JPH0420736A - Air conditioner - Google Patents

Abstract

PURPOSE:To enable a proper control over an air volume of an air blower to be carried out and perform a proper control over an amount of aeration for each of air conditioned rooms by a method wherein an air conditioner is provided with a calculation processing means for controlling an air blower control means to a frequency for providing a maximum pressure difference in air blowing in respect to a sum of required amount of air of an air blowing adjusting means. CONSTITUTION:One damper 9 is fully opened and all other dampers are fully opened. When an operating frequency of an air blower 5 is defined as R1 at this time and an actual amount of blown air is defined as Q1, a pressure loss (i.e., an air blown pressure difference) P1 is calculated in view of a known relation of Q-P-R. In general, a relation between the air blown pressure difference P and the amount of air Q becomes P=CXQ<2>, where C: a loss coefficient. Accordingly, a calculating processing is carried out. An air conditioner is comprised of a damper control means 20 and a calculation processing means 23 for controlling an air blower control means 22 and then an air blowing control having a superior accuracy for each of the air conditioned rooms 1 can be carried out by controlling a power supply frequency inputted to the air blower 5 of a concentrated air blowing means 2 and a degree of opening of a damper 9 of the air blowing adjusting means 8.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an air conditioner having a main duct and branch ducts and employing a variable air volume control system that can independently adjust the room temperature of each room.

(Prior Art) As an air conditioner that employs a variable air volume control system that controls the air volume of a conventional blower, there is an air conditioner that uses a blower to distribute cold or warm air to each room through a duct. However, the branch ducts branching into each room usually have different lengths from the branch point to each room, and the air blowing resistance of each of the stiff branch ducts is different.

Furthermore, the air blowing resistance of each duct is also affected by defects in the duct installation work, such as deformation due to distortion of the cross-sectional shape of the duct, or the presence of foreign matter inside the duct.

In such a situation, especially in the latter case, if the pressure of the common air duct, that is, the root of the main duct, is detected to control the drive of the blower, the difference in pressure loss on the downstream side will be ignored. Accurate ventilation control for each room,
Furthermore, the room temperature cannot be controlled.

In the conventional example shown below, the pressure at the base of the main duct before air is blown into each room is detected to control the drive of the blower.

As a representative example of these conventional examples, see Chapter 2 of the Refrigeration and Air Conditioning Handbook (New Edition/4th Edition Applied Edition) published by the Japan Refrigeration Association.
Figures 2 and 10 listed on page 41 of the air conditioning system
The example (a) will be selected and its operation will be explained below.

FIG. 6 is a configuration diagram showing a conventional air conditioner described in the Refrigeration and Air Conditioning Handbook.

In the figure, 1 is an air-conditioned room to be air-conditioned, and this figure shows a case of four rooms.

2 is a concentrated air blower which is an indoor unit installed in the ceiling of the air-conditioned room 1 and functions as a source of cold or hot air; 3 is an air filter that purifies the air by removing dust and the like from the air; 4 is a heat exchanger that cools or heats air, and 5 is a blower that blows cold or hot air. This indoor unit 2 includes an air filter 3, a heat exchanger 4, and a blower 5. 6 is a main duct that communicates with the air outlet of the indoor unit 2, 7 is a branch duct that branches off from this main duct 6 according to the number of each air-conditioned room 1, and 8 is a branch duct that is attached to the 7 parts of each branch duct and is connected to each cover. 9 is a damper rotatably installed in the throttle-type ventilation adjustment unit 8 that adjusts the amount of air sent to the air conditioned room 1; IO is a damper located at the end of the branch duct 7; Exit, 11 is a suction port installed at the lower part of the door of the air-conditioned room, 12 is a ceiling suction port installed on the ceiling of the hallway outside the air-conditioned room 1, and 13 is a ceiling suction port 12
This is a suction duct that communicates between the indoor unit 2 and the suction port of the indoor unit 2. 1
4 is a room thermostat installed in each air-conditioned room 1 for setting and detecting the room temperature; 15 is a temperature detector in the main duct 6 for detecting the temperature of air blown from the blower 5; 16 is also in the main duct 6; A pressure detector 17 is connected to the heat exchanger 4 to detect the wind pressure caused by the air blown from the blower 5.
It is a heat source device such as a heat pump that controls all heat conversion operations.

