KR100838319B1 - Variable air ventilation control system and methode using constant face-velocity control - Google Patents

Abstract

A variable air control system and a method thereof are provided to manage environment of a working field and to ensure safety of workers by displaying an amount of discharge air. A variable air control system comprises a discharge fan(110), a fume hood(120), an discharge duct(130), an individual hood controller(140), a central control unit(150), a normal hood(160), a normal hood controller(170), and a air feeding fan(180). The discharge fan discharges contaminated materials to an exterior. The fume hood safely discharges harmful gas to ensure pleasant working environment of a laboratory. The fume hood is provided at a front portion thereof with a sliding door(124). The discharge duct is connected to an inner space of the fume hood to discharge contaminated materials. A position sensor(123) is installed in the fume hood to measure an opening area according to the opening degree of the sliding door.

Description

Variable Air Ventilation Control System and Method Using Constant Face-Velocity Control.

1 is a schematic configuration diagram of a variable air volume control system according to an embodiment of the present invention

2 is a flow chart of a variable air volume control method according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

110: exhaust fan 120: fume hood

121: damper 122: flow rate sensor

123: position sensor 124: slide door

130: exhaust duct 140: individual fume hood control unit

150: central control unit 160: normal hood

170: general hood control unit 180: air supply fan

The present invention relates to a variable air volume control system and a variable air volume control method, and more particularly, according to the degree of opening and closing of the front slide, such as a fume hood, or in the case of a local exhaust device having a plurality of hoods By controlling the amount of displacement and the variable amount of displacement according to the operation of individual hoods, it helps to manage workplace environment, protect the safety and health of workers, and to save energy wasted when operating indoor air conditioning and exhaust fan. A variable air volume control system and a variable air volume control method for reducing.

In general, a local exhaust system is applied as a method for reducing the exposure of hazardous substances to workers in a place where hazardous chemicals are handled. In particular, a fume hood in the form of a booth hood is most commonly used in a laboratory.

However, since the power of the exhaust fan is fixed, the following problems occur when the opening area is changed due to the opening and closing of the front slide such as a fume hood, or when the operation rate of individual hoods in the local exhaust system line is not constant. do.

First, if the front slide is designed in the middle position when designing the displacement of the fume hood, if the front slide is opened above the middle position, it becomes less than the required exhaust volume, and the collection speed (surface speed) is lowered. If it is closed below the middle, there is a problem that it is excessive than the required exhaust amount, which is an unnecessary waste factor of indoor heating and cooling and exhaust fan operating energy.

In case of designing the fume hood, the front slide is in the fully open position when designing the displacement of the fume hood, and if the front slide is closed in the fully open position even if the front slide is a little more than the required exhaust volume, unnecessary waste of indoor air-conditioning and exhaust fan operating energy There was a problem that became a factor.

In addition, when the exhaust capacity is designed based on the entire operation of the individual hoods of the local exhaust system line, the amount of exhaust from the remaining hoods is excessively larger than the required exhaust amount by blocking some individual hoods. There was a problem of unnecessary waste.

In addition, it was difficult for workers to check the capture speed of the local exhaust system at all times, especially when the front part was in the form of a slide like a laboratory fume hood, and the capture speed (surface speed) changed according to the degree of opening and closing. It is true that confirmation is necessary, but not realistically.

An object of the present invention devised to solve the above-described problems, according to the opening and closing degree of the front slide, such as a fume hood or the like, or in the case of a local exhaust device connected to a plurality of hoods whether each individual hood is operated or not Control device that can control the amount of displacement according to the variable and variable amount of displacement to display the variable air volume control to help the workplace environment management and the safety and health of the workers, and to save the energy wasted when operating the indoor air conditioning and exhaust fan The present invention provides a system and a variable air volume control method.

In addition, another object of the present invention is to equip the worker with the surface speed display device to monitor the collection speed (surface speed) of the local exhaust system such as fume hood at all times to promote workplace environment management, worker safety and health protection The present invention provides a variable air volume control system and a variable air volume control method.

In order to achieve the above object, the variable air volume control system according to the present invention is opened by a slide door, and in an exhaust system in which harmful chemicals or highly polluted substances are exposed to an operator during operation, Calculate the opening area of the fume hood by calculating the opening height of the slide door, calculate the displacement required to obtain a constant average surface velocity at the opening of the fume hood, and add the required displacement calculated from each fume hood to Set the total required displacement, calculate the current total displacement, and control the exhaust fan to rise or decelerate so that the current total displacement is within the set total required exhaust range, while the current exhaust volume from each individual hood is set to the required exhaust range It characterized in that the damper is controlled to lift.

