CH714367A2 - Thermal insulation for a building wall and building wall with such thermal insulation. - Google Patents

Abstract

The thermal insulation (5) has at least one, advantageously several cavities (6), which are arranged obliquely between thermally insulating slats. The upper and lower cavity walls are highly reflective in the visible spectral range, while the inside cavity wall strongly absorbs in this spectral range and the outside cavity wall (10) has high transmission. The IR emissivity of at least three of the cavity walls is deeply chosen. By this combination, a high efficiency of the collector assembly (13) of the thermal insulation (5) is achieved.

Description

description

FIELD OF THE INVENTION The invention relates to thermal insulation for a building wall and a building wall with such thermal insulation according to the preamble of the independent claims. The thermal insulation has a collector arrangement which allows part of the incident radiation to be used for heating the building.

Background Various types of thermal insulation are provided for building walls, which in addition to thermal insulation also allow the incident solar radiation to be used to heat the building. As an example, reference is made to GB 1 556 434.

SUMMARY OF THE INVENTION It is an object to provide thermal insulation and a building wall with such thermal insulation, which additionally has a collector arrangement for converting solar energy into thermal energy. [0004] This object is achieved by the subject matter of the independent claims.

Accordingly, the invention relates to thermal insulation for a building wall. The thermal insulation has a collector arrangement and a heat insulation body, the collector arrangement being arranged in the heat insulation body.

The thermal insulation has an insulation outside and an insulation inside and at least one cavity arranged between the insulation outside and the insulation inside in the thermal insulation body. The cavity is delimited at least by an upper cavity wall, a lower cavity wall, an inside cavity wall and an outside cavity wall. In addition, further walls, in particular side walls, can also be provided. However, these generally have a significantly smaller surface area, in particular at most one tenth of the surface of the above-mentioned walls.

The thermal insulation body can be designed in one or more parts, i.e. it does not have to be a coherent body. For example, the thermal insulation body can be divided into several sections by the cavity or cavities.

At least three of the cavity walls have an IR emissivity less than 0.2.

The term "IR emissivity" denotes the total hemispherical emissivity in the infrared at a temperature of 100 ° C.

At least three of the cavity walls thus have low IR emissivity and thus, according to Kirchhoff's radiation law, a correspondingly low IR absorption.

As a result, the heat transport by radiation from the warm to the cold side of the cavity is reduced.

In order to better understand this, various preferred embodiments of the collector arrangement can be considered in more detail:

- In a first embodiment, the inside cavity wall has an IR emissivity less than 0.2, i.e. it emits little thermal radiation energy. But in this case too, at least the upper cavity wall and the lower cavity wall can become warm due to convection and / or heat conduction, which is why they should also have an IR emissivity of less than 0.2. The IR emissivity of the cavity wall on the outside is of less importance, since the warmest parts of the thermal insulation radiate little heat. (However, the cavity wall on the outside also preferably has an IR emissivity of less than 0.2, i.e. it reflects the IR radiation back inwards. In this case, all of the cavity walls mentioned have an IR emissivity of less than 0.2.)

In another embodiment, the inside cavity wall has an IR emissivity greater than 0.2, in particular greater than 0.6, i.e. Although it strongly absorbs IR radiation, it also radiates strongly. In this case, however, the remaining three of the four cavity walls mentioned have a deep IR emissivity, i.e. less than 0.2, also the outside cavity wall, in order to prevent IR radiation from getting into the outside cavity wall.

The outside cavity wall preferably has a VIS transmission of at least 10%, in particular at least 60%, in order to let at least part of the sunlight into the cavity. Furthermore, the interior cavity wall has a VTS reflectivity less than 20% and the upper and lower cavity walls have a VTS reflectivity greater than 60%. This means that at least part of the sunlight can be guided through the cavity to the inside cavity wall in order to convert it into heat there.

The term “VIS reflectivity” denotes the average reflectivity of the body over the spectral range from 380 to 780 nm. The term “VIS transmission” denotes the average transmission of the body over the spectral range from 380 to 780 nm.

CH 714 367 A2 [0015] The cavity preferably rises from the outside of the insulation to the inside of the insulation. This means that (if the outside of the insulation is colder than the inside of the insulation), the warm air is trapped at the inner end of the cavity. Conversely, when it is warmer outside than inside, cold air at the inner end of the cavity is replaced by warmer air.