A conventional duct type air conditioner for central cooling and heating is configured as described above, and the air cooled or heated by the heat exchanger 4 is sent to the main duct 6 as cold or warm air by the blower 5.
and/or a concentrated air blowing means 2 that distributes and blows air into each of the plurality of air-conditioned rooms 1 via the branch duct 7, and a means 2 that is attached to each of the branch ducts 7 and sends air to each of the air-conditioned rooms 1; It has a diaphragm-type ventilation adjustment unit 8 which is a ventilation adjustment means that adjusts the amount of air or hot air blown by opening and closing a damper 9.

At this point, the operation of the conventional air conditioner configured as described above will be explained.

First, the opening degree of the damper 9 of the aperture-type ventilation adjustment unit 8 is set to an arbitrary position according to the temperature difference between the set temperature set by the user or the like on each room thermostat 14 and the detected current actual room temperature. Adjust each. The pressure inside the main duct 6 also changes depending on the opening degree of the damper 9. This change in pressure is detected by the pressure detector 16, and the air blowing capacity by the blower 5 is adjusted so that the preset pressure is reached.Furthermore, as the air flow rate changes, the air blowing temperature on the outlet side of the heat exchanger 4 is also adjusted. Since the air temperature changes, this change is detected by the temperature detector 15, and the ability of the heat source device 17 is controlled so that the air blowing temperature reaches a preset temperature.

Through this series of controls, air at an appropriate temperature adjusted to a substantially constant temperature is blown out from the air outlet 10 into the air-conditioned room 1 . That is, the air is blown out at an amount corresponding to the magnitude of the heat load in each air-conditioned room 1. In addition, the air conditioned in the air-conditioned room 1 passes through a space such as a hallway from the suction port 11° to the ceiling suction port 12.
and returns to the indoor unit 2 via the suction duct 13.

First, repeat the same flow according to the above operation.

As mentioned above, in the duct-type central cooling/heating B air conditioner using the conventional, general diaphragm-type moon adjustment unit 8, the air conditioner adjusts according to the fluctuations in the heat load in each air-conditioned room 1. Optimum values for the blowing temperature and blowing pressure are determined, and the capacities of the heat source 17 and the blower 5 are controlled so that these values remain approximately constant.

Note that a device that does not use pressure changes in the main duct 6 as a control index as described above is disclosed in Japanese Patent Publication No. 60-47497. This is to control the blower 5 and the like by giving the terminal air volume control unit of each outlet a function as a wind speed sensor. In this device, when the damper 9 is fully opened and the blower adjustment unit with the most unfavorable blowing condition emits an output below the set airflow rate, the airflow rate of the blower 5 is increased based on this output. , the blower 5 is always controlled to the required minimum capacity.

[Problem to be solved by the invention]

In the conventional air conditioner as described above, in order to keep the root pressure of the main duct 6 constant, in controlling the air blowing capacity of the blower 5 using the root pressure as a control index, the air blowing resistance of each branch duct is different. Therefore, the air volume passing through each branch duct,
That is, the amount of air supplied to each air-conditioned room 1 could not be properly controlled.

In addition, if there is an airflow obstruction in the branch duct due to defects in the duct installation work, such as deformation due to distortion of the cross-sectional shape of the duct, or the presence of foreign matter in the duct, the supply to each air-conditioned room 1 described above will be Maintaining proper airflow was particularly difficult.

Note that with the device disclosed in Japanese Patent Publication No. 60-47497, although it is possible to obtain an appropriate air volume by measuring the wind speed at the outlet in each room, each terminal air volume control unit etc. Since it requires a sensor, it is a major waste of equipment and is extremely expensive. Usually, there are about 5 to 15 terminals for this type of air conditioner, and the price range is extremely important.

This invention was made by solving the above problems.
It is an object of the present invention to provide an air conditioner that can appropriately control the capacity of a blower and the amount of ventilation to each air-conditioned room using a simple configuration and means.

