WO2005100872A1

WO2005100872A1 - Roof light system having an improved ventilation device

Info

Publication number: WO2005100872A1
Application number: PCT/DK2005/000044
Authority: WO
Inventors: Brent MØLLER; Per Jacobsen; Niels A. Larsen; James Eric Brinton; Leonard Kenneth Moody, Jr.
Original assignee: Vkr Holding A/S
Priority date: 2004-04-19
Filing date: 2005-01-24
Publication date: 2005-10-27
Also published as: EP1756481A1; EP1756481B1; DE602005008592D1; DK1756481T3; EP1756481B9; PL1756481T3; ES2311959T3; ATE403117T1

Abstract

The roof light system is composed by a roof unit (10), a light conduit (70) and a diffuser unit (80). A ventilation device has a ventilation tube (60) separate and detached from the light conduit (70). The first end of the ventilation tube is connected with the roof unit (10) and the second end with the diffuser unit (80).

Description

Roof light system having an improved ventilation device

The present invention relates to a roof light system comprising a roof unit, a light conduit and a diffuser unit, said light conduit having a first cross-section and a first length and. extending between the roof unit and the diffuser unit, the roof light system furthermore comprising a ventilation device including a ventilation tube having a second cross-section and a second length extending between a first end and a second end. Traditionally, roof units such as -roof windows, skylights and other more or less light transmissible roof penetrating structures provide natural lighting to a space situated immediately below or only a short unobstructed distance from the part of the roof, in which the roof unit is installed. For illuminating other spaces such as rooms situated further inwards and/or downwards with respect to the roof of the building, artificial lighting has been the dominating source of light. For many reasons, natural lighting may be desirable in a room. In order to provide lighting or supplement artificial lighting of an inner room, roof window assemblies of the kind mentioned in the introduction have been suggested and are well known in the art. In such an assembly, a light conduit is led through the roof structure between the roof unit installed in the roof and a diffuser unit installed in the ceiling of an inner room. Light from the ambience is channelled through the light conduit into the inner room. The light conduit may e.g. be formed as a length of flexible hose, possibly --reinforced by wire hoops, or rigid sections connected with each other to form the desired path of the light conduit between the roof unit and the diffuser unit. In order to ensure that as much natural lighting as possible is channelled from the outside to the inner room, the internal side of the light conduit is usually provided with a light reflective lining or coating, or the entire material of the light conduit is made from a light reflective material. In some fields of application, ventilation of the inner room is desirable or even required, as is e.g. the case in a bathroom. In order to allow moist air to escape from the inner room and fresh air from the outside to enter the room, ventilation means leading from the room to the roof may be provided. In its simplest form such ventilation means is in the form of apertures in the diffuser unit and the roof unit, respectively. Air is thus allowed to flow inside the light conduit itself. Examples of prior art making use of this type of arrangement are US patent No. 5,435,780 and published international application No. WO 02/25032. However, problems of condensation may arise as the warm humid air from the inner room enters the light conduit and is trans- ported in the direction of the roof unit. Furthermore, the apertures in the roof unit, although usually formed in concealed positions, entail a risk of entry of precipitation. In order to alleviate the problems with conden- sation in the light conduit, one example of a solution is represented by US patent No. 6,142,645, in which a separate venting duct is provided. The venting duct is coupled to the diffuser unit at the ceiling of the inner room and is led to an aperture in the roof adjacent the skylight itself. Although this design makes it possible to let moist air flow outside the light conduit, an additional aperture must be formed in the roof, which is not desirable from i.a. an aesthetic point of view. A further development of this concept is known, in which a second tube surrounds a first tube constituting the light conduit. Ventilation is carried out in the space defined by the inner wall of the second tube and the outer wall of the first tube. Although this solution might be satisfactory in use, it is necessary to install the entire system simultaneously as subsequent installation of the second tube is, in most cases, impossible. With this background it is an object of the present invention to provide a roof light system of the kind mentioned in the introduction, in which the risk of condensation is eliminated, and which is at the same time easy to install. This and further objects are met by a roof light system of the kind mentioned in the introduction, which is furthermore characterized in that said ventilation tube is separate from the light conduit, said second cross-section being detached from said first cross-section, and that said first end of the ventilation tube is connected with the roof unit and said second end with the diffuser unit. By the provision of a separate ventilation tube, which is nevertheless connected with the diffuser unit as well as the roof unit, the problem inherent with arrangements making use of the light conduit itself as ventilation passage is completely avoided. At the same time, the provision of an additional opening in the roof is made redundant. As the respective cross-sections of the light conduit and the ventilation tube are detached from each other and do thus not overlap, the ventilation device is not dependent on the remaining parts of the roof light system. It is thus possible to install the ventilation device independently of the roof light system. In a preferred embodiment, the ventilation tube is connected with the frame by means of a manifold member. The function of the manifold member is to allow passage from the ventilation tube to the roof unit and further out to the surroundings . The manifold member may be an integral part of the roof unit or separate therefrom. The use of a separate manifold member facilitates installation and makes it possible to after-mount the ventilation tube on an already installed roof unit not beforehand provided with a ventilation device. In an embodiment, in which the roof unit comprises a frame and a sash carrying a glazing, the manifold member is a separate