A panel system

Abstract

One or more building panels (2) are adapted to be mounted at a ceiling or wall. A flexible sheet (8) is extended between profile members (7) of each panel by spring-biased tensioning mechanisms (10). One or more plate-formed acoustic absorbers (11) are arranged at a building-facing side of the flexible sheet so that a space (13) is formed there between. The flexible sheet is air permeable so that air may pass through the flexible sheet from said space to a room-facing side of the flexible sheet. The panel system is adapted for air supply from an air conditioning system through air inlet openings (14) to said space, an airflow resistance of the flexible sheet is between 50 and 1500 pascal-second per metre, and at least one of the spring-biased tensioning mechanisms of each panel provides a tensioning force of at least 100 newtons in average per metre edge length of the flexible sheet.

Description

[0001] The present invention relates to a panel system including one or more building panels adapted to be mounted at a ceiling or wall of a room so that a framework of each building panel has a room-facing side and a building-facing side, wherein the framework includes a peripheral frame formed by frame profile members, wherein a flexible sheet, such as a textile or foil, is extended over the room-facing side of the framework between the frame profile members, wherein each edge of the flexible sheet is attached to a corresponding frame profile member by means of at least one spring-biased tensioning mechanism tensioning the flexible sheet, wherein the panel system includes one or more plate-formed acoustic absorbers arranged at a building-facing side of the flexible sheet of the one or more building panels and at a distance from the flexible sheet so that a space is formed between the one or more plate-formed acoustic absorbers and the flexible sheet, wherein one or more air inlet openings open into said space, and wherein the flexible sheet is air permeable so that air may pass through the flexible sheet from said space to a room-facing side of the flexible sheet.

[0002] EP 3 080 522 B1 (Kvadrat Acoustics) discloses a sound absorbing panel for use inside a building and designed specifically to be mounted on a surface forming part of a thermally activated building system (TABS). The panel comprises a frame and a front cover placed on said frame facing away from the surface onto which the panel is mounted. A sound absorbing element is placed within said frame in such a way that a first air gap is formed between the absorbing element and the surface on which the panel is mounted, and a second air gap is formed between the sound absorbing element and the front cover. The panel further comprises a first air passage between the first and second air gap and a fan for providing an airstream through said first air passage. Thereby, a thermally transparent sound absorbing panel is achieved which is an advantage in buildings which are provided with thermally activated building systems (TABS), such as cooling of a ceiling. In an embodiment, the front cover allows air to diffuse through it, and an air inlet is provided for air intake from the room in which the panel is mounted, so that a small amount of air may be recirculated through the panel. Thereby, heat exchange between the ceiling onto which the panel is mounted and the surrounding environment is further enhanced due to an additional exchange of heat through air transport. However, although this sound absorbing panel allows for a certain limited air transport through its front cover, the panel is not in any way suitable for actual ventilation of a room with air from an air conditioning system. If the panel would be pressurised by means of air from an air conditioning system in order to obtain a required ventilation flow, the front cover of the panel would bulge down heavily and the distribution of the air exiting through the front cover would be distinctively uneven.

[0003] EP 2 444 561 B1 (Kvadrat Acoustics) also discloses a sound absorbing panel designed specifically to be mounted on a surface forming part of a thermally activated building system (TABS). The panel comprises a frame, a front face and a rear face, and a number of sound absorbing elements. The panel may be provided with a fabric covering the front face of the panel. Subregions without sound absorbing elements are provided between the sound absorbing elements, thereby ensuring thermal transmission through the panel. This panel is neither intended for nor suitable for ventilation of a room with air from an air conditioning system.

[0004] EP 1 959 207 A1 discloses an air-handling ceiling having multiple spaced adjacent cooling elements arranged under a ceiling of a building. An air permeable foil or textile is extended at a distance from the ceiling so that it abuts the lower side of the cooling elements and closes the spaces between the cooling elements. The cooling elements are adapted to draw exhaust air through the air permeable foil from the room below. Furthermore, the cooling elements are adapted to blow cooled air into the spaces between the cooling elements so that the cooled air blows through the air permeable foil to the room below. Plate-formed sound absorbing elements are arranged in the spaces between the cooling elements at a distance from the ceiling and at a distance from the air permeable foil. As a result of the suction effect at the lower side of the cooling elements, the air permeable foil or textile is drawn to the lower side of the cooling elements. Therefore, the foil or textile is supported at regular intervals so that even in large rooms, the foil or textile does not noticeably hang down. However, the actual combination of multiple air intake areas and multiple air outlet areas in the ceiling may lead to unpleasant draught in the ventilated room. Furthermore, the acoustic properties of this system may be impaired by the cooling elements which take up a rather large part of the area of the ceiling.

[0005] US 2,291,220 discloses a ventilation system wherein a false ceiling is formed by means of a number of perforated boards arranged below a permanent ceiling. Air from a blower is passed through a duct into a chamber formed between the false ceiling and the permanent ceiling, and the air flows through the perforations of the boards into the room to be ventilated.

[0006] EP 0 399 935 A1 discloses a device combining heating, ventilating or air-conditioning equipment with a technique for distributing air by blowing it through a false ceiling made of stretched porous fabric. US 3,835,758 similarly discloses air conditioning provided though a false wall.

[0007] Although ventilation of a room through an air permeable foil or textile is known, there exists a need for an aesthetically pleasing panel system having excellent acoustic properties and being adapted for effective and uniform distribution of ventilation air in a room without any draught being felt in the room and without any dead zones being created in which ventilation is not effective.

[0008] The object of the present invention is to provide a panel system of the type mentioned by way of introduction and which is suitable for diffuse ventilation of a room with air from an air conditioning system.

[0009] In view of this object, the panel system is adapted for air supply from an air conditioning system through said one or more air inlet openings to said space, an airflow resistance of the flexible sheet is between 50 and 1500 pascal-second per metre, and at least one of the spring-biased tensioning mechanisms of each building panel in the tensioned state of the flexible sheet provides a tensioning force of at least 100 newtons in average per metre edge length of the flexible sheet.

[0010] In this way, when forcing ventilation air into said space and through the flexible sheet to the room-facing side of the flexible sheet, the combination of an airflow resistance of the flexible sheet of between 50 and 1500 pascal-second per metre and a tensioning force of at least 100 newtons in average per metre edge length of the flexible sheet may ensure that the ventilation air is evenly distributed over the area of the panel system without any visible and / or uneven bulging of the flexible sheet. This is due to the fact that a stable and even airflow may be formed in said space between the one or more plate-formed acoustic absorbers and the flexible sheet as well as through the flexible sheet. Thereby may be obtained a panel system having excellent acoustic properties due to an extensive area of the plate-formed acoustic absorbers, an even distribution of ventilation air in the room, and permanently wrinkle free extended flexible sheet material. The panel system may be used for uniform distribution of ventilation air in even very large rooms.

[0011] In an embodiment, each building panel has a minimum frame profile length, for a building panel having a minimum frame profile length larger than 1.5 metre, at least one of the spring-biased tensioning mechanisms of said building panel in the tensioned state of the flexible sheet provides a tensioning force of at least 125 newtons in average per metre edge length of the flexible sheet, for a building panel having a minimum frame profile length larger than 2 metre, at least one of the spring-biased tensioning mechanisms of said building panel in the tensioned state of the flexible sheet provides a tensioning force of at least 250 newtons in average per metre edge length of the flexible sheet, and for a building panel having a minimum frame profile length larger than 2.5 metre, at least one of the spring-biased tensioning mechanisms of said building panel in the tensioned state of the flexible sheet provides a tensioning force of at least 400 newtons in average per metre edge length of the flexible sheet. Thereby, it may even better be ensured that visible and / or uneven bulging of the flexible sheet may be effectively avoided also for larger panels.

[0012] In an embodiment, the distance between the one or more plate-formed acoustic absorbers and the flexible sheet is at least 25 millimetres, preferably at least 30 millimetres, and most preferred at least 35 millimetres. Thereby, it may even better be ensured that the ventilation air is evenly distributed over the area of the panel system without any visible and / or uneven bulging of the flexible sheet.

[0013] In an embodiment, the airflow resistance of the flexible sheet is between 200 and 900 pascal-second per metre, more preferred between 300 and 800 pascal-second per metre, even more preferred between 350 and 750 pascal-second per metre, and most preferred between 400 and 700 pascal-second per metre. Thereby, it may even better be ensured that the ventilation air is evenly distributed over the area of the panel system without any visible and / or uneven bulging of the flexible sheet. This may in particular be the case in embodiments, wherein a number of building panels are sealed against each other, as it will be discussed in further detail below.

[0014] In an embodiment, the distance between the one or more plate-formed acoustic absorbers and the flexible sheet is not more than 250 millimetres, preferably not more than 150 millimetres, even more preferred not more than 100 millimetres, and most preferred not more than 80 millimetres. Thereby, a reflection of light on a room-facing surface of the one or more plate-formed acoustic absorbers may in a more efficient way facilitate a lighter appearance of the room-facing surface of the flexible sheet when contemplated from the room. Preferably, the room-facing surface of the one or more plate-formed acoustic absorbers is provided with an at least substantially white or at least very light and / or reflective colour, such as by means of paint.

[0015] In an embodiment, at least one of the spring-biased tensioning mechanisms of each building panel in the tensioned state of the flexible sheet provides a tensioning force of at least 300, preferably at least 350, even more preferred at least 400, and most preferred at least 450 newtons in average per metre edge length of the flexible sheet. Thereby, an at least substantially flat appearance of the flexible sheet may be even better ensured, and thereby, the panel system according to the present invention may be even better suited for diffuse ventilation.

[0016] In an embodiment, each building panel has a total area of freely extended flexible sheet corresponding to an area of an open space formed between edges of the frame profile members forming the peripheral frame of the building panel, and both the building-facing side and the room-facing side of the total area of the freely extended flexible sheet is freely exposed to air passing through the flexible sheet. Thereby, because said area of the flexible sheet is freely extended, that is, nothing is touching the part of the flexible sheet being extended between the edges of the frame profile members, i.e. no obstructions to airflow are present, air may freely pass through said part of the flexible sheet. Consequently, an even more uniform distribution of the ventilation air over the area of the panel system may be achieved. Furthermore, because nothing is touching the part of the flexible sheet being extended between the edges of the frame profile members, the appearance of the extended flexible sheet may be smooth and even without any distracting bulging or the like.

[0017] In an embodiment, an additional flexible air permeable layer, such as a web, textile, foil, mesh or the like, is extended between the frame profile members of each building panel, the additional flexible air permeable layer is arranged between the flexible sheet and the one or more plate-formed acoustic absorbers, the additional flexible air permeable layer is arranged at a distance from the flexible sheet and at a distance from the one or more plate-formed acoustic absorbers, and the distance between the additional flexible air permeable layer and the flexible sheet is not more than 250 millimetres, preferably not more than 150 millimetres, even more preferred not more than 100 millimetres, and most preferred not more than 80 millimetres. Thereby, a reflection of light on a room-facing surface of the additional flexible air permeable layer may in an efficient way facilitate a lighter appearance of the room-facing surface of the flexible sheet when contemplated from the room. Preferably, the room-facing surface of the additional flexible air permeable layer is provided with an at least substantially white or at least very light and / or reflective colour, such as by means of paint. By means of the additional flexible air permeable layer, the one or more plate-formed acoustic absorbers may be arranged at a longer distance from the flexible sheet without impairing the preferably light appearance of the flexible sheet when contemplated from the room. Furthermore, the additional flexible air permeable layer may serve as an air filter, thereby contributing to a cleaner environment above the flexible sheet. Thereby, it may be avoided that for instance dust or insects are collected on the building-facing side of the flexible sheet, something that could lead to a less desirable appearance of the panel system.

[0018] In an embodiment, at least one of the one or more air inlet openings is provided through one of the one or more plate-formed acoustic absorbers, between neighbouring ones of the one or more plate-formed acoustic absorbers or between one of the one or more plate-formed acoustic absorbers and one of the frame profile members. Thereby, an even better distribution of the ventilation air over the entire surface of the panel system may be achieved, because the ventilation air may have to travel a shorter distance along the flexible sheet in the space formed between the one or more plate-formed acoustic absorbers and the flexible sheet.