In addition, the variable air volume control system according to the present invention is provided with an exhaust fan for exhausting the harmful chemicals or highly polluted substances discharged through the exhaust duct to the outside, and a slide door that slides open in the front, and installed the harmful chemicals or A fume hood connected to the exhaust duct that discharges highly polluted substances, a general hood that operates on the required exhaust volume according to the detected state by detecting an on or off state from the general hood control unit, a fume hood and An exhaust duct is connected to the general hood and is installed to discharge harmful chemicals or highly polluted substances from the inside of the fume hood or the general hood by the operation of the exhaust fan, and transmits an operation signal of the general hood to a central control unit. Calculate the general hood control, the current displacement in the duct, and apply the opening area value in the fume hood The average fume speed is calculated to display the calculated value and the set surface speed, and the individual fume hood control unit and the individual fume hood control unit calculate the required displacement from the opening area value and the set surface speed in the fume hood and transmit them to the central control unit. A central control unit for controlling the exhaust fan to rise or decelerate by summing up the required exhaust signal received from the exhaust duct to set the total required exhaust volume of the exhaust duct and calculating the current total exhaust volume to fall within the set total required exhaust volume range. Include.

In addition, the variable air volume control system according to the present invention further includes an air supply fan that is linked together in accordance with the operation of the exhaust fan connected to the exhaust duct.

In addition, the fume hood is characterized in that at least one is installed in the exhaust duct.

In addition, the fume hood, a position sensor for transmitting the open height signal to the individual fume hood control unit according to whether the slide door is opened or closed, and a damper for controlling the wind speed of harmful chemicals or highly polluted substances discharged to the exhaust duct And a flow rate sensor for measuring wind speeds of harmful chemicals or highly polluted substances discharged through the exhaust fan through the exhaust duct according to the degree of opening of the damper and transmitting the measured wind speed signals to the individual fume hood controllers.

The central control unit may set all or a part of the sum of the necessary exhaust amounts as a total required air supply amount, convert the current wind speed signal measured by the flow rate sensor into an air supply amount, and the current air supply amount is a preset total required air supply. And controlling the operation of the air supply fan to be raised or lowered so as to fall within the skill range.

In addition, in the variable air volume control system according to the present invention, the damper converts the current wind speed measured by the flow rate sensor into an exhaust amount in an individual fume hood control unit so that the current exhaust amount is appropriate for each hood by the required exhaust amount of each fume hood in which the current exhaust amount is set. The degree of opening is controlled to be distributed.

In addition, in the general hood, a proper required exhaust amount is set in advance according to the installed form, and a flow rate sensor and a damper are installed, and the current exhaust rate is set by converting the current wind speed measured by the flow rate sensor into an exhaust amount in the general hood control unit. The degree of opening is controlled so as to be properly distributed to the hood by the required displacement of the general hood.

In addition, the flow rate sensor is to measure the wind speed of the harmful chemicals or highly polluted material discharged through the exhaust fan in accordance with any one of the pitot tube method, venturi tube method and orifice method according to the degree of damper opening. It features.

The position sensor may measure the opening height of the slide door by using any one of a rotary sensor method, a potential sensor method, and an optical sensor method.

In addition, the variable air volume control system according to the present invention, the individual hood control unit or the general hood control unit, the red LED, if the current surface speed is lower than a predetermined range compared to the set surface speed, a yellow LED, constant It is characterized by displaying with a green LED within the range.

In addition, the variable air volume control system according to the present invention, by directly operating the individual hood control unit and the general hood control unit to fully open the damper of the fume hood and the general hood and to raise the exhaust fan to the highest value to exhaust the maximum. It is characterized by being.