[Means to solve the problem]

Therefore, the air conditioner according to the present invention includes a blower and a heat exchanger, and blows air heat-exchanged by the heat exchanger to a plurality of air-conditioned rooms through a main duct and branch ducts connected to the blower. a concentrated air blowing means installed in each of the air ducts and adjusting the amount of cold air or hot air blown to the air-conditioned room by opening and closing a damper; and a damper controlling opening and closing of the damper of the air blowing adjusting means. a control means, a blower control means for setting the power supply to the blower to a predetermined frequency; and an air volume measuring means for detecting the air flow rate from the blower using an air flow rate detector to measure the actual air flow rate; Control means and wind M? ! Using the respective outputs of the II constant means and the damper control means, the correlation between the IA air volume when the air blow adjustment means is fully opened and the frequency of the power supply that drives the blower is calculated to determine the JA windage loss characteristics of each calibration duct. Based on the ventilation loss characteristic and the ventilation loss characteristic of the damper with respect to the known damper opening/closing degree, the correlation between the communication air volume in each of the ventilation adjustment means, the damper opening/closing degree, and the set frequency of the blower power source is calculated. During air conditioning operation, find the maximum value of the required air blow pressure difference for each air blow adjustment means,
When the air blow pressure difference is the maximum value, each air blow adjustment means controls the damper control means to the degree of opening and closing of each damper that corresponds to the required amount M, and the frequency is set to the maximum value of the air blow pressure difference with respect to the sum of the required air volume of the air blow adjustment means. The above-mentioned object is achieved by a configuration characterized by comprising arithmetic processing means for controlling the blower control means.

[For production]

The air conditioner according to the present invention has one or more configurations, and first performs control such that one of the dampers of the damper control means or the air blow adjustment means is fully opened, and the other is fully closed.

Then, the blower control means inputs power at a predetermined frequency that has been preset to the blower. Furthermore, the amount of air blown by the blower at this time is detected by an air amount detector, and
iil amount measuring means. Then, based on the damper opening/closing information by the damper control means, the blower operating frequency information by the blower control means, the air volume measurement value by the air volume measuring means, and the ventilation loss characteristic information for the known damper opening/closing angle, the calculation processing means is performed. These relationships are calculated and tabulated or formulated.

This series of operations is performed by the number of air blow adjustment means, and information on how to control the operating frequency of the blower and the opening/closing degree of the damper of the air blow adjustment means is accumulated in order to blow a predetermined amount of air to each branch duct. .

During actual air conditioning operation, the arithmetic processing means controls the operating frequency of the blower and the opening/closing degree of the damper of the blow adjustment means based on the above-mentioned accumulated information, thereby controlling the blower operation to the necessary and sufficient capacity. In addition, an appropriate amount of cold air or warm air is appropriately supplied to each air-conditioned room according to the set air volume.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, the air conditioning apparatus based on this invention is demonstrated by an Example.

FIG. 1 is a block diagram showing an air volume control system for an air conditioner according to an embodiment of the present invention. In addition, in the figure, the code 2
．． Portions 4 to 9 and 14 are the same as or correspond to the components of the prior art example, and a redundant explanation will be omitted.

Similar to the conventional example, in this air conditioner, air cooled or heated by a heat exchanger 4 connected to a heat source device (not shown) is converted into cold or warm air by a blower 5 through a main duct 6 and a branch duct 7. A concentrated air blowing means 2 blows air into each of the plurality of air-conditioned rooms 1, and is attached to each branch duct 7 to adjust the amount of cold air or warm air blown to each air-conditioned room 1 by opening and closing a damper 9. It has air blow adjustment means 8. Furthermore, each air-conditioned room 1 is equipped with a room thermostat 14 for setting and detecting room temperature, and is connected to arithmetic processing means 23 . In addition, the normal air conditioning operation of this air conditioner conforms to conventionally well-known operating operations, and the temperature and calorific value control of the heat source device (not shown) also conforms to conventional examples, so explanations will be omitted. The air volume control, which is a feature of this invention, will be explained below.

First, I will explain about the test run part of this air conditioner.
-ru.

In FIG. 1, reference numeral 19 denotes an air volume detector disposed at the base of the main duct 6, which detects the air volume from the concentrated air blowing means 2. 20 is a damper control means for controlling the opening degree of the damper 9 of each air blow adjustment means 8. This damper 9 is connected to a drive mechanism (not shown) that opens and closes each damper 9 individually, and operates each drive mechanism in response to an opening signal from the damper control means 20 to perform the corresponding operation. Controls the opening degree of the damper 9. Reference numeral 21 denotes an air volume measuring means for measuring the actual air volume based on the detection signal of the air volume detector 19.

