frequency and hour, minute, and second counters, and measures time by counting up each counter based on the clock signal. The calibration unit 82A is a sensor that brings the minimum measured value of the CO ₂ concentration in the predetermined measurement cycle Tc measured by the clock unit 84 closer to the calibration reference value (for example, 400 ppm, which is a value indicating the CO ₂ concentration of fresh air). Calibration of the output of the unit 81 is performed. The calibration unit 82A periodically performs calibration processing at a predetermined measurement cycle Tc.

Next, an operation related to the calibration process of the CO ₂ sensor 8A according to the _second embodiment will be described.
FIG. 6 is a flowchart for explaining the calibration process of the CO ₂ sensor of the ventilation apparatus according to Embodiment 2 of the present invention. The flowchart shown on the left side of FIG. 6 is a forced ventilation operation process executed by the control circuit 10, and the flowchart shown on the right side of the page is a calibration process executed by the CO ₂ sensor 8A.

First, forced ventilation operation will be described.
In step S <b> 10, the control circuit 10 acquires the current time T from the clock unit 14.

  The control circuit 10 determines whether or not the acquired current time T is within the range from the start time Ts to the end time Te of the predetermined forced ventilation execution time (S11). If the current time T is within the range from the start time Ts to the end time Te (S11; Yes), the process proceeds to step S12. If the current time T is out of the range (S11; No), the process proceeds to step S13. Here, as in the first embodiment, for example, the start time Ts is 11:00 pm and the end time Te is 5:00 am. Set to be. In the second embodiment, it is determined (estimated) whether or not the room is unattended using the time, and the clock means 14 and the control circuit 10 determine whether or not the room is unattended. It functions as a means.

  In step S12, the control circuit 10 refers to the forced ventilation execution flag F2 and determines whether the forced ventilation operation has already been performed. When the forced ventilation operation has not been performed (S12; No), the process proceeds to step S14, and when the forced ventilation operation has been performed (S12; Yes), the process returns to step S10.

  In step S13, the control circuit 10 clears the forced ventilation execution flag F2 and returns to step S10.

In step S14, the air volume control means 13 controls the air supply fan 4 and the exhaust fan 7 in the same manner as in step S5 of FIG. 3 shown in the first embodiment, and performs forced ventilation operation for a predetermined time with a predetermined ventilation air volume. To implement. The forced ventilation operation is an operation for making the air around the CO ₂ sensor 8A equivalent to fresh air, and the ventilation air volume and time of the forced ventilation operation are determined in advance. When the forced ventilation operation ends, the process proceeds to step S15.

  In step S15, the control circuit 10 sets the forced ventilation execution completion flag F2, and returns to step S10. By determining whether or not the forced ventilation operation is to be performed using the forced ventilation performed flag F2, when the time becomes within the range of the forced ventilation performance from the start time Ts to the end time Te, only once Forced ventilation operation is carried out. Steps S10 to S15 are repeatedly executed, and the forced ventilation operation is periodically executed.

In parallel with such forced ventilation operation, the CO ₂ sensor 8A executes the following calibration process.
The calibration means 82A of the CO ₂ sensor 8A starts measuring the elapsed time of the measurement cycle Tc using the clock means 84 (S20).

  The calibration unit 82A compares the current measurement value measured by the sensor unit 81 with the lowest measurement value in the measurement cycle Tc. If the current measurement value is smaller (S21; Yes), the current measurement value. Is stored in the storage means 83 as the lowest measured value (S22). If the current measurement value is equal to or greater than the measurement minimum value in the measurement cycle Tc (S21; No), the process proceeds to step S23.

In step S23, the calibration means 82A determines whether or not the time of the measurement cycle Tc has elapsed, and if not (S23; No), returns to step S21. Therefore, during the period of the measurement cycle Tc, the sensor unit 81 periodically measures the CO ₂ concentration, and when the lowest value is measured, the process of updating the lowest measured value is repeatedly executed. When the time of the measurement cycle Tc has elapsed (S23; Yes), the process proceeds to step S24.

In step S24, the calibration unit 82A outputs the output of the sensor unit 81 so that the measurement minimum value of the CO ₂ concentration in the measurement period of the measurement cycle Tc is, for example, a value (for example, 400 ppm) indicating the CO ₂ concentration of fresh air. Perform calibration. When step S24 ends, the process returns to step S20, and the next measurement cycle Tc starts.

