JP2861255B2 - Air conditioner - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner having a main duct and a branch duct adopting a variable air volume control system capable of independently adjusting the room temperature of each room.

[Conventional technology]

2. Description of the Related Art As an air conditioner employing a conventional variable air volume control system for controlling an air volume of a blower, there is an air conditioner which distributes and provides cool air or warm air to each room via a duct by a blower. However, the branch ducts branched into the respective rooms usually have different lengths from the branch point to the respective rooms, and the respective branch ducts have different airflow resistances. In addition, the ventilation resistance of each duct is also affected by defects in the duct installation work, for example, deformation due to distortion of the duct cross-sectional shape, or the presence of foreign matter in the duct.

In such a state, particularly in the latter case, if the pressure of the common air passage, that is, the pressure of the root of the main duct is detected to control the drive of the blower, the difference in the pressure loss on the downstream side is ignored. In other words, it is not possible to control the air blowing with high accuracy for each room, and hence to control the room temperature.

The conventional example described below detects the pressure at the root of the main duct before being blown to each room, and controls the drive of the blower.

As a specific example representative of these conventional examples, see FIG. 2 ・ 10 described in Chapter 2 of the Refrigeration and Air Conditioning Handbook issued by the Japan Refrigeration Association (New Edition, 4th Edition Application), page 41 of the air conditioning system.
The example of (a) is selected, and its operation will be described below.

FIG. 6 is a configuration diagram showing a conventional air conditioner described in the aforementioned refrigeration / air conditioning handbook.

In the figure, reference numeral 1 denotes an air-conditioned room to be air-conditioned.
This figure shows the case of four rooms. 2 is a centralized air blowing means which is an indoor unit which is disposed in the ceiling of the room to be air-conditioned 1 and functions as a blowing source of cold air or hot air, 3 is an air filter which removes dust and the like in the air to purify the air, Reference numeral 4 denotes a heat exchanger for cooling or heating air, and reference numeral 5 denotes a blower for blowing cold or hot air. The indoor unit 2 includes an air filter 3, a heat exchanger 4, and a blower 5. Reference numeral 6 denotes a main duct communicating with an air outlet of the indoor unit 2, reference numeral 7 denotes a branch duct branched from the main duct 6 in accordance with the number of air-conditioned rooms 1, and reference numeral 8 denotes a branch duct 7 which is attached to each branch duct 7 to be air-conditioned. A throttle-type air-conditioning unit for adjusting the amount of air blown into the chamber 1, a damper 9 is rotatably mounted in the throttle-type air-conditioning unit 8, and an outlet 10 located at the end of the branch duct 7. , 11 is a suction port provided below the door of the room to be air-conditioned 1, 12 is a ceiling suction port provided on a ceiling surface of a corridor outside the room to be air-conditioned 1, 13 is a ceiling suction port 12. The suction duct communicates with the suction port of the indoor unit 2. 14 is a room thermostat for room temperature setting and room temperature detection installed in each room 1 to be air-conditioned,
Reference numeral 15 denotes a temperature detector for detecting the temperature of air blown from the blower 5 in the main duct 6, 16 denotes a pressure detector for detecting wind pressure generated by air from the blower 5 in the main duct 6, and 17 denotes a heat exchanger.
And a heat source device such as a heat pump that controls the heat conversion operation in the heat exchanger 4.

The conventional duct type air conditioner for centralized cooling and heating is configured as described above, and the air cooled or heated by the heat exchanger 4 is converted into cool air or hot air by the blower 5 and the main duct 6 and / or the branch duct 7. And a centralized air blowing means 2 for distributing and blowing air into each of the plurality of air-conditioned rooms 1 via a plurality of air-conditioned rooms 1; It has a throttle-type airflow adjustment unit 8 which is an airflow adjustment means for adjusting by opening and closing.

Next, the operation of the conventional air conditioner having the above configuration will be described.