Reference numeral 22 is a blower control means for setting the power supply to the blower to a predetermined frequency. 23 is the blower control means 22
and each output of the air volume measuring means 21 and the damper control means 20,
Based on the known information on the ventilation loss characteristics depending on the opening degree of the damper, the passing wind of the ventilation adjusting means 8, the opening/closing degree of the damper 9, and the blower 5 are determined.
This is a calculation processing means that calculates the relationship between the power supply frequency and the power supply frequency and controls the damper control means 20 and the blower control means 22. This arithmetic processing means 23 outputs the measured air volume output from the air volume measurement means 21, the output of the blower operating frequency from the blower control means 22, the damper opening/closing degree information output from the damper control means 20, the known damper opening degree and its ventilation. The loss characteristic information is used manually to calculate and evaluate the stiffness relationship, create a table or formulate it, and calculate the air blowing resistance in each duct.

Next, an example of the function and operation of the arithmetic processing means 23 of the air conditioner configured as described above will be explained with reference to FIG. 2. FIG. 2 is an air blowing characteristic diagram showing the relationship between the operating frequency, air volume, and pressure of the air blower 5 used in the air conditioner according to the embodiment of the present invention.

In FIG. 2, the vertical axis is the static pressure P caused by the blower 5, the horizontal axis is the air volume Q, the solid line is the characteristic curve of the blower 5, and the broken line is the resistance curve showing the air blowing resistance of the branch duct 7, etc. leading to the predetermined damper 9. . The parameter of the characteristic curve shown by the solid line is the operating frequency R of the blower 5.

Note that the relationship between QP and the normal parameter R is known.

That is, if one damper 9 is fully opened and all other dampers are fully closed, and the operating frequency of the blower 5 at this time is R1, and the actual air flow rate is Ql, then the above-mentioned known Q From the relationship -P-R, the pressure loss (that is, the blowing pressure difference) Pl is determined. Generally, the blowing pressure difference P and the air volume Q have the following relationship.

p=CXQ2 Here, C: Loss coefficient Therefore, by calculating the air blowing pressure difference P1 that makes the air flow amount Ql when the operating frequency of the blower 5 is R1, the unknown coefficient C is determined. The air blowing resistance curve (broken line) of the branch duct of system No. 9 is known, and the loss coefficient C (damper fully open) of the branch duct itself can be determined.

Furthermore, as shown in the characteristic diagram of the damper opening/closing angle and the ventilation loss coefficient in FIG.
The ventilation loss coefficient CD changes. The relationship between this opening/closing angle D1 and the ventilation loss coefficient CD is determined by the damper 9 to be used.
The following functional form can be known for .

c,=F[Di] The ventilation resistance due to the degree of opening and closing of the damper 9 and the ventilation resistance of the branch duct are considered to be series resistance. Once upon a time,
Total ventilation resistance CT of the branch duct including the change in the opening degree of damper 9
can be given as the sum of both (C,=C+CD). From the above, the relationship between the blowing pressure difference P, the air volume Qi, and the damper opening degree Di for the blowing system of the branch duct is determined as follows.

P= (C+F [Di co) Q i
2. Then, the operating frequency R corresponding to P and Qi is determined from the explanation of FIG. 2 above.

By performing the same operation as above for the damper 9 of the other blower adjustment means 8, it is possible to create a table or formulate the relationship between the blower operating frequency R, air volume Q1, and damper opening degree Di for each blower system. Become. By using the tabulated or formulated results, the amount of air passing through each air blow adjustment means 8 can be roughly set, and the damper of each air blow adjustment means 8 can be opened when the blower operating frequency R of the concentrated air blow means 2 is determined. Each degree Di can be calculated and converted into a table or a mathematical formula.

Therefore, by implementing the above calculation processing and configuring an air conditioner using the calculation processing means 23 that controls the damper control means 20 and the blower control means 22, each air-conditioned room as required in the past can be Accurate air blow control for each air blower is possible by controlling the power frequency input to the blower 5 of the concentrated air blower means 2 and the opening degree of the damper 9 of the air blow adjustment means 8.

Further, it is not necessary to provide each air-conditioned room with a conventional air flow rate detection sensor function using an expensive wind speed sensor as disclosed in, for example, Japanese Patent Publication No. 60-47.497.

Next, the operation of the air conditioner of this embodiment will be explained.

FIG. 4 is a flowchart showing an example of a control operation during a test run of an air conditioner according to an embodiment of the present invention. In addition,
This control operation is performed using the functions of a microcomputer provided in the arithmetic processing unit 23.

