METHOD FOR INTRODUCTION OF AIR IN A ROOM, VENTILATING/COOLING SYSTEM FOR A ROOM AND LIGHTING ARMATURE FOR INSTALMENT IN A ROOM

Abstract: A method for introducing air into a room (1), where the air is passed in a supply duct in the ceiling and out through a suitable opening and is directed along a heat source (8, 9) in the ceiling. The air is passed in a ceiling space (7) that is separated from the room (1) by an airtight, heat-conducting sub-ceiling (6) and out through one or more slots (15, 16) in a light fitting (8, 9) in the sub-ceiling (6) in a direction such that the air sweeps across the side of the light fitting (8, 9) facing the room (1) and is extracted in the upper area of the room (1).

Description: Method for introducing air into a room, ventilation/cooling system for a room and light fitting for installation in a room. The invention relates to a method for introducing air into a room, where the air is passed in a supply duct in the ceiling and out through a suitable opening and directed along a heat source in the ceiling. Reference is made to NO 167416 as an example of such prior art. Modern ventilating engineering for rooms includes the option of cooling the supply air. When such supply air is introduced into a room directly beneath the ceiling, it is a condition, in order to prevent the occupants of the room from being exposed to the undesirable effects of a draught or from feeling a draught, that the air supplied to the room, which passes along the ceiling to an extract air terminal device, has a temperature of at least about 15°C, so that the air does not fall or drop and is not felt as a draught by the occupants of the room. The object of the invention is to permit ventilation/cooling of the air in a room in such a way that the draught or feeling of draught is eliminated, whilst enabling the system to be made simpler and less expensive. Therefore, according to the invention, a method is proposed as mentioned in the introduction, which method is characterised in that the air is passed in a ceiling space that is separated from the room by an airtight, heat-conducting sub-ceiling, and out through one or more slots in a light fitting in the sub-ceiling in a direction such that the air sweeps across the room-facing side of the light fitting and is extracted in the upper area of the room. Thus, the air is passed in heat exchange with the room air, via the airtight sub-ceiling, and is heated. Further heating takes place by the air sweeping across the light fitting. Thus, relatively cold air can be used as intake or supply air, with heating thereof to such an extent that the draught effect which occurs at temperatures of less than 15°C is eliminated, because the air is heated to a temperature of at least 15°C as a result of the heat exchange via the ceiling and with the light fitting, when the supply air has a temperature of, for example, 10°C. It is previously known to pass air above a sub-ceiling and into a room via slots in the sub-ceiling. According to the prior art, in order for the supply air to "adhere" to the sub- ceiling by utilising the so-called Coanda effect, the air supplied must have a temperature no lower than 15°C, because otherwise the air will fall and be felt as a draught by the occupants of the room. However, with the new method according to the invention, where the air is introduced into the room via slots in light fittings, especially for fluorescent tubes, the air that is delivered to the ceiling space can have a temperature of 10°C. As a result of the heat exchange via the sub-ceiling, the supply air in the ceiling space will reach a temperature of about 12.5°C before the air, after its outflow from the opening or the slots in the light fittings, draws with it air that has been heated by the light elements in the fitting and is therefore delivered to the room at a temperature of 15°C. The temperatures given here apply on the whole and in general to rooms having normal heating and fitted with commonly used light fittings. In conventional cooling where the air is supplied to the ceiling space at 15°C, the volume of air must be increased, or it must undergo a second cooling. An air supply at 10°C results in a greater cooling of the air in such a case, but the extra energy requirement is more than offset by savings on the installation. One effect of the invention is that no extra heating is required in addition to a standard heat exchanger in the winter even though the air is supplied at 10°C instead of 15°C. Calculations have shown that the invention gives a total installation that is 35% cheaper, and that the running costs can be reduced by 30%. In addition, the air supplied at 10°C has less absolute air humidity than the air conventionally supplied at 15°C, which means that problems of condensation are eliminated. Another effect of the invention is that the cooling of the sub-ceiling gives a so-called cooling ceiling principle, which causes the room temperature felt (operative temperature) to be about 1°C less (25°C will be felt as 24°C). A