First, according to the temperature difference between the set temperature set by the user or the like in each room thermostat 14 and the current actual room temperature detected, the opening degree of the damper 9 of the throttle-type ventilation adjustment unit 8 is set to an arbitrary position. Adjust. The pressure in the main duct 6 also changes according to the degree of opening of the damper 9. This change in pressure is detected by the pressure detector 16, and the blowing capacity of the blower 5 is adjusted so as to reach a preset pressure. Further, since the blast temperature at the outlet side of the heat exchanger 4 also changes with the change in the blast amount, the temperature detector 15 detects this change and controls the capability of the heat source device 17 so that the blast temperature becomes a preset blast temperature. I do.

By such a series of controls, an appropriate amount of appropriate temperature air adjusted to a substantially constant temperature is blown from the air outlet 10 into the air-conditioned room 1. That is, the air is blown at an air volume according to the magnitude of the heat load in each air-conditioned room 1. The air conditioned inside the room to be air-conditioned 1 flows into the ceiling suction port 12 from the suction port 11 through a space such as a corridor, and returns to the indoor unit 2 via the suction duct 13 again. Then, the same flow is repeated again according to the above operation.

As described above, in the conventional air conditioning apparatus for centralized cooling and heating using the general throttle type ventilation control unit 8, the ventilation temperature and the ventilation are controlled in accordance with the variation of the heat load in each air-conditioned room 1. The optimum values for the pressure are determined, and the capacities of the heat source unit 17 and the blower 5 are controlled so that these values become substantially constant.

An apparatus that does not use the pressure change 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 providing the terminal air volume control unit of each outlet with a function as a wind speed sensor. In this device, when the damper 9 is fully opened and the air-conditioning unit having the most inferior air-conditioning condition outputs an output less than the set air volume, the air volume of the blower 5 is increased based on the output. , The blower 5 is always controlled to the required minimum capacity.

[Problems to be solved by the invention]

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

Further, in the case where there is a problem in the duct installation work, for example, a deformation due to a distortion of the cross-sectional shape of the duct or the like, or a foreign matter in the duct, etc., the blow duct is present in the branch duct, the supply to the above-mentioned air-conditioned rooms 1 is performed. It was particularly difficult to properly maintain the air volume.

In the apparatus disclosed in Japanese Patent Publication No. 60-47497, an appropriate air volume can be obtained by measuring the wind speed at the air outlet in each room, but each terminal air volume control unit and the like can control the wind speed. Since a sensor is required, the equipment becomes large and extremely expensive. Usually, there are about 5 to 15 terminals of this kind of air conditioner, and the price is extremely important.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has an air conditioner capable of appropriately controlling the capacity of a blower and appropriately controlling the amount of air to each room to be air-conditioned by a simple configuration and means. It is intended to provide a device.

[Means for solving the problem]

An air conditioner according to the present invention has a blower and a heat exchanger, and has a centralized blower for blowing air exchanged by the heat exchanger to a plurality of air-conditioned rooms through a main duct and a branch duct connected to the blower. A blower adjusting unit mounted on each of the branch ducts to adjust a blown amount of cold air or warm air to the room to be conditioned by opening and closing a damper, and a damper control unit that controls opening and closing of a damper of the blower adjusting unit, An air volume measuring unit that detects an air volume from the centralized air blowing unit by an air volume detector and measures an actual air volume, and a pressure detector detects a difference between the air pressure on the blowing side and the air pressure on the suction side of the centralized air blowing unit. Then, the pressure difference measuring means for measuring the blowing pressure difference with respect to the actual duct system, and the ventilation loss characteristics of each branch duct are calculated and obtained by each output of the pressure difference measuring means, the air volume measuring means and the damper control means. Based on the ventilation loss characteristics and the ventilation loss characteristics of the damper with respect to the known degree of opening and closing of the damper, calculate and obtain the correlation between the amount of passing air in each of the ventilation adjusting means, the degree of opening and closing of the damper, and the difference in the blowing pressure, During the air conditioning operation, the operation of the centralized air blowing means is controlled so that the air pressure difference becomes the maximum value of the air pressure differences required by the air-conditioned rooms, and the necessary damper obtained from the correlation is controlled by each damper. It is an object of the present invention to achieve the above-mentioned object with a configuration characterized by comprising arithmetic processing means for controlling the degree of opening and closing through a damper control means.