member connected with the frame . In an advantageous further development of this embodiment, the manifold member is substantially U-shaped and surrounds the light conduit partly. Preferably, the second end of said ventilation tube as well is connected with the diffuser unit by means of a manifold member. In order to facilitate the installation procedure even further, a development of this preferred embodiment is characterized in that the manifold member is releasably connected with the frame by means of a set of flaps on the manifold member cooperating with apertures in the frame. Preferably, these apertures are provided as knock-out plates surrounded by detachment indication lines. Supplemental connection means, such as screw or snap engagement means, may be provided. The manifold member may comprise a series of openings surrounded by upstanding walls. In this manner, water collected in the manifold member as a result of entered precipitation or condensation from humid air is prevented from flowing into the ventilation tube. In order to obtain a higher degree of flexibility with respect to the ventilated areas, the ventilation device may comprise, in addition to said ventilation tube, at least one branch tube extending between a first end and a second end. The second end of the at least one branch tube may be positioned at a distance from the diffuser unit . In order to support natural ventilation, means for mechanical ventilation may be provided. Due to its position in a roof the roof unit may be utilized for the application of solar cells. Such solar cells may be positioned on any part of the roof unit . In case it is desired to make the entrance to the light conduit inconspicuous, a reflective and/or coloured film or coating may be provided on the frame and/or the glazing. In an embodiment, which is particularly advantageous with respect to manufacture and installation, a base module including the roof unit, the light conduit, the diffuser unit and the ventilation device is provided. At least the roof unit and the light conduit include interchangeable elements. With the base module, a functional roof light system is achieved. In case it is desired to supple- ment the base module with optional elements, this may be accomplished by interchanging one or more elements of the base module with additional elements. For instance, the base module of the roof light system may be transformed into a more traditional, openable roof window. The shape of the roof unit and the cross-sectional shape of the light conduit may in principle be arbitrary. For instance, the shapes may match, i.e. a circular light conduit connected with a circular roof unit, or a rectangular roof unit with a rectangular light conduit. In a preferred embodiment, the roof unit includes a frame having a circular aperture and a sash, said frame and sash having a rectangular shape, preferably square. In this manner, the roof light system according to the invention may be built-in in a roof, in which traditional roof windows are installed, without breaking the uniform appearance of e.g. a row of roof windows and roof units. The circular shape of the aperture in the frame entails a number of advantages as regards the installation of the roof light system. As a consequence of the particular shape, a ring may be provided for connection with a rim surrounding said aperture, said ring being provided with pins for engagement with lugs on the rim. In order to improve the retention of the light conduit on the ring, the ring may be provided with a circumferential flange, the light conduit being connected with the ring by means of a draw-band positioned above said flange. In the following the invention will be described in further detail with reference to preferred embodiments and to the schematic drawings . Fig. 1 shows a perspective view of a roof light system in a first embodiment of the present invention; Fig. 2 shows, on a larger scale, a perspective and partial view of the roof light system of Fig. 1; Fig. 3 is a view corresponding to Fig. 2 of the first embodiment of the roof light system shown from the side intended to face inwards into a building; Fig. 4 is a view corresponding to Fig. 3 of a second embodiment of the roof light system; Fig. 5 shows, on a larger scale, a perspective view of a detail of the roof light system shown in Figs. 1-3; Fig. 6 shows a sectional view of the detail shown in Fig. 5 ; Figs. 7 and 8 show perspective views of a detail of the embodiment of the roof light system shown in Figs. 1-3; Fig. 9 shows a perspective view of the roof light system shown in Fig. 3 during installation; Fig. 10 is a partial perspective view of a detail of the roof light system; Fig. 11 is a view corresponding to Fig. 10 of an alternative embodiment of the roof light system according to the present invention; Fig. 12 shows a perspective view of a detail of the roof light system according to the invention; and Fig. 13 is an exploded perspective view of the detail of Fig. 12. Referring to the drawings, the roof light system comprises a roof unit 10, a light conduit 70 and a diffuser unit 80. The roof unit 10 is intended to be installed in the roof of a building and includes a light-admitting aperture 11 formed in a frame 12, cf. Fig. 10. Light is admitted into the aperture 11 through a sash 13 carrying a glazing 14, cf. in particular Figs. 2 and 6. The glazing 14 may be formed in any suitable manner and from any suitable translucent material, e.g. glass or a plastic material. Roof unit 10 furthermore comprises a flashing arrangement intended to provide a substantially weather-tight transition to the surrounding roofing (not shown) . In the embodiment shown, the frame 12 is formed integrally with substantially sheet-shaped portion 15 surrounding the frame 12 and is, in the mounted position, placed beneath the roofing. In order to direct precipitation on to a skirt portion 17 placed on top of the roofing, rails 16 are provided on either side of the frame 12. Furthermore, a sealing strip 18 is connected with the sheet-shaped portion 15 and the skirt portion 17 to prevent water from entering the underlying roof structure. The flashing arrangement may also be provided separately from the frame and sash, or be dispensed with altogether, if the installation conditions allow so. Opposite the aperture 11 in the frame 12 of roof unit 10, one end of the light conduit 70 is connected with the frame 12 in a manner which will be described in detail further on. The light conduit 70 has a first cross-section and a first length which corresponds to or exceeds the distance between the roof unit 10 and the diffuser unit 80. The other end of the light conduit 70 is connected with the diffuser unit 80, likewise to