ANGLE-SELECTIVE IRRADIATION INSULATION ON A BUILDING ENVELOPE

Abstract

In a method for producing a building envelope part (19) for angle-selective irradiation insulation on a building envelope, which building envelope part (19) has an outer surface (29), an inner surface (39) opposite the outer surface (29), and a side edge that bounds the outer surface (29) and the inner surface (39), the outer surface (29) is provided with outer structures (219) and the inner surface (39) is provided with inner structures (319). The outer structures (219) and the inner structures (319) are arranged relative to each other in such a way that the building envelope part (19) has different transparency depending on the spatial angle of incidence. The outer structures (219) and the inner structures (319) are arranged in particular with regard to an orientation of an intended application of the building envelope part (19) and with regard to the latitude of the intended application of the building envelope part (19). By means of the design of the outer structures and the inner structures according to the invention, it is possible that the outer structures and the inner structures are arranged in such a way that a building envelope comprising the building envelope part is optimally adapted to an orientation and in particular to an orientation deviating from southern orientation, to tilted or horizontal arrangements, or to an arbitrary latitude. Thus the transmittance behavior of the building envelope part can be accordingly optimized for the particular situation.

Description

BENEFIT CLAIM

The present application claims the benefit under 35 U.S.C. 119 of priority from international application PCT/EP2012/061835 filed 20 Jun. 2012, which claims priority to European application EP11170686.7 filed 21 Jun. 2011, the entire contents of which are hereby incorporated by reference for all purposes as if fully set forth herein.

TECHNICAL FIELD

The invention relates to a building envelope part according to the preamble of independent claim 1, as well as to a method for manufacturing such a building envelope and a computer program for implementing such a method.

Such building envelope parts exhibit an outer surface with outer structures, an inner surface opposite the outer surface with inner structures, and a side edge that bounds the outer surface and inner surface, wherein the outer structures and inner structures are arranged relative to each other in such a way that the building envelope part has a varying translucency depending on the spatial angle of incidence, for example to solar radiation, and can be used in building technology for angle-selective irradiation insulation on a building envelope.

PRIOR ART

In order to specifically vary the absorbance of a building relative to solar radiation, use is today made of building envelopes or facades with an angle-selective transmittance behaviour. In particular, an irradiation insulation that allows more or less transmittance to arise over the seasonal variation of the sun's trajectory can be achieved in this way. For example, this type of building envelope makes it possible to achieve a high transmittance of direct solar radiation in winter, thereby lending support to the heating process, and a low transmittance in the summer to protect against overheating, so that cooling can be reduced. Angle-selective building envelopes or facades along with transparent thermal insulation are optimized in terms of their seasonal transmittance behaviour for central northern latitudes on south fronts the building or on south facades. For example, European Standard (EN) 13363 “Solar Protection Devices in Combination with Glazing—Calculation of Solar Radiation and Degree of Light Transmittance”, which was adopted by the German Institute for Standardization (DIN), discusses spatial angles with elevations of 0° to 90° and azimuth angles of −90° to +90° for corresponding window blinds or shading elements. In this context, the term “elevation” relates to a vertical angle over a horizontal plane. The term “azimuth” in this sense relates to the deviation from south, wherein an azimuth angle of −90° denotes an east orientation, −45° a southeast orientation, 0° a south orientation, +45° an southwest orientation, and +90° a west orientation. Such angle-selective building envelopes often exhibit lamellar, horizontally arranged structures. The building envelopes are here angle-selective in that the transmittance or degree of transmittance for a south orientation and varying elevations—this direction is referred to as the transversal axis—can change significantly as a function of the angle.

In this conjunction, building envelope parts are among other things fabricated as components for building envelopes that, once built in, permit an angle-selective irradiation insulation for the building envelope. For example, WO 01/53756 A2 describes a glass pane as a component with an outer surface and inner surface, which has prismatic elevations as structures on the outer surface or inner surface. The prismatic elevations are intended to divert light so as to outwardly redirect steeply incident sunlight in the summer, while allowing shallowly incident sunlight to freely pass through the glass pane to the inside in the winter.