(Operation)

The air conditioner according to the present invention has the above configuration,
First, the damper control means fully opens one of the dampers of the air blowing adjustment means and fully closes the other damper, detects the air volume of the centralized air blowing means by the air volume detector, measures the air volume by the air volume measuring means, The pressure difference measuring means measures the pressure difference between the air pressure on the blowing side and the air pressure on the suction side of the blowing means based on the output from the pressure difference detector. Based on the damper control means, the damper opening / closing information, the air flow rate information by the air flow rate measuring means, the blast pressure difference information by the pressure difference measuring means, and the ventilation loss characteristics based on the known damper opening / closing angle, the arithmetic processing means Is calculated and tabulated or formulated. This series of operations is performed by the number of the ventilation adjusting means, and in order to blow a predetermined air volume to each branch duct or the like,
Information on how to control the blow pressure difference and the degree of opening and closing of the damper of the blow adjusting means is sequentially accumulated.

Then, in the actual air conditioning operation, the arithmetic processing means controls the operation of the blower to a necessary and sufficient capacity based on each of the above information, and controls the degree of opening and closing of the damper of the air adjustment means to each air-conditioned room. An appropriate amount of cold air or hot air is appropriately provided according to the set air volume.

〔Example〕

Hereinafter, an air conditioner according to the present invention will be described with reference to embodiments.

FIG. 1 is a configuration diagram showing an air volume control system of an air conditioner according to an embodiment of the present invention. In the figure, portions indicated by reference numerals 2, 4 to 9 and 14 are the same as or correspond to the components of the above-mentioned conventional example, and the duplicate description will be omitted. In this air conditioner, similarly to the conventional example, air cooled or heated by a heat exchanger 4 connected to a heat source device (not shown) is converted into cool air or hot air by a blower 5 through a main duct 6 and a branch duct 7. And a centralized air blower 2 for blowing air into each of the plurality of air-conditioned rooms 1 and a damper 9 attached to each of the branch ducts 7 to control the amount of cool air or hot air to be blown to each of the air-conditioned rooms 1.
And a blower adjusting means 8 for adjusting the opening and closing of the fan.

Each room to be air-conditioned 1 is provided with a room thermostat 14 for setting and detecting a room temperature, and is connected to an arithmetic processing unit 23. The normal air-conditioning operation of this air conditioner is in accordance with a conventionally known operation, and the control of the temperature and the amount of heat generated by the heat source device (not shown) is also in accordance with the conventional example. The air volume control which is a feature of the present invention will be described below.

First, a test operation mode of the air conditioner will be described.

In FIG. 1, reference numeral 18 denotes a pressure difference detector for detecting a pressure difference between the air pressure on the blowing side and the air pressure on the suction side of the centralized blowing means 2 comprising the heat exchanger 4 and the blower 5, and 19 denotes a pressure difference detector disposed at the root of the main duct 6. It is a provided air volume detector and detects the volume of air blown from the centralized air blower 2. Reference numeral 20 denotes damper control means for controlling the degree of opening of the damper 9 of each air flow adjusting means. Driving mechanisms (not shown) for individually opening and closing the respective dampers 9 are connected to the dampers 9, and each of the driving mechanisms is operated in response to an opening degree signal from the damper control means 20, and correspondingly. The opening of the damper 9 is controlled. Reference numeral 21 denotes an air volume measuring means for measuring an actual air volume based on a detection signal of the air volume detector 19. Reference numeral 22 denotes a pressure difference measuring means for measuring an actual blowing pressure difference based on a detection signal of the pressure difference detector 18. Reference numeral 23 denotes a relationship between the outputs of the pressure difference measuring means 22, the air volume measuring means 21, and the damper control means 20, and the relationship between the damper opening and the ventilation loss characteristic, which are known information. The arithmetic processing means calculates the relationship with the blowing pressure difference and controls the centralized blowing means 2 and the damper control means 20. The arithmetic processing means 23 outputs the measured air flow output from the air flow measuring means 21, the measured pressure difference output from the pressure difference measuring means 22, the damper opening / closing degree information output from the damper control means 20, the known damper opening degree, and the ventilation loss. With the characteristics as input, these relationships are calculated and evaluated, and are tabulated or formulated to calculate the airflow resistance in each duct.