As described above, the ventilator 100A of the second embodiment periodically performs forced ventilation operation, while the CO ₂ sensor 8A is automatically and independently from the control circuit 10 periodically (for each measurement cycle Tc). Perform calibration processing. Therefore, if at least one forced ventilation operation is performed during the measurement cycle Tc, a state in which the air around the CO ₂ sensor 8A is equivalent to fresh air during the measurement cycle Tc is included. It will be. Since the CO ₂ sensor 8A detects the CO ₂ concentration when the ambient air becomes equal to fresh air by forced ventilation operation as the lowest measured value, the CO ₂ sensor 8A thereby accurately executes the output calibration process. can do. Therefore, the CO ₂ sensor 8A can measure the CO ₂ concentration more accurately. Since the CO ₂ sensor 8A can detect the CO ₂ concentration with high accuracy, the reliability of the ventilation operation of the ventilation device 100A that executes the ventilation operation according to the detected CO ₂ concentration is increased, and the CO ₂ concentration of the indoor air is a reference value. The following can be accurately maintained. Moreover, useless ventilation operation can be reduced and the energy concerning ventilation operation can be saved.

The measurement cycle Tc and the forced ventilation execution time may be set so that at least one forced ventilation operation is performed during the measurement cycle Tc. For example, the forced ventilation operation is performed twice or more during the measurement cycle Tc. May be implemented.
Specifically, in FIG. 6, the forced ventilation execution flag F2 is cleared in step S13, but this is not performed, and the forced ventilation execution flag F2 is cleared once in a separately defined period Ta. Also good. In this case, the forced ventilation operation is performed once in the period Ta instead of once a day as described above. Here, for example, when the measurement cycle Tc of the CO ₂ sensor 8A is one week, if the period Ta is set to 5 days and the relationship between the period Ta and the measurement cycle Tc is Ta ≦ Tc (the period Ta is Since the period Ta during which the forced ventilation operation is performed is included in the measurement cycle Tc, the automatic calibration is executed more accurately.

Embodiment 3 FIG.
In the first embodiment and the second embodiment described above, the forced ventilation operation is performed for a predetermined time, but when the elapsed time after the room to be ventilated is unmanned is short, sufficient time has passed. Since the difference occurs in the value of the CO ₂ concentration measured by the CO ₂ sensor during the forced ventilation operation, the time required for the forced ventilation operation is different. In order for the CO ₂ sensor to detect a CO ₂ concentration equivalent to fresh outdoor air during forced ventilation operation, even if the elapsed time since the room is unattended, Although it is necessary to take a sufficiently long time, the forced ventilation operation when the elapsed time after the room is unmanned is long may be relatively short. Therefore, in the third embodiment, an example will be described in which the forced ventilation operation is made variable and the forced ventilation operation is performed for the minimum necessary time. In the third embodiment, the difference from the first embodiment will be mainly described.

  FIG. 7 is a diagram showing a configuration of a ventilation device according to Embodiment 3 of the present invention. In FIG. 7, the same elements as those in FIGS. 1 and 4 are denoted by the same reference numerals and description thereof is omitted.

CO ₂ previous measured value storing means 16 in the control circuit 10B in advance for each storage interval Ti of-determined CO ₂ measurements, stores a copy of the stored CO ₂ measurement to CO ₂ measurement value storage unit 11. For example, if the storage interval Ti = 5 minutes, the stored value of the CO ₂ previous measured value storage means 16 is updated every 5 minutes. Immediately before the update timing, the value stored in the CO ₂ previous measurement value storage means 16 indicates the CO ₂ measurement value five minutes before. In the following description, the stored value (that is, the current measured value) of the CO ₂ measured value storage unit 11 is X, and the stored value of the CO ₂ previous measured value storage unit 16 is Xold. Note that whether or not the storage interval Ti has elapsed can be determined by using the clock means 14, for example.

Next, an operation related to the calibration process of the CO ₂ sensor 8A according to the third embodiment will be described.
FIG. 8 is a flowchart for explaining calibration processing of the CO ₂ sensor of the ventilation device according to Embodiment 3 of the present invention. In FIG. 8, the same reference numerals are used for the same processes as those in the flowchart of FIG.