In addition, this control operation during trial operation is performed during trial operation of the air conditioner, when changing equipment or equipment, and during periodic inspections, as well as changes in ventilation load in air-conditioned rooms that require maximum ventilation volume, and other necessary actions. It is desirable to carry out the test when a change in the maximum blowing pressure occurs.

First, in step S1 in FIG. 4, it is determined whether the mote is a running mote or a trial mote. If there is no test run mode, the series of control operations described below will not be performed. If it is a test run mode, the operation of the heat source device (not shown) is stopped in step S2, and the operation of the blower 5 is started in step S3.

Then, in step S4, the number N of dampers 9 of the ventilation adjustment means 8 connected to the branch duct 7 is set, and in step S4
5, the first damper 9 (1=1) is set to fully open, and the remaining dampers 9 are set to fully closed. This opening/closing control of the damper 9 is performed by a damper control means 20. In step S6, the blower control means 22 controls the operating frequency of the blower 5 to a predetermined value.

In step S7, the amount of air blown at that time is measured by the air amount measuring means 21. Then, in step S8, the opening degree of the damper 9 and its ventilation loss characteristic information are read into the arithmetic processing means 23.

In step S9, it is determined whether the damper 9 that has undergone the above procedure is the Nth damper 9 or not. If it is not the Nth yet, step 510 sets I, -1+1, and steps S5 again.
Return to and repeat the above operation.

Therefore, the above operation is performed sequentially for all dampers 9 from I=1 to I=N, and is repeated N times in total. If it is confirmed in step S9 that I=Nth damper 9, step S
In step 11, the stiffness relationship is calculated from each data of the opening degree of each damper 9, the driving frequency of the blower 5, and the air blowing amount obtained in the above series of operations, and is tabulated or formulated for each blower adjusting means 8. This calculation operation is performed by the calculation processing means 23.

Next, an example of the control operation during actual operation of the damper 9 and the blower 5, which is performed using the above-described tabulated or formulated relationship between the opening degree of each damper 9, the driving frequency of the blower 5, and the air blowing amount, will be explained. .

FIG. 5 is a flowchart showing an example of control operation during air conditioning operation of the air conditioner according to an embodiment of the present invention.

First, in step S21, for each air blow adjustment means 8, the air volume, damper opening degree, drive frequency R of the blower 5, and known R are formulated or tabulated for each air blow adjustment means 8 by the arithmetic processing means 23. Using the relationship between and Q-P,
When the air volume in each air blow adjustment means 8 is set to the set air volume, the pressure loss P when the damper opening is fully opened is calculated.

Next, in step S22, the maximum value Pl[[lax] of the pressure loss Pi of each air blow adjustment means 8 is selected. In step S23, the pressure loss P or Pi for each air blow adjustment means 8 is determined.
The opening degree of each damper that provides each set air volume when the air volume is max is determined from the above relationship. At this time, the opening degree of the damper 9 of the air blow adjustment means 8, whose pressure loss Pi was Pimax in step S21, is of course fully open. And step S
24, the damper opening degree obtained in step S23 is instructed to each air blow adjustment means 8 via the damper control means 20,
Operate the damper 9. Then, in step S25, a power supply frequency R is set that provides the maximum value P i wax of pressure loss for the sum ΣQ of the required air volume of each air blow adjustment means 8,
The drive of the blower 5 of the centralized blower means 2 is controlled via the blower control means 22 based on this set value.

By performing such a control operation, operation control that minimizes the blowing power as disclosed in, for example, Japanese Patent Publication No. 60-47497 can be more easily realized.

As mentioned above, in this example, during the commissioning mote,
The damper control means 20 performs control to fully open one of the dampers 9 of the air blow adjustment means 8 and fully close the others.

Accordingly, the blower control means 22 controls the blower control means 22 so that the predetermined frequency is set in advance. Furthermore, the amount of air blown by the concentrated air blowing means 2 at this time is detected by the air amount detector 19 and measured by the air amount measuring means 21.

Then, the opening/closing information of the damper 9 by the damper control means 20, the frequency information of the blower 5 by the blower control means 22, the measured value of the air volume by the air volume measuring means 21, and the ventilation loss characteristic information for the known opening/closing angle of the damper 9. The arithmetic processing means 23 calculates these relationships and creates a table or formula. This series of operations is performed as many times as the air blow adjustment means 8, and in order to blow a predetermined amount of air into each branch duct 7, it is necessary to control the frequency of the blower 5 and the opening/closing degree of the damper 9 of the air blow adjustment means 8. Accumulate information.