[0019] In an embodiment, the total cross-sectional area of the one or more air inlet openings correspond to between 2 per cent and 25 per cent, preferably between 3 per cent and 20 per cent, more preferred between 4 per cent and 18 per cent, even more preferred between 5 per cent and 15 per cent and most preferred between 5 per cent and 12 per cent of the total area of the extended part of flexible sheet of the panel system. Thereby, an appropriate distribution of the ventilation air over the entire surface of the panel system may be achieved without impairing the acoustic performance of the panel system.

[0020] In a structurally particularly advantageous embodiment, at least one air inlet opening is provided as a groove formed between neighbouring ones of the one or more plate-formed acoustic absorbers, and wherein, preferably, said groove extends from a first frame profile member to second frame profile member being opposed to the first frame profile member. Thereby, the manufacture of the panel system may be facilitated in that the at least one air inlet opening may simply be provided by cutting the one or more plate-formed acoustic absorbers into their respective appropriate lengths without having to cut separate openings in the plate-formed acoustic absorbers.

[0021] In an embodiment, at least one air inlet opening provided through one of the one or more plate-formed acoustic absorbers, between neighbouring ones of the one or more plate-formed acoustic absorbers or between one of the one or more plate-formed acoustic absorbers and one of the frame profile members is covered by an air permeable member, such as a filter, in order to contribute to a cleaner environment above the flexible sheet. Thereby, it may be avoided that for instance dust or insects are collected on the building-facing side of the flexible sheet, something that could lead to a less desirable appearance of the panel system.

[0022] In an embodiment, the air permeable member has a room-facing surface facing the flexible sheet, and the room facing surface of the air permeable member has a light reflectance value being within + / -40 per cent, preferably within + / -30 per cent, more preferred within + / -20 per cent, and most preferred within + / -10 per cent of a light reflectance value of a room-facing surface of the one or more plate-formed acoustic absorbers. Thereby, a reflection of light on a room-facing surface of the air permeable member may balance suitably with a reflection of light on a room-facing surface of the one or more plate-formed acoustic absorbers. Thereby, it may be achieved that the appearance of the room-facing surface of the flexible sheet does not vary noticeably over the entire panel system when contemplated from the room. Preferably, the room-facing surface of the one or more plate-formed acoustic absorbers as well as the room-facing surface of the air permeable member is provided with an at least substantially white or at least very light and / or reflective colour, such as by means of paint.

[0023] In an embodiment, the air permeable member has a room-facing surface facing the flexible sheet, and the room-facing surface of the air permeable member is at least substantially flush with a room-facing surface of the one or more plate-formed acoustic absorbers. Thereby, it may be prevented that shadows are created at the border between the air permeable member and the one or more plate-formed acoustic absorbers, and thereby may be achieved an even appearance of the flexible sheet, when contemplated from the room.

[0024] In an embodiment, at least one air inlet opening provided through one of the one or more plate-formed acoustic absorbers, between neighbouring ones of the one or more plate-formed acoustic absorbers or between one of the one or more plate-formed acoustic absorbers and one of the frame profile members is covered by a lamp housing forming an air passage from a building-facing side of the one or more plate-formed acoustic absorbers to a room-facing side of the one or more plate-formed acoustic absorbers. Thereby, a lamp may be arranged in the panel system at the building-facing side of the flexible sheet, and at the same time, an air passage from a building-facing side of the one or more plate-formed acoustic absorbers to a room-facing side of the one or more plate-formed acoustic absorbers may be created without further affecting the appearance of the flexible sheet when contemplated from the room. Indeed, when the lamp is switched on, the light may be visible from the room, but said air passage may be hidden by the lamp and light. Therefore, apart from the light from the lamp, nothing may reveal the presence of said air passage.

[0025] In a structurally particularly advantageous embodiment, the lamp housing is provided with at least one air intake opening through which air may flow from the building-facing side of the one or more plate-formed acoustic absorbers to an inside of the lamp housing, and the lamp housing is provided with at least one air outlet opening through which air may flow from the inside of the lamp housing to the room-facing side of the one or more plate-formed acoustic absorbers.

[0026] In an embodiment, the at least one air intake opening is covered by an air filter. Thereby, it may be avoided that for instance dust or insects are collected on the building-facing side of the flexible sheet, something that could lead to a less desirable appearance of the panel system.

[0027] In a structurally particularly advantageous embodiment, the at least one air outlet opening is provided between a light diffuser and a front cabinet of the lamp housing.

[0028] In an embodiment, the light diffuser covers an opening in a front face of the front cabinet, and the at least one air outlet opening is provided between a periphery of the light diffuser and a periphery of the opening in the front face of the front cabinet. Thereby, the at least one air outlet opening may be even better hidden in the lamp so that the at least one air outlet opening may not be visible from the room.

[0029] In an embodiment, a front cabinet of the lamp housing has a room-facing surface facing the flexible sheet, and the room facing surface of the front cabinet has a light reflectance value being within + / -40 per cent, preferably within + / -30 per cent, more preferred within + / -20 per cent, and most preferred within + / -10 per cent of a light reflectance value of a room-facing surface of the one or more plate-formed acoustic absorbers. Thereby, a reflection of light on a room-facing surface of the front cabinet may balance suitably with a reflection of light on a room-facing surface of the one or more plate-formed acoustic absorbers. Thereby, in particular when the lamp is switched off, the front cabinet itself may not be visible when contemplating the room-facing surface of the flexible sheet. Preferably, the room-facing surface of the one or more plate-formed acoustic absorbers as well as the room-facing surface of the front cabinet is provided with an at least substantially white or at least very light and / or reflective colour, such as by means of paint.

[0030] In an embodiment, a front cabinet of the lamp housing has a room-facing surface facing the flexible sheet, and the room-facing surface of the front cabinet is at least substantially flush with a room-facing surface of the one or more plate-formed acoustic absorbers. Thereby, it may be prevented that shadows are created at the border between the front cabinet and the one or more plate-formed acoustic absorbers. Thereby may be achieved a more even appearance of the flexible sheet, when contemplated from the room.

[0031] In an embodiment, neighbouring building panels are sealed in an at least substantially airtight manner between each other. Thereby, it may be prevented that ventilation air exits to the room between neighbouring building panels, and therefore the entire ventilation air may be directed through the flexible sheet, thereby ensuring an even more uniform distribution of the ventilation air in the room. The panel system may in this way be adapted for air supply from an air conditioning system through said one or more air inlet openings to said space in that the panel system is suitable for creating a pressure chamber for ventilation air above the one or more building panels and below a not shown permanent ceiling of the room so that air from the air conditioning system may be supplied to said pressure chamber.

[0032] In a structurally particularly advantageous embodiment, frame profile members of respective neighbouring building panels are sealed in an at least substantially airtight manner between each other.

[0033] In an embodiment, the one or more plate-formed acoustic absorbers are carried by the frame profile members of the building panel or of the respective building panels. Thereby, no separate support for the one or more plate-formed acoustic absorbers may be required.

[0034] In an embodiment, the panel system includes a grid structure for attachment to the ceiling or wall and for supporting the building panels, the grid structure includes a number of spaced and / or angled bars, and each frame profile member of each building panel is sealed in an at least substantially airtight manner against a respective bar. Thereby, a number of building panels may easily be mounted at the ceiling or wall in an airtight manner, thereby ensuring that ventilation air is forced through the flexible sheets in order to obtain even air distribution. The panel system may in this way be adapted for air supply from an air conditioning system through said one or more air inlet openings to said space in that the panel system is suitable for creating a pressure chamber for ventilation air above the one or more building panels and below a not shown permanent ceiling of the room so that air from the air conditioning system may be supplied to said pressure chamber.

[0035] In an embodiment, each building panel is releasably attached to the grid structure, and a preferably elastic sealing strip is arranged between each frame profile member and the corresponding bar against which the frame profile member is sealed. Thereby, mounting the building panels at the ceiling or wall in an airtight manner and subsequently detaching them therefrom may be facilitated.

[0036] In a structurally particularly advantageous embodiment, the grid structure includes a number of parallel spaced support bars for attachment to the ceiling or wall, and opposed frame profile members of each building panel are releasably attached to and sealed against respective support bars.

[0037] In a structurally particularly advantageous embodiment, the grid structure includes a number of parallel spaced cross bars arranged at right angles to the support bars and being carried by the support bars, and opposed frame profile members of each building panel are sealed against said cross bars.

[0038] In an embodiment, bars forming a periphery of the grid structure are adapted to be sealed in an at least substantially air tight manner against the ceiling or wall, possibly via a neighbouring ceiling or wall. Thereby, a pressure chamber for ventilation air may be formed above the one or more building panels in order to supply the panels with ventilation air.

[0039] In an embodiment, at least some of the bars of the grid structure form an accessory installation channel extending between neighbouring building panels and being open in the direction of the room. Thereby, accessory such as for instance smoke alarms or lamps may easily be mounted in the accessory installation channel.

[0040] In an embodiment, a box-formed pressure chamber is formed by a peripheral box wall having a room-facing side to which the one or more building panels are attached and a building-facing side to which a back cover is attached, and a ventilation air inlet for the air supply from an air conditioning system is provided through the peripheral box wall or through the back cover. The ventilation air inlet may be supplied with ventilation air from an air conditioning system via an air tube. Thereby, a self-contained box-formed ventilation unit may be formed which may be arranged at a ceiling or wall in combination with similar units and / or with standard building panels without integrated ventilation. Said self-contained box-formed ventilation unit may also be arranged at a ceiling or wall for instance in combination with a thermally activated building panel of the type including a metal plate having a room-facing surface and a building-facing surface, a heat-exchanger tube for conveying a cooling or heating medium is in conductive thermal contact with the building-facing surface of the metal plate, and a textile is arranged on the room-facing surface of the metal plate, the textile having a first surface generally contacting the metal plate and a second surface generally visible from said room. According to said embodiment, the panel system is adapted for air supply from an air conditioning system through said one or more air inlet openings to said space by means of the box-formed pressure chamber.

[0041] In an embodiment, each building panel is releasably attached to the peripheral box wall. Thereby, standard building panels may be used, and the building panel may easily be attached or detached.

[0042] In an embodiment, a preferably elastic sealing strip is arranged between frame profile members of the one or more building panels and the room-facing side of the peripheral box wall. Thereby, mounting the building panels on the peripheral box wall in an airtight manner and subsequently detaching them therefrom may be facilitated.

[0043] In an embodiment, the one or more plate-formed acoustic absorbers are carried by the frame profile members of the building panel or of the respective building panels. Thereby, no separate support for the one or more plate-formed acoustic absorbers may be required in the box-formed pressure chamber, and the frame profile members of the respective building panels may provide an airtight connection between a periphery of the one or more plate-formed acoustic absorbers and the edges of the flexible sheet.

[0044] In an embodiment, the one or more plate-formed acoustic absorbers are carried by the peripheral box wall of the box-formed pressure chamber. Thereby, standard building panels without integrated absorber may be attached to the peripheral box wall.

[0045] In an embodiment, the box-formed pressure chamber is adapted for attachment to a structure at the ceiling or wall.

[0046] In an embodiment, the back cover is formed by a flexible foil or the like forming an at least substantially impermeable air barrier. Thereby, the weight of the box-formed ventilation unit may be reduced.

[0047] In a structurally particularly advantageous embodiment, the back cover is formed by the one or more plate-formed acoustic absorbers, and the ventilation air inlet for the air supply from an air conditioning system is provided through the back cover. Thereby, a separate back cover for the box-formed ventilation unit may be dispensed with.

[0048] In a structurally particularly advantageous embodiment, an air inlet box is arranged on the building facing side of the one or more plate-formed acoustic absorbers, the air inlet box covers the ventilation air inlet provided through the back cover in the form of the one or more plate-formed acoustic absorbers, and the air inlet box is provided with a separate ventilation air inlet for the external ventilation air supply. Thereby, a self-contained box-formed ventilation unit may be formed with reduced material consumption. According to said embodiment, the panel system is adapted for air supply from an air conditioning system through said one or more air inlet openings to said space by means of the air inlet box.

