EP2762794A1

EP2762794A1 - Roof-penetrating air outlet

Info

Publication number: EP2762794A1
Application number: EP20140153588
Authority: EP
Inventors: Wac aw Majoch
Original assignee: Fakro PP Sp zoo
Current assignee: Fakro PP Sp zoo
Priority date: 2013-02-04
Filing date: 2014-02-03
Publication date: 2014-08-06
Also published as: PL402646A1; PL229394B1

Abstract

The solution relates to a roof-penetrating air outlet, with an inlet duct (10) for fresh air located at the external side of the roofing, and an outlet hole (41) at the internal side of the roof decking, while the connection of the air outlet with the roof decking is protected from weather conditions by sheet metal flashing, preferably standard roof flashings; the air outlet may be installed in any place of the roof plane and it has no specific requirements as for shape and structure of the roofing.

Description

The present invention relates to an air outlet installed in a sloped roof, beyond the structure of a roof window and independently of the window's location. The air outlet functions as a duct conveying fresh air to rooms in buildings. The necessity to use air outlets occurred as a result of the trend towards a reduction of heat losses in buildings by excessive sealing and blocking of natural air exchange in rooms. In general, air outlets are used in exterior wall windows, or, in the case of attics, integrated with the structure of a roof window. Air outlets installed in the window structure are a natural solution, because of the relative ease of their manufacturing and installation. In this case, making additional air outlet holes in the exterior wall or in the roof is not necessary. However, there is a need for ventilation of attic rooms, which do not have windows installed, or which have windows not equipped with air outlets. It results from a high weathertightness of the roof decking and lack of natural ventilation. The solutions known to this date relating to room ventilation utilise the roofing layer system as a base structure for installation of a set of elements directing the air stream between the room and the exterior. One of the solutions of such a type is shown in Patent Application No. US 2011030293 A1 . The air stream is introduced via a built-in duct penetrating the insulation layer, into the space between the insulation layer and the roofing. In order to facilitate the air flow between the said space and the exterior, an additional spacing element raising the bottom end of the roofing element is used. This solution requires installation of a set of spacing elements at the whole length of the layer, in order to maintain even arrangement of the roofing layer. It is also necessary that a space exists between the insulation layer and the roofing, what limits the applicability of this solutions only to roofings having such a space.
The above solution and similar solutions have a limited application in low-profile roofings, e.g. flat tile decking. It results from the lack of free space between the roofing and the insulation layer in the roof decking.
Another solution free of such a limitation is presented in Japanese Patent Application No. JP 2011032856 A . It is a set with the main element in the form of a multiduct profile installed under the edge tile batten close to the eave or ridge, shown in many embodiment variants. The profile is connected with an opening in the roof insulation by one and, and with the space under the roofing element by the second end, after the edge tile batten, mainly towards the roof slope. The characteristic feature of the solution consists in the required installation point, always located close to the edge of the roof plane.
A specific solution proposed for low-profile roofings is disclosed in Patent Application No. JP 8302919 A . The main element of the solution consists of wedge panels installed on the structure of the roof decking. Lateral dimension of the panels encloses several layers of the roofing. Longitudinal dimension of the panels is not limited and may enclose the whole width of the roof plane. Arrangement of the wedge panels results in formation of a stepped form of the subroofing layer, on which the elements of the low-profile roofing are laid. In the wedge panels, at their higher height side, ventilation ducts are formed, connected with the openings in the decking layer from their internal side. The so-formed ventilation ducts connect the attic interior with the exterior, enabling air exchange. The solution is effective, however it requires a significant number of additional elements, i.e. the wedge panels and sheet metal flashing protecting the air intake at the external side, moreover it upsets the even surface of the roofing.
The proposed solution according to the invention introduces an air outlet that may also function as an air vent and has none of the aforementioned limitations. It may be installed in any location on the roof plane and has no specific requirements as for the shape and structure of the roofing.
The distinguishing feature of the invention consists in an air outlet with construction penetrating the structure of the roof plane. The air outlet has a compact structure with the inlet duct for fresh air is located at the external side of the roofing, while the inlet is located at the internal side of the roofing, i.e. in the attic space. The air outlet may also function as an air vent, depending on its location and the pressure difference between the exterior and the attic. The air outlet is mounted in a pass-through opening in the roof, the opening with the shape and dimensions fitted to the outline of the air outlet. The connection of the air outlet with the roofing is protected from weather conditions by sheet metal flashing, preferably standard roof flashings. An important advantage of the solution consists in its versatility. The air outlet according to the invention may be used with various roofings. Moreover, there are no particular requirements for the sheet metal flashing used.
The air outlet has its external outline basically in the shape of a rectangular prism with protective and mounting elements formed at its exterior, and an air supply duct inside. Dimensions of the outline are defined by its length, width and height. The length is basically the longest dimension of the air outlet, preferably parallel to the tile battens. The length of the air outlet is basically limited by the distance to the neighbouring rafters, however if an explicit need be, construction of the roof framework may be changed in a way enabling installation of an air outlet with a length exceeding the said limitation. The length of the air outlet is not connected with dimensions of the roofing elements, being an advantageous consequence of application of roof flashings according to the standards for installation of roof windows.
Width and height are lateral dimensions of the outline, with width defining the dimension in direction preferably parallel to the rafter in the structure of the roof framework. Generally, the width of the air outlet is not limited, and for typical applications, it preferably fits between two tile battens, allowing for easy installation of the air outlet in the roofing structure, by replacement of a fragment of one layer of the roofing.
Height is defined by dimension perpendicular to length and width, while in the position installed in the roof is basically perpendicular to the surface of the roofing.