As described above, the air path resistance of each branch duct 7 is detected in advance, the air volume of each air blow adjustment means 8 is indirectly estimated, and the appropriate opening/closing degree of the damper 9 and the blower 5 are determined based on the set air volume.
Find the operating frequency.

Then, during actual air conditioning operation, each air-conditioned room 1
can stably supply an appropriate amount of cold or hot air to the

Therefore, in this embodiment, it is possible to very easily distribute an appropriate amount of air and reduce the power of air blowing according to the air blowing resistance of each duct, and the amount of air supplied to each air-conditioned room 1 can be maintained appropriately. Moreover, these controls can be achieved with a simple configuration without using a special terminal air volume control unit or the like having a wind speed sensor function for each air conditioned room. As a result, efficient air conditioning effects can be achieved with an inexpensive configuration.

(Effect of the invention) As explained above, the air conditioner according to the present invention has the following features:
During the test run, the calculation processing means calculates the damper opening/closing information by the damper control means, the blower control information by the blower control means, the air volume information from the air volume measurement means, and the known damper opening degree and its ventilation loss characteristic information. By calculating each relationship and creating a table or formulating it,
By detecting the air path resistance of each duct in advance, and indirectly estimating the air volume to each air-conditioned room, it is possible to determine the appropriate opening/closing degree of the damper and the operating frequency of the blower drive power supply for the set air volume. During actual air conditioning operation, the power supply frequency of the blower and the opening/closing degree of the damper of the blow adjustment means are controlled by the calculation processing means based on the above information to reduce the blow power. It is possible to maintain an appropriate amount of air supplied to each air-conditioned room. Moreover, these controls can be achieved with a simple configuration without the need to equip each air-conditioned room with a special terminal air volume measurement unit equipped with a wind speed sensor, etc., thereby providing an economical and efficient air conditioner. be able to.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing an air volume control system of an embodiment of an air conditioner according to the present invention, Fig. 2 is an air blowing characteristic diagram showing the relationship between air volume and pressure of the blower used in the above embodiment;
The figure is a characteristic diagram showing the relationship between damper opening and ventilation loss coefficient.
FIG. 4 is a flowchart showing an example of the control operation in the test run mote of the above embodiment, FIG. 5 is a flowchart showing an example of the control operation during air conditioning operation of the same embodiment, and FIG. 6 shows a conventional air conditioner. FIG. 1 is an air-conditioned room, 2 is a central blower means, 4 is a heat exchanger, 5 is a blower, 6 is a main duct, 7 is a branch duct, 8 is a blower adjustment means, 9 is a damper, 14 is a room thermostat, 19 is an air volume 20 is a damper control means, 21 is an air volume measuring means, 22 is a blower control means, and 23 is an arithmetic processing means. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] A centralized blower means that includes a blower and a heat exchanger and blows the air heat-exchanged by the heat exchanger to a plurality of air-conditioned rooms via a main duct and branch ducts connected to the blower, and is attached to each of the branch ducts. a blower adjusting means for adjusting the amount of cold air or hot air blown to the air-conditioned room by opening and closing a damper; a damper control means for controlling opening and closing of a damper of the blower; and a predetermined power supply for supplying power to the blower. a blower control means that sets the frequency to a frequency of , an air flow measurement means that measures the actual air flow by detecting the air flow from the blower with an air flow detector, and each of the blower control means, the air flow measurement means, and the damper control means. Based on the output, the correlation between the passing air volume when each of the air blow adjustment means is fully opened and the frequency of the power supply that drives the blower is calculated to determine the airflow loss characteristics of each branch duct, and the airflow loss characteristics and the known opening/closing of the damper are calculated. Based on the ventilation loss characteristics of the damper with respect to the degree, the correlation between the passing air volume in each of the ventilation adjustment means, the degree of opening/closing of the damper, and the set frequency of the blower power source is calculated and determined, and during air conditioning operation, each ventilation adjustment means Find the maximum value of the required blowing pressure difference for
When the air blow pressure difference is the maximum value, each air blow adjustment means controls the damper control means to the degree of opening and closing of each damper that provides the required air volume, and the blower is adjusted to a frequency that provides the maximum value of the air blow pressure difference with respect to the sum of the required air volume of the air blow adjustment means. An air conditioner comprising: arithmetic processing means for controlling the control means.