WO2008058538A1

WO2008058538A1 - A personal climatic device and system for its supply

Info

Publication number: WO2008058538A1
Application number: PCT/DK2007/000499
Authority: WO
Inventors: Jesper Vildsø FLINDT
Original assignee: Exhausto A/S
Priority date: 2006-11-14
Filing date: 2007-11-14
Publication date: 2008-05-22

Abstract

Discomfort due to insufficient air quality in office environments has traditionally been fought by means of local fans, providing a stream of air towards the face and upper body of the user. However, the air is still the surrounding air, and the solution has never been perceived as satisfactory, only ameliorating the condition. According to the invention, there is provided a stream of suitably conditioned air that does not form part of the general office air to the head part of the user by means of a combination of two nozzles (2a, 2b) that by means of specially shaped vanes create a focussing of the stream of air.

Description

A personal climatic device and system for its supply.

The invention relates to an air supply system for local climatization, in particular for supplying a stream of air of a comfortable quality to an individual.

Discomfort due to insufficient air quality in office environments has traditionally been fought by means of local fans or ventilators, providing a stream of air towards the face and upper body of the user. However, the air is still the surrounding air, and the solution has never been perceived as satisfactory, only ameliorating the condition.

Personal environment systems for workplaces, such as cubicles in open-plan offices are known in the form of complete air-conditioning units having an outlet close to the person concerned, and while they are adapted to provide a pleasant conditioning for the person concerned, such units also form part of a general office air conditioning. Environments having a lower content of dust or a particular temperature are also created for workplaces by using curtains of air and avoiding intrusion of dust by special jet structures. One such type of workplace could be a hospital bed or surgical operation area. Recent research at the International Center for Indoor Environment and Energy at the Technical University of Denmark has documented clean air supplied close to the breathing zone of office occupants has substantial potential for improving occupants' inhaled air quality and thermal comfort as well as decrease of SBS (Sick Building Syndrome) Symptoms and increase of their performance.

It has been determined that the comfort of a person is increased by a directed stream of air that blows towards the face and upper part of the body, and the comfort realized for a given air consumption is far greater for this solution than for general office air- conditioning. Simple flexible (and hence corrugated) conduits and simple ejection nozzles have been used, but they are both noisy and not aesthetically pleasing. Furthermore, the stream of air invariably has a velocity profile that provides the highest velocity in the centre of the stream. The workplace becomes cramped and part of the work in adjusting the personal climatization equipment is used in providing space for it relative to the instant sitting position of the person, rather than for adjusting comfort parameters. Attempts to use conduits with joints of the style used for localized fume extraction have reduced the noise somewhat, but the ungainliness remains. It has been tried to provide two simple tubular and axial ejection nozzles, but the air streams do not cooperate and create local vortices.

It is the purpose of the invention to provide a personal climatization that does not display the disadvantages of prior solutions.

This is obtained in a personal climatic device that is particular in that the air exits from two nozzles having a distance between them in the interval 50-30 cm, and in that each nozzle is provided with flow guiding vanes acting on separate parts of the supply stream of air.

An advantageous disposition of the nozzle structure is particular in that the airstream is directed at an angle downwards from above to reach the facial target. This means that when working at a workplace the nozzles will be placed above the eye level of the person receiving the personal climatization.

Due to the side-by-side disposition, the air exits as two converging airstreams, and in an advantageous embodiment the velocities and flow guiding vanes are adjusted such that the airstreams merge at a distance in the interval 35-75 cm from the nozzles.

The velocity profile of the supply air stream before it reaches the nozzles with their flow guiding vanes is important, and thus the air for the outlet is in a further advantageous embodiment furnished in conduits that do not appreciably influence the velocity profile with which the air is provided to the conduit.

On the other hand, it constitutes an advantageous use of conduit space when the air for the outlet is furnished in a conduit or conduits that itself forms and maintains the desired velocity profile along its length. A further advantageous embodiment of the invention permits the regulation of the flow, and it is particular in that the inlet to the conduit is connected to the ceiling air outlets of the office air-conditioning system, and in that there are flow dampers provided in the system to control the amount of air.

A further advantageous embodiment of the invention combines the connection to the ceiling air outlets of the office air-conditioning system with other supplies of communication channels and power to a workspace or workstation.

In the implementation of the present invention it has been found to be essential that the flow velocities are such that inside the conduits such conditions apply that are most frequently covered by the term "laminar flow". This is is a type of flow that does not raise the background noise level noticeably.

The invention will be further described with reference to the drawing, in which

Fig. 1 shows a perspective representation of a nozzle system according to the invention in partial section, and

Fig. 2 shows a section through the nozzle system in a diameter plane from above.

In Fig. 1 is shown a supply conduit 1 that rises vertically from a surface that is not shown, and to which the air is supplied by means that are also not shown. The surface may be the upper surface of a working table, and it may be supplied from below, hidden from sight. As the conduit 1 is bent into an essentially horizontal direction the vertical supply of air is directed into a horizontal stream with a particular velocity profile that reaches the symmetrically built nozzle structure 2. The upper half of the conduit 1 has been cut away for visibility as has the upper part of the nozzle structure 2. Here the stream is split into a left stream L for the left nozzle 2a and a right stream R for the right nozzle 2b, and the two streams meet flow guiding vanes Rl-Rn and Ll-Ln respectively. These vanes have the task to re-direct the flow in an axial direction with respect to the last section of the supply conduit 1. The vanes are distributed in such a way across the cross sections Rc and Lc that each vane only engages part of the flows that are obtained due to the splitting of the supply flow. The end plugs of the nozzles are indicated by the letter E.