Preferably, the thermal insulation has a plurality of the cavities mentioned, each of which can form a heat trap of the type described.

In a structurally simple manner, the insulating body can have a plurality of lamellae which separate the cavities from one another at least in the vertical direction.

Advantageously, the slats have a carrier made of an insulating material, on which a surface layer is arranged, which has an IR emissivity less than 0.2 and a VIS reflectivity greater than 60% to the upper and / or lower cavity wall of the adjacent cavities or to form an adjacent cavity.

The invention also relates to a building wall with masonry and with a thermal insulation connected to the masonry of the type described above.

The thermal insulation body advantageously consists at least predominantly (ie at least 50 percent by volume, in particular at least 95 percent by volume) of an insulating material with a thermal conductivity of less than 0.2 W / (mK), in particular less than 0.04 W / (mK) [0021] in particular the thermal insulation body advantageously at least predominantly (ie at least 50 percent by volume, in particular at least 95 percent by volume) made of mineral wool and / or foam glass, since these materials are not only good thermal insulators, but are also long-term stable at the elevated temperatures that can be achieved in the area of the collector arrangement.

BRIEF DESCRIPTION OF THE DRAWINGS Further refinements, advantages and applications of the invention result from the dependent claims and from the description that follows, using the figures. Show:

1 is a sectional view of a conventional building wall,

Fig. 2 is a sectional view of a building wall with a first embodiment of the thermal insulation in one

Overall representation A and with an enlarged representation B of the cavity,

3 shows the sectional view of a building wall with a second embodiment of the thermal insulation,

4 shows the sectional view of a building wall with a third embodiment of the thermal insulation,

Fig. 5 is a sectional view of a building wall with a fourth embodiment of the thermal insulation and

6 shows a detail from FIG. 3.

Ways of Carrying Out the Invention

definitions:

The terms «outside», «outside», «inside», «inside», «outside» and «inside» etc. are to be understood from the perspective of the building, i.e. inside is the side of the thermal insulation that faces the masonry when properly installed, while the opposite side of the thermal insulation is on the outside.

The terms "top", "bottom", "top", "bottom" etc. refer to the intended installation of the thermal insulation.

Conventional design:

Fig. 1 shows the vertical section through a conventional design of a building wall. The wall has a masonry 1 and adjoining it to the outside is a thermal insulation body 2, which forms thermal insulation 5. The outer end of the building wall is formed by an outer layer 3, e.g. a plaster or a panel cover (e.g. made of fiber cement, wood, glass etc.). An air gap 4 for rear ventilation of the facade can be left out between the insulation layer 2 and the outer layer 3.

In this embodiment, the insulation layer 2 reduces the heat exchange through the building wall.

CH 714 367 A2

First execution:

Fig. 2 shows a first embodiment of a building wall, again as a vertical section. In this embodiment, thermal insulation 5 with a collector arrangement 13 is provided.

The thermal insulation 5 has an insulation outside 5a and an insulation inside 5b, the inside 5b adjoining the masonry 1 and advantageously being connected to it in a heat-conducting manner.

In the present embodiment, the collector arrangement 13 has a cavity 6, which is surrounded by the heat insulating body 2 at least from above and below. The cavity 6 is arranged in the area between the outside of the insulation 5a and the inside of the insulation 5b.

As can best be seen from the enlarged part B of FIG. 2, the cavity 6 has at least an upper cavity wall 7, a lower cavity wall 8, an interior cavity wall 9 and an exterior cavity wall 10.

The upper and lower cavity wall 7, 8 are advantageously formed by one or more coatings, which is or are arranged directly on the material of the thermal insulation body 2 or on the thermal insulation film.

The inside cavity wall 9 is e.g. formed by a plate 11.

The outside cavity wall 10 is formed by a preferably at least partially transparent cover plate 12.

As mentioned at the beginning, the VIS transmission of the outside cavity wall 10 is advantageously at least 10% and the VIS reflectivity of the inside cavity wall 9 is low, while the upper and lower cavity walls 7, 8 can have a high VIS reflectivity. As shown in the figure, incident light is thereby guided in through the cavity 6 and absorbed on the inside cavity wall 9. The heat generated is given off to the masonry 1.

In addition, as also mentioned, at least three of the cavity walls have an IR emissivity less than 0.2, so that the heat transfer due to IR radiation from the inside to the outside is low.

