Title:
Damper apparatus for air conditioning system
Kind Code:
A1


Abstract:
The invention relates to a damper apparatus for an air conditioning system for more accurately adjusting air volume in accordance with opening ratio of a damper blade. The damper apparatus includes a plurality of damper blades and an actuator for rotating the damper blade. The apparatus also includes an air flow path dividing means for dividing an air flow path in a duct into upper and lower regions with respect to a rotation axis of the damper blade and exerting resistance to air flow between the biased damper blade and the air flow path dividing means. The invention effectively suppresses air overflow with the air flow path dividing means to decrease the air volume surpassing the opening ratio, thereby more accurately adjusting air volume.



Inventors:
Baik, Wan-ki (Seoul, KR)
Application Number:
11/717972
Publication Date:
09/20/2007
Filing Date:
03/14/2007
Primary Class:
Other Classes:
454/325
International Classes:
F24F11/00; F24F13/06
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Primary Examiner:
PROBST, SAMANTHA A
Attorney, Agent or Firm:
Paul M. Denk (St. Louis, MO, US)
Claims:
What is claimed is:

1. A damper apparatus for an air conditioning system for adjusting air volume in a duct, comprising: a plurality of damper blades each disposed rotatably to open and close an air flow path; an actuator for rotating the damper blades; and a plurality of air flow path dividing means disposed at an air inlet side for dividing the air flow path inside the duct into an upper region and a lower region with respect to a rotation axis of the damper blades and exerting resistance to air flow between the damper blade biased toward the air inlet side and the air flow path dividing means.

2. The damper apparatus for an air conditioning system according to claim 1, wherein the air flow path dividing means comprises a separation plate disposed at a front side of the damper blade.

3. The damper apparatus for an air conditioning system according to claim 2, wherein the separation plate has sealing material at an end portion and side end portions thereof, the sealing material providing sealing with the rotation axis of the damper blade and with the duct.

4. The damper apparatus for an air conditioning system according to claim 1, wherein the rotation axis of the damper blades and the air flow path dividing means are shifted upward or downward from a center of the damper blades.

5. The damper apparatus for an air conditioning system according to claim 4, wherein an upper part of the damper blades is opened forward and a lower part thereof is opened backward in a position where the rotation axis of the damper blade and the air flow path dividing means are shifted downward from the center of the damper blade.

6. The damper apparatus for an air conditioning system according to claim 4, wherein, an upper part of the damper blades is opened backward and a lower part thereof is opened forward in a position where the rotation axis of the damper blade and the air flow path dividing means are shifted upward from the center of the damper blade.

7. A damper apparatus for an air conditioning system for adjusting air volume in a duct comprising: a plurality of damper blades each disposed rotatably to open and close an air flow path; an actuator for rotating the damper blades; and a plurality of air flow path dividing means disposed at an air inlet side for dividing the air flow path inside the duct into an upper region and a lower region with respect to a rotation axis of the damper blades and exerting resistance to air flow between the damper blade biased toward the air inlet side and the air flow path dividing means; and a plurality of average pressure measuring units and each average pressure measuring unit having an average total pressure measuring part and a static pressure measuring part for measuring an average differential pressure or dynamic pressure of air flowing in the duct.

8. The damper apparatus for an air conditioning system according to claim 7, wherein the air flow path dividing means comprises a separation plate disposed at a front side of the damper blade.

9. The damper apparatus for an air conditioning system according to claim 8, wherein the separation plate has sealing material at an end portion and side end portions thereof, the sealing material providing sealing with the rotation axis of the damper blade and with the duct.

10. The damper apparatus for an air conditioning system according to claim 7, wherein the average pressure measuring unit is provided in a number that corresponds to the number of damper blades.

11. The damper apparatus for an air conditioning system according to claim 7, wherein the average total pressure measuring part comprises a plurality of total pressure measuring holes formed toward the air inlet side, on a front side of the air flow path dividing means, each of the total pressure measuring holes comprising an air induction portion having a sloped inner surface.

12. The damper apparatus for an air conditioning system according to claim 7, wherein the average static pressure measuring part comprises a plurality of static pressure measuring holes formed on an underside of the air flow path dividing means.

13. The damper apparatus for an air conditioning system according to claim 7, wherein the rotation axis of the damper blades and the air flow path dividing means are shifted upward or downward from a center of the damper blades.

