WO1999063280A1

WO1999063280A1 - Solar energy collector roofing for buildings

Info

Publication number: WO1999063280A1
Application number: PCT/ES1998/000160
Authority: WO
Inventors: Eduardo Oistrach Garcia De Castro; Josep Garcia Cors
Original assignee: Biohabitat Sxxi, S.L.
Priority date: 1998-06-03
Filing date: 1998-06-03
Publication date: 1999-12-09

Abstract

Solar energy collecting roofing for buildings, comprising a roof substituting element which absorbs solar radiation, incorporating channels through which a heat-conveying fluid can circulate; a thermo-insulating material layer is applied to said channel; the roofing is comprised of a plurality of impervious panels (1) which are assembled at least along their edges so as to form impervious junctions; the panels (1) comprise on their external face a thermo-conducting board (2) and, on their internal face, back-to-back tubular sections (4) forming said channels; the board (2) and the sections (4) are in contact with the insulating layer (5); the panels (1) extend between a distributor conduit (6) and the collector conduit (7), in transversal relationship with respect to the tubular sections (4) and arranged adjacent to and communicating with the tubular conduits (4); said tubular sections (4) and conduits (6, 7) have a cross-section and configuration such that they provide for a predetermined resistance which is sufficient to support, totally or to a large extent, the calculated load of the roofing, thereby acting as rigidification and supporting elements for the roofing.

Description

SOLAR ENERGY CATCH BUILDING COVER Technical field

The present invention concerns a roof for solar energy collector buildings, especially a roof for buildings of the self-sustaining structural type, capable of replacing a conventional roof at a similar cost, which also fulfills the function of solar energy collector.

The applications of this invention are varied within the scope of thermal installations used in various types of buildings. In the domestic sphere, it is worth highlighting the obtaining of sanitary hot water, underfloor heating, hot air heating, air conditioning by absorption machine, and swimming pool air conditioning. In the agricultural sector it has application, for example, for crop dryers and heating of stables, and in the industrial sector as a contribution to thermal processes of low caloric intensity.

In densely populated countries with a high standard of living, energy consumption per capita is very high, with the general tendency to increase. In this context, there is a deep interest in minimizing the cost of obtaining energy, reducing the environmental pollution involved, obtaining and consuming such energy, and avoiding, or at least delaying, the depletion of some energy sources Non-renewable. Therefore, the use of solar energy makes full sense as a complement to the usual sources of energy production that start from non-renewable sources.

Although at present the technology that allows the direct transformation of solar energy into electrical energy is extremely expensive, being reserved for very specific applications, there is the possibility of thermal use of solar energy at a very low cost. Therefore, although much of the energy consumed in developed countries is in the form of electrical energy, it is widely applicable, especially in the domestic sphere, of solar thermal energy for water heating and for heating. It would be desirable, therefore, to have a solar energy collection system, individual for each building, sufficient to supply it with hot water and heating, at least during periods of heat stroke. Given the renewable, unlimited nature of solar energy, the intrinsic efficiency of the collection system is not as important as the possibility of its massive implementation, on which the present invention is essentially based. Indeed, even if the amount of solar energy collected individually by each building represents a comparatively small amount compared to global consumption, it would have an immediate large-scale impact if it could be applied massively.

As a consequence, the lower use of conventional energy resources would, as a whole, result in economic savings given the virtually unlimited nature of solar energy, a decrease in the consumption of non-renewable raw materials that could be reserved for other more convenient uses, and Less pollution of the environment since the collection and use of solar energy does not lead to the generation of any type of waste. In order for the massive implementation of a roof system for buildings to capture solar energy to be viable, it is required, as an essential point, that it does not have an increase in production and installation costs. This implies the use of materials, techniques and procedures assimilated and commonly used by the construction industry. Background of the invention

The contributions made in the field of architecture for the capture of solar energy with active systems, are mainly based on the technology of the "solar panels". These panels are autonomous and independent elements that have developed their technology, first in the field of practical experimentation and later in the field of engineering and therefore, and until recently, apart from the construction processes of architecture. The result is that solar panels have their application as external elements that must be incorporated, duly oriented, to an existing roof, which entails an additional easement, in the building.

To solve this problem of integration of solar panels, very different solutions have been applied whose conception has always meant traveling the path that goes from the pickup device to the element integrated in the building. This line of development always entails the integration of an additional element, which implies both an additional cost and a difficulty for its integration, constructive and visual, to the whole building.