[0049] In a structurally particularly advantageous embodiment, each frame profile member has an outer, preferably rounded, edge connecting a room-facing side of the frame profile member with a building-facing side of the frame profile member, the flexible sheet is bent about the outer edges of the frame profile members, and edges of the flexible sheet by means of the respective tensioning mechanisms are fixed to the building-facing side of the respective frame profile members.

[0050] The invention will now be explained in more detail below by means of examples of embodiments with reference to the very schematic drawing, in which Fig. 1 is a top view of a panel system according to the present invention; Fig. 2 is a perspective view of the panel system of Fig. 1, seen obliquely from above; Fig. 3 is a perspective longitudinal cross-section of the panel system of Fig. 2; Fig. 4 to 6 illustrate respective details of Fig. 3 on a larger scale; Fig. 7 illustrates the detail of Fig. 5 seen from another angle of view; Fig. 8 illustrates the detail of Fig. 6 seen from another angle of view; Fig. 9 illustrates the detail of Fig. 5 seen from yet another angle of view; Fig. 10 illustrates the detail of Fig. 6 seen from yet another angle of view, and, additionally, a permanent ceiling and wall are indicated; Fig. 11 illustrates a detail of Fig. 5 seen from another angle of view; Fig. 12 illustrates the detail of Fig. 6 seen from yet another angle of view; Fig. 13 is a perspective cross-section through a lamp of the panel system of Fig. 1; Fig. 14 is a perspective cross-section through the lamp of Fig. 13, seen from another angle of view; Fig. 15 is an exploded view of the lamp of Fig. 13; Fig. 16 is a perspective transverse cross-section of the panel system of Fig. 2; Fig. 17 to 19 illustrate respective details of Fig. 16 on a larger scale; Fig. 20 illustrates the detail of Fig. 17 seen from another angle of view; Fig. 21 illustrates the detail of Fig. 18 seen from another angle of view; Fig. 22 illustrates the detail of Fig. 19 seen from another angle of view; Fig. 23 illustrates the detail of Fig. 17 seen from yet another angle of view; Fig. 24 illustrates a detail of Fig. 2; Fig. 25 is a cross-section through the detail of Fig. 24; Fig. 26 is a perspective view of a single panel of the panel system of Fig. 1, seen obliquely from above; Fig. 27 is a perspective cross-section of the panel of Fig. 26; Fig. 28 illustrates a detail of Fig. 27 seen from another angle of view; Fig. 29 illustrates a detail of Fig. 28; Fig. 30 is a perspective view of a U-formed spring seen in the detail of Fig. 29; Fig. 31 is a perspective illustration of part of a single panel of the panel system of Fig. 1, illustrating ventilation airflow; Fig. 32 is a perspective view of a self-contained box-formed ventilation unit forming a panel system according to the present invention, seen obliquely from above; Fig. 33 is a perspective longitudinal cross-section of the self-contained box-formed ventilation unit of Fig. 32 along a plane being at right angles to a general plane of the box-formed ventilation unit; Fig. 34 is a perspective transverse cross-section of the self-contained box-formed ventilation unit of Fig. 32; Fig. 35 is a perspective longitudinal cross-section of the self-contained box-formed ventilation unit of Fig. 32 along a plane being parallel to a general plane of the box-formed ventilation unit; Fig. 36 illustrates a detail of Fig. 34; Fig. 37 is a perspective view of the self-contained box-formed ventilation unit of Fig. 32, seen obliquely from below; Fig. 38 is a perspective view of the self-contained box-formed ventilation unit of Fig. 32, seen from a different angle, and whereby the building panel has been detached from a box-formed pressure chamber of the unit; Fig. 39 is a perspective view of another embodiment of a self-contained box-formed ventilation unit forming a panel system according to the present invention, seen obliquely from above; Fig. 40 is a perspective transverse cross-section of the embodiment of the self-contained box-formed ventilation unit of Fig. 39; and Fig. 41 is a perspective longitudinal cross-section of the embodiment of the self-contained box-formed ventilation unit of Fig. 39 along a plane being at right angles to a general plane of the box-formed ventilation unit.

[0051] In the following, generally, similar elements of different embodiments have been designated by the same reference numerals.

[0052] Figs. 1 and 2 illustrate an embodiment of a panel system 1 according to the present invention, including eight building panels 2 adapted to be mounted at a ceiling or wall of a not shown room so that a framework 3 of each building panel 2 has a room-facing side 4 and a building-facing side 5. Fig. 26 illustrates one of these building panels 2, wherein the framework 3 includes a peripheral frame 6 formed by frame profile members 7. As seen in Figs. 28 and 29, a flexible sheet 8, such as a web, fabric, textile, foil or the like, is extended over the room-facing side 4 of the framework 3 between the frame profile members 7, and each edge 9 of the flexible sheet 8 is attached to a corresponding frame profile member 7 by means of a spring-biased tensioning mechanism 10 tensioning the flexible sheet 8.

[0053] According to the present invention, preferably, the flexible sheet 8 is a textile, because a textile may provide a suitable strength without excessive extension of the textile when loaded by means of spring tension and air pressure as explained in the following. When the textile is loaded, an initial extension will occur, and subsequently, the textile will typically maintain its length without substantial further extension. If for instance a plastic membrane or foil is used, this may be very elastic and may extend more and more as the load is increased.

[0054] The panel system 1 of Figs. 1 and 2 includes a number of plate-formed acoustic absorbers 11 arranged at a building-facing side 12 of the flexible sheet 8 of each building panel 2 and at a distance D from the flexible sheet 8 so that a space 13 is formed in each panel between the plate-formed acoustic absorbers 11 and the flexible sheet 8, as seen for instance in Figs. 4 and 9. Each plate-formed acoustic absorber 11 generally has the form of a plate.

[0055] It is understood that the panel system 1 according to the present invention may include any suitable number of building panels 2 arranged beside each other. Furthermore, it is understood that the panel system 1 according to the present invention may include any suitable number of plate-formed acoustic absorbers 11 arranged beside each other.

[0056] According to the present invention, one or more air inlet openings 14 open into said space 13, and the flexible sheet 8 is air permeable so that air may pass through the flexible sheet 8 from said space 13 to a room-facing side 15 of the flexible sheet 8, as indicated by means of arrows in Fig. 31. In the case of a flexible sheet 8 in the form of textile, the textile may be air permeable by nature in that it is weaved in a way resulting in a porous textile. In the case of a flexible sheet 8 in the form of foil, the foil may be air permeable in that it is perforated or in any other suitable way forms an air permeable membrane-like material. The panel system 1 is adapted for air supply from an air conditioning system through said one or more air inlet openings 14 to said space 13. An airflow resistance of the flexible sheet 8 is between 50 and 1500 pascal-second per metre, and at least one the spring-biased tensioning mechanisms 10 of each building panel 2 provides, in the tensioned state of the flexible sheet 8, a tensioning force of at least 100 newtons in average per metre edge length of the flexible sheet 8.

[0057] Preferably, all the spring-biased tensioning mechanisms 10 arranged along two opposed frame profile members 7 of each building panel 2 provides, in the tensioned state of the flexible sheet 8, a tensioning force of at least 100 newtons in average per metre edge length of the flexible sheet 8.

[0058] As will be explained in the following, the panel system 1 may be adapted for air supply from an air conditioning system through said one or more air inlet openings 14 to said space 13 in different ways.

[0059] By air supply from an air conditioning system (not illustrated) is generally understood that ventilation air may be supplied from an air conditioning system placed at a distance from the room, such as for instance at a roof top or the like. In order to supply external ventilation air through said one or more air inlet openings 14 to said space 13, in one embodiment, a pressure chamber 74 for ventilation air may be formed above the one or more building panels 2 and below a permanent ceiling 72 of the room, as will be discussed in further detail below. The ventilation air may be supplied to said pressure chamber 74 through a duct from said air conditioning system placed at a distance from the room. Although the air conditioning system may be placed at any suitable location, including in said pressure chamber, external ventilation air may supplied from the outside and / or air from the room may be treated by the air conditioning system and supplied as ventilation air to the room.

[0060] When forcing ventilation air into said space 13 and through the flexible sheet 8 to the room-facing side 15 of the flexible sheet 8, the combination of an airflow resistance of the flexible sheet 8 of between 50 and 1500 pascal-second per metre and a tensioning force of at least 100 newtons in average per metre edge length of the flexible sheet 8 may ensure that the ventilation air is evenly distributed over the area of the panel system 1 without any visible and / or uneven bulging of the flexible sheet 8. This is due to the fact that a stable and even airflow may be formed in said space 13 between the plate-formed acoustic absorbers 11 and the flexible sheet 8 as well as through the flexible sheet. Thereby may be obtained a panel system 1 having excellent acoustic properties due to an extensive area of the plate-formed acoustic absorbers 11, an even distribution of ventilation air in the room, and permanently wrinkle free extended flexible sheet material. The panel system 1 may be used for uniform distribution of ventilation air in even very large rooms.

[0061] Preferred minimum tensioning forces of the spring-biased tensioning mechanisms 10 may further be defined as follows. Each building panel 2 has a minimum frame profile length I which corresponds to a length of the shortest one of the frame profile members 7 included by the peripheral frame 6 of said building panel 2. In the case of a rectangular building panel 2, as seen in the embodiment of Fig. 1, the building panel 2 has two frame profile members 7 having the minimum frame profile length I and two frame profile members 7 having a maximum frame profile length. In the case of a square building panel 2, the building panel 2 has four frame profile members 7 all having the minimum frame profile length I. Of course, the building panel 2 may have other forms, such as pentagonal or octagonal, for instance.

[0062] Preferably, all the spring-biased tensioning mechanisms 10 arranged along the two frame profile members 7 having the maximum frame profile length provides, in the tensioned state of the flexible sheet 8, a tensioning force of at least 100 newtons in average per metre edge length of the flexible sheet 8.

[0063] Preferably, for a building panel 2 having a minimum frame profile length I larger than 1.5 metre, at least one of the spring-biased tensioning mechanisms 10 of said building panel 2, preferably one or more of the spring-biased tensioning mechanisms 10 arranged along the two frame profile members 7 having the maximum frame profile length, in the tensioned state of the flexible sheet 8 provides a tensioning force of at least 125 newtons in average per metre edge length of the flexible sheet 8, more preferred at least 150 newtons in average per metre edge length of the flexible sheet 8. Preferably, for a building panel 2 having a minimum frame profile length I larger than 2 metre, at least one of the spring-biased tensioning mechanisms 10 of said building panel 2, preferably one or more of the spring-biased tensioning mechanisms 10 arranged along the two frame profile members 7 having the maximum frame profile length, in the tensioned state of the flexible sheet 8 provides a tensioning force of at least 250 newtons in average per metre edge length of the flexible sheet 8, more preferred at least 300 newtons in average per metre edge length of the flexible sheet 8. Preferably, for a building panel 2 having a minimum frame profile length I larger than 2.5 metre, at least one of the spring-biased tensioning mechanisms 10 of said building panel 2, preferably one or more of the spring-biased tensioning mechanisms 10 arranged along the two frame profile members 7 having the maximum frame profile length, in the tensioned state of the flexible sheet 8 provides a tensioning force of at least 400 newtons in average per metre edge length of the flexible sheet 8, more preferred at least 500 newtons in average per metre edge length of the flexible sheet 8. Thereby, it may even better be ensured that visible and / or uneven bulging of the flexible sheet may be effectively avoided also for larger panels.

[0064] Preferably, in the case of a rectangular building panel 2, as seen in the embodiment of Fig. 1, all of the spring-biased tensioning mechanisms 10 along the two frame profile members 7 having the maximum frame profile length have at least substantially equal tensioning force in average per metre edge length of the flexible sheet 8. In this case, it is preferred that the tensioning force of the spring-biased tensioning mechanisms 10 arranged along the two frame profile members 7 having the maximum frame profile length corresponds to the above defined preferred minimum tensioning forces. The tensioning force of the spring-biased tensioning mechanisms 10 arranged along the two frame profile members 7 having the minimum frame profile may be less important.

