METHOD AND DEVICE FOR VENTILATING A ROOM

Abstract: A method for ventilating a room, wherein air is led into the room through an outflow opening (17) in the ceiling (1) of the room. The outflow opening (17) causes the air to flow out substantially at an angle of less than 45 degrees with the ceiling surface. Preferably said angle is substantially parallel to the ceiling surface (1). The outflow opening (17) has an elongated shape which extends substantially parallel to the ceiling surface (1).

Description: METHOD AND DEVICE FOR VENTILATING A ROOM The invention relates to a method for ventilating a room, wherein air is led into the room through an outflow opening in the ceiling of the room. Generally the air is led into the room through several outflow openings . Such a method can be used in various situations, for example in offices, large rooms where many people meet, and in particular in factory farming for ventilating stables, wherein a relatively large number of living organisms per air volume unit are present, which organisms produce a large amount of heat, C0 2 and/or other waste/residual materials. One drawback of prior art methods for ventilating such rooms, wherein the inflowing air, which is often colder, is usually blown down from the ceiling at a relatively high velocity, is that relatively large temperature differences may develop at the various locations inside said room, as well as draught, due to the fact that the air which is blown into the room does not mix very well with the hot air which is present in the room. When the air is blown down at a relatively low velocity in this manner, the air is distributed irregularly and it will not reach every location in the room. This may result in a less comfortable climate inside the room and may even lead to diseases with people and/or animals. The object of the invention is to provide a method for ventilating a room wherein the inflowing air and the air which is present inside the room are mixed more efficiently, and wherein less draught is produced. In order to accomplish that objective, the outflow opening causes the air to flow out substantially at an angle of less than 45 degrees with the ceiling surface. Preferably, said angle is less than 30 degrees, more preferably less than 15 degrees, and in one preferred embodiment the direction of the outflowing air is substantially parallel to the ceiling surface. In particular when the outflow opening has an elongated shape which extends substantially parallel to the ceiling surface, the air flow that is produced near the ceiling diverges little in horizontal direction and obtains a relatively large horizontal direction component. The inflowing air usually has a temperature which is lower than that of the air which is present inside the room to be ventilated, so that said incoming air will flow in downward direction after having covered some distance along the ceiling. Since the relatively cold air remains longer in the upper part of the room in comparison with ventilation systems which cause the air to flow downwards directly, hot air, which after all rises towards the ceiling, will have more time to mix with the cold air. The air will then flow back along the floor surface to the place above which the inflow opening is disposed, and, heated by the living creatures which are present in said room, rise towards the outflow opening. In this manner an air circulation is started and maintained in the room. Preferably, the air is led along two surfaces which narrow in the direction of the outflow opening. Undesirable turbulence and viscous losses are reduced in this manner and the highest possible kinetic energy, and thus velocity, of the outflowing air is realised at a specific air flow, also when flow rates are low. The shape of the narrowing surfaces is preferably such that the air flow, which is initially directed downwards, is deflected in horizontal direction in the most efficient manner possible, which is achieved by giving both surfaces a flowing curve . Also preferably, the width of the outflow opening is varied in order to regulate the amount of air that flows through and/or to regulate the outflow velocity of the air. The width of the outflow opening is thereby preferably varied in dependence on the difference in pressure between the inflowing air and the outflowing air. In an advantageous embodiment said width is adjusted by means of a valve, which is moved in a direction substantially perpendicularly to the ceiling. As a result, the valve can be moved with little resistance, in contrast to horizontally