This makes the installation of solar collectors on the roofs of the buildings outside the conventional construction system, remaining as a particular option with an additional cost. Thus, the main drawbacks for existing systems to have a massive implementation are:

- an additional cost over the cost of a conventional cover

- need to integrate an unusual exterior appearance to a conventional building

- the absence of a production and installation procedure integrated into the construction industry

Numerous antecedents of solar energy collection devices from a building deck are known in the prior art. Indeed, EP-0 073 843-Al describes a system of plates, equipped with elements for the accumulation of solar energy, which can be extended over a conventional roof. This is an example of a device whose cost is added to that of the conventional cover, and therefore does not constitute an alternative to it.

For its part, in EP-0 270 910-B1 a self-supporting sunroof replacing the roof of buildings is described, which does not require the placement of beams for its support. However, said cover is by no means a conventional cover, since it has, on its upper face, a series of reflective and collector surfaces that form a complex frame of compartments and collapsed in order to optimize the radiation uptake solar, at the bottom of which channels are located, of reduced passage, through which a heat transfer fluid (liquid or gas) circulates.

The orientation of said reflecting and capturing surfaces must be calculated and performed precisely according to the specific location and orientation of each building.

Due to its special configuration, said cover does not have a surface that is sufficiently regular, or strong enough to withstand the weight of a person who climbs on it, for example, for its revision or repair.

On the other hand, the existence of compartments and folded in the face The upper part of said roof makes it very prone to the formation of dust and earth deposits, which can be consolidated by the growth of plants, increasing the weight on the structural elements of the plant and blocking the rainwater evacuation steps. These compartments are also very inconvenient in case of wind or snow.

In addition, the aforementioned roof offers an external appearance very different from that of conventional roofs, which requires additional design work to achieve harmonization and architectural integration of the roof with the rest of the building. Finally, the complexity in the structure and configuration of the sun-exposed part of said roof and the special conditions of its assembly make its cost significantly higher than that of a conventional metal roof, and therefore, hardly its manufacture and installation they can reach the levels of massive implementation within the construction industry required to achieve the purposes of collective energy saving and pollution reduction pursued by the present invention, remaining as a particular option of an owner at the expense of an increase in the costs Brief exposition of the invention

For all the foregoing, an objective of the present invention is to provide a roof for buildings that, in addition to fulfilling the usual functions of structural element, thermal and waterproof insulation, is a solar energy collector, with production and installation costs equivalent to the costs of conventional roofs and with production and installation methods comparable to those currently used for such conventional roofs, to allow their massive implementation within the construction industry, both in new buildings and in renovations of old buildings.

Another objective of the invention is to provide a building roof system with solar energy collection that does not require particular orientation of each of its elements but that it is sufficient to take care of the general orientation of the entire roof, basing its effectiveness more on the exposure of the maximum possible solar radiation sensor surface than in the intrinsic efficiency of each of the catchment elements

Another object of the invention is to provide a building roof system with solar energy collection that is practicable, that is, that allows and supports a person's access to its surface for, for example, inspection or repair.

Another objective of the invention is to provide a roof system for building with solar energy collection that has a clear upper surface and without impediments to water evacuation.

A final objective of the invention is to provide a roof system for building with solar energy collection with an external appearance analogous to that of a conventional metal roof, whose implementation does not entail an additional need for harmonization with the usual construction elements, achieving a total architectural integration of it.

These objectives are achieved, according to the invention, by a system of roof panels for buildings which are solar energy collectors and that include conduits for a heat transfer fluid which in turn constitute structural stiffening elements sufficient for self-sustaining. of said cover, in such a way that the entire surface area of the cover, capable of receiving solar radiation, constitutes a single solar thermal energy collector, said cover being able to be both flat and inclined.