[0065] According to an embodiment of the present invention, the distance D between the one or more plate-formed acoustic absorbers 11 and the flexible sheet 8 is at least 25 millimetres, preferably at least 30 millimetres, and most preferred at least 35 millimetres. Thereby, it may even better be ensured that the ventilation air is evenly distributed over the area of the panel system 1 without any visible and / or uneven bulging of the flexible sheet 8.

[0066] Referring again to the illustration of Fig. 31, it is understood that if the distance D indicated in Fig. 9 between the one or more plate-formed acoustic absorbers 11 and the flexible sheet 8 is too small, this will result in too high a resistance against the airflow in the space 13 on the way from the air inlet opening 14 along the flexible sheet 8. This would create a higher air pressure in the space 13 near the air inlet opening 14 as compared to for instance near the frame profile member 7 seen to the left of the figure. This could result in bulging of the flexible sheet 8 near the air inlet opening 14 and furthermore in an uneven distribution of the airflow through the flexible sheet 8. Moreover, if the airflow resistance of the flexible sheet 8 is too low compared to the resistance against the airflow in the space 13 along the flexible sheet 8, then too much air would flow through the flexible sheet 8 near the air inlet opening 14 as compared to at a longer distance from the air inlet opening 14, something that would result in an uneven distribution of the airflow in the room. On the other hand, if the airflow resistance of the flexible sheet 8 is too high, this would generally result in bulging of the flexible sheet 8.

[0067] It is noted that in the embodiment illustrated in Figs. 1 and 2, the plate-formed acoustic absorbers 11 are carried by the peripheral frame 6 of each building panel 2, and in this embodiment, the peripheral frame 6 also forms a peripheral closure between the plate-formed acoustic absorbers 11 and the flexible sheet 8, so that the space 13 in each building panel 2 may be pressurised. However, in an alternative, not shown embodiment, the plate-formed acoustic absorbers 11 are carried by a support structure at a distance from the building panels 2, and in this embodiment, said support structure and / or an additional closure, possibly including a part of a wall or ceiling of a room, forms a peripheral closure around the entire panel system 1 between the plate-formed acoustic absorbers 11 and the flexible sheets 8 of the respective building panels 2, so that one large space 13 of the panel system 1 may be pressurised. Of course, said one large space 13 could also be separated into any suitable number of smaller spaces by means of appropriate separating closures.

[0068] Furthermore, according to the present invention, preferably, the airflow resistance of the flexible sheet 8 is between 200 and 900 pascal-second per metre, more preferred between 300 and 800 pascal-second per metre, even more preferred between 350 and 750 pascal-second per metre, and most preferred between 400 and 700 pascal-second per metre. Any of these intervals of airflow resistance may be combined with any of the above mentioned preferred limits for the distance D. This may in particular be the case in embodiments, wherein a number of building panels 2 are sealed against each other, as it may even better be ensured that the ventilation air is evenly distributed over the entire area of the panel system 1 without any visible and / or uneven bulging of the flexible sheet 8.

[0069] Furthermore, according to the present invention, preferably, the distance D between the one or more plate-formed acoustic absorbers 11 and the flexible sheet 8 is not more than 250 millimetres, more preferred not more than 150 millimetres, even more preferred not more than 100 millimetres, and most preferred not more than 80 millimetres. Thereby, a reflection of light on a room-facing surface of the one or more plate-formed acoustic absorbers 11 may in a more efficient way facilitate a lighter appearance of the room-facing surface 15 of the flexible sheet 8 when contemplated from the room. Preferably, the room-facing surface 21 of the one or more plate-formed acoustic absorbers 11 is provided with an at least substantially white or at least very light and / or reflective colour, such as by means of paint.

[0070] In an embodiment of the panel system 1 according to the present invention, at least one of the spring-biased tensioning mechanisms 10 of each building panel 2, in the tensioned state of the flexible sheet 8, provides a tensioning force of at least 350, preferably at least 400, and most preferred at least 450 newtons in average per metre edge length of the flexible sheet 8. Thereby, an at least substantially flat appearance of the flexible sheet 8 may be even better ensured, and thereby, the panel system 1 according to the present invention may be even better suited for diffuse ventilation.

[0071] As understood from Figs. 28 and 29, in a preferred embodiment, said tensioning force is applied by means of a number of U-formed springs 56 as the one illustrated in Fig. 30. For instance, four U-formed springs 56 may be applied per metre of edge length of the flexible sheet 8. In this case, if each U-formed spring 56 applies 100 newtons to the edge of the flexible sheet 8, this results in 400 newtons in average per metre edge length of the flexible sheet 8. Of course, any suitable number of U-formed springs 56 may be employed to either frame profile member 7 of the peripheral frame 6 of a building panel 2, such as one two, three, four, five, six, and so forth. The number of U-formed springs 56 may be adapted to the length of the individual frame profile members 7. Each U-formed spring 56 may be understood as a separate spring-biased tensioning mechanism 10 of a building panel 2, or a number of U-formed springs 56 may be understood as a separate spring-biased tensioning mechanism 10.

[0072] In the illustrated embodiment, as seen for instance in Figs. 12 and 29, the edge 9 of the flexible sheet 8 is attached in a way known per se in a toothed notch 67 of a displaceable tensioning profile 66 of the spring-biased tensioning mechanism 10 by means of a keder 65, coiled spring or the like which pinches the edge 9 of the flexible sheet 8. However, according to the present invention, the edge 9 of the flexible sheet 8 may be attached to the displaceable tensioning profile 66 in any other suitable way. The displaceable tensioning profile 66 is arranged displaceably in its traverse direction in a longitudinal channel 68 of the respective frame profile member 7. A number of U-formed springs 56 are arranged in the longitudinal channel 68 between the displaceable tensioning profile 66 and an inside of the edge 16 of the frame profile member 7, thereby spring-biasing the displaceable tensioning profile 66 in a tension direction T illustrated in Fig. 29 so that the flexible sheet 8 which is bent over the preferably rounded edge 16 of the frame profile member 7 is extended over the peripheral frame 6 of the framework 3 of the building panel 2. This kind of spring-biased tensioning mechanism 10 is known in the art, but any other suitable kind of spring-biased tensioning mechanism may be used in accordance with the present invention.

[0073] It is noted that although in Figs. 12 and 29 as referred to just above, all of the displaceable tensioning profile 66 with the toothed notch 67, the keder 65, and the U-formed spring 56 have been illustrated correctly, in many of the other figures, some or all of these elements have not been illustrated, but are implicitly understood to be part of the building panels 2.

[0074] Furthermore, in the embodiment illustrated in Figs. 12 and 29, it is seen that each frame profile member 7 has an outer, preferably rounded, edge 16 connecting a room-facing side of the frame profile member 7 with a building-facing side of the frame profile member 7, the flexible sheet 8 is bent about the outer edges 16 of the frame profile members 7, and edges 9 of the flexible sheet 8 are by means of the respective tensioning mechanisms 10 fixed to the building-facing side of the respective frame profile members 7. The tension direction T illustrated in Fig. 29 is therefore directed obliquely in the direction of a centre of the building panel 2.

[0075] According to the present invention, preferably, as understood from for instance Fig. 27, each building panel 2 has a total area of freely extended flexible sheet 8 corresponding to an area of an open space 13 formed between edges 16 of the frame profile members 7 forming the peripheral frame 6 of the building panel 2, and both the building-facing side 12 and the room-facing side 15 of the total area of the freely extended flexible sheet 8 is freely exposed to air passing through the flexible sheet 8. Thereby, because said area of the flexible sheet 8 is freely extended, that is, nothing is touching the part of the flexible sheet 8 being extended between the edges 9 of the frame profile members 7, i.e. no obstructions to airflow are present, air may freely pass through said part of the flexible sheet 8. Consequently, an even more uniform distribution of the ventilation air over the area of the panel system 1 may be achieved. Furthermore, because nothing is touching the part of the flexible sheet 8 being extended between the edges 9 of the frame profile members 7, the appearance of the extended flexible sheet 8 may be smooth and even without any distracting bulging or the like.

[0076] In an embodiment illustrated in Figs. 39 to 41, an additional flexible air permeable layer 17, such as a web, textile, fabric, foil, mesh or the like, is extended between the frame profile members 7 of each building panel 2. The additional flexible air permeable layer 17 is arranged between the flexible sheet 8 and the one or more plate-formed acoustic absorbers 11. The additional flexible air permeable layer 17 is arranged at a distance d from the flexible sheet 8 and at a distance from the one or more plate-formed acoustic absorbers 11. The distance d between the additional flexible air permeable layer 17 and the flexible sheet 8 is not more than 250 millimetres, preferably not more than 150 millimetres, even more preferred not more than 100 millimetres, and most preferred not more than 80 millimetres. Thereby, a reflection of light on a room-facing surface of the additional flexible air permeable layer 17 may in an efficient way facilitate a lighter appearance of the room-facing surface 15 of the flexible sheet 8 when contemplated from the room. Preferably, the room-facing surface of the additional flexible air permeable layer 17 is provided with an at least substantially white or at least very light and / or reflective colour, such as by means of paint. By means of the additional flexible air permeable layer 17, the one or more plate-formed acoustic absorbers 11 may be arranged at a longer distance from the flexible sheet 8 without impairing the preferably light appearance of the flexible sheet 8 when contemplated from the room. Furthermore, the additional flexible air permeable layer 17 may serve as an air filter, thereby contributing to a cleaner environment above the flexible sheet 8. Thereby, it may be avoided that for instance dust or insects are collected on the building-facing side 12 of the flexible sheet 8, something that could lead to a less desirable appearance of the panel system 1.

[0077] Although an additional flexible air permeable layer 17 has been illustrated only for the embodiment illustrated in Figs. 39 to 41, such additional flexible air permeable layer 17 may be applied to any one of the possible embodiments of the present invention.

[0078] As it will be understood, in the embodiment illustrated in Figs. 39 to 41, an air inlet opening 14 is provided through a single plate-formed acoustic absorber 11 of the panel system 1. Furthermore, it will be understood, in the embodiments illustrated in Figs. 1 to 38, air inlet openings 14 are provided between neighbouring plate-formed acoustic absorbers 11. By these arrangements, a good distribution of the ventilation air over the entire surface of the panel system 1 may be achieved, because the ventilation air may have to travel a shorter distance along the flexible sheet 8 in the space 13 formed between the one or more plate-formed acoustic absorbers 11 and the flexible sheet 8.

[0079] However, in the embodiments illustrated in Figs. 1 to 38, air inlet openings 14 could alternatively be provided through plate-formed acoustic absorbers 11. Likewise, in the embodiment illustrated in Figs. 39 to 41, one or more air inlet openings 14 could alternatively be provided between neighbouring plate-formed acoustic absorbers 11 of the panel system 1. Of course, alternatively, in a panel system 1 according to the present invention, air inlet openings 14 could be provided both through plate-formed acoustic absorbers 11 and between neighbouring plate-formed acoustic absorbers 11.

[0080] It is noted that when in the present description, it is mentioned that the air inlet openings 14 may be provided through the plate-formed acoustic absorbers 11, this is also meant to include one or more air inlet openings 14 provided between a plate-formed acoustic absorber 11 and another element, such as for instance a frame profile member 7 of the respective building profile 2 or an element of a grid structure 36 for attachment to the ceiling or wall and for supporting the building panels 2. In that case, the one or more air inlet opening 14 may be said to form an opening in an end of the plate-formed acoustic absorber 11.

[0081] In an embodiment, the total cross-sectional area of the one or more air inlet openings 14 correspond to between 2 per cent and 25 per cent, preferably between 3 per cent and 20 per cent, more preferred between 4 per cent and 18 per cent, even more preferred between 5 per cent and 15 per cent and most preferred between 5 per cent and 12 per cent of the total area of the extended part of flexible sheet 8 of the panel system 1. Thereby, an appropriate distribution of the ventilation air over the entire surface of the panel system 1 may be achieved without impairing the acoustic performance of the panel system.

