Technical field

The present invention relates to the field of architectural membrane panels containing thermal insulation material, intended for covering the facades and roofs of buildings.

Background art

Tensioned architectural membranes are used as outer envelopes in buildings such as airports, storage facilities, arenas and sports halls, and residential buildings (houses and blocks). Architectural membranes provide great design flexibility and freedom in facades, roofings, canopies, domes and other structures.

Typically, the use of architectural membranes is desirable, because the structures based on them are lighter than traditional structures, are easier to assemble and disassemble, and are more resistant to adverse environmental conditions such as earthquakes. Architectural membranes can also be provided with thermal insulation which has an advantageous effect on their thermal properties.

Designing buildings with architectural membranes takes into account criteria defined by local building codes or other applicable regulations, for example, regarding permissible load or wind pressure and speed. Further, the design process can also include the need to take into account principles related to the tensile geometry of the membrane, stress analysis, and the like.

For example, US20090044459A1, known from the prior art, discloses a roof structure, where the membrane is attached to the arch beams and tensioned with steel cables.

US20170107712A1 relates to a mobile home construction system, wherein the roof is made of roof panels (e.g. plywood) placed over the rafters and then covered with one large piece of material, e.g. a continuous PVC membrane that is attached to a tensioning cable around the top ends of the walls. Water resistance is provided by a PVC membrane. Additionally, the roofing may also include a layer of insulating foam.

On the other hand, EP2142718B1 discloses a membrane structure with thermal insulation in the form of an aerogel disposed between two outer layers, on which the beams are laid to support the entire membrane structure. This structure can be used in applications such as building envelopes, roof coverings, canopies, etc.

Various types of thermal insulation panels are also known in the prior art, for example from US9957715B1, EP2667739B1, EP2404003B1.

Architectural membranes can be characterized in terms of their energy performance, durability, acoustic properties, heat transfer (thermal insulation) coefficient and fire protection properties. Such characterization is performed by means of known techniques using industry standards such as, for example, those developed by the International Organization for Standardization (ISO) or the American Society for Testing and Materials (ASTM). For example, light transmission and spectral reflectance can be determined using ASTM E424, and fire resistance according to ASTM E-108 or ASTM E-84.

An important parameter to determine architectural membrane panels is the heat transfer coefficient U (U-value), as it effectively determines the degree of insulation of building envelopes, which degree must be adapted to the realities of today's construction method. Roofs and flat roofs, external walls and floors are made of various materials. Therefore, when designing a building, the heat transfer coefficients U should be calculated for them, taking into account the properties and thicknesses of individual building materials from which they are made.

The heat transfer coefficient U determines how much energy passes through 1 square meter of the envelope (wall, roof, door, window) when the temperature difference between the two sides is 1 Kelvin. The unit of the heat transfer coefficient is W/(m ² -K). The lower the U- value of the envelope, the better its thermal insulation. Details and appropriate values for the calculation of the U-value can be found in the following standards: PN-EN ISO 6946: 2017-10 "Building components and building elements - Thermal resistance and thermal transmittance - Calculation methods." and PN-EN ISO 13370:2017-09 "Thermal Performance of Buildings - Heat Transfer via the Ground - Calculation Methods".

With increasing demand for energy-saving and environmentally safe building materials and practices, there is still a need for lightweight architectural membranes that allow flexibility in design, have a wide range of applications, while providing good thermal insulation, and are easy to install and suitably light.

Summary of the invention

The invention relates to multi-layer membrane panels, tensioned on frames, which panels provide thermal insulation by filling with thermal insulation.

The objective of the invention is an architectural membrane panel having a membrane, a support frame and a thermal insulation material, wherein the support frame is formed as a flat or spatial structure based on a polygon, the membrane being tensioned on the support frame, and wherein the thermal insulation material is located between the support frame and the membrane, said thermal insulation fills at least the space inside the support frame, said space being defined by the structural components of this support frame.

In a preferred embodiment, a tensioning section extending above the plane of the support frame is attached to the support frame, wherein the membrane is tensioned on said support frame and said tensioning section.