In a preferred embodiment, each of said panels is formed by a single plate of heat-conductive material, with the outer surface dark colored, folded in such a way that it forms longitudinal grooves open at its bottom, within each of which a tubular profile, also of a good heat conducting material, is embedded in pressure for the conduction of the heat transfer fluid. Said plate, including the tubular profiles embedded in its grooves, is covered on its underside with a thick layer of thermally insulating material, which simultaneously fulfills the functions of preventing thermal losses in the heat transfer fluid through the tubular profiles and conventional thermal insulation of the building. Said panels, which can be manufactured on site or prefabricated, include on their sides means to fit together in order to form large surface covers. As it is a collector without a glass cover, it is evident that its energy losses will be greater, although its performance will not be much lower than that of a conventional closed collector, provided that it works at moderate fluid temperatures (up to 45 ° C) . However, this unfavorable factor is compensated by the fact that it has a large catchment area, provided by the optimal use of the entire available area of the building's roof surface.

In summary, the essential properties offered by the roof system for solar energy collector buildings object of the present invention are: it constitutes an integral part of the building, not representing a set of elements added to an already covered building is a self-sustaining roof system , with built-in stiffening elements, which in addition to fulfilling the conventional functions as a waterproofing and thermal insulating element, performs the additional function of capturing solar energy, has a clear upper surface and without impediments to the evacuation of water, its external appearance does not differ substantially from of conventional metal roofs does not necessarily imply an increase in manufacturing and installation costs since; Each element fulfills its own functions of the solar energy collection device in addition to the conventional functions; and each element is capable of being produced and installed in accordance with current conventional techniques in the sector, so that said cover is capable of being immediately integrated into the usual procedures of the construction industry for its massive implementation Brief description of the drawings

The invention is explained in more detail below by means of a specific example of embodiment that is represented in the accompanying drawings, which are provided for illustrative purposes only, without being limited in any case. In these drawings: Fig. 1 is a partial sectional view of a panel according to a preferred embodiment of a cover system according to the present invention, with its separate components.

Fig. 2 shows a complete sectional view of the panel of Fig. 1 with all its components assembled, including an enlarged view of "a detail of the assembly.

Fig. 3 shows an elevation view of several panels such as that of Fig. 1 assembled together by their sides, including an enlarged view of a detail of the assembly. Fig. 4 is a partial elevational view of a cover according to a preferred embodiment of the system of the present invention, in which its main elements are shown.

Fig. 5 is a complete elevational view of the cover of Fig. 4, (in this example, on two sides), showing the elements of the thermal transfer system.

Fig. 6 is a top plan view of the roof of Fig. 5, in which one of the formative panels thereof is shown for each slope.

Fig. 7 is an enlarged elevational view of a detail of the cover of Fig. 5, showing the ridge thereof and the elements of the thermal transfer system.

Fig. 8 is a plan view showing the elements of the thermal transfer system in a cover according to the present invention.

Fig. 9 is an elevation view of a variant in the embodiment of a panel of a cover according to the present invention. Fig. 10 is an enlarged view in detail of the side assembly between two panels like those in Fig. 9.

Fig. 11 is an elevation view of another variant in the embodiment of a panel of a cover according to the present invention.

Fig. 12 is an enlarged view in detail of the side assembly between two panels like those in Fig. 11.

Finally, Fig. 13 shows the two-panel assembly according to the example of embodiment of Fig. 9, useful for length slopes extraordinarily long.

Detailed description of the preferred embodiments

The system according to the invention consists of three essential elements (see Figs. 4 to 6): a roof itself, solar energy collector, formed by one or more panels 1, partially or fully self-sustaining, joined together and carriers multi-conduit 4 for a heat transfer fluid A; a distributor element 6 of said heat transfer fluid A to the multiple conduits 4 of the panels 1 and support of the lower end of the cover; and a collecting element 7 of the fluid A of the multiple ducts 4 of the panels 1 and support of the upper end of the cover. The conduits 4, which also perform the structural function of supporting the roof, rest at their closed ends on the distributor and collector ducts 6 and communicate with them through perforations made in each other and by some connection sleeves 9 connected to the plug and provided with elastic seals 21. Said distributor ducts 6 and manifold 7 are covered by a layer 25 of thermal insulating material.

With this arrangement, a circuit is obtained in which the heated heat transfer fluid A, enters a temperature T, in the distributor element 6, where it is distributed through the different conduits 4 of the panels 1 solar radiation collectors 1, where it is heated , then passing to the collecting element 7, from which it exits at a temperature T ₂ higher than T ,, suitable for thermal use.

The cover is completed with a gutter 11, rainwater collector, located at one of the lower edges of the roof, which is extended by its back by an inverted groove 20 that hugs the distributor conduit 6, which acts as stiffening and leveling element of said gutter 11 and with a plate 12 with folds 13 that is fixedly covering the ends of the panels 1 supported on the collecting duct 7, constituting the ridge 14 of said cover.