14. The damper apparatus for an air conditioning system according to claim 13, wherein an upper part of the damper blades is opened forward and a lower part thereof is opened backward in a position where the rotation axis of the damper blade and the air flow path dividing means are shifted downward from the center of the damper blade.

15. The damper apparatus for an air conditioning system according to claim 13, wherein, an upper part of the damper blades is opened backward and a lower part thereof is opened forward in a position where the rotation axis of the damper blade and the air flow path dividing means are shifted upward from the center of the damper blade.

Description:

CLAIM OF PRIORITY

This application claims the benefit of Korean Patent Application No. 2006-24934 filed on Mar. 17, 2006, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an air volume control apparatus (hereinafter, referred to as a damper apparatus) for automatically controlling air volume supplied to and exhausted from a room in accordance with temperature change therein. More particularly, the invention relates to a damper apparatus for an air conditioning system which exerts air resistance in accordance with open angle of the damper blade to air flow in a duct to effectively suppress air overflow due to the biased damper blade, and which measures average air flow velocity by measuring average differential pressure or dynamic pressure at many locations within the duct to accurately calculate air volume, thereby more accurately adjusting air volume in accordance with opening ratio of the damper blade.

2. Description of the Related Art

In general, an air conditioning system as a part of an automatic control system for a building includes a damper apparatus for adjusting volume of air supplied to or exhausted from a room in order to maintain pleasant room temperature or conserve energy by optimally controlling the room temperature.

FIG. 1 is an overall configuration view of such an air conditioning system.

As shown in FIG. 1, conventional damper apparatuses 200 are provided in the air conditioning system, more particularly, installed in a supply air duct 210 through which outside air is supplied, an exhaust air duct 310 through which outgoing air is exhausted, and a return duct 410 for returning the re-circulated air. Each of the damper apparatuses 200 includes a plurality of damper blades 230 for adjusting air volume flowing therethrough and an actuator 240 for rotating the damper blades 230.

The conventional air conditioning system also includes a filter 332 for filtering out foreign material in the supply air, and a heating unit 222 for heating the supply air to a predetermined temperature, a cooling unit 223 for cooling down the supply air to a predetermined temperature and a humidifier 224 for providing moisture to the supply air.

In addition, a supply air fan 232 is disposed inside the supply air duct 210, and an exhaust air fan 234 is disposed inside the exhaust air duct 310.

As shown in FIG. 2, in the conventional damper apparatus 200 for an air conditioning system, when outside air is introduced to the air introduction duct 210, a differential pressure sensor 250 senses pressures from the front and back sides of the damper blade 230 to input the differential pressure to a controller 260. The controller 260 arithmetically calculates the differential pressure of the outside air sensed by the differential pressure sensor 250 and the cross-sectional area of the duct 210 to calculate the air volume inside of the duct 210.

In order to adjust the opening ratio of the damper blade 230, the controller 260 calculates the difference between the current room temperature and the desired room temperature and calculates the air volume that needs to be supplied to the room considering the volume of the room. Then, the controller 260 calculates the opening ratio of the damper blade 230 corresponding to the air volume to be supplied.

Then, the controller 260 operates the actuator 240 to control the damper blade 230 in accordance with the opening ratio calculated.

Therefore, in the conventional damper apparatus 200 for the air conditioning system, the actuator 240 rotates the damper blade 230 in accordance with the calculated result of the controller 260, increasing or decreasing the opening ratio to adjust the temperature as desired by the user. As such, the conventional damper apparatus 200 for the air conditioning system achieves air volume control through adjusting the opening ratio of the damper blade 230, and thus it is essential that the air volume should be accurately adjusted corresponding to the opening ratio.

FIG. 3 is a graph showing the opening ratio and the air volume change ratio obtained by the above conventional damper apparatus 200 for the air conditioning system.

The most ideal characteristics of the damper apparatus 200 for the air conditioning system is to obtain an air volume change ratio line B identical with line A in direct proportion to the opening ratio. When these lines are in agreement, it is most desirable because the controller 260 provided in the damper apparatus 200 for the air conditioning system is able to adjust the opening ratio as desired via the actuator 240 and the damper blade 230, thereby providing accurate volume of air corresponding to the opening ratio.

Examining the air volume change ratio line B as shown in FIG. 3, as the damper blade 230 is rotated in an arbitrary angle θ to be at about 50% of the opening ratio, the resultant air volume change ratio is too large at about 80% or more due to air overflow.