be described in detail further on. The diffuser unit 80 is intended to be installed in the ceiling of an inner room in the building, and light conduit 70 thus extends through at least the roof structure of the building. In the embodiment shown, light conduit 70 is formed as a length of flexible hose reinforced by wire hoops 71. However, the light conduit may be formed by rigid sections connected with each other to form the desired path of the light conduit between the roof unit and the diffuser unit. Furthermore, the light conduit may have any suitable cross-sectional dimension and be of arbitrary shape. In order to ensure that as much natural lighting as possible is channelled from the outside to the inner room, the internal side of the light conduit is usually provided with a light reflective lining or coating, or the entire material of the light conduit is made from a light reflective material. Eventually, a ventilation device is provided for allowing moist air to escape from the inner room and fresh air from the outside to enter the room. The ventilation device comprises a ventilation tube 60, which may be formed from any suitable, preferably flexible, material and may have any cross-sectional shape. There may be more than one ventilation tube. The ventilation tube 60 has a second cross-section and a second length extending between a first end 60a and a second end 60b. As is the case with the light conduit 70, the second length corresponds to or exceeds the distance between the roof unit 10 and the diffuser unit 80. In the first end 60a the ventilation tube 60 is connected with the roof unit 10 and in the second end 60b with the diffuser unit 80. As the ventilation tube 60 is separate from the light conduit 70 and the cross-section of the ventilation tube 60 is detached from, i.e. does not overlap at any point, the cross-section of the light conduit 70, the ventilation device may be installed independently of the other parts of the roof light system. It is furthermore noted that the respective cross-sections may vary over the length of the light conduit and the ventilation tube, respectively. The cross-sections may, as indicated in the drawings, be entirely different. The respective lengths and courses of the light conduit 70 and the ventilation tube 60 may vary as well, e.g. to adapt to installa- tion conditions. In Fig. 4, a second embodiment is shown. In addition to the ventilation tube 60, the ventilation device comprises a first branch tube 160 extending between a first end 160a and a second end 160b and a second branch tube 260 extending between a first end 260a and a second end 260b. In the embodiment shown, the first end 260a is positioned between the first end 60a and the second end 60b of the ventilation tube 60, i.e. the second branch tube 260 is branched off from the ventilation tube 60a. It is of course conceivable to let the second branch tube 260 branch off from the first branch tube 160, or to position the branch-off site arbitrarily along the ventilation tube 60 or the first branch tube 160. In the embodi- ment shown, the branch-off is situated virtually at the first end 60a of the ventilation tube 60. An obvious manner of obtaining this configuration is to cut the ventilation tube 60 and the branch tubes 160 and 260, connect part of the circumferences and let the three tubes merge into the mouth piece 61. In order to support the natural draught in the ventilation tube 60, means for providing mechanical ventilation may be present in the ventilation device. Such means are known per se and may e.g. include an electrically operated fan. The fan or fans may be positioned arbitrarily in the ventilation device, e.g. in the roof unit or at the mouth piece 62, 162 arid/or 262. It may be advantageous to position a fan at the intended branch-off site or sites on the ventilation tube 60. In this case, the fan may be provided with two or more inlet ends, possibly covered by knock-out plates, and one outlet end facing the first end 60a of the ventilation tube 60. Details regarding the connection between the light conduit 70 and the ventilation tube 60, and the roof unit 10 will be described with particular reference to Figs. 5 to 9. One particularly advantageous manner of in- stalling the roof light system according to the present invention comprises the following steps : The roof unit 10 is mounted in an aperture in the roof prepared to that purpose . Attachment of the roof unit may be performed in any suitable manners known per se from skylights, roof windows and other roof penetrating structures, comprising e.g. the use of mounting brackets secured to the underlying roof structure in the form of rafters and laths, or sheathing. Roofing is placed on top of the sheet- shaped portion 15 of the flashing arrangement up to a suitable distance from the frame 12 and sash 13 of the roof unit, and the skirt portion 17 is made to abut against the upper face of the roofing below the frame 12 and sash 13. Referring now to Figs. 5 and 6, a ring 30 is provided for connection with a rim 19 surrounding the aperture 11 in the frame 12. In the vicinity of one edge of the ring 30, a plurality of pins 31 are distributed over the circumference of the ring for engagement with lugs 20 on the rim 19. By positioning the pins 31 in front of a keyhole-shaped track 21 in each lug 20 and then rotating the ring 30 slightly, a safe engagement between the ring 30 and the frame 12 is obtained. Subsequently, the light conduit 70 is attached to the ring 30 by first guiding one end of light conduit 70 past a circumferential flange 32 at the other edge of the ring 30, and then secure the light conduit 70 to the ring 30 and thus in turn to the frame 12 by means of a draw-band (not shown) positioned above the flange 32. It is noted that the ring may be made integral with the frame, or dispensed with altogether, the connection thus being carried out in any suitable manner. In the embodiment shown, the light conduit thus extends substantially perpendicularly to and almost up to the glazing 14 near the roof unit 10. This provides for an optimum influx of light. A small spacing between the light conduit, or in this case the ring, is left up to the glazing in order to avoid condensation. When the light conduit 70 has thus been connected with the roof unit 10, a manifold member 40 shown in detail in Figs. 7 and 8 is connected with the roof unit 10. The manifold member 40 is mainly U- shaped and at the ends of legs 41, engagement means in the form of protruding flaps 42 are provided. These flaps 42 are inserted into corresponding apertures in the frame 12. In the embodiment shown, these openings are provided by detaching two knock- out plates 22 at the bottom of the frame 12, cf. Fig.