In Figs. 1 and 2, there is shown a panel 1 formed by an outside plate 2, of a thermoconductive material, which has parallel grooves 3, with its openings directed towards the inside of panel 1, in each of which a housing is arranged tubular profile 4. Covering the underside of said plate 2, with said tubular profiles 4 housed, there is a layer 5 of a thermal insulating material. For those cases in which said panel must be visible from the bottom, an iron or finishing sheet 18 is optionally included below said layer 5. In order to achieve a quick oppression coupling, and to guarantee a intimate contact between the collector plate 2 - and the tubular profiles 4, the grooves 3 have a substantially rectangular cross-section with its slightly narrowed mouth (see Fig. 1) suitable for housing and retaining a corresponding tubular profile 4 of rectangular section, the depth of the corresponding groove with the greater side of said rectangular section.

Said panels 1 are assembled laterally between them to form a cover of greater extension. To do this (see Fig. 3), each plate 2 that forms the outer face of a panel 1 has, in the vicinity of a first assembly side, one of said grooves 3 integrating a tubular profile 4 and, protruding from the other overhang. lateral, an open groove 8, of greater amplitude, susceptible to fit on a groove 3 of another panel corresponding to said first lateral.

In order to enable the entire useful surface of the cover to be protected by the insulating layer 5, said insulating material layer 5 covers the entire inner face of the panel 1 except the ends of the tubular profiles 4 that support the distributor ducts 6 and manifold 7, as well as freeing the area of the open groove 8 protruding in cantilever, lateral.

The outer plate 2 fulfills the function of waterproofing the building and solar collection. The material used for its construction is chosen from the group consisting of stainless steel, galvanized or lacquered steel, copper, aluminum or any non-metallic material that had the characteristic of being a thermal conductor, of which they are usually used in the construction of roofs. The outer surface is dark, preferably black.

The tubular profile 4 performs a double function; on the one hand it constitutes a structural stiffening element, totally or partially self-sustaining, and on the other hand it forms a conduit for the heat transfer fluid A. The material of the profile 4 must be in accordance with the material chosen for the cover, in order to avoid the formation of galvanic pairs causing corrosion problems.

The function of the insulation layer 5 is to thermally insulate the external collector plate 2 and the tubular profiles 4 coupled therein, avoiding losses of heat energy in the sensor system, while performing the usual function of thermal and acoustic insulation of the building. The material of the insulating layer 5 is chosen from the group consisting of blanket of glass wool, rock wool, polyurethane foam, or any other of similar characteristics.

The fluid A used as a heat carrier is chosen from the group consisting of water from the network, deionized water or treated with corrosion and / or antifreeze inhibitors, thermal oil, air or any other fluid appropriate to the specific application in question . The nature of said fluid A will determine the dimensions and materials characteristic of the structural tubular profiles 4 and the conditions for its maintenance.

The materials used for the elements distributor 6, manifold 7, gutter 11 and ridge 14 are analogous to those used for the panels, taking care of the compatibility between them at the time of selection to avoid problems due to the aforementioned galvanic pairs.

It may happen that in some parts of a roof, because of its orientation or due to the presence of permanent shadows, solar radiation does not affect at any time. For these cases the use of the same elements described above is foreseen but without the inclusion of those specific parts whose sole function is to collaborate in the capture of solar energy.

In addition to the aforementioned constituent elements of the roof, a series of auctions and special accessory connecting parts are provided for use according to the usual technique of installing metal roofs.

For all those applications that require a dosage of the heat energy obtained by the system, or in which the fluid B destined for consumption is not the same heat transfer fluid A flowing through the cover circuit or primary circuit, the use is foreseen of a heat exchange system between said primary circuit and one or more secondary or consumer distribution circuits, through which a fluid B circulates. A closed primary circuit will then be established comprising the following elements; distributor 6; channels 4; collector 7; one or more heat exchangers 17; and its connection with the distributor 6.

The heat exchange system, located in a sector 15 of said primary circuit (see Figs. 5, 7 and 8), is constituted by one or more reservoirs 16 of accumulation of fluid A heated in the panels 1 of the cover by the solar energy. Said tanks 16 have inside one or more heat exchange devices, in this example of embodiment coils 17. The accumulation tanks 16 can both be airtight and pressurized (in which case they will be provided with an expansion vessel and a valve overpressure as auxiliary safety elements), or open at atmospheric pressure, but always properly thermally insulated by a layer 19 of insulating material to minimize heat losses.