In addition, the variable air volume control method according to the present invention, the experimental space is formed inside, the variable air volume control system and variable air volume discharged by the hazardous chemical substances or high pollutant substances exposed to the worker opened by the slide door, during operation In the control method, (a) the wind speed is measured in the exhaust duct through the flow rate sensor, and (b) the current amount of exhaust in the exhaust duct is calculated by the individual hood control unit by the wind speed signal measured and received through the flow rate sensor And (c) measuring the opening height of the slide door through a position sensor formed in the fume hood; and (d) openings in the fume hood in the individual hood control unit through the opening height signal measured and received by the position sensor. Calculating an average capture speed by applying an area value, and (e) the calculated average capture speed is visually displayed. (F) calculating a necessary exhaust amount from the opening area and the set surface velocity calculated by each individual fume hood control unit, and transmitting it to a central control unit; and (g) an on-off state of the general hood in the general hood control unit. If it is detected that the predetermined required exhaust amount is transmitted to the central control unit, (h) the total required exhaust amount of the exhaust duct by summing the required exhaust amount in the duct transmitted from each individual fume hood control unit and the general hood control unit from the central control unit And controlling the exhaust fan to raise or lower the operation so that the current total exhaust amount is within the set total required exhaust amount range. Existing wind speed measured by the flow rate sensor of the duct is converted into the displacement, and the required displacement of each hood for which the current displacement is set And controlling the opening degree of each damper to fall within a range.

In addition, the step (a), the flow rate sensor measures the wind speed of the harmful chemicals or highly polluted material discharged through the exhaust fan according to the degree of opening of the damper of any one of the pitot tube method, venturi tube method and orifice method. It is characterized by measuring in a manner.

In the step (c), the position sensor measures the opening height of the slide door by using any one of a rotary sensor method, a potential sensor method, and an optical sensor method. It is done.

In addition, in the step (h), the central control unit sets all or a part of the sum of the necessary exhaust air amounts to the total required air supply amount to convert the current wind speed signal measured by the flow rate sensor into the air supply amount, and the current air supply amount And controlling the operation of the air supply fan to rise or decelerate so as to fall within a preset total required air supply amount range.

In addition, in the step (i), the damper is converted into an exhaust amount by the current fume hood control unit by converting the current wind speed measured by the flow rate sensor so as to be appropriately distributed to each hood by the required exhaust amount of each fume hood in which the current exhaust amount is set. The degree is controlled.

Hereinafter, a variable air volume control system and a variable air volume control method according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic configuration diagram of a variable air volume control system according to an embodiment of the present invention.

Referring to FIG. 1, the variable air volume control system according to the present invention includes an exhaust fan 110, a fume hood 120, an exhaust duct 130, an individual fume hood control unit 140, a central control unit 150, and a general hood. It comprises a 160, the general hood control unit 170 and the air supply fan 180.

First, the exhaust fan 110 discharges harmful chemicals or highly polluted substances discharged through the exhaust duct 130 connected to the top of the fume hood 120 and the general hood 160 to the outside.

The fume hood 120 is configured to handle chemicals that normally hinder a working environment and generate harmful gases, odor gas vapors, ie harmful chemicals or highly polluted substances, in a laboratory. It is an essential facility to maintain a pleasant laboratory work environment by discharging.

The fume hood 120 according to the present invention is a fume hood having a booth shape which is generally used in a laboratory, but is not limited thereto and may be configured in various forms.

On the other hand, the fume hood 120 according to the present invention, the slide door 124 is provided with a slide opening on the front, the interior space is connected to the exhaust duct 130 so that harmful chemicals or highly polluted substances are discharged. It is.

In addition, a position sensor 124 is installed inside the fume hood 120 to measure an opening area that varies depending on the degree of opening and closing of the slide door 124.

The position sensor 123 transmits an open height signal to each individual fume hood controller 140 according to whether or not the slide door 124 is opened or closed.

At this time, the position sensor 123 measures the opening height of the slide door using any one of a rotary sensor method, a potential sensor method and an optical sensor method to measure the opening height of the slide door 124, The position sensor 123 is most preferably a rotary sensor method.

The flow rate sensor 122 measures wind speeds of harmful chemicals or highly polluted substances discharged through the exhaust fan 110 via the exhaust duct 130 according to the degree of opening of the damper 121 to individually measure the wind speed signals measured. Transmission to the fume hood control unit 140.

At this time, the flow rate sensor 122 measures the wind speed of the harmful chemicals or highly polluted substances discharged through the exhaust fan 110 according to the opening degree of the damper 121 to be described later, pitot tube method, venturi tube method and orifice While measuring by any one of the methods, the flow rate sensor 122 according to the present invention is most preferably measured by the pitot tube method.