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

In FIG. 2, the vertical axis represents the blowing pressure difference P obtained from the pressure difference between the blowing side air pressure and the suction side air pressure of the centralized blowing means 2 by the blower 5, the horizontal axis represents the air volume Q, the solid line represents the characteristic curve of the blower 5, and the broken line represents 6 is a resistance curve showing a blowing resistance of a branch duct 7 and the like reaching a predetermined damper 9.

In addition, the blower characteristic curve of the solid line shows the case where the rotation speed of the blower 5 is fixed at a predetermined rotation speed. The airflow resistance of the branch duct indicated by the broken line changes depending on the airflow Qi as shown.

That is, one damper 9 is fully opened and all the other dampers 9 are fully closed, and the air volume Q _{i1 at} this time and the air pressure difference P1 corresponding thereto are measured. Generally, the blowing pressure chamber P and the air volume Q have the following relationship.

P = R × Q ² where R: loss coefficient Therefore, the air volume Q _i1 and the corresponding air pressure difference P
When 1 is measured, the unknown coefficient R is determined, so that the airflow resistance curve of the branch duct of the damper 9 which is fully opened (broken line)
Is known, and the loss coefficient R (damper fully open) of the branch duct itself can be obtained.

Further, as shown in the characteristic diagram of the opening / closing angle of the damper and the ventilation loss coefficient in FIG. 3, the ventilation loss coefficient _RD of the damper 9 changes depending on the opening / closing angle Di. The relationship between the opening / closing angle Di and the ventilation loss coefficient _RD can be known for the damper 9 used in advance in the following functional form.

R _D = F [Di] The ventilation resistance depending on the degree of opening and closing of the damper 9 and the ventilation resistance of the branch duct are considered to be a series resistance. Therefore, the total ventilation resistance of the branch duct including the change in the opening of the damper 9
R _T can be given as the sum of the two (R _T = R + R _D ). From the above, the relationship among the blowing pressure difference P, the air volume Qi, and the damper opening Di for the blowing system is determined as follows.

P = (R + F [Di]) Qi ² By performing the same operation as above for the dampers 9 of the other airflow adjusting means 8, the airflow pressure difference P, the airflow Qi, the damper opening Di and the airflow pressure difference for each airflow system are obtained. Can be tabulated or formulated. Then, by using the tabulated or formulated results, it is possible to calculate each air volume Qi, assuming that the blowing pressure difference P and the damper opening Di of each blowing adjusting means are known. Alternatively, if the amount of air passing through each of the ventilation adjustment units is set in advance, the damper opening Di of each of the ventilation adjustment units when the ventilation pressure difference P of the centralized ventilation unit 2 is determined can be calculated.

Therefore, by performing the above-described arithmetic processing and configuring the air conditioner using the arithmetic processing means 23 for controlling the blower 5 and the damper control means, the accuracy required for each air-conditioned room conventionally required is high. Ventilation control is possible by controlling the opening degree of each damper 9 and the air volume of the centralized ventilation means. It is not necessary to provide each air-conditioned room 1 with a conventional air volume detection sensor function using an expensive wind speed sensor as disclosed in, for example, Japanese Patent Publication No. 60-47497.

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

FIG. 4 is a flowchart showing an example of a control operation at the time of a test operation of the air conditioner of one embodiment of the present invention. Note that this control operation is performed using the function of the microcomputer provided in the arithmetic processing means 23. The control operation at the time of this test operation is performed at the time of test operation of the air conditioner, at the time of equipment or equipment change, at the time of periodic inspection, fluctuation of ventilation load of the air-conditioned room that requires the maximum ventilation amount,
It is desirable to carry out when the required maximum blowing pressure difference changes.