The reason for this is because, at an arbitrary opening ratio, the damper blade 230 induces the air flow to move from an upper region (front side) to a lower region (back side) with respect to the rotation axis 230a. In this process, the biased damper blade 230 exerts acceleration to the air flow to result in air overflow in which greater volume of air flows in the lower region of the damper blade 230.

Therefore, the air volume change ratio with respect to the opening ratio is expressed as a saturation curve of line B, greatly deviating from line A which is in direct proportion to the opening ratio.

Therefore, the air volume change ratio curve B obtained by the damper apparatus 200 for the air conditioning system is completely different from line A which is in direct proportion to the opening ratio, indicating as a result, that it is difficult for the user to adjust air volume via adjusting the open angle of the damper blade. Therefore, the air overflow occurring with the conventional damper apparatus 200 for the air conditioning system must be suppressed to accurately adjust air volume in accordance with the opening ratio.

Therefore, there have been suggested several conventional technologies to overcome such a problem.

An example of such conventional technologies is suggested in Japanese Patent Application Publication Hei 6-337162.

In this conventional technology, each of a plurality of blades are designated into each of a plurality of regions with each blade individually controlled in a different direction from one another, thereby obtaining an air volume change ratio for the entire damper apparatus, which approximates to the line in direct proportion to the opening ratio of the damper apparatus.

However, as the damper blades are divided into regions and controlled respectively, a plurality of actuators are needed to rotate the damper blades in different directions, which in turn increases the total manufacture costs of the damper apparatus.

Moreover, such a conventional damper apparatus fails to obtain an air volume change ratio that is approximate to the opening ratio to a satisfactory level.

Another conventional technology is suggested in U.S. Pat. No. 5,730,652, entitled “Damper With Stationary Pitot-Static Sensing Vanes.”

This conventional damper apparatus has sensors installed between the damper blades for sensing the air volume flowing through the damper blades. The opening ratio of the damper blade is adjusted using the dynamic pressure measured via these sensors.

Such a conventional structure is practical such that dynamic pressure can be accurately measured to adjust air volume.

However, the problem with this conventional technology is that as the damper apparatus is used over time, measurement errors occur due to the structure of the sensors. That is, due to back flow of the air passing through the damper blade, the static pressure measuring portion is clogged by foreign material.

Thus, precision and operational reliability of the conventional damper apparatus is degraded over time.

In addition, the conventional apparatus yields too small an open area at a low opening ratio, impossible to adjust the air volume, which leaves room for improvement.

Further, in this conventional structure, the number of sensors for sensing air volume via measuring dynamic pressure is less than that of the damper blades. That is, three sensors are disposed in comparison to four damper blades. This is because the sensors are disposed between the damper blades, and thus the number of sensors is smaller than the number of damper blades by 1.

Therefore, the conventional technology has room for improvement in terms of a need for measuring the average dynamic pressure at greater number of locations in a duct to more accurately measure the air volume.

SUMMARY OF THE INVENTION

The present invention has been made to solve the foregoing problems of the prior art and therefore an object of certain embodiments of the present invention is to provide a damper apparatus for an air conditioning system capable of effectively suppressing air overflow due to a biased damper blade, with simple structural improvements, thereby accurately adjusting air volume.

Another object of certain embodiments of the invention to provide a damper apparatus for an air conditioning system which measures average differential pressure, i.e., dynamic pressure at more various and greater number of locations in a duct to accurately measure air volume, thereby accurately adjusting air volume.

According to an aspect of the invention for realizing the object, there is provided a damper apparatus for an air conditioning system for adjusting air volume in a duct, including: a plurality of damper blades each disposed rotatably to open and close an air flow path; an actuator for rotating the damper blades; and an air flow path dividing means disposed at an air inlet side for dividing the air flow path inside the duct into an upper region and a lower region with respect to a rotation axis of the damper blades and exerting resistance to air flow between the damper blade biased toward the air inlet side and the air flow path dividing means.

According to another aspect of the invention for realizing the object, there is provided a damper apparatus for an air conditioning system for adjusting air volume in a duct including: a plurality of damper blades each disposed rotatably to open and close an air flow path; an actuator for rotating the damper blades; and an air flow path dividing means disposed at an air inlet side for dividing the air flow path inside the duct into an upper region and a lower region with respect to a rotation axis of the damper blades and exerting resistance to air flow between the damper blade biased toward the air inlet side and the air flow path dividing means; and an average pressure measuring unit having an average total pressure measuring part and a static pressure measuring part for measuring an average differential pressure or dynamic pressure of air flowing in the duct.