The transmittance or degree of transmittance remains approximately constant or at most tapers off in border areas for a light source moving from east to west given an identical elevation—this direction is referred to as the longitudinal axis. As a result, the known building envelopes of building envelope parts are either unsuitable or limitedly effective for orientations that deviate from the south, for inclined or horizontal configurations, for example roof surfaces, as well as for other geographic latitudes. For example, the stipulation that the solar altitude be high in the summer and low in the winter is not applicable. In these orientations, the strongly transmitting area of the angular range is rather traversed during sunrise or sunset, while the high solar altitude is encountered only in a border area or not at all in these orientations. As a consequence, the irradiation on the building is often very high when the building exhibits such a known building envelope, and the amount of irradiated energy is often significant given the longer duration of sunshine in the mornings and evenings, and can help cause the building to overheat.

Therefore, the object of the present invention is to propose a building envelope part or the manufacture of a building envelope part that enables an angle-selective irradiation insulation on the building envelope for any orientations and inclinations of the building envelope part, as well as for any geographic latitudes of the building location.

DESCRIPTION OF THE INVENTION

According to the invention, the object is achieved by a building envelope part as defined by the features in independent claim 1, as well as by a method as defined by the features in independent claim 10, and a computer program as defined by the features in independent claim 18. Advantageous embodiments of the invention may be gleaned from the features in the dependent claims.

The gist of the invention is as follows: A building envelope part for angle-selective irradiation insulation on a building envelope exhibits an outer surface with outer structures, an inner surface opposite the outer surface with inner structures, and a side edge that borders the outer surface and inner surface, or joins the outer surface with the inner surface. The outer structures and inner structures are here arranged relative to each other in such a way that the translucency of the building envelope part varies as a function of the spatial angle of incidence. The outer structures and inner structures are here arranged at an acute angle to the side edge.

In connection with the invention, the term “building envelope part” relates to parts exposed to direct or diffuse solar radiation or artificial light, attachment or mounting elements of a building, such as facades, façade elements, transparent thermal insulation elements (TWD), windows, roofs and porches, to energy generating systems, such as thermal, photovoltaic and hybrid collectors, as well as to targeted light or visual guidance systems. In particular, the term “building envelope part” can be construed as any suitable, preferably plate-type construction having a round, triangular, square or hexagonal shape, whose border is designated as a side edge in terms of this invention, for use in a building envelope, for example a preferably structured glass or acrylic glass pane, a plastic plate, a metallic, mineral or wooden construction or something similar. In particular, a low-iron glass can be used as the building envelope part. The building envelope part can be configured as a one-piece component or composed of several elements. For example, it can also be designed as laminated glass, in which in particular correspondingly printed glass panes are used, and prefabricated films or switchable layers are applied to panes of glass, or attached between several glass panes. In conjunction with the invention, the term “spatial angle of incidence” is understood as the angle doublet comprised of a zenith angle between the perpendicular to the outer surface of the building envelope part or the light incident on the building envelope part, as well as of an azimuth angle between a defined angle of the outer structure and the perpendicularly projected light incident on the outer surface of the building envelope part. Without any explicit other explanations, the terms “south”, “north”, “north hemisphere”, “June 21” and “December 21” used in conjunction with the invention refer to locations in the northern hemisphere. The latter are replaced by “north”, “south”, “south hemisphere”, “December 21” and “June 21” respectively for locations in the southern hemisphere in these cases.

The outer structures and inner structures can extend from one side edge to a possible other side edge on the outer surface or on the inner surface. In particular, they can also each exhibit an oblong expansion, wherein this oblong expansion can define an axis of the outer structures. The areas of the exterior side between the outer structures and the areas of the interior side between the inner structures can remain unchanged or unmachined and translucent. The outer structures and/or inner structures can be covered by a protective layer as a safeguard against damaging influences, for example in the case of a laminated glass. The acute angle between the outer structures or inner structures according to the invention relates to the plane of the outer surface or inner surface, so that it becomes particularly evident from a top view of the outer surface or inner surface. In particular, it can encompass all angles that are smaller than 90°, and especially significantly smaller than 90°, i.e., for example smaller than 85°, smaller than 80°, smaller than 70°, smaller than 60°, smaller than 50°, smaller than 40°, smaller than 30°, smaller than 20°, smaller than 10° or smaller than 5°. Concurrently with acute-angled arrangement of the outer structures or inner structures and the side edge, the outer structures and inner structures can also be arranged at an obtuse angle relative to the side edge. For example, the sum of this obtuse angle and the acute angle yields 180° at the tangent of the side edge.

