GB2026682A

GB2026682A - Ventilating Air Vent

Info

Publication number: GB2026682A
Application number: GB7921609A
Authority: GB
Original assignee: Gebrueder Trox GmbH
Current assignee: Gebrueder Trox GmbH
Priority date: 1978-06-24
Filing date: 1979-06-21
Publication date: 1980-02-06
Also published as: GB2026682B; NO791932L; JPS556194A; DE2827910A1; FR2429390A1; SE441958B; DK256979A; NO143390C; BE877179A; BR7903960A; FR2429390B3; NO143390B; SE7905332L

Abstract

An air vent, particularly a ceiling mountable air vent for ventilation and air-conditioning systems with a variable air in-flow volume, comprises a hollow cylindrical air vent casing (2) having an axially directed air inlet (3) and a radially directed air outlet [5). An axially movable deflection member (7) is mounted within the casing for deflecting air introduced through the inlet (3) towards the outlet (5). <IMAGE>

Description

SPECIFICATION An Air Vent This invention relates to an air vent, and particularly, but not exclusively to a ceiling mountable air vent for ventilation and air conditioning systems having a variable air inflow volume.

In air vents for ventilation and air-conditioning systems it is important that the discharge velocity and, therefore, the depth of penetration into the room should on the one hand be sufficient to attain a uniform temperature distribution, and on the other hand not be so great as to cause considerable movement of air together with draughts and loud air noises. If such ventilation, and air-conditioning systems are regulated by varying the air inflow volume, difficulties arise in designing the cross-section of the air vents. If the cross-section designed for an optimum discharge velocity is estimated according to the maximum air inflow volume, then in the case of small air inflow volumes discharge velocities occur which are generally too low and therefore the depth of penetration is insufficient. In these cases the room is not uniformly ventilated or heated.

This is particularly disadvaptageous for airconditioning systems in hot-air operation. In relation to cold-air operation, relatively small air inflow volumes, of the order of magnitude of 20%, may be sufficient for heating a room. In order to attain a uniform temperature distribution however, these quantities of air must penetrate as deep as possible into the dwelling area of the room, since otherwise only the ceiling area would be heated. With the smallest air inflow volumes therefore high discharge velocities must be achieved. This is not possible however with the known air vents with constant air discharge crosssections.

The invention provides an air vent comprising an air vent casing having an axially directed air inlet and a radially directed air outlet and an axially movable deflection member within the casing for deflecting air introduced through the inlet towards the outlet.

Thus by moving the deflection member in the axial direction the throughflow cross-section in the air vent casing may be altered in such a way that the discharge velocity can be kept substantially constant. In particular it is also possible in the case of low air inflow volumes, particularly in hot-air operation, to increase the discharge velocity by appropriate reduction of the through-flow cross-section so that a great depth of penetration is attained. By adjusting the position of the deflection member in accordance with the air inflow volume in each case an optimum temperature distribution in the room may be achieved, without the occurrence of draughts or excessive outflow noise.

Preferably, the deflection member is wider than the air inlet. This improves the guiding of the air in the deflection region.

Preferably, a servomotor is provided for moving the deflection member axially. Thus it is possible to meet the requirements for automatic adjustment in connection with the air inflow volume.

Advantageously, the deflection member comprises a flat deflection plate, which may have radially extending grooves on its side facing the air inlet. The grooves provide an air flow passage between air inlet and air outlet when the deflection plate abuts the portion of the air vent casing surrounding the air inlet. By appropriate dimensioning of the cross-sections of these grooves in relation to the air inflow volume it is possible to attain a greater velocity of the outflowing air than in the case of the other positions of the deflection plate. This is of particular advantage for hot-air operation.

Desirably, the air vent casing has an air inlet opening behind the deflection member when viewed in an air inflow direction. When the air inflow volume is below 100%, air can be sucked infrom the room through this air inlet opening in accordance with the jet pump principle and is mixed in the air vent casing with the air flowing in from the ventilation or air-conditioning apparatus.

In this way optimum intermixture of the room air is effected. Preferably, the deflection member is wider than the air inlet opening, in order to attain an optimum jet pump effect.

Desirably, that edge of the air outlet on the side of the vent casing in which the air inlet is provided has a deflection flange directed towards the opposite side of the vent casing. In the case of small air inflow volumes, which occur in particular in the case of hot-air operation, approximately all the air will be guided towards this deflection flange and in this way is directed downwards. The hot air thus penetrates deep into the room so that even in hot-air operation a substantially uniform temperature distribution may be effected.

Preferably, the air outlet has deflection vanes aligned in the peripheral direction. In this way a swirling motion in the peripheral direction is imparted to the outflowing air, thus ensuring a particularly good intermixture with the room air.

Advantageously the deflection vanes are adjustable.

Conveniently, the air vent casing has a hollow connection member which is disposed in front of the air inlet and which extends in the axial direction. Thus, the air vent casing may be connected to the pipe system of the ventilation or air-conditioning apparatus, to ensure that the inflowing air impinges upon the deflection member in the axial direction.