In another embodiment, in the presence of a tensioning section, the thermal insulation material additionally fills a portion of the space between the support frame and the membrane tensioned on said support frame and said tensioning section.

Alternatively, in the presence of a tensioning section, the thermal insulation material fills the entire space between the support frame and the membrane tensioned on said support frame and said tensioning section.

In one embodiment, the support frame is tightly closed from its underside, preferably by a vapour-barrier membrane, so that the thermal insulation material is located between said vapour-barrier membrane and said membrane. Preferably, the support frame consists of metal sections in the form of channel sections connected to each other.

In yet another embodiment, the metal sections in the form of channel sections are arranged so that their parallel upper walls and lower walls point with their free edges towards the outside of the support frame, and the connecting walls extending transversely thereto are closer to the enclosed space inside the support frame.

In one embodiment, the membrane is attached to the connecting walls of the support frame.

In one embodiment, the support frame is provided with mounting means for mounting the membrane panel to the support structure.

In one embodiment, the thermal insulation material is selected from materials such as mineral wool, PIR foams, extruded polystyrene, expanded polystyrene, and aerogels.

In one embodiment, the support frame is made of aluminium or steel.

In one embodiment, the tensioning section is made of aluminium or steel.

In one embodiment, the support frame has a quadrilateral shape.

In one embodiment, the support frame has a square shape.

The subject matter of the invention is also a system of at least two connected membrane panels as defined above, wherein at the joints between the membrane panels there are fillings of thermal insulation material to reduce thermal bridges.

Advantageous effects of the invention

The prefabricated membrane structure according to the invention makes use of the advantages of the known membrane envelopes while at the same time eliminating the existing disadvantages of the membrane building envelopes. The membrane panels, due to their modular nature, meet the market needs and allow to reduce the costs of panel installation at the construction site, as well as provide high flexibility in construction and allow for the creation of a variety of even relatively complex structures. Prefabrication and modularity of membrane systems enable pre-assembly to be performed in the hall and allow for immediate production quality control in stable conditions. Panels can be custom made in a variety of shapes and also sold as pre-assembled modules. It is a much more convenient, safer and cheaper solution compared to the traditional assembly of large-space membranes at the construction site. The panels according to the invention have further a low selfweight, which translates into additional ease of their installation and increased application possibilities. Moreover, importantly, the panels according to the invention, by filling the space under the membranes tensioned on the sections with a material with increased thermal insulation, ensure high thermal insulation of the building envelope. This translates into the possibility of their wide use in general construction, high energy efficiency and lower operating costs. In addition, the developed panels are distinguished by special aesthetics due to the membrane curvatures, which translates into a change in the appearance and character of modern cities.

Brief description of Drawings

The present disclosure will be now explained in more detail in preferred embodiments with reference to the accompanying drawings, wherein:

Fig. 1 shows a view of a single membrane panel;

Fig. 2a shows a frame for tensioning an architectural membrane;

Fig. 2b shows the cross section through a frame made of channel sections in the plane A-A;

Fig. 3a shows a view of a combined assembly of the support frame and the tensioned membrane filled with a thermal insulation material;

Fig. 3b shows the cross section through the combined assembly of the support frame and the tensioned membrane, filled with a thermal insulation material;

Fig. 4a-4c show the cross sections through the membrane panel, wherein the thermal insulation material fills the space inside the support frame, in the planes B-B, C-C, and D-D, respectively;

Fig. 5a-5c show cross sections through the membrane panel, wherein the thermal insulation material fills the space between the bottom of the support frame and a certain level above the upper edge of the frame, limited by the membrane stretched on the tensioning section, in the planes B-B, C-C, and D-D, respectively; Fig. 6a-6c show the cross sections through the membrane panel, wherein the thermal insulation material fills entirely the space between the support frame and the membrane stretched on the tensioning section, in the planes B-B, C-C and D-D, respectively;

Fig. 7a shows several interconnected membrane panels with fillings that eliminate thermal bridges at the joints of individual panels;

Fig. 7b shows, marked as E-E in Fig. 7a, the cross-section through interconnected panels with visible joining;

Fig. 8a, 8b present examples of how panels can be placed on a building envelope.