10, from the remaining portion of the frame 12 by an appropriate tool. The position shown in Fig. 7 has now been attained. Manifold member 40 is then swung around flaps 42 at the end of legs 41 until the bottom of the U-shape is brought into abutment with the under side of the upper part of the frame 12. Appropriate fastening means, such as screws, are then inserted through upstanding reception elements 45 and further into the frame 12, cf . Fig. 8. The manifold member 40 may be connected with the frame in other ways than that described in the above, including screw fastening, fastening by adhesion, interlocking elements, snap connection etc. The manifold member 40 could have one of a variety of designs. One possibility is to form the manifold member integral with the frame 12. In its simplest form, the manifold member is constituted by a socket piece connected with the roof unit . The socket piece may e.g. be provided with knock-out plates which are detached when the ventilation device is to be installed. The manifold member may also provide for connection of more than one mouth piece, e.g. one mouth piece for each of the ventilation tube and the branch tube or tubes. Mouth pieces having one opening in the end facing the manifold member and two or more openings in the opposite end are also conceivable, i.e. one opening for each of the ventilation tube and the branch tube or tubes . The openings not in use may be covered by knock-out plates. The ventilation tube 60 is then connected with the manifold member 40 by means of its mouth piece 61. This connection is not shown in detail but may be carried out in any suitable manner, e.g. by snap engagement or screws. The position shown in Fig. 3 is now attained. Ventilation of the inner room is performed by means of the following features in the manifold member 40 and the roof unit 10: At the bottom of the U-shape of manifold member 40, a series of arc-shaped openings 43 surrounded by walls 44c is provided. Air flowing to or from the ventilation tube 60 is allowed to pass through these openings 43. The manifold member 40 is in fluid communication with the outside by means of a plurality of apertures in the frame 12. As is the case with the flap receiving apertures, such apertures may be obtained by detaching knock-out plates 23 in the frame 12 from the remaining part of the frame, cf . Figs. 6 and 10. In the installed condition of the roof light system, the sash 13 and the frame 12 form a kind of labyrinth seal, which allows air to escape from and enter into the ventilation tube, but which at the same time makes it difficult for precipitation to enter into the manifold and possibly the ventilation tube. In case precipitation nevertheless enters the manifold member 40, or in case condensation is formed, a controlled drainage is provided, as water collected in the trough defined by outer walls 44a and 44c and upstanding walls 44b surrounding openings 43 may flow out of the frame 12 through the apertures receiving flaps 42. Upstanding wall sections 44b prevent flow of water into the ventilation tube 60. Upstanding wall sections 46 form a labyrinth seal in order to secure that precipitation that might have entered the manifold member 40 through these apertures does not flow in the opposite direction. The respective shape of the frame 12 and the sash 13 may be arbitrary and is traditionally chosen to match possible other roof penetrating structures, such as skylights and roof windows, installed in the roof. In the embodiment shown in the drawings, the frame 12 and sash 13 have a substantially square shape, but other shapes, such as polygonal, e.g. a rectangular shape other than square, circular, oval or any other shape, are conceivable as well. As a consequence of the square shape of the frame 12 and sash 13 in combination with the circular cross- section of the light conduit 70 in the preferred embodiment, an area 12a exists between the aperture 11 and the frame 12. This area 12a may be utilized for positioning solar cells, preferably connected to battery means, to provide energy for e.g. a screening arrangement in the form of a dimmer situated in the roof light system, or possibly even for controlling or operating a drive motor of an electrically operated fan. Such solar cells may of course also be positioned on other places of the roof unit. For instance, the glazing may be covered by solar cells, in particular in the section corresponding to the area 12a of the frame, e.g. on the inner side of the glazing. The area 12 a may have a coloured and/or reflective film or coating in order to obtain a uniform appearance of the roof unit . Such film or coating may also be provided on the glazing 14. The roof light system may be provided as a base module comprising roof unit, light conduit, diffuser, and, in the present invention, ventilation device. However, parts of the base module may be exchanged or supplemented. For instance, the light conduit may be customized for e.g. very long or complicated routing through the roof structure. Furthermore, the roof light system may be modified into a traditional openable window. This modification is carried out in the following manner, referring in particular to Figs. 10 and 11: Light conduit 70 is removed substantially in reverse manner in relation to the installation operation as described in the above. Sash 13 is removed from the frame 12. In the state of delivery of the roof light system, the sash 13 is advantageously connected with the frame 12 by means of a hinge connection at the top of the sash 13 and frame 12. When the roof light system is in use, the sash 13 is most often secured to the frame by means of screws or similar fastening means to prevent the sash 13 from being opened inadvertently. Hinge connection may, however, be provided separately. The area 12a surrounding the aperture 11 in the frame 12 is detached from the remaining part of the frame 12. The detachment is facilitated by detachment indication lines 24. Detachment indication lines 24 may be provided by means of visual indication only, or as weakening lines. An aperture at the bottom of the frame 12 is obtained by means of a knock-out plate 25, the function of which is apparent from Fig. 11, viz. to accommodate the passage of an extending device or a stay 26. Sash 13 is re-connected with the frame 12, possibly after the application of a hinge connection, and the extending device 26 is attached to the sash