[0082] Contemplating the embodiment of the panel system 1 illustrated in Fig.1, it is seen that in each of the four building panels 2 to the left hand side of the figure, air inlet openings 14 are provided as two grooves 18, each of which is formed between neighbouring plate-formed acoustic absorbers 11. In each of these four building panels 2 to the left hand side of the figure, on either side of each groove 18, three plate-formed acoustic absorbers 11 are arranged abutting each other, so that, as seen, each of these four building panels 2 includes a total of nine plate-formed acoustic absorbers 11.

[0083] As seen, said grooves 18 extends from a first frame profile member 7 to second frame profile member 7 being opposed to the first frame profile member 7. Said grooves 18 are further seen in the embodiments illustrated in Figs. 16, 19, 22, 31, 33, 34 and 35. According to these embodiments, the manufacture of the panel system 1 may be facilitated in that the at least one air inlet opening 14 may simply be provided by cutting the one or more plate-formed acoustic absorbers 11 into their respective appropriate lengths without having to cut separate openings in the plate-formed acoustic absorbers 11.

[0084] Any suitable number of grooves 18 may be arranged in each building panel 2. A preferred transverse dimension of the grooves 18 may be 100 to 500 millimetres, and more preferred 200 to 400 millimetres, in order to ensure good air distribution.

[0085] In the embodiment of the panel system 1 illustrated in Fig. 1, in each of the four building panels 2 to the left hand side of the figure, the air inlet openings 14 provided between neighbouring plate-formed acoustic absorbers 11 are covered by an air permeable member 19, such as a filter. This is illustrated in further detail in Figs. 16, 19 and 22. Furthermore, in the embodiment of the panel system 1 seen in Fig. 33, the air inlet openings 14 provided between neighbouring plate-formed acoustic absorbers 11 are covered by an air permeable member 19, such as a filter. In the embodiment of the panel system 1 seen in Figs. 39 to 41, the air inlet opening 14 provided through the plate-formed acoustic absorber 11 is covered by an air permeable member 19, such as a filter.

[0086] The air permeable member 19 described just above may contribute to a cleaner environment above the flexible sheet 8, so that it may be avoided that for instance dust or insects are collected on the building-facing side 12 of the flexible sheet 8, something that could lead to a less desirable appearance of the panel system 1.

[0087] In an embodiment, the air permeable member 19 has a room-facing surface 20 facing the flexible sheet 8, and the room facing surface 20 of the air permeable member 19 has a light reflectance value being within + / -40 per cent, preferably within + / -30 per cent, more preferred within + / -20 per cent, and most preferred within + / -10 per cent of a light reflectance value of a room-facing surface 21 of the one or more plate-formed acoustic absorbers 11. Thereby, a reflection of light on a room-facing surface 20 of the air permeable member 19 may balance suitably with a reflection of light on a room-facing surface 21 of the one or more plate-formed acoustic absorbers 11. Thereby, it may be achieved that the appearance of the room-facing surface 15 of the flexible sheet 8 does not vary noticeably over the entire panel system 1 when contemplated from the room. Preferably, the room-facing surface 21 of the one or more plate-formed acoustic absorbers 11 as well as the room-facing surface 20 of the air permeable member 19 is provided with an at least substantially white or at least very light and / or reflective colour, such as by means of paint.

[0088] As seen in the embodiments seen in Figs. 19, 22, 33, 40 and 41, the air permeable member 19 has a room-facing surface 20 facing the flexible sheet 8, and the room-facing surface 20 of the air permeable member 19 is at least substantially flush with a room-facing surface 21 of the one or more plate-formed acoustic absorbers 11. Thereby, it may be prevented that shadows are created at the border between the air permeable member 19 and the plate-formed acoustic absorbers 11, and thereby may be achieved an even appearance of the flexible sheet 8, when contemplated from the room.

[0089] In the embodiments illustrated in Figs. 19 and 22, it is seen that the air permeable member 19 is mounted flush with the room-facing surface 21 of the plate-formed acoustic absorbers 11 by means of attachment brackets 63.

[0090] Contemplating the embodiment of the panel system 1 illustrated in Fig.1, it is seen that in each of the four building panels 2 to the right hand side of the figure, an air inlet opening 14 provided between neighbouring plate-formed acoustic absorbers 11 is covered by a lamp housing 22 forming an air passage 23 from a building-facing side 24 of the plate-formed acoustic absorbers 11 to a room-facing side 25 of the plate-formed acoustic absorbers 11 as further illustrated in Figs. 4, 13 and 14. As seen, each of the four building panels 2 to the right hand side of Fig. 1 includes eight plate-formed acoustic absorbers 11 surrounding the air inlet opening 14 covered by the lamp housing 22. It is noted that the lamp formed by the lamp housing as described and defined in this patent application is a separate invention which may be applied to other types of building panels and panel systems than those described in this patent application.

[0091] One of said four building panels 2 of Fig. 1 provided with a lamp housing 22 is illustrated in Figs. 26 and 27. As seen, a lamp may be arranged in the panel system 1 at the building-facing side 12 of the flexible sheet 8, and at the same time, an air passage 23 from a building-facing side 24 of the plate-formed acoustic absorbers 11 to a room-facing side 25 of the plate-formed acoustic absorbers 11 may be created without further affecting the appearance of the flexible sheet 8 when contemplated from the room. Indeed, when the lamp is switched on, the light may be visible from the room, but said air passage 23 may be hidden by the lamp and light. Therefore, apart from the light from the lamp, nothing may reveal the presence of said air passage 23.

[0092] As illustrated in the embodiment of Figs. 1 and 13 to 15, the lamp housing 22 is provided with four air intake openings 26 through which air may flow from the building-facing side 24 of the one or more plate-formed acoustic absorbers 11 to an inside of the lamp housing 22, and the lamp housing 22 is provided with one air outlet opening 27 through which air may flow from the inside of the lamp housing 22 to the room-facing side 25 of the one or more plate-formed acoustic absorbers 11. Furthermore, as illustrated, the air intake openings 26 are covered by respective air filters 28. Thereby, it may be avoided that for instance dust or insects are collected on the building-facing side 12 of the flexible sheet 8, something that could lead to a less desirable appearance of the panel system 1. As further seen, the air outlet opening 27 is provided between a light diffuser 29 and a front cabinet 30 of the lamp housing 22.

[0093] In the illustrated embodiment, the light diffuser 29 covers an opening 31 in a front face 32 of the front cabinet 30, and the air outlet opening 27 is provided between a periphery 33 of the light diffuser and a periphery 34 of the opening 31 in the front face 32 of the front cabinet 30. Thereby, the air outlet opening 27 may be even better hidden in the lamp so that the air outlet opening may not be visible from the room.

[0094] In the illustrated embodiment, a front cabinet 30 of the lamp housing 22 has a room-facing surface 35 facing the flexible sheet 8, and the room facing surface 35 of the front cabinet 30 has a light reflectance value being within + / -40 per cent, preferably within + / -30 per cent, more preferred within + / -20 per cent, and most preferred within + / -10 per cent of a light reflectance value of a room-facing surface 21 of the one or more plate-formed acoustic absorbers 11. Thereby, a reflection of light on a room-facing surface 35 of the front cabinet 30 may balance suitably with a reflection of light on a room-facing surface 21 of the plate-formed acoustic absorbers 11. Thereby, in particular when the lamp is switched off, the front cabinet 30 itself may not be visible when contemplating the room-facing surface 15 of the flexible sheet 8. Preferably, the room-facing surface 21 of the one or more plate-formed acoustic absorbers 11 as well as the room-facing surface 35 of the front cabinet 30 is provided with an at least substantially white or at least very light and / or reflective colour, such as by means of paint.

[0095] In the illustrated embodiment, a front cabinet 30 of the lamp housing 22 has a room-facing surface 35 facing the flexible sheet 8, and the room-facing surface 35 of the front cabinet 30 is at least substantially flush with a room-facing surface 21 of the one or more plate-formed acoustic absorbers 11. Thereby, it may be prevented that shadows are created at the border between the front cabinet 30 and the plate-formed acoustic absorbers 11. Thereby may be achieved a more even appearance of the flexible sheet 8, when contemplated from the room.

[0096] In the embodiment of the panel system 1 illustrated in Figs. 1 and 2, neighbouring building panels 2 are sealed in an at least substantially airtight manner between each other in that frame profile members 7 of respective neighbouring building panels 2 are sealed in an at least substantially airtight manner between each other. Thereby, it may be prevented that ventilation air exits to the room between neighbouring building panels 2, and therefore the entire ventilation air may be directed through the flexible sheet 8, thereby ensuring an even more uniform distribution of the ventilation air in the room. The panel system 1 may in this way be adapted for air supply from an air conditioning system through said one or more air inlet openings 14 to said space 13 in that the panel system 1 is suitable for creating the pressure chamber 74 for ventilation air above the one or more building panels 2 and the permanent ceiling 72 of the room so that air from the air conditioning system may be supplied to said pressure chamber 74.

[0097] Furthermore, in the embodiment of the panel system 1 illustrated in Figs. 1 and 2, the plate-formed acoustic absorbers 11 are carried by the frame profile members 7 of the respective building panels 2. Thereby, no separate support for the plate-formed acoustic absorbers 11 may be required.

[0098] Furthermore, in the embodiment of the panel system 1 illustrated in Figs. 1 and 2, the panel system 1 includes a grid structure 36 for attachment to the ceiling or wall and for supporting the building panels 2. The grid structure 36 includes a number of spaced and angled bars 37, and each frame profile member 7 of each building panel 2 is sealed in an at least substantially airtight manner against a respective bar 37. Thereby, the building panels 2 may easily be mounted at the ceiling or wall in an airtight manner in relation to each other, thereby ensuring that ventilation air may be forced through the flexible sheets 8 in order to obtain even air distribution in the room. The panel system 1 may in this way be adapted for air supply from an air conditioning system through said one or more air inlet openings 14 to said space 13 in that the panel system 1 is suitable for creating the pressure chamber 74 for ventilation air above the one or more building panels 2 and below the permanent ceiling 72 of the room so that air from the air conditioning system may be supplied to said pressure chamber 74.

[0099] Furthermore, in the embodiment of the panel system 1 illustrated in Figs. 1 and 2, each building panel 2 is releasably attached to the grid structure 36, and an elastic sealing strip 38 is arranged between each frame profile member 7 and the corresponding bar 37 against which the frame profile 7 member is sealed. Thereby, mounting the building panels 2 at the ceiling or wall in an airtight manner and subsequently detaching them therefrom may be facilitated.

[0100] Furthermore, in the embodiment of the panel system 1 illustrated in Figs. 1 and 2, and as illustrated in further detail in Figs. 5, 7 and 9, the grid structure 36 includes a number of parallel spaced support bars 39 for attachment to the ceiling or wall, and opposed frame profile members 7 of each building panel 2 are releasably attached to and sealed against respective support bars 39. Each support bar 39 includes a flat top plate 70 and an S-formed plate 60 arranged on either side thereof. The flat top plate 70 is adapted to extend in parallel with the ceiling or wall. Furthermore, a straight cover plate 69 extends on either side of the flat top plate 70 in downward direction as seen in the figures and at right angles to the flat top plate 70. Each straight cover plate 69 is provided with an extension flange 71 extending in the direction of the respective building panel 2, so that a respective sealing strip 38 of the building panel 2 may abut the extension flange 71 as further explained below.

