DESCRIPTION

The invention relates to a ceiling system according to the preamble of claim 1. The invention also relates to a method for installing a ceiling system or for modifying an already installed ceiling system.

In particular, however not exclusively, the invention relates to a so-called dropped ceiling system, i.e. a lowered (secondary) ceiling, hung below and mainly parallel to the main (structural) ceiling. They may also be referred to as a drop ceiling, false ceiling, or suspended ceiling. The area above the dropped ceiling is called the plenum space, as it is sometimes used for HVAC air return. The plenum space is also very commonly used to conceal piping, wiring, and/or ductwork.

A typical dropped ceiling consists of a grid-work of metal profiles in the shape of an upside-down "T", suspended on wires from the overhead structure. These profiles snap together in a regularly spaced pattern - typically a 2x2 or 2x4 foot grid in the US, or 600x600 mm grid in Europe. Each cell is filled with lightweight "tiles" or "panels" which simply drop into the grid. Tiles may be selected from a variety of materials, including wood, metal, plastic, or mineral fibers, and may come in almost any color. Light fixtures, HVAC air grilles, and other fixtures are available, which may fit within the same space as a tile for easy installation. Most tile material is easy cuttable to allow fixtures in other shapes, such as incandescent lights, speakers, and fire sprinkler heads.

An earlier patent application WO2009005344 of applicant discloses a ventilation method and system respectively for ventilating rooms like classrooms and the like, comprising a surface structure mainly extending parallel to the ceiling, and means for forced air inlet from the outside air into the room between said surface structure and the ceiling. Air outlet openings are provided, which are mainly evenly spaced over the whole surface of the surface structure. Preferably, the hydraulic diameter of the outlet openings is between 0.1 and 6 cm. The means for forced air inlet from the outside air into the room (or plenum space) between the surface structure and said wall, ceiling or floor are formed by an electrical fan.

In the embodiments shown in WO2009005344 the panels concerned are provided with holes which can be made during the manufacturing process of the panels or -e.g. when already installed panels are used- by drilling. Disadvantageous is that: - the holes have to be made, either during production or afterwards;

- panels with and without holes should be held in stock separately;

- the (plurality of) holes in the ceiling panels are considered to be not aesthetical.

It would therefore be desirable to provide a system which e.g. is arranged to perform a method as presented in WO2009005344, however without the obligation to provide -during or after their manufacture- the relevant panels with holes. It would also be desirable to provide means by which standard panels can be used, even if already installed in an existing ceiling system.

For these purposes it is known from US3207057A and US4611444A to provide a ceiling system according to the preamble of claim 1. The ceiling system according to the preamble of claim 1 comprises a plurality of ceiling panels and a ceiling framework for supporting those panels, said framework including panel support profiles each including a vertical portion and a horizontal portion, and further comprises spacing means arranged to create, per panel concerned, a vertical gap between relevant vertical portions of the profiles and at least one of the side edges of the panel, as well as a horizontal gap between relevant horizontal portions of the profiles and the horizontal lower surface of the panel. By using spacing means for creating a vertical gap between the vertical portions of the profiles and the side edges of the panel, as well as a horizontal gap between the horizontal portions of the profiles and the horizontal lower surface of the panel the panels do not need to be provided with ventilation holes. Moreover, standard panels can be used, even if already installed in an existing ceiling system. The vertical and horizontal ventilation gaps can be obtained by insertion of the spacing means between the panels concerned and the surrounding portions of the support frame.

However, the ceiling systems known from US3207057A and US4611444A suffer from the drawback that the ventilation flow, which has successively passed said vertical ventilation gap and said horizontal ventilation gap, is lacking substantial flow into downward direction away from the horizontal lower surfaces of the ceiling panels. This is disadvantageous in that the ventilation air does not mix well enough with the air mass in the room to be ventilated and in that deposition of dust against the ceiling panels is promoted.

In this regard it is remarked that it is known from US3475869A to realize vertical down flow via apertures 26 in horizontal portions of the panel support profiles. However, a drawback is that the realization of these apertures 26 is labour-intensive. Furthermore, it is remarked that it is known from US3429250A to provide notches 15 along edges of the ceiling panels. However, here a drawback is that the realization of these notches 15 is labour-intensive. It is an object of the invention to provide a solution according to which, even in an existing ceiling system, the downward ventilation flow downstream of the ceiling system is increased, requiring only little labour intensiveness, hence without needing labour-intensive measures such as applying flow passageways in the ceiling panels or in the panel support profiles. For that purpose, the invention provides a ceiling system according to claim 1. The invention is also embodied in a method according to claim 5. Specific embodiments of the invention are set forth in the dependent claims.

Climate chamber tests have shown that, thanks to the elongated walls of the spacing means, the ventilation flow leaving the ventilation openings is substantially increased in downward direction, whereby the ventilation air mixes very well with the air mass in the room to be ventilated. The elongated walls having the spacing elements protruding laterally therefrom can simply be interposed in-between the ceiling panels and the panel support profiles in order to obtain said ventilation openings. Hence, according to the invention there is no need for applying flow passageways in the ceiling panels or in the panel support profiles, or for applying other labour- intensive measures. Also in case of an existing, already installed ceiling system, the system may quickly be modified by simply interposing the elongated walls with their spacing elements in- between the ceiling panels and the panel support profiles.

