Air terminal device for control of air flow in a ventilation system

Abstract

Disclosed is an air terminal device for a ventilation system for a building. The air terminal device includes a pressure box, with an inlet admitting supply air into the pressure box and outlet openings for admitting supply air out. The device further includes first and second cover plates, each arranged to control and change the open area of a plurality of the outlet openings. The outlet openings are arranged in a wall of the pressure box forming an outlet surface of the pressure box. The cover plate or cover plates are arranged to be in contact with and slide relative the outlet surface while changing the open area of the outlet openings. The first cover plate and the second cover plate are arranged to slide relative each other and to be in contact with and slide relative the outlet surface while changing the open area of the outlet openings.

Claims

1. An air terminal device for a ventilation system, e.g. a Heating and Ventilation Air Conditioning (HVAC) system, for a building, said air terminal device comprising: a pressure box, provided with at least one inlet for admitting supply air into the pressure box and a plurality of outlet openings for admitting supply air out of the pressure box, a first cover plate, and a second cover plate, wherein each of the first and second cover plates is arranged to control and change the open area of a plurality of said outlet openings, and said plurality of outlet openings are arranged on an outlet surface of the pressure box, wherein the first cover plate and the second cover plate are arranged to slide relative each other and to be in contact with and slide relative the outlet surface while changing the open area of the outlet openings, wherein the plurality of outlet openings are arranged on an outlet surface having at least four edges, including a quadratic or rectangular surface, and there are provided outlet openings along at least four edges, and wherein the first cover plate is arranged to change the area of the outlet openings for openings along a first edge and a second edge being adjacent to each other, and wherein the second cover plate is arranged to change the area of the outlet openings for openings along a third edge and a fourth edge being adjacent to each other, by the first and second cover plates being arranged to change the configuration at all groups outlet openings simultaneously by moving the first and second cover plates in different directions.

2. The air terminal device according to claim 1, wherein said plurality of outlet openings are arranged along one or several edges of the outlet surface.

3. The air terminal device according to claim 2, wherein said area of the outlet openings are changed to be smaller by moving the first and second cover plates towards the edge or edges of the outlet surface.

4. The air terminal device according to claim 3, wherein said plurality of outlet openings are shaped as elongated slits.

5. The air terminal device according to claim 2, wherein said plurality of outlet openings are shaped as elongated slits.

6. The air terminal device according to claim 1, wherein said plurality of outlet openings are shaped as elongated slits.

7. The air terminal device according to claim 6, wherein said elongated slits are arranged such that their longitudinal extension direction is angled less than 30 degrees relative its closest edge.

8. The air terminal device according to claim 6, wherein said elongated slits are arranged such that their longitudinal extension direction is angled less than 30 degrees relative its closest edge, arranged such that their longitudinal extension direction is essentially perpendicular to the extension direction of the closest edge.

9. The air terminal device according to claim 1, wherein said first and second cover plates are arranged to move non linearly, e.g. by a circular or orbital motion, when sliding in order to change the area of the outlet openings.

10. The air terminal device according to claim 9, wherein the first and second cover plates are moved by a rotating actuator.

11. The air terminal device according to claim 10, wherein the outlet surface has been provided with a first actuating rod attached to the first cover plate at its first end and attached to the second cover plate at its second end and having a pivotal point attached at the centre of the first rod to the outlet surface, said first actuating rod being connected to the rotating actuator so as to be rotated around its pivotal point.

12. The air terminal device according to claim 11, wherein the outlet surface has also been provided with a second actuating rod attached to the first cover plate at its first end and attached to the second cover plate at its second end and having a pivotal point attached at the centre of the second rod to the outlet surface, said second actuating rod caused to rotate by the movement of the first and second cover plates induced by the first actuating rod.

13. The air terminal device according to claim 1, wherein the first cover plate is arranged to change the area of the outlet openings for openings along a first edge and a second edge being adjacent to each other and whereby the second cover plate is arranged to change the area of the outlet openings for openings along a third edge and a fourth edge being adjacent to each other.