A frame fixed to elements of the roof framework is the basic element of the air outlet. In the frame, a single or multiple through air supply duct is made, connecting the inlet duct with the space at the internal side of the window. The inlet duct is a niche, defined by an eave and a channel connected with a roof flashing.
The height of a complete set of the air outlet depends on the roof decking thickness. Considering the diverse roof decking thickness, as well as the method for finishing its internal layer, the air outlet is equipped with an extension duct, with length being selected individually. The extension duct constitutes a continuation of the air supply duct made in the frame of the air outlet. Number and size of the air supply duct holes should be adjusted to the designed volume of the air stream flowing through the air outlet. Considering the mechanical strength, particularly with long frames of the air outlet, it is more preferable to use an air supply duct with a higher number of smaller openings than with one wide opening along the frame of the air outlet.
For adjustment of the volume of the air stream, known solutions applied in windows may be used, e.g. automatic: pressure-controlled, humidity-controlled or other. The simplest and cheapest solution is to use a manually-removable blanking plug, covering the extension duct from the side of the space at the internal side of the window. In special cases, when the roof decking thickness is in the range of height of the air outlet frame, the extension duct may be unnecessary. In such case, the blanking plug is installed directly at the outlet of the air supply duct.
The eave is fixed to the external surface of the frame and when assembled, it is tightly connected with the top flashing, being a fragment of the roof flashing. The bottom edge of the eave protrudes beyond the outline of the frame, covering part of the channel. The distance between the eave and the top edge of the channel determines the size of the clearance of the inlet duct and it should be adjusted to the designed size of the air supply duct. Excessive distance will increase the possibility for water to penetrate the interior in case of heavy rainfall, while too short distance will increase resistance of the air flow.
The shape of the sheet metal flashing of the air outlet depends on the type of the roofing and it is known from many solutions of the sheet metal flashing used for roof windows. A favourable solution consists in such a selection of dimensions of the air outlet which enables using standard roof windows flashings manufactured by one or preferably many manufacturers, leading to a significant reduction of costs of the set. It may be achieved by selection of the air outlet length, positioned in parallel to the tile battens, according to standard width of roof windows available in the market.
General view of the air outlet in the roof structure is shown as isometric drawing in Fig. 1.
The air outlet with its sheet metal flashing is shown as isometric drawing in Fig. 2, while the air outlet without the sheet metal flashing installed on the elements of the roof framework is shown as isometric drawing in Fig. 3.
A cross-section of the air outlet and adjacent roof elements is shown in Fig. 4.
In the proposed embodiment, the air outlet is mounted in a pass-through opening in the roof with tile roofing. A frame 1 fixed to elements of the roof framework is the main element of the air outlet . An exemplary method and place of installation of the air outlet is shown in Fig. 3. In the frame, a through air supply duct 11 is made, connecting the niche located at the external side of the roof, defined by an eave 2 and a channel 3, being a part of the sheet metal flashing of the air outlet, with an extension duct 4. The height of a complete set of the air outlet depends on the roof decking thickness. The height of the air outlet is a dimension preferably parallel to the air supply duct 11, and while assembled in the roof, it is the dimension of the air outlet basically perpendicular to the surface of the roof plane. The extension duct 4 is a continuation of the air supply duct 11 and its outlet hole 41 is located at the external side of the roof plane. The length direction of the extension duct is parallel to the height direction of the air outlet. The length of the extension duct 4 may be adjusted individually to the thickness of the roof decking. For adjustment of the volume of the air stream, e.g. one of the simplest and cheapest solutions may be used, in the form of a manually-removable blanking plug 5, covering the extension duct 4 from the side of the space at the internal side of the window. In case when the roof decking thickness is in the range of height of the air outlet frame 1, the extension duct 4 is unnecessary. In such case, the blanking plug is installed directly at the outlet of the air supply duct 11.
The air outlet has its external outline basically in the shape of a rectangular prism. Dimensions of the outline are defined by its length, width and height. The length is basically the longest dimension of the air outlet, preferably parallel to the tile battens. The length of the air outlet in the proposed embodiment is limited by the distance to the neighbouring rafters and is preferably equal to one of the standard widths of roof windows. Such selection of dimensions allows using the sheet metal flashing in the form of a standard roof flashing 6 used for sealing of connections of a roof window with roof decking.
The width of the air outlet frame 1 fits preferably between the two adjacent tile battens 7, allowing for its easy installation into the structure of a layered roofing, by replacement of a fragment of one layer of the roofing. In the case shown in Fig. 4, when the spacing between the tile battens is significantly larger than the width of the frame 1, an installation batten 8 fixed to the rafters and laid in parallel with the tile battens 7 should be used, preferably made of the same sections as the tile battens 7. The empty spaces between the tile battens may be filled with insulation material in order to improve thermal performance of the connection. The so-connected elements mentioned above form a carrying part of the pass-through opening in the roof. The other fragment of the pass-through opening penetrates basically the external layers 9 of the decking.
The eave 2 is fixed to the external surface of the frame 1 and when assembled, it is tightly connected with the top flashing 61, being an element of the roof flashing 6. The bottom edge 21 of the eave 2 protrudes beyond the outline of the frame 1, covering part of the channel 3. The distance between the eave 2 and the top edge 31 of the channel 3 determines the size of the clearance of the inlet duct 10 and it should be adjusted to the designed volume of the air supply duct 11. The bottom edge 32 of the channel 3 is tight, preferably as a lap joint, connected with the bottom flashing 62, which is an element of the roof flashing 6.
The shape of the roof flashing 6 and the elements included in it, among others the top flashing 61 and the bottom flashing 62, is adjusted to the type of the roofing. A economically favourable solution consist in such a selection of dimensions of the air outlet that enables using standard roof windows flashings manufactured by one or preferably many manufacturers.