Preferably, the air flow path dividing means comprises a separation plate disposed at a front side of the damper blade.

Preferably, the separation plate has sealing material at an end portion and side end portions thereof, the sealing material providing sealing with the rotation axis of the damper blade and with the duct.

Preferably, the average pressure measuring unit is provided in a number that corresponds to the number of damper blades.

Preferably, the average total pressure measuring part comprises a plurality of total pressure measuring holes formed toward the air inlet side, on a front side of the air flow path dividing means, each of the total pressure measuring holes comprising an air induction portion having a sloped inner surface.

Preferably, the average static pressure measuring part comprises a plurality of static pressure measuring holes formed on an underside of the air flow path dividing means.

Preferably, the rotation axis of the damper blades and the air flow path dividing means are shifted upward or downward from a center of the damper blades.

Preferably, an upper part of the damper blades is opened forward and a lower part thereof is opened backward in a position where the rotation axis of the damper blade and the air flow path dividing means are shifted downward from the center of the damper blade.

Preferably, an upper part of the damper blades is opened backward and a lower part thereof is opened forward in a position where the rotation axis of the damper blade and the air flow path dividing means are shifted upward from the center of the damper blade.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a configuration view of an air conditioning system according to prior art;

FIG. 2 is a configuration view of a damper apparatus for the air conditioning system according to prior art;

FIG. 3 is a graph showing the air volume change ratio obtained by the conventional damper apparatus for the air conditioning system in comparison to a line in direct proportion to the opening ratio;

FIG. 4 is a perspective view illustrating the exterior of a damper apparatus for an air conditioning system according to the present invention;

FIG. 5 is a sectional view illustrating the damper apparatus for the air conditioning system according to the present invention;

FIG. 6 is an enlarged sectional view illustrating in detail the damper apparatus for the air conditioning system according to the present invention;

FIG. 7 is a partially cut and enlarged perspective view illustrating an air flow path dividing means and an average pressure measuring unit in the damper apparatus for the air conditioning system according to the present invention;

FIG. 8 is a sectional view illustrating a variation of the damper apparatus for the air conditioning system according to the present invention, in which a rotation axis of a damper blade and the air flow path dividing means are shifted from a center of the damper blade; and

FIG. 9 is a graph showing the air volume change ratio line with respect to the opening ratio, obtained by the damper apparatus for the air conditioning system according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

As shown in FIGS. 4 and 5, a damper apparatus 1 for an air conditioning system according to the present invention includes a plurality of damper blades 20 rotated inside a duct for opening and closing an air flow path and an actuator for rotating the damper blades 20.

In addition, the damper apparatus 1 includes an air flow path dividing means 40 for dividing the air flow path inside the duct 10 at an air inlet side into an upper region and a lower region with respect to a rotation axis 20a of the damper blade 20 and for exerting resistance to air flow between the damper blade 20 biased toward the air inlet side and the air flow path dividing means 40.

In addition, the air flow path dividing means 40 preferably is disposed at a front side of each of the damper blades 20 in alignment with the rotation axis 20a of the damper blades 20. The air flow path dividing means 40 comprises a separation plate 42 (see FIG. 7) for dichotomizing air flow passing through the damper blade 20 into upper and lower flows, and can be installed inside the duct 10 using additional installation piece (not shown).

The separation plate 42 has sealing material (not shown) at an end portion and side portions thereof, i.e., at a portion of the rotation axis 20a and side surface portions of the duct 10. The sealing material (not shown) provides sealing between the separation plate 42 and the rotation axis of the damper blade 20 and between the separation plate 42 and side surface portions of the duct 10.

In addition, as shown in FIGS. 6 and 7, each of the air flow path dividing means 40 includes an average pressure measuring unit 50 having an average total pressure measuring part 52 and an average static pressure measuring part 54 to measure average differential pressure, i.e., dynamic pressure in the air flow inside the duct 10.

The average pressure measuring unit 50 is provided in a number corresponding to the number of damper blades 20. As shown in FIGS. 6 and 7, the average total pressure measuring part 52 of the average pressure measuring unit 50 comprises a plurality of total pressure measuring holes 52b formed on the front side of the air flow path dividing means 40, i.e., at the air inlet side. Each of the total pressure measuring holes 52b comprises an air induction portion 52a having a sloped inner surface to facilitate inflow of air for measuring the average total pressure.