  In step S10, as in the second embodiment, the control circuit 10B acquires the current time T from the clock means 14.

  As in the second embodiment, the control circuit 10B determines whether or not the acquired current time T is within the range from the start time Ts to the predetermined forced ventilation execution time to the end time Te (S11). If it is within (S11; Yes), the process proceeds to step S12, and if it is outside the range (S11; No), the process proceeds to step S13. In the third embodiment, it is determined (estimated) whether or not the room is unattended using the time, and the clock means 14 and the control circuit 10B determine whether or not the room is unattended. It functions as a means.

  In step S12, the control circuit 10B refers to the forced ventilation execution flag F2 as in the second embodiment, and determines whether the forced ventilation operation has already been performed. When the forced ventilation operation has not been performed (S12; No), the process proceeds to step S14, and when the forced ventilation operation has been performed (S12; Yes), the process returns to step S10.

  In step S13, as in the second embodiment, the control circuit 10B clears the forced ventilation execution flag F2 and returns to step S10.

In step S14, the air volume control means 13 controls the supply fan 4 and the exhaust fan 7 in the same manner as in step S5 of FIG. 3 described in the first embodiment, and starts the forced ventilation operation with a predetermined ventilation air volume. . The forced ventilation operation is an operation for making the air around the CO ₂ sensor 8A equal to fresh air, and the ventilation air volume of the forced ventilation operation is determined in advance. When the storage interval Ti for the CO ₂ measurement value elapses after the forced ventilation operation is started, the process proceeds to step S16.

In step S16, the control circuit 10 determines whether to continue the forced ventilation operation. Specifically, the control circuit 10 calculates the difference between the stored value Xold of the CO ₂ previous measured value storage unit 16 and the stored value X of the CO ₂ measured value storage unit 11, and sets the CO ₂ measured value storage interval Ti. Obtain how much the measured value of CO ₂ concentration has decreased in the meantime. In order to perform this calculation correctly, step S16 is preferably executed immediately before the update timing of Xold. The control circuit 10 compares the obtained decrease amount with a predetermined threshold value Xsh, and if the decrease amount of the CO ₂ concentration is equal to or less than the threshold value Xsh (S16; Yes), the air volume control means 13 ends the forced ventilation operation. Then, the process proceeds to step S15. When the decrease amount of the CO ₂ concentration is larger than the threshold value Xsh (S16; No), the control circuit 10 returns to Step S14 and continues the forced ventilation operation. That is, the forced ventilation operation is continued until the decrease amount of the CO ₂ concentration becomes equal to or less than the threshold value Xsh.

  In step S15, the forced ventilation execution completion flag F2 is set as in the second embodiment, and the process returns to step S10. These processes are repeatedly executed, and the forced ventilation operation is periodically executed.

Although omitted in FIG. 8, in parallel with the forced ventilation operation as described above, the CO ₂ sensor 8A periodically performs the calibration process similar to step S20 to step S24 in FIG. 6 of the second embodiment. To run.

By configuring as described above, sufficient forced ventilation operation has been executed when the amount of decrease in the measured CO ₂ value per unit time (time Ti) during forced ventilation operation is equal to or less than the threshold value Xsh. The forced ventilation operation can be automatically terminated. Even in a situation where an error occurs in the output of the CO ₂ sensor 8A and calibration is necessary, for example, if the time Ti is about several minutes, the amount of change in the CO ₂ concentration measured during that time is a relative value. Therefore, this determination that the forced ventilation operation is terminated by assuming that the surroundings of the CO ₂ sensor 8A is equivalent to fresh air is appropriate. Therefore, the output of the CO ₂ sensor 8A can be calibrated more accurately without performing unnecessary forced ventilation operation even though sufficient ventilation operation has already been performed. Since the CO ₂ sensor 8A can detect the CO ₂ concentration with high accuracy, the reliability of the ventilation operation of the ventilation device 100B that executes the ventilation operation according to the detected CO ₂ concentration is increased, and the CO ₂ concentration of the indoor air is a reference value. The following can be accurately maintained. Moreover, useless ventilation operation can be reduced and the energy concerning ventilation operation can be saved.