The acute-angled arrangement according to the invention of the outer structures or an axis thereof and the inner structures or an axis thereof relative to the side edge makes it possible to arrange the outer structures and inner structures in such a way as to optimally adjust a building envelope encompassing the building envelope part to an orientation deviating from the south, to an inclined or horizontal arrangement, or to any geographic latitude. As a consequence, the transmittance behaviour of the building envelope part can be appropriately optimized to the respective situation. For example, the circumstances presented by a roughly east or west orientation of the building envelope part can be taken into account in a relatively effective way. A transmittance of about 60% can take place with respect to angles of incidence typically encountered in winter, for example, while a transmittance of about 20% can take place for those typically encountered in summer, for example. The building envelope part typically has strictly a passive effect, and can be adjusted not just to the solar altitude and façade orientation, but rather also to the length of the heating or cooling period of a building. For example, the building envelope part can further be comparatively durable as a glazing, and provide good weather protection for the building. In addition, the building envelope part can be manufactured in a comparatively cost effective manner, and visually adjusted to be suitable for residential, commercial and industrial premises. The rear section of the building envelope part according to the invention can also be combined with housing panels comprised of massive wood, other materials or structures as the thermal capacity store and/or provided with ventilation dampers to utilize cooling through natural convection, which can be opened or closed seasonally or as needed.

According to the invention, then, the irradiation insulation on the building can be controlled to conform to the situation, wherein the outer structures or an axis thereof and the inner structures or an axis thereof to this end run inclined at a specific angle relative to a side edge, depending on the respective celestial orientation of the provided application for the building envelope part and the latitude. For example, the solar radiation can accordingly also be used at orientations other than toward the south for heating purposes, and at the same time offer irradiation insulation to protect against overheating. As may be gleaned from the aforementioned EN 13363, for example, the latter standard is not to be used for elevations of less than 0°, which is factually tantamount to saying that only horizontally lying lamellae or structures can be considered according to the standard. If the lamellae or structures are inclined, irradiation elevations of less than 0° are also possible, which lie outside the evaluation range of this standard. As a consequence, it can be inferred that the same method can also yield clearly better results in the fight against overheating, especially in the summer, and in the generation of energy during the winter even at latitudinal lines other than the average and at façade orientations other than toward the south. Since a comparatively finely resolving angular function can be taken into account in the building envelope part according to the invention, the focus can be placed on situations with more than one heating and/or cooling period. In addition, the building envelope part according to the invention can also be configured to serve as angle-selective, situation-adapted irradiation insulation for artificial light.

In one exemplary embodiment of the building envelope part, the outer structures are designed as light diffusers, and the inner structures are designed as optically opaque. In this conjunction, the term “light diffusers” relates in particular to structures that diffusely scatter incident light. For example, the outer structures as light diffusers can be applied to the glass pane through printing, etching, sandblasting, roughening, as a film or in some other way. As a consequence, the angle-dependent transmittance can be achieved via the diffusely scattering, e.g., printed, sandblasted, etched or roughened outer structures and reflecting or absorbing inner structures, and optimized for the exact requirements. For example, optically opaque structures can be applied to the building envelope part through printing, as a film or in some other way, especially if the building envelope part is designed as a glass or acrylic glass pane. Outer structures and inner structures configured in this way make it possible to scatter the solar radiation incident on the exterior side of the building envelope part in a specific first spatial angle of incidence range on the outer structures in such a way that at least a portion thereof is deflected on the optically opaque inner structures while penetrating the building part. This allows additional solar radiation other than the solar radiation directly incident on the optically opaque inner structures in the first spatial angle of incidence range to be incident on the optically opaque inner structures, which can in particular elevate the radiation insulation, for example in the summer. At the same time, the outer structures and inner structures configured in this way can scatter the solar radiation incident on the exterior side of the building envelope part in a specific second spatial angle of incidence range in such a way that at least a portion thereof is guided between and through the optically opaque inner structures while penetrating the building part. This allows additional solar radiation other than the solar radiation that passes directly by the optically opaque inner structures to penetrate through the building envelope part in the second spatial angle of incidence range, which in particular can diminish the irradiation insulation, for example in winter.