On the other hand, each of the average static pressure measuring parts 54 comprises a plurality of static pressure measuring holes 54a in an underside of the air flow path dividing means 40 and downstream of the air flow from the total pressure measuring holes 52b. Such a configuration minimizes chances of foreign material in the air clogging the static pressure measuring holes 54a and the effect of turbulence to allow accurate measurement of the static pressure.

As shown in FIG. 7, the average total pressure measuring part 54 and the average static pressure measuring part 54, constituting the average pressure measuring unit 50, each has a structure having one side obstructed by a plug 56a, 56b and the other side connected to a sensor (not shown) of the average pressure measuring unit 50.

According to a certain embodiment of the present invention, the rotation axis 20a of the damper blade 20 and the air flow path dividing means 40 are shifted (offset) upward or downward from a center of each of the damper blades 20. As shown in FIG. 8, the rotation axis 20a of the damper blade 20 and the air flow path dividing means 40 can be shifted downward.

In these structures, a closed space S3 enclosed by the damper blade 20 and the air flow path dividing means 40 is formed larger, resulting in a larger area of resistance to the air flow, and thereby air overflow is more effectively prevented.

As shown in FIG. 5, the damper apparatus 1 for the air conditioning system with above described configuration adjusts air volume within a range from vertical position of the damper blade 20 completely blocking the air flow path where the open angle θ is 0° to horizontal position of the damper blade 20 completely opening the air flow path where the open angle θ is 90°.

In this process, in the damper apparatus 1 according to the present invention as shown in FIG. 6, when the plurality of damper blades 20 are simultaneously opened in an arbitrary angle θ by the actuator 30, each of the damper blades 20 is provided with the air flow coming from the air inlet side, divided by the air flow path dividing means 40 into the air flow in the upper region S1 and the air flow in the lower region S2.

In the upper region S1 where the upper air flow is provided, an upper part of each of the damper blades 20 is biased forward. Therefore, in each of the closed spaces S3 enclosed by the air flow path dividing means 40 and the damper blade 20, air flow is blocked from moving from the upper part of the damper blade 20 to the lower part thereof, causing great resistance. Thus, the air flow moving into the enclosed space S3 finely changes its direction upward to flow through an open region S1-1.

In this process, according to a certain embodiment of the present invention, the air flow moving from the upper region S1 to the lower region S2 of each of the damper blades 20 is blocked due to the closed space S3.

On the other hand, as the damper blade 20 is biased backward in the lower region S2 of the air flow path dividing means 40, the air introduced into the lower region of the air flow path dividing means 40 flows well along the biased surface of the damper blade 20 through an open region S2-1. There is no air flow moving in from the upper region S1 by the air overflow.

As described above, according to the present invention, in the damper apparatus 1 for the air conditioning system, the closed space S3 enclosed by each of the damper blade 20 and air flow path dividing means 40 blocks the air flow moving from the upper region S1 to the lower region S2, causing great resistance to the air flow in the upper region S1. Therefore, air overflow in which the air flow moves over the biased damper blade 30 with the conventional damper apparatus is effectively suppressed.

In addition, according to a certain embodiment of the present invention, each of the average pressure measuring units 50 provided in each of the air flow path dividing means 40 measures average values of total pressures and static pressures at each location. Then, the average pressure measuring unit 50 transmits the differential pressure, i.e., dynamic pressure as an electric signal to the controller (not shown) by a differential pressure measuring device, and the controller calculates the air volume based on this signal.

In this process, the average total pressure measuring part 52 of the average pressure measuring unit 50 is disposed on the front side of the air flow path dividing means 40, i.e., the air inlet side. In addition, the average total pressure measuring part 52 comprises a plurality of air induction portions 52a having a sloped inner surface to facilitate inflow of air, corresponding to the number of total pressure measuring holes 52b. The average static pressure measuring part 54 of the average pressure measuring unit 50 comprises a plurality of static pressure measuring holes 54a formed in an underside of the air flow path dividing means 40, downstream of the air flow from the total pressure measuring holes 52b. Therefore, chances of foreign material in the air getting inside and also the effects of turbulence are minimized to accurately measure the static pressure.

Particularly, air inflow to the average pressure measuring unit 50 is facilitated even at low air flow velocity and thus even subtle differential pressure can easily be measured. Also, the static pressure measuring holes 54a are located in the downstream of the air flow from the total pressure measuring holes 52b and on the underside of the air flow path dividing means 40, and thus minimally affected by turbulence.