13 and cooperating fixture means to the frame 12. Such extending devices, fixtures and other kinds of operating devices, e.g. an electrically operated chain, are known per se and are not the subject of detailed description. It is of course conceivable to exchange the sash 13 of the base module with any other kind of sash, e.g. a sash having a different glazing with respect to colour, translucency or shape. For instance, the glazing may be substantially dome-shaped. The diffuser unit 80 depends from the light conduit of the roof light system described above, and transmits light received from the light conduit into the interior of the building room. The diffuser unit may take many different forms and is as such not a central part of the present invention. In the following an embodiment of the diffuser unit corresponding to the embodiment of Fig. 3 will be described. The diffuser unit includes a ceiling ring, a dual diffuser, a trim ring, a ceiling ring gasket, and a diffuser gasket . With reference to Figs . 12 and 13 , diffuser unit 80 is depicted. Ceiling ring 82 includes a plurality of flanges 84 configured for receipt of the light conduit from the roof light system. As will be appreciated, flanges 84 are configured for mating attachment with the distal end of the light conduit, whether the light conduit is constructed of a flexi- ble tube or of a solid membe . The light conduit may be attached to the flanges 84 by screws, banding attachment, or the like. It will be observed in Fig. 13 that gasket 99 is also provided. Gasket 99 is disposed for receipt above flange 83 of ceiling ring 82, to provide a seal between flange 83 and gypsum, sheetrock, or like ceiling material upon installation of the diffuser unit in a building. Ceiling ring 82 also includes a plurality of adjustable mounting cams 86. Mounting cams 86 are activated by screws 88, the heads of which are accessible from beneath ceiling ring 82. By turning screws 88, mounting cams 86 are drawn downward, with the gypsum boards, sheetrock:, or like material by which the interior room ceiling is constructed disposed between mounting cams 86 and flange 83, thereby attaching ceiling ring 82 to the ceiling. Each screw 88 also includes at its head a mounting tab (not shown in detail) . Mounting tabs are configured to swing about the head of screws 88 to allow for receipt and attachment of the diffuser unit