In another exemplary embodiment, the outer structures are prismatic, and the inner structures optically opaque in design. When the outer structures and inner structures are configured in this way, the solar radiation incident on the external side of the building envelope part in a specific first spatial angle of incidence range can be bundled on the outer structures in such a way that at least a portion thereof is deflected on the optically opaque inner structures while penetrating through the building envelope part. This allows additional solar radiation other than the solar radiation directly incident on the optically opaque inner structures in the first spatial angle of incidence range to be incident on the optically opaque inner structures, which can in particular elevate the radiation insulation, for example in the summer. At the same time, the outer structures and inner structures configured in this way can bundle the solar radiation incident on the exterior side of the building envelope part in a specific second spatial angle of incidence range in such a way that at least a portion thereof passes the optically opaque inner structures while penetrating the building part. This allows additional solar radiation other than the solar radiation that passes directly through the optically opaque inner structures to penetrate through the building envelope part in the second spatial angle of incidence range, which in particular can diminish the irradiation insulation, for example in winter.

In the two exemplary embodiments of outer structures and inner structures described above, the optically opaque inner structures can be configured as light reflectors. For example, the inner structures can be designed as a mirror coating, such as a printed silver layer, an opaque coloration or a geometric, reflecting structure, in particular in glass pane-like building envelope parts. This allows the irradiation incident on the inner structures in particular in the first spatial angle of incidence range to be reflected via the outer surface out of the building envelope part. As a result, the building envelope part can be kept deeply heated. As an alternative, the optically opaque inner structures in the mentioned two exemplary embodiments of outer structures and inner structures described above can be configured as light absorbers, wherein the light absorbers are preferably photovoltaic light absorbers. This makes it possible to prevent radiation incident on the inner structure from penetrating through the building envelope part on the one hand, while the energy of the irradiation to be insulated can be used for photovoltaic power production on the other, in particular in the summer. Light bundling allows this to happen with a high efficiency.

In another exemplary embodiment, the outer structures are designed to be light polarizing in a first way, and the inner structures are designed to be light polarizing in a second way complementary to the first way. This type of configuration for the outer structures and inner structures makes it possible to completely cancel out direct radiation at certain angles of irradiation. Given the other extreme, i.e., at certain other angles of irradiation, a transmittance of about 50% relative to non-polarizing inner and outer structures can be achieved, for example. Comparatively high contrast ratios can be achieved as a result.

In particular the outer structures can also be designed as a three-dimensional structure, for example an inclined flank, as a result of which both the degree of transmittance and reflection can be elevated depending on the angle of irradiation. The outer structures and inner structures can also be contiguous in design, for example have an L-shaped cross section. The outer surface and/or inner surface can be provided with anti-reflective coatings, making it possible to increase the degree of transmittance. The outer surface and/or inner surface can be provided with wavelength-selective infrared reflectors, as a result of which the heat dissipation of the underlying building envelope layer can be reduced without significantly diminishing the degree of transmittance for visible light.

The outer structures preferably encompass parallel stripes arranged in a common plane, and the inner structures encompass parallel stripes arranged in a common plane. The stripes of the outer structures and the stripes of the inner structures can here each exhibit straight sides and a fixed width. This type of configuration for the outer structures and inner structures enables a comparatively simple, expedient construction of the building envelope part. The outer structures are here preferably arranged parallel to the inner structures, wherein the common plane of the outer structures and the common plane of the inner structures are different. The stripes of the outer structures and the stripes of the inner structures are here established by mathematical expressions that correlate the variables r, d, m, c, α_± and n, and are preferably formulated according to the equations

$\frac{r}{d}=\frac{\sin \left({\alpha }_{+}\right)}{\sqrt{n^2-{\sin }^2\left({\alpha }_{+}\right)}}-\frac{\sin \left({\alpha }_{-}\right)}{\sqrt{n^2-{\sin }^2\left({\alpha }_{-}\right)}}$

and m=c=r, wherein m is the width of one of the stripes of the outer structures, for example in [mm], r is the width of one of the stripes of the inner structures, for example in [mm], c is the distance between the stripes of the outer structures, for example in [mm], d is the thickness of the building envelope part, for example in [mm], n is the average refraction index of the building envelope part, α₋ is the projected angle of incidence for light to be insulated, and α₊ is the projected angle of incidence for light not to be insulated. This type of configuration for the outer structures and inner structures enables a comparatively efficient, readily calculable construction of the building envelope part.