In the above description, the forced ventilation operation is terminated when the amount of decrease in the CO ₂ measurement value per time Ti becomes equal to or less than the threshold value Xsh. However, for example, the amount of decrease in the CO ₂ measurement value per time Ti is continuously several times. The forced ventilation operation may be terminated when the threshold value Xsh is reached. By doing in this way, the influence of the measurement error of the CO ₂ sensor 8A is suppressed, and it can be accurately determined that the forced ventilation operation has been sufficiently performed.

In the above description, as in the second embodiment, the example using the CO ₂ sensor 8A having the automatic calibration function has been described. However, the present invention is not limited to this, and the CO ₂ sensor is calibrated with the same configuration as in the first embodiment. May be implemented.

Embodiment 4 FIG.
In Embodiments 1 to 3, in order to perform forced ventilation operation in an unattended state, it is determined whether or not the room is unattended based on the time and date. Other examples are also conceivable as unattended determination means for determining whether or not the person is unattended. In the fourth embodiment, a configuration example using a human sensor as the unmanned determination means will be described. In the fourth embodiment, the difference from the first to third embodiments will be mainly described.

  FIG. 9 is a diagram showing a configuration of a ventilation device according to Embodiment 4 of the present invention. In FIG. 9, the same elements as those of FIG.

  The human sensor interface 17 in the control circuit 10 </ b> C is a communication unit that is connected to the human sensor 20 installed in the ventilation target room via the communication line 18 and acquires a signal transmitted from the human sensor 20. The human sensor 20 detects whether or not a person is present in the room by an arbitrary method using, for example, infrared rays or captured images, and the detection target is the same room as the ventilation target room of the ventilator 100C. Yes. The human sensor interface 17 acquires the determination result of whether the room to be ventilated detected by the human sensor 20 is manned or unmanned via the communication line 18. The human sensor interface 17 makes a final determination based on the result obtained from the human sensor 20 whether the room is unmanned or manned, and holds the result. For example, in order to avoid judging that the human sensor 20 is unattended when the human sensor 20 detects a temporary unmanned state for a short time of about several minutes, the human sensor interface 17 sets a threshold ( (E.g., 1 hour or more) is provided, and a final determination is made that the person is unattended with an unmanned state for a time longer than the threshold. In the fourth embodiment, the human sensor 20 and the human sensor interface 17 function as an unattended determination unit that determines whether the room is unattended.

The CO ₂ sensor measurement cycle changing means 19 in the control circuit 10 is connected to the CO ₂ sensor 8A via the communication line 9. The CO ₂ sensor measurement cycle changing means 19 has a function of changing the measurement cycle Tc for the CO ₂ sensor 8A to perform automatic calibration.

Next, an operation related to the calibration process of the CO ₂ sensor 8A according to the fourth embodiment will be described.
FIG. 10 is a flowchart for explaining calibration processing of the CO ₂ sensor of the ventilation device according to Embodiment 4 of the present invention. 10, the same reference numerals are used for the same processes as those in the flowchart of FIG.

In step S30, the CO ₂ sensor measurement cycle changing unit 19 sets the execution interval Tk of the forced ventilation operation to a value that is smaller by a predetermined time Tm than the measurement cycle Tc of the CO ₂ sensor 8A. For example, if the initial value of the measurement cycle Tc is 1 week (168 hours) and the time Tm is 24 hours, the forced ventilation operation execution interval Tk is 6 days (144 hours). After setting, the process proceeds to step S31.

In step S31, the CO ₂ sensor measurement cycle changing unit 19 acquires an elapsed time Tj from the previous forced ventilation operation. This elapsed time Tj is measured using the clock means 14, for example. After obtaining the elapsed time Tj, the process proceeds to step S32.

In step S32, the CO ₂ sensor measurement cycle changing unit 19 determines whether the elapsed time Tj from the previous forced ventilation operation is equal to or longer than the execution interval Tk of the forced ventilation operation. As a result of the determination, if the elapsed time Tj is equal to or greater than the execution interval Tk of the forced ventilation operation (S32; Yes), the process proceeds to step S33. When the elapsed time Tj is less than the forced ventilation operation execution interval Tk (S32; No), the process returns to step S31.