[0101] A top side of the S-formed plate 60 may be attached to a general support structure arranged at the ceiling or wall. As illustrated in further detail in Figs. 11, 12, 25 and 28, the frame profile members 7 of each building panel 2 are releasably attached to the respective support bars 39 in a manner known per se by means of V-formed suspension spring clips 57. Each suspension spring clip 57 is attached to a frame profile member 7 by means of an attachment clip 62 engaging a suspension channel 61 extending in a longitudinal direction of the frame profile member 7. In the attached position of the building panel 2 on the support bars 39, two legs of each V-formed suspension spring clip 57 engages an engagement opening 59 in the respective S-formed plate 60 of the support bar 39. From this mounted position, the building panel 2 may be pulled downwards to a not shown pulled-down position, in which the building panel 2 is still hanging from the support bars 39. During the displacement from the mounted position to the pulled-down position, the two legs of each V-formed suspension spring clip 57 are pressed against each other in the engagement opening 59, and in the pulled-down position, the V-formed suspension spring clip 57 is hanging in the engagement opening 59 by means of hooks 64 formed at free ends of its respective legs. In the pulled-down position, V-formed suspension spring clips 57 along one of the frame profile members 7 of the building panel 2 may be fully detached from the support bar 39 by pressing their legs further against each other so that their hooks 64 may pass through the respective engagement openings 59. By doing so, V-formed suspension spring clips 57 along another, opposed frame profile members 7 of the building panel 2 may allow the building panel 2 to swing down to a position in which a general plane of the building panel 2 extends vertically. From that position, the rest of the V-formed suspension spring clips 57 along the other frame profile members 7 of the building panel 2 may be fully detached from the support bar 39 for complete detachment of the building panel 2 from the support bars 39.

[0102] As further seen in the figures, the opposed frame profile members 7 of each building panel 2 are sealed against respective support bars 39 by means of elastic sealing strips 38 abutting respective extension flanges 71.

[0103] Furthermore, in the embodiment of the panel system 1 illustrated in Figs. 1 and 2, and as illustrated in further detail in Figs. 17, 20 and 23 to 25, the grid structure 36 includes a number of parallel spaced cross bars 40 arranged at right angles to the support bars 39 and being carried by the support bars 39, and opposed frame profile members 7 of each building panel 2 are sealed against said cross bars 40 by means of elastic sealing strips 38. As seen, each cross bar 40 has the form of an inverted T as seen in the figures, and the elastic sealing strips 38 abut the lower side of the inverted T form of the cross bar 40. As seen in Fig. 24, each cross bar 40 is attached at right angles to a support bar 39.

[0104] Furthermore, in the embodiment of the panel system 1 illustrated in Figs. 1 and 2, and as illustrated in further detail in Figs. 4, 6, 8, 10, 16, 18 and 21, bars 41 forming a periphery 42 of the grid structure 36 are adapted to be sealed in an at least substantially air tight manner against the not shown ceiling or wall, possibly via a neighbouring ceiling or wall. Thereby, a pressure chamber 74 for ventilation air may be formed above the one or more building panels and below a permanent ceiling 72 of the room in order to supply the panels with ventilation air. The ventilation air may be supplied to said pressure chamber through a duct from an air conditioning system placed at a distance from the room. For instance, in the case of ceiling panels, the bars 41 forming a periphery 42 of the grid structure 36 seen in Fig. 2 may be mounted to four respective walls 73 surrounding the ceiling 72 of the room. As seen in for instance Fig. 21, each bar 41 of the periphery 42 of the grid structure 36 includes a top plate 55 and a straight cover plate 69 extending at right angles to the top plate 55 and in downward direction therefrom as seen in the figures.

[0105] As seen for instance in Fig. 7, some of the bars 37 of the grid structure 36 may form an accessory installation channel 43 extending between neighbouring building panels 2 and being open in the direction of the room. Thereby, not illustrated accessories such as for instance smoke alarms or lamps may easily be mounted in the accessory installation channel 43.

[0106] In the embodiments illustrated in Figs. 32 to 41, a box-formed pressure chamber 44 is formed by a peripheral box wall 45 having a room-facing side 46 to which the one or more building panels 2 are attached and a building-facing side 47 to which a back cover 48 is attached, and a ventilation air inlet 49 for the air supply from an air conditioning system is provided through the peripheral box wall 45 or through the back cover 48. The ventilation air inlet 49 may be supplied with ventilation air from a not illustrated air conditioning system via an air tube or duct. Thereby, a self-contained box-formed ventilation unit may be formed which may be arranged at a ceiling or wall in combination with similar units and / or with standard building panels without integrated ventilation. Said self-contained box-formed ventilation unit may also be arranged at a ceiling or wall for instance in combination with a thermally activated building panel of the type including a metal plate having a room-facing surface and a building-facing surface, wherein a heat-exchanger tube for conveying a cooling or heating medium is in conductive thermal contact with the building-facing surface of the metal plate, and wherein a textile is arranged on the room-facing surface of the metal plate, the textile having a first surface generally contacting the metal plate and a second surface generally visible from said room.

[0107] In the embodiments illustrated in Figs. 32 to 41, as seen in Fig. 38, each building panel 2 is releasably attached to the peripheral box wall 45 in a manner similar to what has been explained above for the embodiment of Figs. 1 and 2. Thereby, standard building panels may be used, and the building panel 2 may easily be attached or detached. As seen, a preferably elastic sealing strip 38 is arranged between frame profile members 7 of the building panel 2 and the room-facing side 46 of the peripheral box wall 45. Thereby, mounting the building panels on the peripheral box wall in an airtight manner and subsequently detaching them therefrom may be facilitated.

[0108] In the embodiments illustrated in Figs. 32 to 41, the one or more plate-formed acoustic absorbers 11 are carried by the frame profile members 7 of the building panel 2. Thereby, no separate support for the one or more plate-formed acoustic absorbers 11 may be required in the box-formed pressure chamber 44, and the frame profile members 7 of the building panel 2 may provide an airtight connection between a periphery of the one or more plate-formed acoustic absorbers 11 and the edges 9 of the flexible sheet 8.

[0109] In an alternative, not shown embodiment, the one or more plate-formed acoustic absorbers 11 are carried by the peripheral box wall 45 of the box-formed pressure chamber 44. Thereby, standard building panels without integrated absorber may be attached to the peripheral box wall 45. In this not shown embodiment, an alternative or additional air inlet opening for ventilation air could be provided through the peripheral box wall 45 of the box-formed pressure chamber 44 between the one or more plate-formed acoustic absorbers 11 and the flexible sheet 8. This could be done by placing the ventilation air inlet 49 for the air supply from an air conditioning system as illustrated in Fig. 38 between the one or more plate-formed acoustic absorbers 11 and the flexible sheet 8, and by possibly omitting the air inlet openings 14 illustrated in Fig. 35. It is noted that, for illustration purposes only, in Fig. 38, the ventilation air inlet 49 is indicated as if the back cover 48 were transparent.

[0110] In the embodiments illustrated in Figs. 32 to 41, the box-formed pressure chamber 44 is adapted for attachment to a structure at the ceiling or wall by means of suspension rods 58.

[0111] In the embodiment illustrated in Figs. 32 to 38, the back cover 48 is formed by a flexible foil or the like forming an at least substantially impermeable air barrier. Thereby, the weight of the box-formed ventilation unit may be reduced.

[0112] In the embodiment illustrated in Figs. 39 to 41, the back cover 48 is formed by the one or more plate-formed acoustic absorbers 11, and the ventilation air inlet 49 for the air supply from an air conditioning system is provided through the back cover 48. Thereby, a separate back cover for the box-formed ventilation unit may be dispensed with.

[0113] Furthermore, in the embodiment illustrated in Figs. 39 to 41, an air inlet box 50 is arranged on the building facing side 24 of the one or more plate-formed acoustic absorbers 11. The air inlet box 50 covers the ventilation air inlet 49 provided through the back cover 48 in the form of the one or more plate-formed acoustic absorbers 11, and the air inlet box 50 is provided with a separate ventilation air inlet 51 for the external ventilation air supply. Thereby, a self-contained box-formed ventilation unit may be formed with reduced material consumption.

[0114] According to the embodiments illustrated in Figs. 32 to 41, the panel system 1 is adapted for air supply from an air conditioning system through said one or more air inlet openings 14 to said space 13 by means of the box-formed pressure chamber 44 or by means of the air inlet box 50 as explained above.

[0115] It is noted that the embodiments illustrated in Figs. 39 to 41, as described and defined in this patent application are separate inventions according to which the building panel may incorporate a flexible sheet having an airflow resistance of the flexible sheet 8 being different than the airflow resistance defined in this patent application, and according to which the building panel may incorporate spring-biased tensioning mechanisms 10 which in the tensioned state of the flexible sheet 8 provides a tensioning force being different from the tensioning force defined in this patent application.

[0116] Purely as an example, a suitable pressure of the ventilation air in said space 13 could be in the range of 1 to 5 pascal, and preferably in the range of 2 to 3 pascal. Furthermore, purely as an example, a building panel 2 of the panel system 1 according to the present invention may have a size of for instance 2.5 x 5 metres; 1.5 x 3.5 metres; 1 × 4 metres or 3 x 7 metres. Any suitable size may be possible.