The outer structures are preferably arranged in a direction perpendicular to the outer surface and inner surface, offset in relation to the inner structures. Because the outer structures and inner structures thus do not lie on top of each other, angle-selective irradiation insulation can be efficiently achieved by the building envelope part. The angular ranges in which the irradiation is to be insulated or not insulated can be comparatively easily adjusted by suitably selecting the offset for the outer structures in relation to the inner structures in the direction perpendicular to the outer surface and inner surface.

The acute angle preferably ranges between about 25° and about 55°, or about −55° and about −25°. With such an acute angle, an optimized building envelope part can be fabricated in particular for European latitudinal lines, and especially for building envelope parts oriented toward the east or west. Smaller angles are best used for building envelope parts more strongly oriented toward the south, while larger angles are best used for building envelope parts more strongly oriented toward the north.

The building envelope part preferably exhibits an essentially rectangular shape with four side edges. This type of basic shape for the building envelope part enables a comparatively simple manufacture, as well as a comparatively simple, efficient integration into a building envelope. The side edge arranged at an acute angle in relation to the outer structures or an axis thereof and the inner structures or an axis thereof is here preferably essentially horizontally aligned in a provided application for the building envelope part.

The outer structures and inner structures are preferably essentially lamellar in design. For example, the term “lamellar” can be understood as a parallel arrangement of stripes in a plane, wherein these stripes exhibit straight sides and a certain width. This type of lamellar configuration for the outer structures and inner structures enables a comparatively simple, efficient construction and manufacture of the building envelope part.

The building envelope part according to the invention described above can also be used for artistically designing the building envelope or for other visual purposes by adjusting the outer structures and inner structures so that a desired graphic pattern of whatever geometry desired can be achieved, e.g., via discontinuous stripes or dot-like patterns, or by using colour adjusted building envelope parts. While this allows for numerous possibilities in relation to the artistic design of the facades, it can also easily have a negative influence on the contrast ratio for the structures. Striped structures in a transverse direction can also generate a Moire Effect. When passing in front of a façade equipped with such a building envelope part, these Moire stripes can wander along, so that corresponding effects can be used in targeted fashion. Likewise, the building envelope part can give rise to wavelength-dependent effects at the boundaries of light diffusing to right on the outer surface owing to the colour dispersion of direct radiation during reflection on the inner surface of the glass, as a result of which the blues or reds of the spectrum can be reflected or filtered out. This can slightly alter the hue of the reflected and transmitted light, and targeted use can be made of the corresponding effects. In addition, the direct portion of reflection can essentially be eliminated by suitably selecting the shape and position of the outer structures and inner structures. This can be of interest with respect to the appearance of the building, or so as to avoid disturbing reflection effects. In addition, for example, building envelope parts designed as glass panes can offer an infinitely variable screen, and the essentially dull effect produced by the glass surface itself can prevent accidents that involve flying birds, even given a comparatively low dullness portion. For example, the building envelope part can be mounted as façade glass in front of windows, opaque walls and insulations or in front of transparent insulation (TWD). Any air space between the glass and façade lying behind it can be naturally or artificially ventilated, or used for generating energy. For diffuse, i.e., non-direct solar radiation, the building envelope part can exhibit an elevated transmittance for diffuse light, for example, which can be advantageous in the summer during bad weather, which creates a demand for heating energy.

Another aspect of the invention relates to a method for manufacturing a building envelope part for angle-selective irradiation insulation on a building envelope, such as a building envelope part of the kind described above, wherein the building envelope part exhibits an outer surface, an inner surface opposite the outer surface, and a side edge that borders the outer surface and inner surface or joins the outer surface with the inner surface. The outer surface is provided with outer structures, and the inner surface is provided with inner structures, wherein the outer structures and inner structures are arranged in relation to each other in such a way that the building envelope part varies in translucence depending on the spatial angle of incidence. The arrangement of the outer structures and inner structures includes the orientation of a provided application for the building envelope part and the latitude of the provided application for the building envelope part. In this conjunction, the term “provided orientation” relates to the alignment and inclination in which the building envelope part is to be incorporated, for example in which it is to be built into a building envelope. In this conjunction, the term “provided latitude” relates in particular to the location of the place at which the building envelope part is to be used or applied.