14. The air terminal device according to claim 1, wherein the outlet openings are directed to a mixing chamber where to a stream of air from the space to be ventilated is induced by the flow of the supply air through the outlet openings such that the stream of supply air is mixed with room air.

15. The air terminal device according to claim 1, wherein the air terminal device is provided with an air temperature regulating device in order to condition the air flowing through the air terminal device.

16. The air terminal device according to claim 1, wherein there is at least one outlet opening being partly covered by one of the first and second cover plates also when the device is set to a maximum flow.

17. The air terminal device according to claim 1, wherein said first and second cover plates are made of a thin flexible sheet having a thickness of 0.15 to 0.60 mm made of a polymer.

18. The air terminal device according to claim 17, wherein said first and second cover plates are located on the high pressure side of the outlet surface.

19. The air terminal device according to claim 1, wherein said first and second cover plates are made of a thin flexible sheet.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1A discloses an air terminal device designed as an induction unit comprising an air temperature conditioner

(2) FIG. 1B discloses an air terminal device designed as an induction unit without temperature conditioning

(3) FIG. 1C discloses an air terminal device designed as an air diffuser without air temperature conditioner or induction arrangement

(4) FIG. 2A discloses an outlet surface provided with ordinary outlet openings having the same length

(5) FIG. 2B discloses an outlet surface provided with a mix of ordinary outlet openings and longer outlet openings

(6) FIG. 3A discloses an outlet surface as in FIG. 2A provided with cover plates when the cover plates are controlled to be in an open position

(7) FIG. 3B discloses an outlet surface as in FIG. 2A provided with cover plates when the cover plates are controlled to be in a covering position

(8) FIG. 4A discloses a circular outlet surface provided with cover plates when the cover plates are controlled to be in an open position

(9) FIG. 4B discloses a circular outlet surface provided with cover plates when the cover plates are controlled to be in a closed position

DETAILED DESCRIPTION OF THE DRAWINGS

(10) In FIG. 1A is disclosed an air terminal device 1 for delivering air to a space to be ventilated. The air terminal device 1 comprises a pressure box 2 connected to a supply air inlet 3 through which an air stream of supply air (F) enters. The supply air may for example be provided by a central Air handling Unit (AHU) (not shown) connected to the air terminal device via a ducting system. The pressure box 2 further comprises a multitude of outlet openings 4 located in an outlet surface 5 in the pressure box for delivering a flow of supply air (F) from the pressure box 2 to a mixing chamber 8. The outlet openings are located along a first edge 7a of the outlet surface 5 and a third edge 7c. The outlet surface 5 and the outlet openings 7a, 7c will be shown in detail in FIG. 2. When the supply air flows into the mixing chamber 8 will it induce a flow I from the space where the air terminal unit 1 is located via an air temperature conditioner 9, e.g. a heat exchanger having a liquid based heating media such as water for cooling or heating air passing through the heat exchanger. The induced flow I will mix with the supply air flow F in the mixing chamber where after a mixed flow F+I will be admitted from the mixing chamber 8 via air terminal outlets 10 to the space to be ventilated. Hence, the air terminal device 1 in FIG. 1 is designed as a cooling beam or comfort cassette for heating or cooling of an air to be admitted from the air terminal device 1.

(11) In FIG. 1b is disclosed a similar device but with the difference no air temperature conditioner 9 is included. Hence, this device works as an induction unit without any temperature conditioning. The induced air flow from the space to be ventilated will however help to improve the mixing of the air in the space and thus cause a more even temperature profile in the room and reduce hot or cold streams arising from the air terminal device.

(12) In FIG. 1c is disclosed still an alternative air terminal unit without air temperature conditioner or induction arrangement and thus will function as an ordinary air diffuser.