First, in step S1 in FIG. 4, it is determined whether the operation mode is the test operation mode. If it is not the test operation mode, a series of control operations described below are not performed. If the test operation mode is set, the operation of the heat source unit (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 the dampers 9 of the ventilation adjusting means 8 connected to the branch duct 7 is set. In step S5, the first (I = 1) damper 9 is set to fully open, and the remaining dampers 9 are set. Make it fully closed. The opening / closing control of the damper 9 is performed by the damper control means 20. Then, in step S6, the actual air volume of the centralized air blowing means 2 by the air blower 5 at this time is measured by the air volume detector 19 and the air volume measuring means 21, and in step S7, the air blowing pressure of the central air blowing means 2 by the air blower 5 at this time. The difference is measured by the pressure difference detector 18 and the pressure difference measuring means 22. Subsequently, in step S8, the known ventilation loss characteristics corresponding to the opening degree of the first (I = 1) damper 9 are read into the arithmetic processing means 23. Next step
In S9, it is determined whether or not the damper 9 having performed the above procedure is the N-th damper 9. If not the Nth step
In S10, I = I + 1, and the process returns to step S5 to repeat the above operation. Therefore, the above operation is sequentially performed for all of the dampers 9 from I = 1 to I = N, and a total of N
Will be repeated several times. Then, in step S9, I = N
If it is confirmed that the damper 9 has become the first damper 9, the data of the air flow amount and the air pressure difference of the centralized air blower 2 when the respective dampers 9 are fully opened obtained by the above series of operations in step S11, and the damper 9 These relationships are calculated from the ventilation loss characteristics depending on the degree of opening, and a table or a formula is formed for each ventilation adjusting means. This calculation operation is performed by the calculation processing means 23.

Next, each of the dampers 9 tabulated or formulated as described above is used.
A control operation example at the time of actual operation of the damper 9 and the blower 5 performed using the relationship among the opening degree, the blown air amount, and the blow pressure difference will be described. FIG. 5 is a flowchart showing an example of a control operation at the time of air conditioning operation of the air conditioner of one embodiment of the present invention.

First, in step S21, for each of the blower adjusting means 8, the calculation processing means 23 formulates or tabulates the airflow of the centralized blower 2, the opening degree of the damper 9, and the blower pressure difference for each blower adjusting means 8. Using the relationship, the required air pressure difference Pi when the damper opening is fully opened is calculated for each of the required air volume required for air conditioning required by each air flow adjusting means 8. Next, in step S22, the maximum value Pima of the blowing pressure difference Pi required by the blowing adjustment means 8 of each air-conditioned room 1
Select x. In step S23, for each of the blower adjustment means 8, the respective damper opening which gives each set airflow when the blower pressure difference Pi is Pimax is obtained from the above relationship. At this time,
In step S21, the opening degree of the damper 9 of the ventilation adjusting means whose required ventilation pressure difference Pi is Pimax naturally becomes a fully opened state. Then, in step S24, the damper opening degree obtained in step S23 is instructed through the damper control means 20 to each of the ventilation adjusting means 8 to operate the damper 9. Then, in step S25, the blowing pressure difference of the centralized blowing means 2 becomes Pimax, and P
The blower 5 and the like of the centralized blower 2 are automatically controlled so as to maintain imax. With this control, the sum of the required air blowing amounts and the actual air blowing amount of the centralized air blowing means 2 become equal.

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

As described above, in this embodiment, in the test operation mode, the damper control means 20 performs control to open one damper 9 of the blower adjusting means 8 and fully close the other damper 9.
At this time, the air volume of the centralized air blowing means 2 is measured by the air volume measuring means 21 via the air volume detector 19. At this time, the pressure difference of the centralized air blower 2 caused by the air blower 5 is measured by the pressure difference measuring means 22 via the pressure difference detector 18. Then, from the relationship between the opening / closing information of the damper 9 by the damper control means 20, the air flow information by the air flow measuring means 21 and the information of the blowing pressure difference by the pressure difference measuring means 22, and the relationship between the previously known damper opening and its ventilation loss characteristic. The arithmetic processing means 23 calculates these relations to form a table or a formula. This series of operations is performed by the number of the ventilation adjusting means 8, and in order to blow a predetermined air volume to each branch duct 7 and the like,
Information on how to control the air pressure difference and the degree of opening / closing of the damper 9 of the air adjusting means 8 is sequentially accumulated.