side-effect of the invention is that the light elements, in particular fluorescent tubes, will have a longer useful life. Advantageously, the air is passed in through a damper device controlled by an extract air temperature sensor. According to the invention, the damper device can advantageously be set at a certain, constant minimum supply air flow rate, the temperature sensor being used for the opening/closing movement of a damper in the damper device in order to supply extra air volume in accordance with the temperature sensed. According to the invention, there is also proposed a ventilation/cooling system for a room, comprising a ceiling space delimited by a sub-ceiling and at least one light fitting in the sub-ceiling, which system is characterised in that the sub-ceiling is airtight and heat-conducting, that a supply air terminal device is connected to the ceiling space, that an extract air terminal device is arranged in the upper area of the room, and that the light fitting has an opening for the passage of air from the ceiling space to the room in a direction that causes the air to sweep across the light fitting in the direction of the extract air terminal device. It is particularly advantageous if a temperature sensor that controls a supply air damper device can be arranged in the extract air terminal device. Furthermore, the supply air terminal device may advantageously include an adjustable passage outside the damper device. According to the invention, there is also proposed a light fitting for installation in a sub- ceiling in a room and comprising a housing containing light elements, characterised by an opening, preferably one or more slots in the housing, for directing an air flow from above the sub-ceiling and along the light elements to sweep over these elements on the room side. The invention will now be explained in more detail with reference to the drawings, wherein: Fig. 1 is a purely schematic section through a room fitted with a ventilation/cooling system according to the invention; Fig. 2 shows on a larger scale a regulating device that is used in the system in Fig. 1 ; Fig. 3 is a purely schematic cross-section through a light fitting containing a fluorescent tube; and Fig. 4 is a view of the housing shown in Fig. 3 seen from the right-hand side in Fig. 3. Fig. 1 shows a room 1 with a floor 2, a ceiling 3 and walls 4, 5. Arranged immediately beneath the ceiling 3 is a sub-ceiling 6 that defines a ceiling space 7. In the exemplary embodiment, two light fittings 8 and 9, in this case in the form of respective box-shaped fittings with fluorescent tubes arranged therein, are provided in the sub-ceiling 6. A more detailed description of this arrangement will be given in connection with an exemplary embodiment in Figures 3 and 4. Through a regulating box 10, air is passed into the ceiling space 7, through a suitable air diffuser 11. The air passes out through slots or openings in the light fittings, as indicated by the arrows in connection with the individual light fitting 8, 9, and passes to an extract air terminal device 12. Reference will now be made to Figures 3 and 4. Figs. 3 and 4 show a light fitting 8, primarily consisting of a fitting housing 13 and fluorescent tubes 14 arranged therein. The housing 13 is arranged in a way that is known per se in the corresponding opening in the sub-ceiling 6, and the fluorescent tubes 14 illuminate the room 1 below in a known way. The supply air that is passed into the ceiling space 7 (see Fig. 1) will create a small overpressure in the ceiling space 7, and the air will flow from the ceiling space 7 out through slots 15, 16 in the light fitting, i.e., the housing 13. The slots 15, 16 are so positioned that the air will be delivered to the room at a small angle relative to the sub-ceiling 6, as indicated by the arrows in Fig. 3. Furthermore, the slots 15, 16 are so positioned that, as shown by the arrows, the air will sweep across the light elements (the fluorescent tubes) 14, and pass in the direction of the extract air terminal device 12 (see Fig. 1). The ventilating/ cooling air (the supply air) will draw with it air that has been heated by the light elements 14, as indicated by the arrows inside the housing 13, and will also draw with it air from the room 1 towards the extract air terminal device 12. The slots in the light fitting can preferably have a horizontal lip (not shown) at their lower edge so as to ensure that the air is supplied at a small angle relative to the sub- ceiling 6. However, under the conditions that apply in the illustrated technical solution, the Coanda effect will work even though the supply air has an angle of up to about 30° relative to the horizontal plane (the surface of the sub-ceiling). The supply air that enters the ceiling space 7 will have a heat exchange relationship with the warmer air in the room 1 through the airtight and heat-conducting sub-ceiling 6, and the supply air will thus be heated in the ceiling space. Further heating of the supply air is achieved when the supply