Possible materials of the cavity walls with corresponding properties are described below.

Second version:

Fig. 3 shows a second embodiment with thermal insulation 5. It differs from the first embodiment in that the cavity 6 runs obliquely. Its outer end 6a is lower than its inner end 6b.

As a result, the convection-related heat exchange is dependent on the direction of the heat gradient. If it is colder on the outside than on the inside, an area of warm air is created at the inner end 6b of the cavity 6 and remains trapped there. At most, there is very little convective heat exchange. However, if it is warmer on the outside than on the inside, the cold air flows out at the inner end 6b of the cavity 6 towards the outside and is replaced by warmer air from the outer end 6a. This then cools down again, so that a convective heat exchange occurs.

The rise angle α of the cavity 6 is preferably greater than 0 °, in particular greater than 10 °, and / or less than 50 °, in particular less than 40 °.

Third version:

The first and second embodiment can be modified such that several cavities 6 are provided in the thermal insulation 5. This is illustrated for oblique cavities 6 in the embodiment according to FIG. 4. This means that a stronger collector effect can be achieved for each facade surface.

Advantageously, the cavities 6 run horizontally and parallel to one another in the facade width (i.e. parallel to the facade).

Fourth version:

In the previous versions, the cavities 6 are shown as individual recesses in the insulation layer 2. 5 shows that a plurality of lamellae 15 are provided which separate the cavities 6 from one another at least in the vertical direction.

The slats 15 together form the insulating body 2.

Each lamella 15 preferably has a carrier 16 made of thermally insulating material, on which a surface layer 17 is arranged, which has an IR emissivity less than 0.2 and a VIS reflectivity greater than 10%, in particular greater than 60%.

The slats 15 are advantageously arranged horizontally in their longitudinal direction, i.e. their horizontal extension parallel to the outside of the facade is considerably greater than the extension perpendicular to the facade and that

CH 714 367 A2 in the vertical direction. In this way, structurally simple, sufficiently deep cavities 6 can be formed.

As shown for a slat 15a in Fig. 5, the slats can taper towards the outside of the insulation. As a result, the outside cross section of the cavities 6 is increased and the proportion of the incident light which is reflected on the outer edges of the lamella 15 and is not used can be reduced.

5, the fins 15 are arranged obliquely, in such a way that the cavities 6 run obliquely and rise towards the inside. However, a horizontal arrangement is also conceivable (so that horizontally extending cavities are created according to FIG. 2).

In another embodiment, the angle of the slats 15 can also be adjustable, so that the angle of rise α of the cavities 6 is adjustable and can be adapted to the respective requirements.

[0049] This is particularly advantageous if the sign of the angle of rise can be changed. If the cavity rises inwards, the heat transfer, as described above, is favored from the outside in. If, on the other hand, it rises to the outside, the heat transfer from the inside to the outside is favored, so that e.g. in the hot season, heat can be better dissipated from the building, especially at night.

Due to the simple and robust construction, an assembly of the slats 15 at a fixed angle α can be advantageous.

Materials for the inside, top and bottom cavity wall:

As mentioned, the inside cavity wall 9 is advantageously formed by a plate 11, which forms the inside termination of the thermal insulation 5. You can use the masonry 1 e.g. be connected by gluing or screws so that good heat transfer is guaranteed.

For constructional reasons, however, it can also make sense to arrange the plate 11 at a small distance from the masonry, e.g. to create play for wall movements.

As mentioned, the cavity wall 9 on the inside preferably has an IR emissivity of less than 0.2, in particular less than 0.1, and moreover it has a VIS reflectivity of at most 20%, in particular at most 10%. For example, the optical surface of the interior cavity wall can at least partially consist of an aluminum sheet with the Tinox-energy coating from Almeco Group, in which case an IR emissivity of 4% and a VIS reflectivity of 5% can be achieved.

However, as mentioned, it is also conceivable to use a material with IR emissivity greater than 0.2, provided that the other three main walls of the cavity have an IR emissivity of at most 0.2.

For this purpose, for example, the optical surface of the interior cavity wall can at least partially consist of a steel sheet which is painted with black stovepipe paint, in which case an IR emissivity of around 90% and a VIS reflectivity of 10% can be achieved.