The illustrated example corresponds to a typical case of a multi-dwelling community building, in which the collector roof feeds a set of tanks 16 of the primary circuit. Each dwelling has a secondary circuit with a heat exchanger 17 located within one of the community tanks 16, so that a system with a single primary circuit is established through which the heat transfer fluid A and several independent secondary circuits circulate through those that circulate the fluid B destined to the consumption of each house.

In Figs. 9 and 11 show two examples of embodiment of the panels 1 in which the ducts 4 are adhered by the inner face of the plate 2, together with the insulator 5, said panel 1 showing an upper surface devoid of grooves, except together to its lateral edges, where there are grooves 23.

In Figs. 10 and 12 show in detail the side assembly systems of panels 1 of the examples in Figs. 9 and 11 respectively. In said details it is seen that said grooves 23 are next two to two when the panels 1 are laterally attached, forming ridges susceptible to receiving, fixed to pressure, sealing gaskets 24 of the joint.

In Fig. 13 an example of a two-panel assembly is shown as in Fig. 9, for a case of a roof with an extraordinarily long slope, where the respective profiles 4 are connected to the plug, with the profile 4a of the upper panel the one introduced in the profile 4b of the lower panel Ib, and with extensions 26 of the plate 2a of the upper panel overlapping the plate 2b of the lower panel Ib, the covers 24 (not shown in said Fig. 13) must be placed so that the cover corresponding to the upper panel overlaps the corresponding cover to the lower panel Ib. Finally, and for a better understanding of the implementation of the invention, a brief description of a possible assembly process is made. For this implementation, it is based on a finished floor, and an example of embodiment is assumed in which the panels are prefabricated at the factory and assembled and assembled on site. The assembly process (see Figs. 4 and 7) is as follows; first the tanks 16 are placed and then the collecting element 7 is placed, which can have its own feet or be supported on the tanks 16 themselves or on a structure made in situ; the distributor element 6 is then placed, which draws a regular line over the boundary of the floor; the gutter 11 is then placed with the fold 20 embracing said distributor 6; then the self-supporting panels 1 are placed with the corresponding tubular profiles 4 supported by the lower part in the distributor 6 and the upper part in the manifold 7, and connected therewith by means of the sleeves 9 provided with elastic joints 21; afterwards the exchange coils 17 and the corresponding pipes are placed; and finally the ridge piece 14 is placed centered by the folds 13.

The industrial application of the invention follows sufficiently from the above.

Describing sufficiently the nature of the invention, as well as the way of putting it into practice, it should be noted that the above-mentioned provisions are subject to modifications in detail as long as their essential principles are not altered.

For the subsequent effects, the claims that follow are declared novelty and property for the authors.

Claims

1.- Cover for solar energy collector buildings of the type comprising a solar radiation absorbing element replacing the roof which integrates a plurality of channels through which a heat transfer fluid circulates, below whose surface a layer of material is applied thermal insulator characterized in that said cover is constituted by a plurality of waterproof panels (1) assembled at least by its sides establishing waterproof joints, whose panels (1) integrate in its outer face a plate (2) in thermoconductive material and by its face inside they have fixed, attached in intimate contact, a plurality of tubular profiles (4) constituting the said channels, said plate (2) and profiles (4) being in contact with said inner insulating layer (5), whose panels (1) ) extend between a distributor duct (6) and a collector duct (7), both transverse to the series of tubular profiles (4) and arranged adjacent to and communicated with the ends of said tubular ducts (4), and because said tubular profiles (4) and ducts (6, 7) have a cross section and configuration such that they provide a resistance intended to support, totally or in large part, the load calculation of the roof, acting as elements of stiffening and support of the roof.

2. Cover, according to claim 1, characterized in that said distributor (6) and manifold (7) ducts are covered by a layer (25) of thermal insulating material.

3. Cover, according to claim 2, characterized in that said plate (2) has parallel grooves (3), with their openings directed towards the inside of the panel (1) in each of which a tubular profile is disposed (4) constituting one of the aforementioned channels.