The method according to the invention allows the individualized manufacture of a building envelope part, so that the highest possible efficiency in application can be achieved. In particular, the method according to the invention also makes it possible to efficiently implement the advantages described above in conjunction with the building envelope part according to the invention.

The longitudinal axes of the outer structures and inner structures are preferably aligned parallel to an intersecting line between the plane of the solar ecliptic and the plane of the building envelope part in the provided application if the building envelope part can be reached by direct solar radiation on all days of a calendar year in the provided application. This enables a comparatively efficient usage for this type of application for the building envelope part. The acute angle between the outer structures and side edge or between the inner structures and side edge is here established for building envelope parts inclined however desired by a mathematical expression that correlates the variables ω, β, γ and φ, preferably according to the equation

$\omega =-\mathrm{sgn}\left(\phi *\sin \left(\gamma \right)\right)*\arccos \hspace{1em}\left(\frac{\sin \left(\phi \right)*\sin \left(\beta \right)+\cos \left(\phi \right)*\cos \left(\beta \right)*\cos \left(\gamma \right)}{\sqrt{{\cos \left(\phi \right)*\cos \left(\beta \right)+\sin \left(\phi \right)*\cos \left(\gamma \right)*\sin \left(\beta \right))}^2+{\sin }^2\left(\gamma \right)*{\sin }^2\left(\beta \right)}}\right)$

and for vertically inclined building envelope parts by a mathematical expression that correlates the variables ω, γ and φ, preferably according to the equation

$\omega =-\mathrm{sgn}\left(\phi *\sin \left(\gamma \right)\right)*\arccos \left(\frac{\sin \left(\phi \right)}{\sqrt{1-{\cos }^2\left(\phi \right)*{\cos }^2\left(\gamma \right)}}\right),$

wherein ω is the acute angle, β is an inclination (vertical: β=90°) and γ is an alignment (south: γ=0°, west: γ positive) of the building envelope part and φ is the latitude (equator: φ=0°, north hemisphere: φ positive) in the provided application. Such a calculation method can be used to precisely dimension the building envelope part for the further type of application in a comparatively simple manner.

The longitudinal axes of the outer structures and inner structures are preferably aligned perpendicular to an intersecting line between the plane of the solar ecliptic and the plane of the building envelope part in the provided application if the building envelope part cannot be reached by direct solar radiation on all days of a calendar year in the provided application. For example, this condition can be satisfied on the northern hemisphere if the building envelope part is aligned toward the north. This also enables a comparatively efficient usage for this additional type of application for the building envelope part by having the degree of transmittance for the projected angle of incidence be as small as possible during sunrise and/or sunset, and otherwise as large as possible to utilize the diffuse sunlight in winter.

A first projected angle of incidence with a maximum light transmittance through the building envelope part is preferably established. The first projected angle of incidence is preferably established taking into account the projected angle of incidence on December 21 in the provided application of the building envelope part, which can be expedient in particular for a provided application of the building envelope part on the northern hemisphere. The first projected angle of incidence is established by a mathematical expression that correlates the variables α₊, β, γ, ε and φ, preferably according to the equation α₊=arcsin(cos(φ)*cos (γ))+(β−90°)−ε, wherein α₊ is the first projected angle of incidence, β is an inclination and γ is an alignment of the building envelope part in the provided application, and ε is the obliqueness of the ecliptic relative to the equator. In particular, ε can be about 23.4°. Given such a first projected angle of incidence calculated in particular using this equation, the building envelope part can comparatively easily be dimensioned so as to efficiently establish a spatial angle of incidence range intended to allow as much transmittance through the building envelope part as possible.