In principle, a single such elongated wall may comprise only one of said spacing elements. In a preferable embodiment of the invention, however, a single such elongated wall comprises at least two of said spacing elements being spaced relative to one another along said elongated wall. This provides the advantage that it is easier to place the ceiling panels neatly on the ceiling framework.

In another preferable embodiment of the invention, the elongated wall further comprises at least one protrusion protruding laterally from the wall towards said horizontal portion of the panel support profile, the at least one protrusion being arranged for guaranteeing the presence of said at least one ventilation opening. The at least one protrusion provides the advantage that, when it is placed in abutment with the horizontal portion of the panel support profile, a predetermined magnitude of the ventilation openings is obtained.

Further details, aspects and embodiments of the invention will be described, by way of non-limiting example only, with reference to the schematic drawing, in which: Figure 1 shows a prior art ceiling system including ceiling panels and a ceiling framework

including panel support profiles with vertical and horizontal portions. Figure 2 shows the ceiling system of Figure 1 , however, including spacing means arranged to create a vertical gap and a horizontal gap between the panel support profiles and a ceiling panel.

Figure 3 shows an example of spacing means in the form of an elongated wall that interconnects spacing elements, the shown spacing means being part of a ceiling system according to an example of an embodiment of the invention.

Figure 4 shows the spacing means of Figure 3 together with a ceiling panel and a panel support profile of an example of an embodiment of a ceiling system according to the invention.

Figure 1 shows a prior art ceiling system including ceiling panels 1 and a ceiling framework including panel support profiles 2 with vertical portions 3 and horizontal portions 4. The framework is hung below and mainly parallel to the main (structural) ceiling by means of hooks 5.

Figure 2 shows the ceiling system of Figure 1 including spacing means 6 arranged to create a vertical ventilation gap and a horizontal ventilation gap between the profiles 2 and the panel 1. The vertical and horizontal ventilation gaps together are forming a continuous ventilation gap between the upper side and the lower side of the panel.

Figures 3 and 4 show, as a preferred embodiment of spacing means 6 used in a ceiling system according to the invention, an elongated wall 7 interconnecting a series of spacing elements 8 which are intended to be mounted between the panel support profiles 2 and the ceiling panel 1. Normally, four of such elongated walls 7, having a length equal to about the length or width of the panel, will be mounted per ceiling panel 1 of the ceiling system, thus creating a mainly continuous gap surrounding that ceiling panel 1. The spacing elements 8 each consist of a vertical spacer 9 for spacing the side edge of the ceiling panel 1 from the vertical side surface of the vertical portion 3 of the support profile 2, as well as a horizontal spacer 10 for spacing the lower surface of the ceiling panel 1 from the upper surface of the horizontal portion 4 of the support profile 2. The spacers 9 and 10 are interconnected by an interconnection part 11 which extends further to an optional side protrusion 12 provided on the elongated wall 7. The elongated wall 7 has the shape of a vertical wall which is arranged to deflect a ventilation stream, caused by overpressure at the upper side of the panels, passing the vertical and horizontal ventilation gaps between the panel and the vertical and horizontal profile portions, into downward direction, away from the lower (horizontal) surface of the panel. The optional protrusion 12 functions as a vertical spacer between the edge of the horizontal portion 4 of the support profile and the deflection surface 17 (see Fig. 3) of the elongated wall 7. Figure 4 shows the elongated vertical wall 7 of the spacing means 6, shown in Figure 3, wherein the spacing elements 8 have been installed between the (right) surface of the vertical part 3 and the upper surface of the horizontal part 4 of the support profile 2 and the (left) vertical side surface and the lower surface of the panel 1 , wherein the elongated wall 7 is arranged to deflect the last part of a ventilation stream, originating from the plenum space above the ceiling panels and indicated by the arrows 13, 14 and 15, into downward direction, via the ventilation openings 18 between said elongated wall 7 and the side edge of the horizontal part 4 of the support profile 2.

In the foregoing specification, the invention has been described with reference to specific examples of embodiments of the invention. It will, however, be evident that various modifications and changes may be made therein without departing from the broader scope of the invention as set forth in the appended claims.

For example, in the specific examples the ceiling system according to the invention is described and shown with reference to a mounted condition of the ceiling system and as referenced per ceiling panel concerned, per panel support profile concerned and per spacing means concerned, in which mounted condition the ceiling panel and the profile direction of the panel support profile are both extending horizontally. Also in the appended claims the ceiling system and method according to the invention are specified with reference to said (horizontally mounted) manner, however, with the horizontal mounting condition merely being used as a clearly understandable reference condition of the ceiling system. Evidently, it is also possible to mount a ceiling system according to the appended claims in such manner that a concerned mounted ceiling panel and a profile direction of a concerned mounted panel support profile are not extending horizontally, but inclined relative to the horizontal, for example as part of an inclined secondary ceiling under an inclined main ceiling. Furthermore, other modifications, variations and alternatives are also possible. The specifications and drawings are, accordingly, to be regarded in an illustrative rather than in a restrictive sense.