In step S < _b > 33, the CO ₂ sensor measurement cycle changing unit 19 obtains a determination result as to whether or not the room to be ventilated is unattended from the human sensor interface 17. When it is determined that the room to be ventilated is unattended (S33; Yes), the process proceeds to step S34. When it is determined that the room is not unattended (S33; No), the process returns to step S31.

In step S34, the CO ₂ sensor measurement cycle changing means 19 determines whether the elapsed time Tj from the previous forced ventilation operation is less than the time of the measurement cycle Tc of the CO ₂ sensor 8A. As a result of the determination, if the elapsed time Tj is less than the time of the measurement cycle Tc (S34; Yes), the process proceeds to step S14. If the elapsed time Tj is greater than or equal to the measurement cycle Tc (S34; No), the process proceeds to step S35. move on.

In step S35, the CO ₂ sensor measurement cycle changing means 19 performs a process of changing the measurement cycle Tc of the CO ₂ sensor 8A as shown below. Here, the state that has proceeded to step S35 represents that a time equal to or longer than the measurement cycle Tc of the CO ₂ sensor 8A has elapsed since the previous forced ventilation operation was performed. Therefore, the forced ventilation operation cannot be performed during the measurement cycle Tc. In this state, the CO ₂ sensor 8A cannot detect a CO ₂ concentration equivalent to fresh outdoor air, so the CO ₂ sensor 8A cannot be correctly calibrated. Therefore, the CO ₂ sensor measurement cycle changing means 19 changes the measurement cycle Tc so that the period of the measurement cycle Tc becomes longer, for example, when the number of times reaching step S35 is greater than or equal to a predetermined number. In this case, based on the elapsed time Tj from the previous forced ventilation operation, the measurement cycle Tc is changed so as to be a value larger than the elapsed time Tj. At this time, instead of the elapsed time Tj from the previous forced ventilation operation, an average value of a plurality of elapsed times Tj when reaching step S35 may be used. After changing the measurement cycle Tc of the CO ₂ sensor 8A, the process proceeds to step S36.

  In step S36, the air volume control means 13 makes the execution interval Tk of the forced ventilation operation smaller by a predetermined time Tm than the measurement cycle Tc based on the measurement cycle Tc changed in step S35, as in step S30. The execution interval Tk is reset. Then, it progresses to step S14.

In step S14, the air supply fan 4 and the exhaust fan 7 are controlled as in the second embodiment, and the forced ventilation operation is performed for a predetermined time with a predetermined ventilation air volume. The forced ventilation operation is an operation for making the air around the CO ₂ sensor 8A equivalent to fresh air, and the ventilation air volume and time of the forced ventilation operation are determined in advance. When the forced ventilation operation ends, the process proceeds to step S37.

  In step S37, the elapsed time Tj from the previous forced ventilation operation is cleared, and the process returns to step S31.

Although not shown in FIG. 10, in parallel with the forced ventilation operation as described above, the CO ₂ sensor 8A executes the same calibration process as steps S20 to S24 of FIG. 6 of the second embodiment. . At this time, the measurement cycle Tc, which is the interval at which the CO ₂ sensor 8A executes the calibration process, is a value set by the CO ₂ sensor measurement cycle changing means 19.

Thus, at time intervals ranging measurement cycle Tc of CO ₂ sensor 8A from practice interval Tk of forced ventilation operation, when the indoor ventilation target becomes unattended, forced ventilation operation is performed, the CO ₂ sensor 8A Automatic calibration is performed appropriately.

Further, when the room to be ventilated is not unattended during the measurement cycle Tc of the CO ₂ sensor 8A, the measurement cycle Tc is automatically updated based on the time interval until the room is actually unattended. Therefore, the automatic calibration of the CO ₂ sensor 8A is appropriately performed at the timing according to the entry / exit situation of the person in the room to be ventilated. Accordingly, the output of the CO ₂ sensor 8A can be calibrated more accurately. Since the CO ₂ sensor 8A can detect the CO ₂ concentration with high accuracy, the reliability of the ventilation operation of the ventilator 100C that performs the ventilation operation according to the detected CO ₂ concentration is increased, and the CO ₂ concentration of the indoor air is a reference value. The following can be accurately maintained. Moreover, useless ventilation operation can be reduced and the energy concerning ventilation operation can be saved.