92. As depicted in Fig. 13, diffuser unit 80 in- eludes flange 83 about the exterior. Flange 83 is configured for co-planar disposition against the interior ceiling of a building. As noted in Fig. 13, flange 83 also includes a plurality of apertures 94. Apertures 94 are configured for receipt of the ventilation tube 60 of the roof light system. The apertures 94 are advantageously provided by detaching knock-out plates, as has been described in further detail with respect to other parts of the roof light system. When installing the ventilation device, mouth piece 62, which constitutes a manifold member having at least one opening to form a fluid communication with the ventilation tube 60, is connected with the diffuser unit 80 in any suitable manner. It will be appreciated that, by engagement of such a ventilation tube with apertures 94 upon ceiling ring 82, only a single penetration of an interior building ceiling would be necessary for installation of both a roof light system as well as a roof ventilation system. Diffuser unit 80 also includes diffuser pan 96 and diffuser 92. Diffuser pan 96 is configured to slide within the interior opening defined within ceiling ring 82. Likewise, diffuser 92 is configured for fitting within the aperture defined within ceiling ring 82. Diffuser pan 96 receives diffuser 92 so as to allow a space of air between diffuser 92 and the pane 97 of diffuser pan 96. So disposed, the combination of diffuser pan 96 and diffuser 92 creates a thermal barrier to the transmission of heat to or from the roof light system. Once diffuser pan 96 and diffuser pan 92 are installed within the aperture defined through the center of ceiling ring 82, mounting tabs 90 are swung into position to hold diffuser 92, and thus also diffuser pan 96, within ceiling ring 82, blocking their removal. Disposed above diffuser pan 96 is gasket 98 , providing a seal of the roof light system against the intrusion of humidity, dust, and insects to the interior of the roof light system. Finally provided is trim ring 100, adapted for a snap fit engagement with ceiling ring 82. Trim ring 100 provides a finished outward surface for diffuser unit 80 upon installation of diffuser unit 80 into a ceiling. So configured, installation of diffuser unit 80 into a building may proceed as follows. Upon installation of a roof unit in accordance with the present invention, an aperture may be cut through a ceiling of a building of appropriate size for receipt of diffuser unit 80. With gasket 99 in place about ceiling ring 82 above flange 83, ceiling ring 82 and gasket 99 may be inserted through such hole. So inserted, screws 88 are then turned so as to engage mounting cams 86, so as to capture between mounting cams 86 and flange 83 the ceiling gypsum board, sheetrock, or the like, thereby attaching ceiling ring 82 into the ceiling. The light conduit may then be attached to flanges 84. In the embodiment shown in Figs. 12 and 13, the ventilation tube 60 is attached to apertures 94 by means of mouth piece 62 constituting a manifold member as described in the above . Gasket 98 may then be installed within the aperture defined within ceiling ring 82 . With gasket 98 in place , diffuser pan 96 and diffuser 92 may be installed within the aperture of ceiling ring 82 , with mounting tabs then turned to hold diffuser 92 within ceiling ring 82 against gravity. The trim ring 100 may then be installed over the exposed flange 83 of ceiling ring 82 , snap fitted into place . The invention should not be regarded as being limited to the embodiments shown and described in the above . Various modifications and combinations may be carried out without departing from the scope of the appended claims .