Exhaust duct 130 is a duct (duct) that is generally used in the air exhaust system is installed so that harmful chemicals or highly polluted substances in the fume hood 120 by the operation of the exhaust fan 110. .

In addition, the damper 121 controls the wind speed of the harmful chemicals or the highly polluted substances discharged to the exhaust duct 130.

In addition, the damper 121 converts the current wind speed measured by the flow rate sensor 122 into an exhaust amount in an individual fume hood control unit 140 to be described later, so that the amount of exhaust gas of each fume hood 120 for which the current exhaust amount is set is the above. Preferably, the degree of opening is controlled so as to be properly distributed to the hood.

When the general hood 160 detects an on or off state by the general hood control unit 170, a predetermined amount of exhaust gas, which is preset according to the detected state, is transmitted to the central control unit.

In addition, the general hood 160 is preferably provided with a damper 121 and a flow rate sensor 122 between the exhaust duct 130 connected to the upper portion, similar to the fume hood 120 described above.

In addition, the general hood 160 is set in advance in the general hood control unit 170 according to the required amount of necessary exhaust.

In addition, as described above, the flow rate sensor 122 and the damper 121 are installed between the general hood 160 and the exhaust duct 130, and the current wind speed measured by the flow rate sensor 122 is used to control the general hood control unit. The opening degree is controlled so that the current displacement is appropriately distributed to the hood by the required displacement of the general hood, which is converted into the displacement at 170.

The individual fume hood control unit 140 calculates a current amount of exhaust in the exhaust duct 130, calculates an average collection speed by applying an opening area value in the fume hood 120, and visually displays the calculated value.

In addition, the individual hood control unit 140 or the general hood control unit 170 is a red LED, if the current surface speed is lower than a predetermined range compared to the set surface speed, a yellow LED, a green LED within a certain range. It may be displayed or other visual display means.

The central control unit 150 adds the necessary exhaust amount signals from the individual fume hood control unit 140 and the general hood control unit 170 to set the total required exhaust amount of the exhaust duct 130, calculates the current total exhaust amount, and calculates the current total amount. The exhaust fan 110 is controlled to be raised or lowered so that the displacement amount is within the set total required exhaust amount range.

In addition, the central control unit 150 sets all or a part of the sum of the necessary exhaust amounts as the total required air supply amount, converts the current wind speed signal measured by the flow rate sensor 122 into the air supply amount, and the current air supply amount is preset. The operation of the air supply fan 180 is controlled to be raised or lowered to fall within the total required air supply amount range.

The air supply fan 180 is interlocked together according to the operation of the exhaust fan 110 connected to the exhaust duct 130.

In addition, one or more fume hoods 120 may be installed in the exhaust duct 130, that is, the present invention is not limited thereto.

In addition, the individual hood control unit 140 and the general hood control unit 170 can be directly manipulated by the user to completely open the damper 121 of the fume hood 120 and the general hood 160, and the exhaust fan 110 to the highest value. It can also raise and exhaust it to the maximum.

2 is a flow chart of a variable air volume control method according to an embodiment of the present invention.

Referring to Figure 2, it will be described in detail with respect to the variable air volume control method according to an embodiment of the present invention.

First, the flow rate sensor 122 installed at the top inside the fume hood 120 measures the wind speed in the exhaust duct 130.

At this time, the flow rate sensor 122 transmits the measured wind speed signal to each individual fume hood control unit 140.

At this time, the flow rate sensor 122 measures the wind speed of the harmful chemicals or highly polluted substances discharged through the exhaust fan 110 according to the opening degree of the damper 121, among the pitot tube method, venturi tube method and orifice method While measuring in any one way, the flow rate sensor 122 according to the present invention is measured by the pitot tube method (step S210).

Then, the current amount of exhaust in the exhaust duct 130 is calculated by the individual hood controller 140 through the wind speed signal measured and received through the flow rate sensor 122 (S220).

Then, the open height signal is transmitted to each individual fume hood control unit 140 according to whether the slide door 124 is opened or closed through the position sensor 123.

At this time, the position sensor 123 measures the opening height of the slide door 124 using any one of a rotary sensor method, a potential sensor method and an optical sensor method to measure the opening height of the slide door 124, Position sensor 123 according to the present invention is measured by a rotary sensor method (step S230).

Then, the average collection speed is calculated by applying the opening area value in the fume hood 120 in the individual hood controller 140 through the open height signal measured and received through the position sensor 123 (S240).