  In the above description, the human sensor 20 is installed in a room alone and connected to the ventilation device 100C. However, the human sensor 20 is built in an air conditioner provided separately. It may be a thing. Some air conditioners have built-in human sensors for efficient air conditioning operation, while some ventilators are connected to the air conditioner with communication lines to improve the efficiency of air conditioning. Some have a function of performing a linkage operation such as raising. In such an air conditioning system that combines an air conditioner and a ventilator, it is possible to use the detection information of the human sensor of the air conditioner in the ventilator without substantially increasing the manufacturing cost.

Further, the specific configuration of the unmanned determination means for determining whether or not the room to be ventilated is unmanned is not limited to the above-described human sensor, and even if it is other than the human sensor, the CO is similar to the above. Calibration of the output of the _two sensors 8A can be performed. Another example of the unattended determination means is shown below.

  For example, a method of determining unmanned when the illumination in a room to be ventilated is off can be considered. In this case, the communication device (communication interface) for obtaining the output of the illuminance sensor is provided in the ventilator and the illuminance sensor and the ventilator are connected. Whether or not the room to be ventilated is unattended can be determined based on whether or not the room is ventilated. In addition, for example, a communication means (communication interface) for obtaining an output of a lighting switch that switches between a lighting state and a lighting state of the lighting device is provided in the ventilation device, the lighting switch and the ventilation device are connected by communication, and the lighting switch is in an ON state. By determining which is the OFF state, it is possible to determine whether the room to be ventilated is unattended.

  In addition, when the ventilator is equipped with a remote control that accepts operation inputs, the room to be ventilated is unmanned by determining that there is a person in the room for a certain period of time after the operation input to the remote control is received. It can be determined whether or not. In addition, in the case of an air conditioning system in which a ventilator and an air conditioner are communicatively connected, in addition to or instead of the remote controller of the ventilator, the room to be ventilated depends on the presence of operation input to the remote controller of the air conditioner. It can also be determined whether or not it is in an unattended state. In a centralized management system in which multiple ventilators and air conditioners are centrally managed, there is a possibility that the ventilators and air conditioners may be remotely operated from outside the room, so the remote control source is in the room being ventilated. It is determined whether there is any, and only the operation from the room is used for the unattended determination.

  A plurality of configurations (time, human sensor, illuminance sensor, lighting switch, ventilation device remote controller, and air conditioner remote controller) for determining whether the ventilation target is unmanned may be combined. By doing in this way, it can be determined more correctly whether the room for ventilation is unattended.

In the first to fourth embodiments, it has been described that the CO ₂ sensor 8 or the CO ₂ sensor 8A calibrates its own output. However, a physical configuration corresponding to the calibration means 82 or the calibration means 82A is used. It can also be provided in the control circuit of the ventilation device.

In the first to fourth embodiments, supply and exhaust are mechanically performed by a supply fan (supply fan 4) and an exhaust fan (exhaust fan 7), respectively. Although the description has been given taking the type of ventilator as an example, the present invention can also be applied to a second type ventilator and a third type ventilator.
When the present invention is applied to a ventilator of the second type ventilation system in which a supply air blower provided in the ventilator is operated to supply air while naturally exhausting, the CO ₂ sensor is connected to the outdoor side. Provided at a position that avoids an air supply passage from the air supply opening to the indoor air supply opening and that can measure the CO ₂ concentration of the indoor air. For example, a CO ₂ sensor can be provided at a position where indoor air circulates, such as a housing surface of a ventilator facing the room, and in that case, indoor air supply (outside air) is difficult to directly hit the CO ₂ sensor. Thus, it is preferable to provide the CO ₂ sensor at a position as far as possible from the air supply port. Alternatively, the CO ₂ sensor may be installed indoors apart from the housing of the ventilator, and the detected value of the CO ₂ sensor may be input to the ventilator by wired or wireless communication.
In addition, when the present invention is applied to a third type ventilation type ventilator that exhausts air by operating an exhaust fan provided in the ventilator, the CO ₂ sensor is implemented. It can arrange | position similarly to the form 1. Alternatively, the detected values of CO ₂ sensor disposed in a room away from the housing of the ventilator, may be input to the ventilator in a wired or wireless communication.