Claims

C L A I M S 1. A roof light system comprising a roof unit (10) , a light conduit (70) and a diffuser unit (80) , said light conduit having a first cross-section and a first length and extending between the roof unit and the diffuser unit, the roof light system furthermore comprising a ventilation device including a ventilation tube (60) , said ventilation tube having a second cross-section and a second length extending between a first end (60a) and a second end (60b) , c h a r a c t e r i z e d in that said ventilation tube (60) is separate from the light conduit (70) , said second cross-section being detached from said first cross- section, and that said first end (60a) of the venti- lation tube is connected with the roof unit (10) and said second end (60b) with the di fuser unit (80) . 2. A roof light system according to claim 1, wherein the ventilation tube (60) is connected with the frame by means of a manifold member (40) . 3. A roof light system according to claim 2, wherein the roof unit (10) comprises a frame (12) and a sash (13) carrying a glazing (14) , and the manifold member (40) is a separate member connected with the frame (12) . 4. A roof light system according to claim 3, wherein the manifold member (40) is substantially U- shaped and surrounds the light conduit (70) partially. 5. A roof light system according to any one of claims 2 to 4 , wherein the second end (60b) of said ventilation tube (60) is connected with the diffuser unit (80) by means of a manifold member (62) . 6. A roof light system according to any one of claims 2 to 5, wherein the manifold member (40,62) is releasably connected with the frame or diffuser unit (12,80) by means of engagement means (42) on the manifold member cooperating with apertures (22,94) in the frame or diffuser unit. 7. A roof light system according to claim 6, wherein said apertures are provided as knock-out plates (22) surrounded by detachment indication lines . 8. A roof light system according to claim 6 or 7, wherein supplemental connection means (45) are provided to fasten the manifold member (40,62) to the frame or diffuser unit (12,80) . 9. A roof light system according to any one of claims 2 to 8, wherein said manifold member (40) comprises a series of openings (43) surrounded by upstanding walls (44b) . 10. A roof light system according to any one of the preceding claims, wherein the ventilation device in addition to said ventilation tube (60) comprises at least one branch tube (160,260) extending between a first end (160a, 260a) and a second end (160b, 260b) . 11. A roof light system according to claim 10, wherein the second end (160b, 260b) of the at least one branch tube (160,260) is positioned at a distance from the diffuser unit (80) . 12. A roof light system according to any one of the preceding claims, wherein means for mechanical ventilation is provided. 13. A roof light system according to any one of the preceding claims, wherein a plurality of solar cells is provided on the roof unit. 14. A roof light system according to any one of claims 3 to 13, wherein a reflective and/or coloured film or coating is provided on the frame and/or on the glazing. 15. A roof light system according to any one of the preceding claims, wherein a base module including the roof unit (10) , the light conduit (70) , the diffuser unit (80) and the ventilation device (60) is provided, and wherein at least the roof unit and the light conduit include interchangeable elements. 16. A roof light system according to any one of the preceding claims, wherein the roof unit (10) coτnprises a frame (12) having a circular aperture (11) and a sash (13), said frame and sash having a rectangular shape, preferably square. 17. A roof light system according to claim 16, wherein a ring (30) is provided for connection with a rim (19) surrounding said aperture, said ring being provided with pins (31) for engagement with lugs (20) on the rim. 18. A roof light system according to claim 17, wherein said ring (30) is provided, with a circumfer- ential flange (32) , said light conduit being connected with the ring by means of a draw-band positioned above said flange.