moving valves. The shape of the valve makes it possible to seal the outflow opening hermetically in a simple manner through elastic deformation at the edges of the valve. The valve is preferably moved by a motor, in particular an electric motor. This makes it possible to regulate the ventilation in an efficient manner in dependence on the conditions in the stable, without human interference being required. Preferably, the air is directed in two horizontally opposed directions from substantially the same location near the ceiling. According to another possibility, the air flows out horizontally in only one direction for use near the sides of the room to be ventilated. Although the shape of the outflow opening according to the invention may be different, the outflow opening preferably has an elongated shape which extends substantially parallel to the ceiling. The advantages of the present ventilation system are utilized particularly well in that case when the air flows out from at least two locations near the ceiling, wherein elongated outflow openings preferably extend substantially parallel to each other. It is preferable to direct the air flows from two adjacent locations towards each other. This will cause outflowing air to flow downwards approximately between two outflow openings, and an air circulation will be maintained in an efficient manner through induction. The inflowing air is thereby mixed well with the air which is present in the room. A good air circulation can also take place when only one outflow opening is used in smaller rooms. In one embodiment the air flows to the room as a result of an underpressure being generated in the room. Alternatively, an overpressure can be generated in the supply space above the outflow openings. The invention furthermore relates to a device comprising a room which includes a ceiling in which an outflow opening for air is present, wherein said outflow opening is formed so that the outflowing air in essence makes an angle of less than 45 degrees with the ceiling surface. The invention furthermore relates to an outflow fixture to be mounted in a ceiling, comprising an air outflow opening, wherein said outflow opening includes two elongated and substantially parallel parts, which are capable of directing the air in horizontally opposed directions. Said parallel elongated parts may be interconnected at their ends, thus forming a through opening. Furthermore the two parts can each form an outflow opening. In order to explain the invention more fully, an exemplary embodiment of an outflow fixture for supplying air to a room will be described hereafter with reference to the drawing. Figure 1 is a perspective view of an outflow fixture; Figure 2 is a partial sectional view of said fixture; Figure 3 shows the fixture with the cover removed; Figure 4 shows the air flow through the fixture; and Figure 5 shows the air flow through a space . The embodiment described herein comprises outflow openings on either side, but an embodiment comprising an outflow opening on one side is also possible. The figures are merely schematic representations, wherein corresponding parts are indicated by the same numerals . The outflow fixture according to Figures 1, 2 and 3 includes a fixed part 2, which can be mounted in a ceiling, and a movable part, or valve 7, which can be moved in vertical direction with respect to the fixed part 2. Fixed part 2 consists of an upper part 3 and a lower part . Figure 2 shows part of a ceiling plate 1, which forms part of a ceiling of the room which is to be ventilated. The fixed part 2 of the fixture can be attached to the ceiling plate 1 by placing it into a recess in the ceiling plate in such a manner that the upper part 3 abuts with a flange 15 against the ceiling plate 1 on the upper side and the part 4 of the fixed part 2 abuts with a flange 16 against the underside of the ceiling plate 1. The upper part 3 and the lower part 4 are interconnected by means of bolts 5, which are screwed into holes in upper part 3. The bolts 5 are tightened so that the flanges 15, 16 clamp against the ceiling plate 1. The fixed part 2 of the fixture which is mounted in the ceiling plate 1 bounds an opening, through which air is led downwards from the upper side as a result of the fact that the air pressure above ceiling plate 1 is higher than under ceiling plate 1. This difference in air pressure can be effected by drawing off air from the space under the ceiling and/or by supplying air above the ceiling plate 1. Mounted within the fixed part 2 of the fixture is a valve 7, which