The calculated average capture rate is then visually displayed.

At this time, if the individual hood control unit 140 or the general hood control unit 170, the current surface speed is lowered below a predetermined range compared to the set surface speed, the red LED, if the predetermined range exceeds the yellow LED, green LED within a certain range It may be displayed as, or may be displayed by other visual display means (step S250).

Then, in each individual fume hood control unit 140 and the general hood control unit 170, the required exhaust amount calculated from the opening area and the set surface speed is received by the central control unit 150 (step S260).

At this time, the central control unit 150 adds the necessary exhaust amount signals received from the individual fume hood control unit 140 and the general hood control unit 170 to set the total required exhaust amount of the exhaust duct 130, and calculates the current total exhaust amount. The exhaust fan 110 is controlled to be raised or lowered so that the current total exhaust amount is within a set total required exhaust amount range.

Next, the central control unit 150 sets all or a part of the sum of the necessary exhaust amounts as the total required air supply amount, converts the current wind speed signal measured by the flow rate sensor 122 into the air supply amount, and provides the current air supply amount. The operation of the air supply fan 180 is controlled to be raised or lowered so as to fall within the set total required air supply amount range (step S270).

Subsequently, the individual hood controller 140 converts the current wind speed measured by the flow rate sensor 122 of the exhaust duct 130 above each fume hood 120 into an displacement, so that each fume hood having the current displacement is set. An opening degree of each damper 121 is controlled to fall within the required exhaust amount range of the 120 or the general hood 160.

In addition, the air supply fan 180 may be linked together according to the operation of the exhaust fan 110 connected to the exhaust duct 130 (step S280).

In addition, the individual hood control unit 140 and the general hood control unit 170 can be directly manipulated by the user to completely open the damper 121 of the fume hood 120 and the general hood 160, and the exhaust fan 110 to the highest value. It can also raise and exhaust it to the maximum.

The present invention is not limited to the above-described preferred embodiments and can be easily modified by anyone of ordinary skill in the art without departing from the gist of the invention claimed in the claims, Such changes are intended to fall within the scope of the claims.

As described above, according to the present invention, when the opening and closing of the front slide such as a fume hood or the like changes, or in the case of a local exhaust device having a plurality of hoods, the amount of displacement varies depending on whether each individual hood is operated. Variable air volume control system and variable air volume control method to control workplace environment management and workers' safety and health by displaying adjustable control device and variable variable displacement, and to save energy wasted when operating indoor air conditioning and exhaust fan Can be provided.

In addition, according to the present invention, by mounting the surface speed display device so that the worker can always observe the capture speed (surface speed) of the local exhaust system such as fume hood, variable for promoting workplace environment management, worker safety and health protection The air volume control system and the variable air volume control method can be provided.

Claims (12)