Further, the average pressure measuring unit 50 according to a certain embodiment of the present invention is formed integral with the air flow path dividing means 40 installed for each of the damper blades 20. This allows measuring the differential pressure, i.e., dynamic pressure at various locations and at greater number of locations, thereby allowing more accurate air volume measurement and accurate adjustment of air volume.

In addition, according to a certain embodiment of the present invention, in the damper apparatus 1′ for the air conditioning system, the rotation axis 20a of the damper blade 20 and the air flow path dividing means 40 are shifted (offset) in a predetermined distance L from a center of the damper blade 20.

Such a shifted structure is illustrated in FIG. 8. In the damper apparatus 1′ for the air conditioning system shown in FIG. 8, the rotation axis 20a of the damper blade 20 and the air flow path dividing means 40 are shifted downward from the center K of the damper blade 20 in a predetermined distance L. This shift is effective in a structure in which the upper part of the damper blade 20 is opened forward and the lower part thereof is opened backward.

Shifting the rotation axis 20a of the damper blade 20 and the air flow path dividing means 40 downward from the center K of the damper blade 20 further enlarges the closed space S3 enclosed by the damper blade 20 and the air flow path dividing means 40, increasing resistance to the air flow in the upper region of the damper blade 20. Thereby, the air overflow caused by the air flowing from the upper region to the lower region over the damper blade 20 is more effectively suppressed.

Although FIG. 8 illustrates the structure in which the rotation axis 20a of the damper blade 20 and the air flow path dividing means 40 are shifted in a predetermined distance L from the center K of the damper blade 20, the present invention is not limited by such. Alternatively, the rotation axis 20a of the damper blade 20 and the air flow path dividing means 40 can be shifted upward from the center K of the damper blade 20.

In this case, air overflow can be effectively suppressed even in a structure in which the upper part of the damper blade 20 is opened backward and the lower part thereof is opened forward.

Therefore, according to certain embodiments of the present invention, the shift distance L of the rotation axis 20a of the damper blade 20 and the air flow path dividing means 40 can be adjusted from the center K of the damper blade 20 to adjust resistance to the air flowing through the damper blade 20, thereby more effectively controlling air overflow due to the biased damper blade 20.

FIG. 9 is a graph showing the air volume change ratio with respect to the opening ratio obtained by certain embodiments of the present invention.

The damper apparatus 1 for the air conditioning system according to the present invention allows an air volume change ratio line B′ approximating greatly to line A in direct proportion to the opening ratio. Therefore, the controller provided in the damper apparatus 1 for the air conditioning system according to the present invention can adjust the opening ratio as desired via the actuator 30 and the damper blade 20, thereby providing exact corresponding air volume to a room.

According to the air volume change ratio line B′, even if the opening ratio of the damper blade 20 is at 50%, the corresponding air volume change ratio is considerably reduced from 80% obtained by the conventional apparatus, thereby greatly improving air overflow occurring with the conventional apparatus.

The reason for this is because the air flow path dividing means 40 is installed at the front side of the rotation axis 20a of the damper blade 20 to divide the air flow path inside the duct 10 into upper and lower regions with respect to the rotation axis 20a of each of the damper blades 20, exerting resistance to the air flow between the damper blade 20 biased toward the air inlet side and the air flow path dividing means 40, thereby effectively suppressing air overflow.

As a result, according to certain embodiments of the present invention, the damper apparatus 1 for the air conditioning system yields the air volume change ratio expressed as curve B′ with respect to the opening ratio in FIG. 9. Curve B′ approximates more greatly to line A in direct proportion to the opening ratio than the conventional air volume change ratio curve B.

Therefore, with the damper apparatus 1 for the air conditioning system according to the present invention, by adjusting the opening ratio, the user is able to accurately adjust air volume approximating to the opening ratio.

According to certain embodiments of the invention as set forth above, an air flow path dividing means can effectively suppress air overflow passing through the damper blade to decrease the excessive air volume with respect to the opening ratio, thereby allowing more accurate adjustment of air volume.

Furthermore, according to certain embodiments of the invention, average differential pressure, i.e., dynamic pressure can be measured at more various and greater number of locations in a duct to enable accurate measurement of air volume, thereby allowing accurate adjustment of air volume.

Certain exemplary embodiments of the invention have been explained and shown in the drawings as presently preferred. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. While the present invention has been shown and described in connection with the preferred embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.