The invention will now be more particularly described with reference to the accompanying drawing which is a sectional view of one embodiment of an air vent according to the invention.

Referring to the drawing there is shown therein a ceiling mountable air vent 1 which comprises a box-type hollow cylindrical vent casing 2 having a tubular connection member 4 mounted on the casing in coaxial relationship with a centrally located axially directed air inlet 3 in the upper end of the casing 2. By means of the connection member 4 the air vent 1 can be connected to the pipe system of ventilation or air-conditioning apparatus. In addition the member 4 ensures that inflowing air flows into the air vent casing 2 in the axial direction corresponding to the arrows A.

The air vent casing 2 has a radially directed air outlet 5 which extends over the casing periphery, which as shown is circular, and in which curved deflection vanes 6 are mounted. The vanes 6 are aligned in the peripheral direction and their angular position is adjustable. In this way a swirling motion in the peripheral direction may be imparted to the outflowing air stream (arrow B).

In the deflection region of the air vent casing 2, i.e. where the air flow is deflected on all sides from an axial direction to a radial direction (arrows C), there is disposed a flat, circular deflection plate 7 which is disposed symmetrically with respect to the air inlet 3 and which is connected to a servomotor 9 by way of a shaft 8. The deflection plate 7 may be moved up and down in the axial direction (double arrow D) by the servomotor 9 in dependence upon the air inflow volume. An air inlet opening 10 having a grill is provided in the casing 2 directly below the deflection plate 7.

When the air inflow volume is at its maximum the deflection plate 7 is in its lowest position. As the air inflow volume is reduced the deflection plate 7 is raised. In this manner the throughflow cross-section between the deflection plate 7 and the upper wall of the air vent casing 2 is reduced in such a way that the discharge velocity remains practically the same despite the reduction in the air inflow volume. At the same time more air is sucked in through the air inlet opening 10 in the direction of the arrows G in accordance with the jet pump principle and mixes with the air flowing in from the ventilation or air-conditioning apparatus. Since the discharge velocity of the air inflow volume remains the same, the ratio of the induction air flowing in through the air inlet opening 10 with respect to the air inflow volume increases.This induction air is likewise blown out again through the air outlet 5 with a swirling motion imparted thereto in the peripheral direction. In this way an optimum air exchange and, therefore, a uniform temperature distribution are attained.

In addition a peripherally extending downwardly directed deflection flange 11 is provided on the- upper edge of the air outlet 5. The effect of this deflection flange 11 is that as the deflection plate 7 is moved up and down the discharge direction continuously changes, in such a way that as the deflection plate 7 is raised the air blown out is always further deflected downwards and vice versa. The smaller the air inflow volume therefore, the more the air jet blown out is directed downwards. In this way there is an adequate depth of penetration into the room even in the case of a small air throughput.

If the air inflow volume is further reduced the deflection plate 7 is raised still further, until at approximately 20% throughput it comes to bear against the upper wall of the air vent casing 2. In order that the air may still flow between the inlet 3 and outlet 5, the upper side of the deflection plate is provided with radially extending grooves (not shown), the total cross-sectional area of which is such that the air discharge velocity is increased. At the air outlet 5 the air jets emerging from the grooves flow almost entirely against the peripherally extending downwardly directed deflection flange 11 which deflects the air jets downwards so that they penetrate deep into the room.

Claims

1. An air vent comprising an air vent casing having an axially directed air inlet and a radially directed air outlet, and an axially movable deflection member within the casing for deflecting air introduced through the inlet towards the outlet.

2. An air vent according to Claim 1, wherein the deflection member is wider than the air inlet.

3. An air vent according to Claim 1 or 2, wherein a servomotor is provided for moving the deflection member in an axial direction.

4. An air vent according to any one of Claims 1 to 3, wherein the deflection member comprises a flat deflection plate.

5. An air vent according to Claim 4, wherein the deflection plate is provided with radially extending grooves on its side facing the air inlet.

6. An air vent according to any one of Claims 1 to 5, wherein the vent casing has an air inlet opening behind the deflection member when viewed in an air inflow direction.

7. An air vent according to Claim 6, wherein the deflection member is wider than the air inlet opening.

8. An air vent according to any one of Claims 1 to 7, wherein that edge of the air outlet on the side of the vent casing in which the air inlet is provided has a deflection flange directed towards the opposite side of the vent casing.

9. An air vent according to any one of Claims 1 to 8, wherein the air outlet has deflection vanes aligned in the peripheral direction.

10. An air vent according to Claim 9, wherein the deflection vanes are adjustable.

11. An air vent according to any one of Claims 1 to 10, wherein the air vent casing has a hollow cbnnsction member which is disposed in front of the air inlet and which extends in the axial direction.

12. An air vent substantially as hereinbefore described with reference to and as shown in the accompanying drawing.