[0117] The following embodiments of the present invention are disclosed: Embodiment 1: A panel system 1 including one or more building panels 2 adapted to be mounted at a ceiling or wall of a room so that a framework 3 of each building panel has a room-facing side 4 and a building-facing side 5, wherein the framework 3 includes a peripheral frame 6 formed by frame profile members 7, wherein a flexible sheet 8, such as a web, textile, foil or the like, is extended over the room-facing side 4 of the framework 3 between the frame profile members 7, wherein each edge 9 of the flexible sheet 8 is attached to a corresponding frame profile member 7 by means of at least one spring-biased tensioning mechanism 10 tensioning the flexible sheet 8, wherein the panel system 1 includes one or more plate-formed acoustic absorbers 11 arranged at a building-facing side 12 of the flexible sheet 8 of the one or more building panels 2 and at a distance D from the flexible sheet 8 so that a space 13 is formed between the one or more plate-formed acoustic absorbers 11 and the flexible sheet 8, wherein one or more air inlet openings 14 open into said space 13, and wherein the flexible sheet 8 is air permeable so that air may pass through the flexible sheet 8 from said space 13 to a room-facing side 15 of the flexible sheet 8, characterised in that the panel system 1 is adapted for air supply from an air conditioning system through said one or more air inlet openings 14 to said space 13, in that an airflow resistance of the flexible sheet 8 is preferably between 50 and 1500 pascal-second per metre, and in that, preferably, at least one of the spring-biased tensioning mechanisms 10 of each building panel 2 in the tensioned state of the flexible sheet 8 provides a tensioning force of at least 100 newtons in average per metre edge length of the flexible sheet 8. Embodiment 2: A panel system according to embodiment 1, wherein each building panel 2 has a minimum frame profile length I, wherein for a building panel 2 having a minimum frame profile length I larger than 1.5 metre, at least one of the spring-biased tensioning mechanisms 10 of said building panel 2 in the tensioned state of the flexible sheet 8 provides a tensioning force of at least 125 newtons in average per metre edge length of the flexible sheet 8, wherein for a building panel 2 having a minimum frame profile length I larger than 2 metre, at least one of the spring-biased tensioning mechanisms 10 of said building panel 2 in the tensioned state of the flexible sheet 8 provides a tensioning force of at least 250 newtons in average per metre edge length of the flexible sheet 8, and wherein for a building panel 2 having a minimum frame profile length I larger than 2.5 metre, at least one of the spring-biased tensioning mechanisms 10 of said building panel 2 in the tensioned state of the flexible sheet 8 provides a tensioning force of at least 400 newtons in average per metre edge length of the flexible sheet 8. Embodiment 3: A panel system according to embodiment 1, wherein each building panel 2 has a minimum frame profile length I, wherein for a building panel 2 having a minimum frame profile length I larger than 1.5 metre, at least one of the spring-biased tensioning mechanisms 10 of said building panel 2 in the tensioned state of the flexible sheet 8 provides a tensioning force of at least 150 newtons in average per metre edge length of the flexible sheet 8, wherein for a building panel 2 having a minimum frame profile length I larger than 2 metre, at least one of the spring-biased tensioning mechanisms 10 of said building panel 2 in the tensioned state of the flexible sheet 8 provides a tensioning force of at least 300 newtons in average per metre edge length of the flexible sheet 8, and wherein for a building panel 2 having a minimum frame profile length I larger than 2.5 metre, at least one of the spring-biased tensioning mechanisms 10 of said building panel 2 in the tensioned state of the flexible sheet 8 provides a tensioning force of at least 500 newtons in average per metre edge length of the flexible sheet 8. Embodiment 4: A panel system according to any one of the preceding embodiments, wherein the distance D between the one or more plate-formed acoustic absorbers 11 and the flexible sheet 8 is at least 25 millimetres, preferably at least 30 millimetres, and most preferred at least 35 millimetres. Embodiment 5: A panel system according to any one of the preceding embodiments, wherein the airflow resistance of the flexible sheet 8 is between 200 and 900 pascal-second per metre, more preferred between 300 and 800 pascal-second per metre, even more preferred between 350 and 750 pascal-second per metre, and most preferred between 400 and 700 pascal-second per metre. Embodiment 6: A panel system according to any one of the preceding embodiments, wherein the distance D between the one or more plate-formed acoustic absorbers 11 and the flexible sheet 8 is not more than 250 millimetres, preferably not more than 150 millimetres, even more preferred not more than 100 millimetres, and most preferred not more than 80 millimetres. Embodiment 7: A panel system according to any one of the preceding embodiments, wherein at least one of the spring-biased tensioning mechanisms 10 of each building panel 2 in the tensioned state of the flexible sheet 8 provides a tensioning force of at least 300, preferably at least 350, even more preferred at least 400, and most preferred at least 450 newtons in average per metre edge length of the flexible sheet 8. Embodiment 8: A panel system according to any one of the preceding embodiments, wherein each building panel 2 has a total area of freely extended flexible sheet 8 corresponding to an area of an open space 13 formed between edges 16 of the frame profile members 7 forming the peripheral frame 6 of the building panel 2, and wherein both the building-facing side 12 and the room-facing side 15 of the total area of the freely extended flexible sheet 8 is freely exposed to air passing through the flexible sheet 8. Embodiment 9: A panel system according to any one of the preceding embodiments, wherein an additional flexible air permeable layer 17, such as a web, textile, foil, mesh or the like, is extended between the frame profile members 7 of each building panel 2, wherein the additional flexible air permeable layer 17 is arranged between the flexible sheet 8 and the one or more plate-formed acoustic absorbers 11, wherein the additional flexible air permeable layer 17 is arranged at a distance d from the flexible sheet 8 and at a distance from the one or more plate-formed acoustic absorbers 11, and wherein the distance d between the additional flexible air permeable layer 17 and the flexible sheet 8 is not more than 250 millimetres, preferably not more than 150 millimetres, even more preferred not more than 100 millimetres, and most preferred not more than 80 millimetres. Embodiment 10: A panel system according to any one of the preceding embodiments, wherein at least one of the one or more air inlet openings 14 is provided through one of the one or more plate-formed acoustic absorbers 11, between neighbouring ones of the one or more plate-formed acoustic absorbers 11 or between one of the one or more plate-formed acoustic absorbers 11 and one of the frame profile members 7. Embodiment 11: A panel system according to any one of the preceding embodiments, wherein the total cross-sectional area of the one or more air inlet openings 14 correspond to between 2 per cent and 25 per cent, preferably between 3 per cent and 20 per cent, more preferred between 4 per cent and 18 per cent, even more preferred between 5 per cent and 15 per cent and most preferred between 5 per cent and 12 per cent of the total area of the extended part of flexible sheet 8 of the panel system 1. Embodiment 12: A panel system according to any one of the preceding embodiments, wherein at least one air inlet opening 14 is provided as a groove 18 formed between neighbouring ones of the one or more plate-formed acoustic absorbers 11, and wherein, preferably, said groove 18 extends from a first frame profile member 7 to second frame profile member 7 being opposed to the first frame profile member 7. Embodiment 13: A panel system according to any one of the preceding embodiments, wherein at least one air inlet opening 14 provided through one of the one or more plate-formed acoustic absorbers 11, between neighbouring ones of the one or more plate-formed acoustic absorbers 11 or between one of the one or more plate-formed acoustic absorbers 11 and one of the frame profile members 7 is covered by an air permeable member 19, such as a filter. Embodiment 14: A panel system according to embodiment 13, wherein the air permeable member 19 has a room-facing surface 20 facing the flexible sheet 8, and wherein the room facing surface 20 of the air permeable member 19 has a light reflectance value being within + / -40 per cent, preferably within + / -30 per cent, more preferred within + / -20 per cent, and most preferred within + / -10 per cent of a light reflectance value of a room-facing surface 21 of the one or more plate-formed acoustic absorbers 11. Embodiment 15: A panel system according to embodiment 13, wherein the air permeable member 19 has a room-facing surface 20 facing the flexible sheet 8, and wherein the room-facing surface 20 of the air permeable member 19 is at least substantially flush with a room-facing surface 21 of the one or more plate-formed acoustic absorbers 11. Embodiment 16: A panel system according to any one of the preceding embodiments, wherein at least one air inlet opening 14 provided through one of the one or more plate-formed acoustic absorbers 11, between neighbouring ones of the one or more plate-formed acoustic absorbers 11 or between one of the one or more plate-formed acoustic absorbers 11 and one of the frame profile members 7 is covered by a lamp housing 22 forming an air passage 23 from a building-facing side 24 of the one or more plate-formed acoustic absorbers 11 to a room-facing side 25 of the one or more plate-formed acoustic absorbers 11. Embodiment 17: A panel system according to embodiment 16, wherein the lamp housing 22 is provided with at least one air intake opening 26 through which air may flow from the building-facing side 24 of the one or more plate-formed acoustic absorbers 11 to an inside of the lamp housing 22, and wherein the lamp housing 22 is provided with at least one air outlet opening 27 through which air may flow from the inside of the lamp housing 22 to the room-facing side 25 of the one or more plate-formed acoustic absorbers 11. Embodiment 18: A panel system according to embodiment 17, wherein the at least one air intake opening 26 is covered by an air filter 28. Embodiment 19: A panel system according to embodiment 17 or 18, wherein the at least one air outlet opening 27 is provided between a light diffuser 29 and a front cabinet 30 of the lamp housing 22. Embodiment 20: A panel system according to embodiment 19, wherein the light diffuser 29 covers an opening 31 in a front face 32 of the front cabinet 30, and wherein the at least one air outlet opening 27 is provided between a periphery 33 of the light diffuser and a periphery 34 of the opening 31 in the front face 32 of the front cabinet 30. Embodiment 21: A panel system according to any one of the embodiments 16 to 20, wherein a front cabinet 30 of the lamp housing 22 has a room-facing surface 35 facing the flexible sheet 8, and wherein the room facing surface 35 of the front cabinet 30 has a light reflectance value being within + / -40 per cent, preferably within + / -30 per cent, more preferred within + / -20 per cent, and most preferred within + / -10 per cent of a light reflectance value of a room-facing surface 21 of the one or more plate-formed acoustic absorbers 11. Embodiment 22: A panel system according to any one of the embodiments 16to 20, wherein a front cabinet 30 of the lamp housing 22 has a room-facing surface 35 facing the flexible sheet 8, and wherein the room-facing surface 35 of the front cabinet 30 is at least substantially flush with a room-facing surface 21 of the one or more plate-formed acoustic absorbers 11. Embodiment 23: A panel system according to any one of the preceding embodiments, wherein neighbouring building panels 2 are sealed in an at least substantially airtight manner between each other. Embodiment 24: A panel system according to embodiment 23, wherein frame profile members 7 of respective neighbouring building panels 2 are sealed in an at least substantially airtight manner between each other. Embodiment 25: A panel system according to any one of the preceding embodiments, wherein the one or more plate-formed acoustic absorbers 11 are carried by the frame profile members 7 of the building panel or of the respective building panels 2. Embodiment 26: A panel system according to any one of the preceding embodiments, wherein the panel system 1 includes a grid structure 36 for attachment to the ceiling or wall and for supporting the building panels 2, wherein the grid structure 36 includes a number of spaced and / or angled bars 37, and wherein each frame profile member 7 of each building panel 2 is sealed in an at least substantially airtight manner against a respective bar 37. Embodiment 27: A panel system according to embodiment 26, wherein each building panel 2 is releasably attached to the grid structure 36, and wherein a preferably elastic sealing strip 38 is arranged between each frame profile member 7 and the corresponding bar 37 against which the frame profile 7 member is sealed. Embodiment 28: A panel system according to embodiment 26 or 27, wherein the grid structure 36 includes a number of parallel spaced support bars 39 for attachment to the ceiling or wall, and wherein opposed frame profile members 7 of each building panel 2 are releasably attached to and sealed against respective support bars 39. Embodiment 29: A panel system according to embodiment 28, wherein the grid structure 36 includes a number of parallel spaced cross bars 40 arranged at right angles to the support bars 39 and being carried by the support bars 39, and wherein opposed frame profile members 7 of each building panel 2 are sealed against said cross bars 40. Embodiment 30: A panel system according to any one of the embodiments 26 to 29, wherein bars 41 forming a periphery 42 of the grid structure 36 are adapted to be sealed in an at least substantially air tight manner against the ceiling or wall, possibly via a neighbouring ceiling or wall. Embodiment 31: A panel system according to any one of the embodiments 26to 30, wherein at least some of the bars 37 of the grid structure 36 form an accessory installation channel 43 extending between neighbouring building panels 2 and being open in the direction of the room. Embodiment 32: A panel system according to any one of the embodiments 1 to 24, wherein a box-formed pressure chamber 44 is formed by a peripheral box wall 45 having a room-facing side 46 to which the one or more building panels 2 are attached and a building-facing side 47 to which a back cover 48 is attached, and wherein a ventilation air inlet 49 for the air supply from an air conditioning system is provided through the peripheral box wall 45 or through the back cover 48. Embodiment 33: A panel system according to embodiment 32, wherein each building panel 2 is releasably attached to the peripheral box wall 45. Embodiment 34: A panel system according to embodiment 33, wherein a preferably elastic sealing strip 38 is arranged between frame profile members 7 of the one or more building panels 2 and the room-facing side 46 of the peripheral box wall 45. Embodiment 35: A panel system according to any one of the embodiments 32 to 34, wherein the one or more plate-formed acoustic absorbers 11 are carried by the frame profile members 7 of the building panel 2 or of the respective building panels 2. Embodiment 36: A panel system according to any one of the embodiments 32 to 34, wherein the one or more plate-formed acoustic absorbers 11 are carried by the peripheral box wall 45 of the box-formed pressure chamber 44. Embodiment 37: A panel system according to any one of the embodiments 32 to 36, wherein the box-formed pressure chamber 44 is adapted for attachment to a structure at the ceiling or wall. Embodiment 38: A panel system according to any one of the embodiments 32 to 37, wherein the back cover 48 is formed by a flexible foil or the like forming an at least substantially impermeable air barrier. Embodiment 39: A panel system according to any one of the embodiments 32 to 37, wherein the back cover 48 is formed by the one or more plate-formed acoustic absorbers 11, and wherein the ventilation air inlet 49 for the air supply from an air conditioning system is provided through the back cover 48. Embodiment 40: A panel system according to embodiment 39, wherein an air inlet box 50 is arranged on the building facing side 24 of the one or more plate-formed acoustic absorbers 11, wherein the air inlet box 50 covers the ventilation air inlet 49 provided through the back cover 48 in the form of the one or more plate-formed acoustic absorbers 11, and wherein the air inlet box 50 is provided with a separate ventilation air inlet 51 for the external ventilation air supply. Embodiment 41: A panel system according to any one of the preceding embodiments, wherein each frame profile member 7 has an outer, preferably rounded, edge 16 connecting a room-facing side of the frame profile member 7 with a building-facing side of the frame profile member 7, wherein the flexible sheet 8 is bent about the outer edges 16 of the frame profile members 7, and wherein edges 9 of the flexible sheet 8 by means of the respective tensioning mechanisms 10 are fixed to the building-facing side of the respective frame profile members 7. Embodiment 42: A panel system according to any one of the preceding embodiments, wherein at least one air inlet opening 14 provided through one of the one or more plate-formed acoustic absorbers 11, between neighbouring ones of the one or more plate-formed acoustic absorbers 11 or between one of the one or more plate-formed acoustic absorbers 11 and one of the frame profile members 7 is covered by an air permeable member 19, such as a filter, or is covered by a lamp housing 22 forming an air passage 23 from a building-facing side 24 of the one or more plate-formed acoustic absorbers 11 to a room-facing side 25 of the one or more plate-formed acoustic absorbers 11. List of reference numbers