in an upper position (shown in Figure 2) joins the fixed part 3, and which in a lower position (shown in Figure 1) forms the lower boundary of an outflow opening 17, such that the entire outflow opening 17 is located under the level of ceiling 1, wherein the plane in which the outflow opening lies is oriented substantially vertically. Flange 16 thereby forms the upper boundary of said outflow opening 17. The fixed part 2 and the valve 7 are shaped such that the narrowing of the outflow opening 17 takes place gradually in any open position of the valve 7, so that a directed air flow along ceiling plate 1 is obtained. The edge of valve 7 is so flexible that a proper seal is obtained in the closed position of the valve, wherein the material of the valve is deformed near the edge thereof. The illustrated fixture includes two elongated parts which form the outflow opening 17 for the air, which parts extend parallel to the ceiling. As a result of this arrangement, the air is blown substantially in two opposed directions. The parts are interconnected at their ends, so that a small amount of air flows in other directions. The width of an outflow opening is less than 5 cm, whilst the length of an elongated part is more than 50 cm. The position of valve 7 in the fixed part 2 of the fixture is adjusted by means of a stepping motor 8 (Figure 3) which is mounted in valve 7. To that end valve 7 forms a hollow space, which is covered by means of a cover 11, which is clamped to the other part of fixed 7 or otherwise attached thereto. Stepping motor 8 includes a vertical shaft, on which the arm 9 is mounted. Two pull/push rods 10 are attached to the end of arm 9, which rods are each connected to a lever 6. In the closed position as shown in Figure 2 the part of the lever 6 which is connected to lower part 4 extends upwards from part 4 at an angle of about 30° with the horizontal plane, seen in projection on a vertical plate which intersects the fixture in longitudinal direction. When the arm 9 is rotated by the stepping motor 8 , the levers 6 are moved via the pull/push rods 10 in such a manner that the valve 7 moves down from the closed position with respect to fixed part 2, wherein the part of lever 6 that is connected to part 4 moves through the horizontal plane and extends downwards from part 4 at angle of approximately 30° in the most open position, seen in the aforesaid projection. Thus a substantially vertical movement of valve 7 is effected in a simple manner and the width of the opening between valve 7 and the fixed part 2 of the fixture can be adjusted in dependence on the prevailing conditions. Stepping motor 8 can be rotated in the opposite direction so as to close valve 7. Figure 4 shows the air flow through the outflow fixture, which is represented very schematically in said figure. Arrow 18 indicates the possible movement of valve 7. The other arrows broadly indicate the direction and the order of magnitude of the velocity of the air flow. The air flow 19 from above is led to the narrowest part 17 of the fixture and accelerated by the walls of the fixed part 2 and the movable part 7 (valve) , which narrowest part 17 forms the outflow opening. The air which exits the outflow opening 17 is directed along the ceiling plate 1, as is indicated by arrows 21. The air 22 that rises under the fixture, which is indicated by arrows, is carried along by the air flowing out of openings 17, which enhances the rising of said air. The convex shape of cover 7 is conducive towards said flow. Figure 5 shows a room in which several elongated outflow fixtures are disposed in parallel relationship, preferably substantially along the entire length or width of the room, wherein the air flows in two opposed directions from each fixture (2, 7), so that the air flows from two adjacent fixtures are directed towards each other. In the upper layer near ceiling 1 said air flows, which are relatively cool in comparison with the air which is present inside the room, mix with the hot air that has risen to said upper layer, and subsequently meet halfway between the fixtures. At this point the combined air flow moves downwards in the direction of the floor 12 of the room, where a moderate air flow is formed, which feels pleasant to the people and/or animals that are present there. The air which is heated by said people and/or animals will finally rise to the ceiling 1 near the fixtures and thus complete the circulation. Generally the inflowing air will flow out via ventilation openings in the walls of the room after having circulated a number of times.