Detailed description of preferred embodiments

Membrane panels according to the invention are modular which means that they can be combined in different combinations. The modular nature of the panels provides a high degree of flexibility and allows for the creation of more complex structures than can be achieved with the use of the technology of tensioned large-space membranes.

A single architectural membrane panel 1, according to the invention, in its finished state, is shown in the outside view in Fig. 1. The cross section planes B-B, C-C and D-D, to which references are given in the Figures referred to below, are indicated in Fig. 1.

The shape of the panel 1 membrane is designed parametrically using dedicated computer applications. The individual strips of material (gores 2) of the membrane 3 are prepared and joined together by welding. The joined gores 2, forming the membrane 3, are tensioned on the support frame 4. The support frame 4 is shown in Fig. 2a, which shows a view of a single panel 1 without the membrane 3, wherein the cross section plane A-A is indicated in this Fig. 2a. The support frame 4 is made of a material of suitable strength, for example aluminium or steel. In the embodiment, the support frame 4 is formed in a square shape. The tensioned membrane 3 is attached to this frame in any known manner - for example by mechanical fastening. The shape and arrangement of the frame 4 is designed and calculated so that this support frame 4 is able to transfer stresses resulting from the tensioning of the membrane 3 without deforming the structure of the panel 1. The support frame 4 in the embodiment is in the form of a channel section, as shown in Fig. 2b, and is formed by the upper wall 4a, the lower wall 4b, and the connecting wall 4c, i.e. the web. On the underside of the support frame 4, in the embodiment in the lower wall 4b, mounting holes 5 are formed to attach the panel 1 to a support structure, for example a wall or a carcass structure.

The mounting holes 5 in the embodiment are arranged symmetrically with respect to the centre of a given side of the square support frame 4 (in the lower wall 4b). A tensioning section 6 is guided through the middle of the panel 1, from one side to the opposite side. The tensioning section 6 is attached to the frame 4, essentially to the two opposite sides of the polygon forming the frame 4. In the embodiment of Fig. 2a, the tensioning section 6 is attached to the opposite connecting walls 4c of the square frame 4 (in their middle part) and has the form of a convex arch rising upwards above the plane of the support frame 4. The tensioning section 6 is made of a material with suitable stiffness and strength, for example stainless steel. The arc of the tensioning section 6 determines the maximum volume of the space inside the panel 1.

The combined assembly of the support frame 4 and the tensioned membrane 3 is filled with a material with high thermal insulation, as shown in the view in Fig. 3a and in the plane A-A in Fig. 3b. In the embodiment, the entire assembly is tightly closed from the underside, for example by a vapour-barrier membrane 7 extending between all sides of the support frame 4. The thermal insulation material 8 fills the space between all sides of support frame 4. The thermal insulation material 8 may fill the space between the vapour-barrier membrane 7 and the membrane 3 stretched over the tensioning section 6 partially or entirely, depending on the thermal conductivity coefficient [W/mK] of the material used.