In an exhaust system in which an experiment space is formed inside, opened by a slide door, and discharges harmful chemicals or highly polluted substances exposed to workers during work, An exhaust fan for exhausting harmful chemicals or highly polluted substances discharged through the exhaust duct to the outside; A fume hood installed at a front surface of the slide door and connected to an exhaust duct for discharging harmful chemicals or highly polluted substances; A general hood that detects an on or off state in the general hood control unit and operates as required by a predetermined exhaust amount according to the detected state; An exhaust duct connected to the fume hood and the general hood, the exhaust duct being installed to discharge harmful chemicals or highly polluted substances from the fume hood or the general hood by the operation of the exhaust fan; A general hood control unit which transmits a signal indicating whether the general hood is operated to a central control unit; Calculate the current exhaust volume in the exhaust duct, calculate the average capture speed by applying the aperture area value in the fume hood, and display the calculated value and the set surface speed; and the required displacement from the aperture area value and the set surface speed in the fume hood An individual fume hood controller for calculating and transmitting the calculated fume hood to the central controller; And The exhaust fan is raised or decelerated so as to sum the required exhaust gas signals received from the individual fume hood controllers to set the total required exhaust gas of the exhaust duct, calculate the current total exhaust gas, and make the current total exhaust gas fall within the set total required exhaust gas. A central control unit for controlling; Variable air volume control system comprising a. The method according to claim 1, wherein the fume hood, At least one exhaust duct is installed, the variable air volume control system further comprises an air supply fan interlocked together in accordance with the operation of the exhaust fan connected to the exhaust duct. The fume hood according to claim 1 or 2, A position sensor for transmitting an open height signal to an individual fume hood control unit according to whether the slide door is opened or closed; Dampers for controlling the wind speed of the harmful chemicals or highly polluted substances discharged to the exhaust duct; And A flow rate sensor for measuring wind speeds of harmful chemicals or highly polluted substances discharged through the exhaust fan through the exhaust duct according to the degree of opening of the damper and transmitting the measured wind speed signals to the individual fume hood controllers; Variable air volume control system comprising a. The method of claim 1, wherein the central control unit, Set all or a part of the sum of the necessary exhaust amounts as the total required air supply amount, convert the current wind speed signal measured by the flow rate sensor into the air supply amount, and make the current air supply amount fall within the preset total required air supply amount range of the supply fan. Variable air volume control system, characterized in that for controlling the operation to rise or decelerate. The method of claim 3, The damper is variable in that the opening degree is controlled to convert the current wind speed measured by the flow rate sensor to the displacement amount in the individual fume hood control unit so as to be appropriately distributed to each hood by the required exhaust amount of each fume hood in which the current displacement is set. Air flow control system. The method of claim 1, wherein the general hood, According to the installed type, the required amount of exhaust is set in advance, and the flow rate sensor and damper are installed.The current wind speed measured by the flow rate sensor is converted into the displacement from the general hood control unit, and the hood is set as the required displacement of the general hood. Variable air volume control system characterized in that the degree of opening of the damper is controlled to be appropriately distributed to. The method of claim 3, The flow rate sensor measures a wind speed of a harmful chemical substance or a highly polluted substance discharged through the exhaust fan according to the degree of opening of the damper by any one of a pitot tube method, a venturi tube method, and an orifice method. The position sensor may measure the opening height of the slide door by using any one of a rotary sensor method, a potential sensor method, and an optical sensor method. . The method of claim 1, The individual hood control unit or the general hood control unit, if the current surface speed is lower than a predetermined range compared to the set surface speed, a red LED, a yellow LED, if exceeding a predetermined range, characterized in that the green LED display within a certain range Variable air volume control system. In the variable air volume control system and variable air volume control method is formed in the experiment space is opened by the slide door, the hazardous chemicals or highly polluted substances exposed to the worker during the operation, (a) measuring wind speed in the exhaust duct through a flow rate sensor; (b) calculating a current amount of exhaust in the exhaust duct by an individual hood controller based on a wind speed signal measured and received by the flow rate sensor; (c) measuring the opening height of the slide door through a position sensor formed in the fume hood; (d) calculating an average collection speed by applying an opening area value in the fume hood in the individual hood control unit by using the open height signal measured and received by the position sensor;  (e) visually displaying the calculated average capture rate; (f) calculating a necessary exhaust amount from the opening area and the set surface velocity calculated by each individual fume hood control unit, and transmitting the required exhaust amount to the central control unit; (g) when the general hood controller detects an on-off state of the general hood, a predetermined required displacement is transmitted to a central controller; (h) In the central control unit, the required exhaust amount in the duct transmitted from each individual fume hood control unit and the general hood control unit is added to set the total required exhaust amount of the exhaust duct, and the current total exhaust amount is calculated to calculate the current total exhaust amount. Controlling the operation of the exhaust fan to be raised or lowered so as to fall within a required exhaust gas range; (i) The individual hood controller converts the current wind speed measured by the flow rate sensor of the upper duct of each fume hood into the displacement, and controls the opening degree of each damper so that the current displacement falls within the required exhaust volume of each hood set. Doing; Variable air volume control method comprising a. The method of claim 9, wherein step (a) comprises: The flow rate sensor measures the wind speed of a hazardous chemical substance or a highly polluted substance discharged through the exhaust fan according to the degree of opening of the damper by any one of pitot tube method, venturi tube method and orifice method. Control method. The method of claim 9, wherein step (c) comprises: And the position sensor measures the opening height of the slide door by using any one of a rotary sensor method, a potential sensor method, and an optical sensor method. The method of claim 9, wherein step (h) is A central control unit sets all or a part of the sum of the necessary exhaust amounts as the total required air supply amount, converts the current wind speed signal measured by the flow rate sensor into the air supply amount, and the current air supply amount falls within the preset total required air supply amount range. Controlling the operation of the air supply fan to be raised or lowered; Variable air volume control method further comprising.

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