In principle the two parts to the left and to the right of the nozzle structure 2 may be rotated on their axis to vary the direction of the two streams L and R in order that their convergence at the head and face of the user may be adjusted in height, bearing in mind that the preferable direction is from slightly above. The velocity of the air streams may be 30 cm/s, or it may be 10 cm/s, but it will be varied according to the requirements and the dimensions of the nozzle structure 2. This variation is fully within the capabilities of the skilled person.

Fig. 2 essentially shows the same features as Fig. 1 , but in a longitudinal section. The symmetrical construction is very clearly represented. It is important that the air flow and the air flow profile across the cross section of the supply conduit is disturbed as little as possible, and the "slicing" action of the vanes is intended to create as little turbulence as possible. This ensures among other things that there is no energy loss and no noise generation.

The supply of air comes from a vertical conduit or riser in the present embodiment, and this is a different embodiment of the invention. The important issue is that the flow has to be laminar, and that the means for obtaining the velocity profile may be designed to enable the efficient splitting and redistribution of the airflow by the vanes. Such a velocity profile may be created by delaying parts of a flow that starts out with a "piston"-like profile, and the constructor will decide where this flow manipulation is to occur. Equally, it will be the work of the skilled person to devise the precise means for obtaining the desired flow structure. If it occurs inside the downstream part of the conduit, such as the part designated 1 in Figs. 1 and 2 and by means of special cross sections of the conduit, then the actual profile upstream of this element is of less importance, however if it occurs closer to the supply conduit of the general airconditioning plant, then the conduits ending in the riser 1 must be able to maintain this profile. In all cases the damper will be placed upstream of any flow velocity profile modifying elements. The damper may be purely mechanical or it may be remotely controlled, such as from the workplace, and hence be electrically, pneumatically, or hydraulically activated. Summing up, discomfort due to insufficient air quality in office environments has traditionally been fought by means of local fans, providing a stream of air towards the face and upper body of the user. However, the air quality remains that of the surrounding air, and the solution has never been perceived as satisfactory, only ameliorating the condition. According to the invention, there is provided a stream of suitably conditioned air that does not form part of the general office air to the head part of the user by means of a combination of two nozzles (2a, 2b) that by means of specially shaped vanes create a focussing of the stream of air.

The invention has been described in some detail above, but this is not limiting per se, as the skilled person will be able to devise additional mechanical solutions that perform in an equivalent manner, thereby obtaining similar advantageous results.

The foregoing description of the specific embodiments will so fully reveal the general nature of the present invention that others skilled in the art can, by applying current knowledge, readily modify or adapt for various applications such specific embodiments without undue experimentation and without departing from the generic concept, and therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. The means, materials, and steps for carrying out various disclosed functions may take a variety of forms without departing from the invention.

Thus, the expressions "means to ... " and "means for ...", or any method step language, as may be found in the specification above and/or in the claims below, followed by a functional statement, are intended to define and cover whatever structural, physical, chemical, or electrical element or structure, or whatever method step, which may now or in the future exist which carries out the recited functions, whether or not precisely equivalent to the embodiment or embodiments disclosed in the specification above, i.e., other means or steps for carrying out the same function can be used; and it is intended that such expressions be given their broadest interpretation.

Claims

PATENT CLAIMS

1. An air supply system for local climatization, in particular for supplying a stream of air of a comfortable quality to an individual, in which the stream of air is directed essentially towards the head region of a human body, characterized in that the air exits from two nozzles (2a, 2b) having a distance between them in the interval 50-30 cm, and in that each nozzle is provided with flow guiding vanes (Ll- Ln; Rl-Rn) acting on separate parts (L, R) of the supply stream of air.

2. A system according to claim 1, characterized in that the airstream is directed at an angle downwards from above to reach the facial target.

3. A system according to claim 1, characterized in that the airstream velocities and flow guiding vanes (Ll-Ln; Rl-Rn) are adjusted such that the airstreams merge at a distance in the interval 35-75 cm from the nozzles (2a, 2b).

4. A system according to claim 1, characterized in that the air for the outlet nozzles (2a, 2b) is furnished in conduits that do not appreciably influence the velocity profile with which the air is provided to the conduit.

5. A system according to claim 4, characterized in that said conduits are merged into one conduit.

6. A system according to claim 1, characterized in that the air for the outlet nozzles (2a, 2b) is furnished in conduits that form and maintain a desired velocity profile along its length.

7. A system according to claim 6, characterized in that said conduits are merged into one conduit.

8. A system according to any of the claims 4- 7, characterized in that the inlet to the conduit or conduits is connected to ceiling air outlets of an office air- conditioning system, and in that there are flow dampers provided in the conduit to control the amount of air passed through the conduit.

9. A system according to claim 8, characterized in that the connection to ceiling outlets occurs via vertical risers.

10. A system according to claim 9, characterized in that said vertical risers are integral with power and communication lines supplying a workspace.