The upper and / or lower cavity wall 7 or 8 should advantageously have a VIS reflectivity of at least 60%, in particular at least 80%, and advantageously an IR emissivity less than 0.2. For this, e.g. the surface is at least partially formed by a metal-plastic composite film, e.g. An aluminum-plastic composite film in which the aluminum layer forms the optical surface is particularly suitable for this purpose. In this case, an IR emissivity of 0.01 to 0.02 and a VIS reflectivity of around 80% can be achieved.

In an advantageous embodiment, the optical surface of the upper and / or the lower cavity wall 7, 8 is thus at least partially formed by aluminum, in particular by an aluminum-plastic composite film. Ideally, the aluminum layer is thinner than 500 nm in order to keep the undesired heat conduction in this layer small.

External cavity wall:

As mentioned, the designs of the thermal insulation 5 shown have an outside cavity wall 10 formed from at least one cover plate 12. Depending on the design, it has various advantageous effects.

On the one hand, the outside cavity wall 10 protects the cavities 6 from weather influences, e.g. from pollution. It also prevents gusts of wind from causing undesired heat exchange and / or damaging the thermal insulation 5.

Advantageously, the outside cavity wall 10, at least in the area of the cavity or cavities 6, consists of a material with a VIS transmission of at least 10%, in particular at least 60%.

[0061] For example, the outside cavity wall 10 can be made of glass or transparent plastic.

If the outside cavity wall 10 is to have an IR emissivity of less than 0.2, in particular less than 0.1, it can e.g. be provided with a suitable IR-reflecting layer. For example, a glass pane with the Silverstar Zero E coating from Glas Trösch or a similar product can be used.

On the outside, one or more cover plates 12a, 12b can be provided on the thermal insulation 5.

CH 714 367 A2 An air gap 18 for the rear ventilation can be present between the outermost cover plate 12b and the insulation layer, as shown in FIGS. 2-4.

The cavities are preferably sealed airtight with a cover plate (in the example according to FIG. 5 of the inner cover plate 12a) in order to prevent the cavities 6 from being contaminated. At the same time, it can be prevented that the cavities 6 in the insulation level, especially in the edge area of the cover plate are rinsed with cold outside air by wind effects and thus cooled.

Alternatively, it is also conceivable to apply the outermost cover plate directly to the insulating body 2 and to close the cavities 6 in an airtight manner, as is shown in the area 23 of FIG. 5 (in this case there is only one cover plate). In this case, however, the sun protection for the summer valley should advantageously be weatherproof on the outside. Such a solution also has a massive impact on the appearance of a building, which is not always desirable.

In the version with an air gap 18, a shielding device (e.g. a blind, see below) can be guided in this air gap; it is protected from the weather and also discreetly supplied. Solutions are also conceivable in which the sun protection is integrated in the cover glass (switchable glazing).

Accordingly, in one embodiment, the insulation can be designed in such a way that the outside cavity wall 10 closes the cavity 6 in an airtight manner.

And in another embodiment, the insulation can be designed such that the outer cavity wall 10 is spaced from the upper and / or lower cavity wall 7 or 8, so that an air gap 18 is formed, over which the cavity 6 with at least one communicates another cavity 6 and / or with the environment.

Thus, in one embodiment, the outside cavity wall 10 can be formed by at least two cover plates 12a, 12b, between which at least one air gap 18 is present.

Furthermore, the thermal insulation 5 for the summer valley, as mentioned, can have a shielding device 20, as shown by way of example in FIG. 5. With this shielding device 20, the collector arrangement 13 can optionally be shielded and thus deactivated.

The shielding device 20 can preferably be used to reduce the VIS transmission of the outer cavity wall 10 from at least 10%, in particular at least 60%, to less than 20%, in particular less than 5%, even to 0%. The shielding device 20 preferably has an average reflection of at least 60%, in particular at least 80%, for visible light coming from outside.

With the shielding device 20, the collector arrangement 13 can optionally be deactivated. This is particularly desirable when the sun is high and further heating of the building is not desired, which can be the case especially in the summer months.

Preferably, the shielding device 20 is a movable element which can be optionally (i.e. as required) arranged on the outside of the thermal insulation 5 and which, e.g. can be wound on a roll 21 and lowered and raised in the form of a sun blind.