air sweeps across the light fittings on their light sides. If, for example, air having a temperature of 10°C is delivered to the ceiling space, the supply air above the sub-ceiling will reach a temperature of about 12.5°C because of the heat exchange with the sub-ceiling, which is heated due to the heat from the room, where the temperature is, for example 25°C. When the air passes through the openings or slots and sweeps across the light elements of the light fittings, a further heating of the air will take place, thereby ensuring that the air has a temperature of at least 15°C, so that the air is prevented from falling and being felt as a draught by the occupants of the room 1. The ventilation/cooling system has a regulating device 10, comprising a thermosensor in the extract air terminal device 12. This thermosensor regulates the air supply and air extraction flow rate by directly actuating a valve body in the supply air supply. One example of such a regulating device is shown in Fig. 2. The regulating device is in the form of a casing that is divided into two sections, namely a supply air terminal device 17 and an extract air terminal device 12. In the supply air terminal device 17 there is a dividing wall 18 equipped with an opening 19 and an opening 20. The opening 20 is adjusted by a preferably manually adjustable damper 21. By turning the damper 21 , the air volume that passes through the opening 20 can be set permanently. The opening 20 thus forms a permanent by-pass as regards the opening 19 through which supply air whose flow rate is determined by the damper 22 passes. The damper 22 is connected to an adjustment bar 23 that is rotatably supported at 24, between the supply air terminal device 17 and the extract air terminal device 12, and is connected to a thermosensor 25, arranged in the extract air terminal device 12. The extract air that enters from the right in Fig. 2 will actuate the thermosensor 15 which in turn causes a turning of the adjustment rod 23, whereby the damper or the plate 22 is moved in order to allow more or less supply air to pass through the opening 19, in addition to the permanent supply air volume that passes through the damper-adjusted opening 20. Thus, if the temperature of the extract air rises, the thermosensor 25 will react and open the damper device 19, 22, i.e., the plate 22 is moved to the right as indicated by the dotted lines, so that a greater volume of cold air can be supplied to the ceiling space 7.

Claims: P a t e n t c l a i m s 1. A method for introducing air into a room (1), where the air is passed in a supply duct in 5 the ceiling and out through a suitable opening and directed along a heat source (8, 9) in the ceiling, characterised in that the air is passed in a ceiling space (7) that is separated from the room (1) by an airtight, heat-conducting sub-ceiling (6) and out through one or more slots (15, 16) in a light fitting (8, 9) in the sub-ceiling (6) in a direction such that the air sweeps across the side of the light fitting (8, 9) facing the room (1) and is l o extracted in the upper area of the room ( 1 ) . 2. A method according to claim 1 , characterised in that the air is passed in through a damper device (19, 22) controlled by an extract air thermosensor (25). 15 3. A method according to claim 2, characterised in that the damper device is set at a certain constant minimum air flow rate and that the thermosensor (25) is used for the opening/closing movement of a damper (22) in order to supply extra air volume in 20 accordance with the temperature sensed. 4. A ventilation/cooling system for a room (1), comprising a ceiling space (7) defined by a sub-ceiling (6) and at least one light fitting (8, 9) in the sub-ceiling (6), characterised in 25 that the sub-ceiling (6) is airtight and heat-conducting, that an extract air terminal device (12) is provided in the upper area of the room (1), and that the light fitting has an opening (15, 16) for passage of air from the ceiling space (7) to the room (1) in a direction that causes the air to sweep across the light fitting (8, 9) in the direction of the extract air terminal device (12). 30 5. A system according to claim 4, characterised in that in the extract air terminal device (12) there is arranged a thermosensor (25) that controls a supply air damper device (19, 22). 35 6. A system according to claim 5, characterised in that the supply air terminal device (17) includes an adjustable passage (20) outside the damper device (19, 22). 7. A light fitting for installation in a sub-ceiling (6) in a room (1) and including a housing (13) containing light elements (14), characterised by an opening, preferably one or more slots (15, 16), in the housing (13) for directing an air flow from above the sub-ceiling (6) and along the light elements (14) to sweep over these elements on the room side.

Inventors: FAUGLI MAARTEN, FAUGLI, MAARTEN
Applicants: FAUGLI MAARTEN, VENTILASJONSTEKNIKK AS, FAUGLI, MAARTEN
Application year: 2001
Main classification: F24F3
IPC codes: F21V29, F21V33, F24F3