[0118] Ddistance between flexible sheet and plate-formed acoustic absorber ddistance between flexible sheet and additional flexible air permeable layer Ttension direction of displaceable tensioning profile 1panel system 2building panel 3framework of building panel 4room-facing side of framework 5building-facing side of framework 6peripheral frame of framework 7frame profile member of peripheral frame 8flexible sheet 9edge of flexible sheet 10spring-biased tensioning mechanism 11plate-formed acoustic absorber 12building-facing side of flexible sheet 13space between plate-formed acoustic absorbers and flexible sheet 14air inlet opening 15room-facing side of flexible sheet 16edge of frame profile member 17additional flexible air permeable layer 18groove between neighbouring plate-formed acoustic absorbers 19air permeable member 20room-facing surface of air permeable member 21room-facing surface of plate-formed acoustic absorber 22lamp housing 23air passage formed by lamp housing 24building-facing side of plate-formed acoustic absorber 25room-facing side of plate-formed acoustic absorber 26air intake opening of lamp housing 27air outlet opening of lamp housing 28air filter of lamp housing 29light diffuser of lamp housing 30front cabinet of lamp housing 31opening in front face of front cabinet 32front face of front cabinet 33periphery of light diffuser 34periphery of opening in front face 35room-facing surface of front cabinet 36grid structure of panel system 37bar of grid structure 38sealing strip 39support bar of grid structure 40cross bar of grid structure 41bar forming periphery of grid structure 42periphery of grid structure 43accessory installation channel formed by bar 44box-formed pressure chamber 45peripheral box wall forming pressure chamber 46room-facing side of peripheral box wall 47building-facing side of peripheral box wall 48back cover of box-formed pressure chamber 49ventilation air inlet of box-formed pressure chamber 50air inlet box 51separate ventilation air inlet of air inlet box 52LED (Light Emitting Diode) plate of lamp housing 53back cover of lamp housing 54power adapter of lamp housing 55top plate of bar forming periphery of grid structure 56U-formed spring of spring-biased tensioning mechanism 57suspension spring clip 58suspension rod for self-contained box-formed ventilation unit 59engagement opening for suspension spring clip 60S-formed plate of bar of grid structure 61suspension channel of frame profile member 62attachment clip for suspension spring clip 63attachment bracket for air permeable member 64hook of suspension spring clip 65keder for attachment of edge of flexible sheet to displaceable tensioning profile 66displaceable tensioning profile of spring-biased tensioning mechanism 67toothed notch of displaceable tensioning profile 68longitudinal channel of frame profile member 69straight cover plate 70flat top plate of support bar of grid structure 71extension flange of straight cover plate 72permanent ceiling of room 73permanent wall of room 74pressure chamber between permanent ceiling of room and building panel

Claims

1. A panel system (1) including one or more building panels (2) adapted to be mounted at a ceiling or wall of a room so that a framework (3) of each building panel has a room-facing side (4) and a building-facing side (5), wherein the framework (3) includes a peripheral frame (6) formed by frame profile members (7), wherein a flexible sheet (8), such as a web, textile, foil or the like, is extended over the room-facing side (4) of the framework (3) between the frame profile members (7), wherein each edge (9) of the flexible sheet (8) is attached to a corresponding frame profile member (7) by means of at least one spring-biased tensioning mechanism (10) tensioning the flexible sheet (8), wherein the panel system (1) includes one or more plate-formed acoustic absorbers (11) arranged at a building-facing side (12) of the flexible sheet (8) of the one or more building panels (2) and at a distance (D) from the flexible sheet (8) so that a space (13) is formed between the one or more plate-formed acoustic absorbers (11) and the flexible sheet (8), wherein one or more air inlet openings (14) open into said space (13), and wherein the flexible sheet (8) is air permeable so that air may pass through the flexible sheet (8) from said space (13) to a room-facing side (15) of the flexible sheet (8), characterised in that the panel system (1) is adapted for air supply from an air conditioning system through said one or more air inlet openings (14) to said space (13), in that an airflow resistance of the flexible sheet (8) is between 50 and 1500 pascal-second per metre, and in that at least one of the spring-biased tensioning mechanisms (10) of each building panel (2) in the tensioned state of the flexible sheet (8) provides a tensioning force of at least 100 newtons in average per metre edge length of the flexible sheet (8).

2. A panel system according to claim 1, wherein each building panel (2) has a minimum frame profile length (l), wherein for a building panel (2) having a minimum frame profile length (l) larger than 1.5 metre, at least one of the spring-biased tensioning mechanisms (10) of said building panel (2) in the tensioned state of the flexible sheet (8) provides a tensioning force of at least 125 newtons in average per metre edge length of the flexible sheet (8), wherein for a building panel (2) having a minimum frame profile length (l) larger than 2 metre, at least one of the spring-biased tensioning mechanisms (10) of said building panel (2) in the tensioned state of the flexible sheet (8) provides a tensioning force of at least 250 newtons in average per metre edge length of the flexible sheet (8), and wherein for a building panel (2) having a minimum frame profile length (l) larger than 2.5 metre, at least one of the spring-biased tensioning mechanisms (10) of said building panel (2) in the tensioned state of the flexible sheet (8) provides a tensioning force of at least 400 newtons in average per metre edge length of the flexible sheet (8).

3. A panel system according to claim 1 or 2, wherein the distance (D) between the one or more plate-formed acoustic absorbers (11) and the flexible sheet (8) is at least 25 millimetres, preferably at least 30 millimetres, and most preferred at least 35 millimetres.

4. A panel system according to any one of the preceding claims, wherein the distance (D) between the one or more plate-formed acoustic absorbers (11) and the flexible sheet (8) is not more than 250 millimetres, preferably not more than 150 millimetres, even more preferred not more than 100 millimetres, and most preferred not more than 80 millimetres.

5. A panel system according to any one of the preceding claims, wherein each building panel (2) has a total area of freely extended flexible sheet (8) corresponding to an area of an open space (13) formed between edges (16) of the frame profile members (7) forming the peripheral frame (6) of the building panel (2), and wherein both the building-facing side (12) and the room-facing side (15) of the total area of the freely extended flexible sheet (8) is freely exposed to air passing through the flexible sheet (8).

6. A panel system according to any one of the preceding claims, wherein at least one of the one or more air inlet openings (14) is provided through one of the one or more plate-formed acoustic absorbers (11), between neighbouring ones of the one or more plate-formed acoustic absorbers (11) or between one of the one or more plate-formed acoustic absorbers (11) and one of the frame profile members (7).

7. A panel system according to any one of the preceding claims, wherein the total cross-sectional area of the one or more air inlet openings (14) correspond to between 2 per cent and 25 per cent, preferably between 3 per cent and 20 per cent, more preferred between 4 per cent and 18 per cent, even more preferred between 5 per cent and 15 per cent and most preferred between 5 per cent and 12 per cent of the total area of the extended part of flexible sheet (8) of the panel system (1).

8. A panel system according to any one of the preceding claims, wherein at least one air inlet opening (14) is provided as a groove (18) formed between neighbouring ones of the one or more plate-formed acoustic absorbers (11), and wherein, preferably, said groove (18) extends from a first frame profile member (7) to second frame profile member (7) being opposed to the first frame profile member (7).

9. A panel system according to any one of the preceding claims, wherein at least one air inlet opening (14) provided through one of the one or more plate-formed acoustic absorbers (11), between neighbouring ones of the one or more plate-formed acoustic absorbers (11) or between one of the one or more plate-formed acoustic absorbers (11) and one of the frame profile members (7) is covered by an air permeable member (19), such as a filter.

10. A panel system according to claim 9, wherein the air permeable member (19) has a room-facing surface (20) facing the flexible sheet (8), and wherein the room facing surface (20) of the air permeable member (19) has a light reflectance value being within + / -40 per cent, preferably within + / -30 per cent, more preferred within + / -20 per cent, and most preferred within + / -10 per cent of a light reflectance value of a room-facing surface (21) of the one or more plate-formed acoustic absorbers (11).

11. A panel system according to claim 9, wherein the air permeable member (19) has a room-facing surface (20) facing the flexible sheet (8), and wherein the room-facing surface (20) of the air permeable member (19) is at least substantially flush with a room-facing surface (21) of the one or more plate-formed acoustic absorbers (11).

12. A panel system according to any one of the preceding claims, wherein at least one air inlet opening (14) provided through one of the one or more plate-formed acoustic absorbers (11), between neighbouring ones of the one or more plate-formed acoustic absorbers (11) or between one of the one or more plate-formed acoustic absorbers (11) and one of the frame profile members (7) is covered by a lamp housing (22) forming an air passage (23) from a building-facing side (24) of the one or more plate-formed acoustic absorbers (11) to a room-facing side (25) of the one or more plate-formed acoustic absorbers (11).

13. A panel system according to claim 12, wherein the lamp housing (22) is provided with at least one air intake opening (26) through which air may flow from the building-facing side (24) of the one or more plate-formed acoustic absorbers (11) to an inside of the lamp housing (22), and wherein the lamp housing (22) is provided with at least one air outlet opening (27) through which air may flow from the inside of the lamp housing (22) to the room-facing side (25) of the one or more plate-formed acoustic absorbers (11).

14. A panel system according to claim 13, wherein the at least one air intake opening (26) is covered by an air filter (28).

15. A panel system according to any one of the preceding claims, wherein neighbouring building panels (2) are sealed in an at least substantially airtight manner between each other.

16. A panel system according to any one of the preceding claims, wherein the one or more plate-formed acoustic absorbers (11) are carried by the frame profile members (7) of the building panel or of the respective building panels (2).

17. A panel system according to any one of the preceding claims, wherein the panel system (1) includes a grid structure (36) for attachment to the ceiling or wall and for supporting the building panels (2), wherein the grid structure (36) includes a number of spaced and / or angled bars (37), and wherein each frame profile member (7) of each building panel (2) is sealed in an at least substantially airtight manner against a respective bar (37).

18. A panel system according to claim 17, wherein each building panel (2) is releasably attached to the grid structure (36), and wherein a preferably elastic sealing strip (38) is arranged between each frame profile member (7) and the corresponding bar (37) against which the frame profile (7) member is sealed.

19. A panel system according to claim 17 or 18, wherein bars (41) forming a periphery (42) of the grid structure (36) are adapted to be sealed in an at least substantially air tight manner against the ceiling or wall, possibly via a neighbouring ceiling or wall.

20. A panel system according to any one of the claims 1 to 15, wherein a box-formed pressure chamber (44) is formed by a peripheral box wall (45) having a room-facing side (46) to which the one or more building panels (2) are attached and a building-facing side (47) to which a back cover (48) is attached, and wherein a ventilation air inlet (49) for the air supply from an air conditioning system is provided through the peripheral box wall (45) or through the back cover (48).

21. A panel system according to claim 20, wherein the back cover (48) is formed by the one or more plate-formed acoustic absorbers (11), and wherein the ventilation air inlet (49) for the air supply from an air conditioning system is provided through the back cover (48).

22. A panel system according to claim 21, wherein an air inlet box (50) is arranged on the building facing side (24) of the one or more plate-formed acoustic absorbers (11), wherein the air inlet box (50) covers the ventilation air inlet (49) provided through the back cover (48) in the form of the one or more plate-formed acoustic absorbers (11), and wherein the air inlet box (50) is provided with a separate ventilation air inlet (51) for the external ventilation air supply.

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