As illustrated by way of example in FIG. 5, the shielding device 20 is preferably combined with the above-mentioned embodiment in which the outside cavity wall 10 is formed by at least two cover plates 12a, 12b. In this case, the shielding device 20 can be arranged in the air gap 18, thereby protecting it from the weather.

Remarks:

As shown in Fig. 6, the "depth" T of the cavity 6, i.e. the expansion of the cavity 6 between its outer end 6a and its inner end 6b, advantageously much larger than the height H of the cavity 6, i.e. its largest free extension in the vertical direction. In this way, radiation losses in the infrared due to multiple reflections are reduced, on the one hand, and, on the other hand, undesired gas exchange is reduced.

T> H, in particular T> 5 H, preferably applies.

While preferred embodiments of the invention are described in the present application, it should be clearly pointed out that the invention is not limited to these and can also be carried out in other ways within the scope of the following claims.

Claims (16)

claims 1. Thermal insulation for a building wall with a collector arrangement (13), the thermal insulation having a heat insulation body (2) in which the collector arrangement (13) is arranged, with an insulation outside (5a) and an insulation inside (5b) and at least one cavity (6) in the thermal insulation body (2) arranged between the outside of the collector (5a) and the inside of the insulation (5b), the cavity (6) at least through an upper cavity wall (7), a lower cavity wall (8) an inside cavity wall (9) and an outside cavity wall (10) is limited, CH 714 367 A2, characterized in that at least three of the cavity walls (7-10) have an IR emissivity less than 0.2. 2. Thermal insulation according to claim 1, wherein the inside cavity wall (9), the upper cavity wall (7) and the lower cavity wall (8) have an IR emissivity less than 0.2, in particular less than 0.1. 3. Thermal insulation according to claim 7, wherein the inside cavity wall (9) has an IR emissivity greater than 0.2, in particular greater than 0.6. 4. Thermal insulation according to one of the preceding claims, wherein the cavity (6) rises from the outside of the insulation (5a) to the inside of the insulation (5b) and in particular wherein an angle of increase (a) of the cavity (6) with respect to the horizontal is less than 50 ° , in particular less than 40 ° and / or greater than 0 °, in particular greater than 10 °. 5. Thermal insulation according to one of the preceding claims, wherein it has a plurality of said cavities (6). 6. Thermal insulation according to claim 5, wherein the heat insulating body (2) has a plurality of lamellae (15) which separate the cavities (6) from one another at least in the vertical direction. 7. Thermal insulation according to claim 6, wherein each lamella (15) has a carrier (16) made of an insulating material, on which a surface layer (17) is arranged, which has an IR emissivity less than 0.2 and a VIS reflectivity greater than 60%. 8. Thermal insulation according to one of claims 6 or 7, wherein the slats (15) are arranged horizontally in the longitudinal direction. 9. Thermal insulation according to one of claims 6 to 8, wherein the slats (15) taper towards the outside of the collector (5a). 10. Thermal insulation according to one of the preceding claims, wherein an optical surface of the upper and / or the lower cavity wall (7, 8) is at least partially formed by aluminum, in particular by an aluminum-plastic composite film, in particular wherein the aluminum layer is thinner than 500 nm is. 11. Thermal insulation according to one of the preceding claims with a shielding device (20) with which the collector arrangement (13) can be shielded and deactivated, and in particular wherein with the shielding device (20) the VIS transmission of the outer cavity wall (10) optionally of at least 10%, in particular at least 60%, can be reduced to less than 20%, in particular less than 5%. 12. Thermal insulation according to one of the preceding claims, wherein the thermal insulation body (2) consists at least predominantly of an insulating material with a thermal conductivity less than 0.2 W / (mK), in particular less than 0.04 W / (m K). 13. Thermal insulation according to one of the preceding claims, wherein the outside cavity wall (10) has a VIS transmission of at least 10%, in particular at least 60%. 14. Thermal insulation according to one of the preceding claims, wherein the interior cavity wall (9) has a VIS reflectivity less than 20% and / or the upper and lower cavity walls (7, 8) have a VIS reflectivity greater than 10%, in particular greater than 60%. 15. Thermal insulation according to one of the preceding claims, wherein the outside cavity wall (10) closes the cavity (6) airtight. 16. Building wall with masonry (1) and with the masonry (1) adjoining thermal insulation (5) according to one of the preceding claims. CH 714 367 A2 CH 714 367 A2 CH 714 367 A2 CH 714 367 A2