(13) In FIG. 2A-B are disclosed two different configurations of outlet openings 4 in a square shaped outlet surfaces 5. In both FIG. 2a and FIG. 2b are there a multitude of outlet openings 4 along the first edge 7a, the second edge 7b, the third edge 7c and the fourth edge 7d. The outlet openings 4 are designed as elongated slits or slots having a longitudinal extension perpendicular to the extension of the edges 7a-d closest to the outlet openings.

(14) The configurations in FIG. 2A and 2B differ in that in FIG. 2B are there some outlet openings 4′ which are longer than the ordinary outlet openings 4. By this arrangement is it facilitated to have some outlet openings which are only partly open also when the cover plates (not shown, see FIG. 3) are set to maximum flow in order to keep the cover plate close to outlet surface 5 provided the cover plate is located on the high pressure side, i.e. inside the pressure box (see FIG. 1).

(15) Hence, these outlet surfaces are suitable to be used in the devices in FIG. 1.

(16) In FIG. 3 is disclosed the outlet surface 5 from FIG. 2A which has been provided with a first cover plate 6a and a second cover plate 6b. The outlet surface 5 has further been provided with a first actuating rod 11 attached to the first cover plate 6a at its first end 11a and attached to the second cover plate 6b at its second end 11b and having a pivotal point 11c attached at the centre of the first rod 11 to the outlet surface 5. Furthermore, the outlet surface 5 has also been provided with a second actuating rod 12 attached to the first cover plate 6a at its first end 12a and attached to the second cover plate 6b at its second end 12b and having a pivotal point 12c attached at the centre of the first rod 11 to the outlet surface 5.

(17) In FIG. 3A the cover plates are controlled to be in an open position and thus keeping the outlet openings 4 completely open. In this position is thus intended that a maximum flow is allowed to flow through the outlet openings 4.

(18) In FIG. 3B are the cover plates controlled to be in a covering position and thus completely covering the outlet openings 4. In this position is thus intended that no air should flow through the outlet openings 4.

(19) The position in FIG. 3A is switched by turning the actuating rods 11, 12 about 40-50 degrees counter clockwise. The actuating rods 11, 12 will thus cause the cover plates 6a, 6b to move in different directions by a rotating movement. As can be understood by the positioning of the rods in FIG. 3A respectively FIG. 3B will the plates, when changing from the position in FIG. 3A to the position in FIG. 3B, first move more in the lateral direction, i.e. changing its distance relative the lateral edges 7a, 7c while at the end of the transition move more in a straight direction, i.e. changing its distance relative the other edges 7b, 7d. However, by designing the rotational movement adequately it may be possible to provide an almost uniform motion. In order to return to from the closed position in FIG. 3B is the actuating rods turned back, clockwise, the same degrees (40 to 50 degrees). An actuator 13 causing a rotational movement may thus be connected to either of the actuating rods 11, 12 in order to provide a rotation, e.g. to the first actuating rod. The other actuating rod, e.g. the second actuating rod, will thus be forced to turn around its pivotal point 12c due to its attachment to the cover plates 6a, 6b at its ends 12a, 12b. The second actuating rod 12 will functions as a guiding member in order to assure the cover plates 6a, 6b will move as desired.

(20) In these figures, only the extreme positions are disclosed, i.e. when the devices are set to maximum flow or completely shut off. The number of intermediate positions depends on the actuator; if the actuator is analogue there may be an endless number of intermediate positions thus allowing the cover plates 6a, 6b to change the flow of air through the outlet surface by step less motion. In case the actuator is moved stepwise, it may have predefined positions with a known configuration of the coverage of the outlet openings such that an air flow may be calculated from these known positions and a pressure difference between the pressure box and the outside pressure.

(21) FIG. 4 discloses a device which is circular and having a circle shaped outlet surface 5 having 4 cover sheets 6a-6d which are positioned in an open position in FIG. 4A and in a closed position in FIG. 4B.