As described above, the difference in the air path resistance of each duct is detected in advance, the air volume passing through each air flow adjusting means 8 is indirectly estimated, and the opening / closing degree of the damper 9 and the operation of the air blower 5 appropriate for the required air volume. Find control conditions.

At the time of actual air-conditioning operation, by controlling the degree of opening and closing of the damper 9 of the centralized air blowing means 2 and the air blowing adjusting means 8 based on the above information, an appropriate amount of cold air or hot air is supplied to each air-conditioned room 1. The wind can be supplied stably.

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

〔The invention's effect〕

As described above, the air-conditioning apparatus according to the present invention provides, during a test operation, information on opening / closing of the damper by the damper control means, information on the air volume of the centralized air blowing means by the air volume measuring means, and information on the blowing pressure difference by the pressure difference measuring means. Further, the arithmetic processing means calculates each of these relationships from the information on the relationship between the known opening degree of the damper and its ventilation loss characteristics and tabulates or formulates the relationship to detect the air path resistance of each duct in advance. Then, it is possible to indirectly estimate the air volume to each of the air-conditioned rooms, and obtain an appropriate degree of opening and closing of the damper with respect to the required air volume. And in the case of actual air conditioning operation,
Based on each of the above information, the operation of the centralized air blower and the degree of opening / closing of the damper of the air blower adjuster are controlled by the arithmetic processing means, whereby the blower power can be reduced,
In addition, the amount of air supplied to each room to be air-conditioned can be appropriately maintained. Moreover, since these controls can be achieved with a simple configuration without providing a special terminal air volume measurement unit or the like having a wind speed sensor or the like in each room to be air-conditioned, it is possible to provide an economical and efficient air conditioner. Can be.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an air volume control system of one embodiment of an air conditioner according to the present invention, and FIG. 2 is an air flow characteristic diagram showing a relationship between an air volume of an air blower used in the embodiment and a blowing pressure difference. 3 is a characteristic diagram showing the relationship between the opening degree of the damper and the ventilation loss coefficient, FIG. 4 is a flowchart showing an example of the control operation in the test operation mode of the embodiment, and FIG. Flowchart showing a control operation example,
FIG. 6 is a configuration diagram showing a conventional air conditioner. 1 is a room to be air-conditioned, 2 is a centralized blower, 4 is a heat exchanger, 5 is a blower, 6 is a main duct, 7 is a branch duct, 8 is a blower adjuster, 9 is a damper, 14 is a room thermostat, and 18 is a pressure. A difference detector, 19 is an air volume detector, 20 is a damper control unit, 21 is an air volume measurement unit, 22 is a pressure difference measurement unit, and 23 is an arithmetic processing unit. In the drawings, the same reference numerals indicate the same or corresponding parts.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F24F 11/02

Claims (1)

(57) [Claims] 1. A centralized blower having a blower and a heat exchanger, and blowing air exchanged in the heat exchanger to a plurality of air-conditioned rooms through a main duct and a branch duct connected to the blower;
Blower adjusting means mounted on each of the branch ducts to adjust the amount of cool air or warm air to the room to be air-conditioned by opening and closing a damper; damper control means for controlling opening and closing of a damper of the air adjuster; and the blower Air volume measuring means for detecting the air volume from the air flow detector and measuring the actual air volume,
Pressure difference measuring means for detecting the difference between the air pressure on the outlet side and the air pressure on the suction side of the centralized air blowing means with a pressure detector, and measuring the air blowing pressure difference with respect to the actual duct system; the pressure difference measuring means and the air volume measuring means And the respective outputs of the damper control means to calculate and calculate the ventilation loss characteristics of each branch duct. Based on the ventilation loss characteristics and the ventilation loss characteristics of the damper with respect to the known degree of opening and closing of the damper, the passage in each of the ventilation adjusting means is determined. A correlation between the air volume, the degree of opening and closing of the damper, and the blast pressure difference is calculated and obtained, and during the air-conditioning operation, the blast pressure difference is the maximum value of the blast pressure differences required by the air-conditioned rooms. And an arithmetic processing means for controlling the operation of the centralized air blowing means and controlling each damper via the damper control means so that each damper has a required opening / closing degree obtained from the correlation. Conditioning apparatus.