1 outdoor side air inlet, 2 heat exchange element, 3 indoor side air inlet, 4 air supply fan, 5 indoor side exhaust port, 6 outdoor side exhaust port, 7 exhaust fan, 8, 8A CO ₂ sensor, 9 communication line 10, 10A, 10B, 10C control circuit, 11 CO ₂ measurement value storage means, 12 CO ₂ sensor calibration execution instruction means, 13 air volume control means, 14 clock means, 16 CO ₂ previous measurement value storage means, 17 human sensor Interface, 18 Communication line, 19 CO ₂ sensor measurement cycle changing means, 20 Human sensor, 81 Sensor unit, 82, 82A Calibration means, 83 Storage means, 84 Clock means, 100, 100A, 100B, 100C Ventilation device, 101 housing Body, 102 air supply passage, 103 exhaust passage.

Claims (12)

A ventilator that performs either or both of an exhaust operation for operating a blower to exhaust indoor air to the outside and an air supply operation for operating a blower to supply outdoor air to the room,
A CO ₂ sensor for measuring the carbon dioxide concentration in the room;
Calibration means for calibrating the output of the CO ₂ sensor based on the measurement value of the CO ₂ sensor during a measurement period that is a periodic measurement cycle ;
Control means for controlling the blower;
Unmanned judging means for judging whether or not the room is unmanned,
When the control means determines that the room is unattended by the unattended determination means,
Forced ventilation operation is performed by operating the blower for a predetermined time ,
In parallel with the forced ventilation operation, the calibrating means calibrates the output of the CO ₂ sensor so that the minimum value of the carbon dioxide concentration measured by the CO ₂ sensor during the measurement period approaches the calibration reference value. the stomach line,
The length of the measurement period is equal to or longer than a period from when the unattended determination unit determines that the room is unattended until it is next determined to be unattended . The forced ventilation operation is performed a plurality of times during the measurement period.
The ventilation apparatus according to claim 1. The control means includes CO ₂ sensor measurement cycle changing means,
The CO ₂ sensor measurement cycle changing means, the length of the measurement period, that the unmanned determining means is adjusted such that the chamber is longer than the period until it determines that the next unattended since it is determined that the unmanned The ventilator according to claim 1 or 2, characterized by the above. The measurement period is provided periodically, and the forced ventilation operation is periodically executed,
The ventilation device according to any one of claims 1 to 3, wherein a period of performing the forced ventilation operation is a length equal to or less than a period in which the measurement period is provided. The control means adjusts the time per one time of the forced ventilation operation based on a change amount per unit time of the carbon dioxide concentration measured by the CO ₂ sensor during the forced ventilation operation. The ventilation apparatus as described in any one of Claims 1-4. A clock means,
The said unattended determination means determines whether the said room is unattended based on either or both of the time and the date which the said clock means time-measured. A ventilation device according to claim 1. Equipped with human sensor,
The ventilation according to any one of claims 1 to 5, wherein the unmanned determination means determines whether or not the room is unattended based on a detection result of the human sensor. apparatus. Comprising communication means for communicating with other devices equipped with human sensors,
The unattended determination unit determines whether or not the room is unattended based on a detection result of the human sensor of the other device acquired through the communication unit. The ventilator according to any one of claims 5 to 6. An illuminance sensor that detects whether the indoor lighting is turned off,
The ventilator according to any one of claims 1 to 5, wherein the unmanned determination means determines whether the room is unattended based on a detection result of the illuminance sensor. . Comprising a communication means for performing communication between a lighting switch for switching between a lighting state and a lighting state of the lighting device;
The unattended determination means determines whether or not the room is unattended based on a detection result of whether or not the lighting device acquired through the communication means is in an extinguished state. The ventilation apparatus as described in any one of Claims 1-5. An operation means for accepting an operation input is provided,
The ventilation according to any one of claims 1 to 5, wherein the unmanned determination means determines whether or not the room is unattended based on the presence or absence of an operation on the operation means. apparatus. The ventilator according to any one of claims 1 to 11,
An air-conditioning system comprising: an air-conditioning device that performs air conditioning in the room that is to be ventilated by the ventilation device.

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