Claims: CLAIMS 1. A method for ventilating a room, wherein air is led into the room through an outflow opening in the ceiling of the room, characterized in that the outflow opening causes the air to flow out substantially at an angle of less than 45 degrees with the ceiling surface. 2. A method according to claim 1, characterized in that said angle is less than 30 degrees, preferably less than 15 degrees, and in that the direction of the outflowing air is more preferably substantially parallel to the ceiling surface. A method according to any one of the preceding claims, characterized in that the outflow opening has an elongated shape which extends substantially parallel to the ceiling surface. A method according to any one of the preceding claims, characterized in that the air is led along two surfaces which narrow in the direction of the outflow opening. 5. A method according to any one of the preceding claims, characterized in that the width of the outflow opening is varied in order to regulate the amount of outflowing air and/or the outflow velocity of said air. 6. A method according to claim 5, characterized in that the width of the outflow opening is varied in dependence on the difference in pressure between the inflowing air and the outflowing air. 7. A method according to claim 5 or 6, characterized in that the width of the outflow opening is direction substantially perpendicularly to the ceiling. 8. A method according to claim 7, characterized in that the valve is moveα by a motor, in particular an electric motor. 9. A method according to any one of the preceding claims, characterized in that the air is directed in two horizontally opposed directions from substantially the same location near the ceiling. 10. A method according to any one of the preceding claims, characterized in that the air flows out from at least two locations near the ceiling. 11. A method according to claim 10, characterized in that at least two elongated outflow openings extend substantially parallel to each other. 12. A method according to claim 10 or 11, characterized in that the air flows from two locations near the ceiling are directed towards each other. 13. A method according to any one of the preceding claims, characterized in that the air flows to the room as a result of an underpressure being generated in the room or an overpressure being generated in a space above the ceiling. 1 . A device comprising a room which includes a ceiling in which an outflow opening for air is present, characterized in that said outflow opening is formed so that the outflowing air substantially makes an angle of less than 45 degrees with the RECTIFIED SHEET (RULE 91) ISA/EP ceiling surface. 15. A device according to claim 14, characterized in that said angle is less than 30 degrees, preferably less than 15 degrees, and the direction of the outflowing air is substantially parallel to the ceiling surface. 16. A device according to claim 14 or 15, characterized in that the outflow opening has an elongated shape which extends substantially parallel to the ceiling surf ce . 17. A device according to any one of the claims 14 - 16, characterized in that outflow opening is made up of the ends of two narrowing surfaces. 18. A device according to any one of the claims 14 - 17, characterized in that the width of the outflow opening can be varied in order to regulate the amount of outflowing air and/or the outflow velocity of said air. 19. A device according to claim 18, characterized in that means are provided for regulating the width of the outflow opening in dependence on the difference in pressure between the inflowing air and the outflowing air. 20. A device according to claim 18 or 19, characterized in that the width of the outflow opening is adjusted by means of a valve, which can be moved in a direction substantially perpendicularly to the ceiling. 21. A device according to claim 20 , characterized in that the valve is connected to a motor, in RECTIFIED SHEET (RULE 91) ISA/EP particular an electric motor, which is capable of moving the valve . 22. A device according to any one of the claims 14 - 21, characterized in that the valve, at least in the edge area thereof, is made of a flexible material, so that the material of the valve will deform upon closing of the outflow opening. 23. A device according to any one of the claims 14 - 22, characterized in that the outflow openings are directed in two horizontally opposed directions from substantially the same location near the ceiling. 24. A device according to any one of the claims 14 - 23, characterized in that outflow openings are provided at at least two locations near the ceiling. 25. A device according to claim 24, characterized in that at least two elongated outflow openings extend substantially parallel to each other. 26. A device according to claim 24 or 25, characterized in that outflow openings at at least two different locations are directed substantially towards each other. 27. A device according to any one of the claims 14 - 26, characterized in that means are provided for generating an underpressure in the room or an overpressure in a space above the ceiling. 28. An outflow fixture to be mounted in a ceiling, comprising an air outflow opening, characterized in that said outflow opening includes two elongated and substantially parallel parts, which are capable of directing the air in horizontally opposed directions .

Inventors: DE VRIES ANTONIUS FRANCISCUS, DE VRIES ROBERTUS HENRICUS ADR, DE VRIES, ANTONIUS, FRANCISCUS, DE VRIES, ROBERTUS, HENRICUS, ADRIANNS
Applicants: VRIES ANTONIUS FRANCISCUS DE, VRIES ROBERTUS HENRICUS ADRIAN, DE VRIES, ANTONIUS, FRANCISCUS, DE VRIES, ROBERTUS, HENRICUS, ADRIANNS
Application year: 2000
Main classification: F24F13
IPC codes: F24F13