4. Cover, according to claim 2, characterized in that said tubular profiles (4) are arranged attached to the inner face of the plate (2) together with the layer (5) of insulating material.

5. Cover, according to claim 2, characterized in that the panels further include, below said layer of thermal insulating material, an iron or finishing sheet (18).

6. Cover according to claim 3, characterized in that said grooves (3) have a substantially rectangular cross-section with its slightly narrowed mouth suitable for housing and retaining a corresponding tubular profile (4) of rectangular section, the depth of the corresponding groove being with the greater side of said rectangular section.

7. Cover according to claim 3, characterized in that each plate

(2) that forms the outer face of a panel (1) has, in the vicinity of a first assembly side, one of said grooves (3) integrating a tubular profile (4) and, protruding in cantilever from the other side, a open groove (8) and larger, extended by a flap (22), said open groove (8) being able to fit on a groove (3) of another panel (1), corresponding to said first side.

8. Cover, according to claim 7, characterized in that the layer of insulating material (5) covers the entire inner face of the panel (1) except the ends of the tubular profiles (4) that rest on the distributor ducts (6) and collector (7), as well as freeing the area of the open groove (8) protruding in cantilever, lateral.

9. Cover, according to claim 4, characterized in that said plate (2) has, along with the lateral edges of its outer face, grooves (23) which are approximately two to two when the panels (1) are laterally attached, forming flanges capable of receiving, fixed to pressure, some covers (24) for waterproofing the joint.

10. Cover, according to claim 2, characterized in that means are provided for the assembly at the front of two or more panels in which each of the profiles (4a) of the upper panel (la) is capable of being connected tightly with each of the profiles (4b) of the lower panel (Ib), and with extensions (26) of the lower portion of the plate (2a) of the upper panel (la) capable of overlapping the upper portion of the plate (2b ) of the lower panel (Ib).

11. Cover, according to claim 2, characterized in that the tubular profiles (4) rest at their closed ends on the distributor (6) and manifold (7) conduits and communicate with them through perforations made in each other and by connecting sleeves (9) provided with elastic seals (21).

12. Cover according to claim 2, characterized in that a rainwater collector gutter (11), located at one of the edges of the cover, is extended at its rear by an inverted groove (20) that hugs the conduit distributor (6), which acts as a stiffening element and leveling of said gutter (11).

13. Cover, according to claim 12, characterized in that the outer vertical branch of said groove (20) of the gutter (11) is covered by an extension (27) of the plate (2) of the panel (1).

14. Cover according to claim 12, characterized in that an iron (12) with folds (13) is fixed overlapped with a waterproof joint covering the ends of the panels (1) resting on the collecting duct (7), constituting the ridge (14) of said cover.

15- Cover, according to claim 2, characterized in that the set of distributor ducts (6), channels (4) of the different assembled panels (1) and collecting duct (7) form part of an open circuit in which a fluid ( A) at a temperature T, it circulates so that it enters the distributor duct (6) and exits through the collecting duct (7) at a higher temperature T ₂ , from where it is sent to a service point.

16. Cover according to claim 2, characterized in that the set of distributor ducts (6), channels (4) of the different assembled panels (1) and collector duct (7) are part of a closed circuit in which a fluid (A) heat carrier circulates so that the heated fluid leaves the collecting duct (7) to pass to a heat exchange sector (15) for energy use and returns cooled to the distributor duct (6).

17. Cover, according to claim 16, characterized in that said heat exchange sector (15) for use of energy comprises at least one tank (16), covered with a layer (19) of insulating material, fluid accumulator (A ) that circulates through the cover or primary circuit, within which at least one tank (16) access one or more sections (17) of accumulation and thermal exchange of corresponding secondary circuits, for a fluid (B), which They extend to various parts of the building.

18. Cover, according to claim 17, characterized in that said less a tank (16) partially or totally supports the collecting duct (7).

19. Cover, according to claim 2, characterized in that said panels extend between a distributor duct (6) located next to the eave edge and a collector duct (7) located next to the ridge edge of the building, at different levels .

20. Building such as a dwelling, industrial or agricultural building or sports hall characterized by integrating a roof according to one of claims 1 to 19.

21. Building according to claim 20, characterized in that said roof has one or more slopes, each of which is obtained from a series of panels (1), assembled, comprising at least one distributor conduit (6) and one conduit collector (7) that delimit each slope.