The membrane panel 1 is designed to function as an energy-efficient building envelope with a heat transfer coefficient U (determining thermal insulation) up to 0.20 W/m ² K. This condition can be met by the use of materials with different thermal conductivity coefficients A.. Different heat transfer coefficients can be achieved either by selecting materials with different thermal conductivity coefficients and by varying the thickness of the thermal insulation material 8 used, as shown in Fig. 4a-4c, Fig. 5a-5c, Fig. 6a-6c. Fig. 4a, 5a, and 6a show the cross sections in the plane B-B, Fig. 4b, 5b, and 6b - in the plane C-C, and Fig. 4c, 5c, and 6c - in the plane D-D, wherein the position of the membrane 3 in a given cross section is shown with bold line in each case. In Fig. 4a-4c, the thermal insulation material, for example with thermal conductivity coefficient X = 0.20 W/mK, is arranged over the entire thickness of the support frame 4 (that is, between its bottom edge and top edge). In other words, it basically fills the entire space defined by the polygonal, in this case square, support frame 4. In Fig. 5a-5c, the thermal insulation material 8, for example, with thermal conductivity coefficient A. = 0.24 W/mK, protrudes above the upper edge of the support frame 4 - filling the space inside the support frame 4 and a portion of the space between the upper edge of the support frame 4 and the membrane 3. With reference to the embodiment, it protrudes above the upper wall 4a and is partially in contact with a portion of the membrane 3. In turn, in Fig. 6a-6c, the thermal insulation material 8, for example, with thermal conductivity coefficient X = 0.32 W/mK, fills the entire space between the membrane 3 and the support frame 4 - at the thickest point it reaches the highest point of the arc of the tensioning section 6. In other words, in the embodiment the thermal insulation material 8 fills the entire space between the vapour-barrier membrane 7 and the membrane 3.

The flexibility of the thermal insulation material 8 used extends the functionality of the invention, for example, by allowing light panels to be installed in the space between this thermal insulation material 8 and the membrane 3. The thermal insulation material 8 can be selected from materials such as mineral wool, PIR foams, extruded polystyrene, expanded polystyrene, and aerogels (or other materials with suitable thermal characteristics).

When the panels 1 are joined into an envelope on a given support structure, heat bridges are formed at the joints 9 of individual panels 1. The heat transfer coefficient U of up to 0.20 W/m2K is assumed for the entire envelope made up of panels 1, which is achievable by the use of fillings 10 that eliminate thermal bridges at the joints 9 of the individual panels 1. A view of a few connected panels is shown in Fig. 7a, while the cross section at the joint E-E is shown in Fig. 7b.

Fig. 8a and 8b show exemplary possibilities of arranging and connecting panels on a building envelope - in Fig. 8a panels 1 are arranged evenly so that one side of the panel 1 contacts over the entire length the side of the adjacent panel 1, and in Fig. 8b the adjacent panels 1 are shifted with respect to each other by half a side.

The embodiment described above is not limiting. For example, the support frame 4 can be a triangle, rectangle, pentagon, hexagon, etc. The support frame 4 can also be spatial one, e.g. formed as the outer edges of a hyperbolic paraboloid. The tensioning section 6 may be attached to the sides of the frame not necessarily at their centre of the frame, but may be also placed closer to one end of a given side, or even in a corner of a polygon, and may also have a different shape from that of an arc. Further, the panel 1 can be devoid of the tensioning section 6 and the membrane 3 in this case spans only on the structural components of the flat or spatial support frame 4.

It is possible to make membrane panels in various sizes, i.e. differing in length, thickness and shape of the sections of the support frame 4.

Further, the membrane panel 1 can, in the support frame 4, comprise a mounting flat bar (not shown) attached to the connecting walls 4c of the channel sections that make up the support frame 4, for mounting the membrane 3. The mounting flat bar is made of aluminium or steel and may have mounting holes for mounting the membrane 3, in which the membrane 3 engages in any known way, but the membrane 3 can be attached to it in any other way, for example by gluing. It is possible to make the panel without the mounting flat bar, e.g. using a frame with the shape of the outer edges of a hyperbolic paraboloid.

Further, the support frame 4 can be made of sections with a different shape than the channel section, as long as it fulfils its function, i.e. it is sufficiently rigid and allows the membrane 3 to be mechanically tensioned and the panel 1 to be attached to the support structure.

In addition, the membrane 3 can be manufactured as a whole and be a single piece, i.e. be not composed of joined pieces of material (gores 2).

In conclusion, thermal insulation of membrane systems (their energy efficiency) is achieved by filling the space under the membranes 3 tensioned on the (aluminium or steel) frames 4 with a thermal insulation material 8 with enhanced thermal insulation. This translates into the possibility of a wide range of applications of the developed architectural membrane panels in general construction, energy efficiency and reduced manufacturing, assembly and operating costs.