Claims

An air outlet, installed in a sloped roof, equipped with an air supply duct connecting the internal space with the exterior above the surface of the roofing, characterised in that the air outlet penetrates the whole roof structure and its construction does not depend on the type of the roofing.
An air outlet according to claim 1, characterised in that it is mounted in a pass-through opening in the roof, the opening with the shape and dimensions fitted to the outline of the air outlet.
An air outlet according to claim 1, characterised in that the inlet duct (10) is located at the external side of the roofing, a outlet hole (41) of the extension duct (4), at the internal side of the roof decking.
A window set according to claim 1, characterised in that it has a roof flashing (6), sealing the connection of the air outlet with the roof decking, with shape chosen accordingly to the type of the roofing elements.
An air outlet according to claim 1, characterised in that the shape and dimensions of the air outlet do not depend on the shape and dimensions of the roof elements.
A window set according to claim 2, characterised in that the air outlet has its external outline basically in the form of a rectangular prism.
An air outlet according to claim 6, characterised in that the width of the air outlet is preferably smaller or equal to the distance between the tile battens (7) of the roof framework structure.
An air outlet according to claim 3, characterised in that it has an air supply duct (11) made in the frame (1), a channel (3), and an eave (2).
An air outlet according to claim 8, characterised in that it has an extension duct (4), being an extension of the air supply duct (11) to the internal side of the roof.
An air outlet according to claims 8 and 4, characterised in that the top edge (31) of the channel (3) is mounted on the frame (1) along the longitudinal edge, and the bottom edge (32) of the channel (3) is connected with the bottom flashing (62).
An air outlet according to claim 8, characterised in that the eave (2) is shaped preferably in parallel to the surface of the roof.
An air outlet according to claim 8, characterised in that the air supply duct (11) constitutes a single or multiple air duct, connecting the inlet duct (10) defined by the eave (2) and the channel (3), with the extension duct (4).
An air outlet according to claims 8 or 9, characterised in that it has a removable blanking plug (5), covering the air supply duct (11) or extension duct (4) at the external side of the roof.
An air outlet according to claims 8 or 9, characterised in that it has a blanking plug with an automatically adjustable clearance, covering the air supply duct (11) or extension duct (4) at the external side of the roof.