A second projected angle of incidence with a minimum light transmittance through the building envelope part is preferably established. The second projected angle of incidence is preferably established taking into account the projected angle of incidence on June 21 in the provided application of the building envelope part, which can be expedient in particular for a provided application of the building envelope part on the northern hemisphere. The second projected angle of incidence is established by a mathematical expression that correlates the variables α₋, β, γ, ε and φ, preferably according to the equation α₋=arcsin(cos(φ)cos(γ))+(β−90°)−ε, wherein α₋ is the second projected angle of incidence, β is an inclination and γ is an alignment of the building envelope part in the provided application, and ε is the obliqueness of the ecliptic relative to the equator. Given such a second projected angle of incidence calculated in particular using this equation, the building envelope part can comparatively easily be dimensioned so as to efficiently establish a spatial angle of incidence range intended to allow as little transmittance through the building envelope part as possible.

The building envelope part is preferably configured in such a way that the outer structures in a common plane encompass parallel arranged stripes, and the inner structures in a common plane encompass parallel arranged stripes. The stripes of the outer structures and inner structures can each exhibit straight sides and a fixed width. This type of configuration for the outer structures and inner structures enables a comparably simple, efficient construction of the building envelope part. The building envelope part is here configured in such a way that the outer structures are arranged parallel to the inner structures, wherein the common plane of the outer structures and common plane of the inner structures are different, and that the stripes of the outer structures and stripes of the inner structures are established by a mathematical expression that correlates the variables r, d, α_± and n, preferably formulated according to the equation

$\frac{r}{d}=\frac{\sin \left({\alpha }_{+}\right)}{\sqrt{n^2-{\sin }^2\left({\alpha }_{+}\right)}}-\frac{\sin \left({\alpha }_{-}\right)}{\sqrt{n^2-{\sin }^2\left({\alpha }_{-}\right)}},$

wherein r is the width of one of the stripes of the inner structures, for example in [mm], d is the thickness of the building envelope part, for example in [mm], n is the average refraction index of the building envelope part, α₊ is the first projected angle of incidence, and α₋ is the second projected angle of incidence. This type of configuration for the outer structures and inner structures enables a comparatively efficient, readily calculable construction of the building envelope part. The building envelope part is preferably configured in such a way that a width of the stripes of the exterior side, a width of the stripes of the interior side, and a respective distance between the stripes are essentially identically dimensioned. This type of configuration can yield a preferred contrast ratio, wherein it is also possible to deviate from such a configuration, for example, if the building envelope part in its provided application is preferably to have heating or cooling properties.

The outer structures are preferably designed to diffuse light, wherein a light-diffusing effect for the outer structures is provided in such a way that a light band passing through the building envelope part is widened by a factor of roughly three from the exterior side up to the interior side. This type of configuration for the outer structures makes it comparatively easy to manufacture an efficient building envelope part with light diffusers as the outer structures as described above. However, the mentioned expansion factor can also be differently configured depending on the situation, wherein it can range from 2 to 5, for example.

The outer structures and inner structures are preferably given a lamellar design. For example, the term “lamellar” can be understood as a parallel arrangement of stripes in a plane, wherein these stripes exhibit straight sides and a specific width, for example. This type of lamellar configuration for the outer structures and inner structures enables a comparatively simple, efficient construction and manufacture of the building envelope part.

Another aspect of the invention relates to a computer program, which exhibits program code means configured to at least partially implement the method described above when the computer program is run on a computer. This type of computer program makes it possible to comparatively easily, quickly and precisely carry out the method according to the invention. In addition, this type of computer program makes it possible to implement and distribute the method according to the invention in an expedient and efficient manner.

BRIEF DESCRIPTION OF THE DRAWINGS

The building envelope part according to the invention and the method according to the invention will be described in greater detail below with reference to the attached drawings based upon exemplary embodiments. Shown on:

FIG. 1 is a diagrammatic cross sectional view depicting part of a first exemplary embodiment for a building envelope part according to the invention;

FIG. 2 is a diagrammatic view on the building envelope part from FIG. 1, for example for an east-oriented façade for a latitude of the object location measuring 45°;

FIG. 3 is a diagrammatic cross sectional view of the building envelope part from FIG. 1 in a wintertime functional mode;

FIG. 4 is a diagrammatic cross sectional view of the building envelope part from FIG. 1 in a summertime functional mode;

FIG. 5 is a diagrammatic cross sectional view depicting part of a second exemplary embodiment for a building envelope part according to the invention;

FIG. 6 is a diagrammatic cross sectional view depicting part of a third exemplary embodiment for a building envelope part according to the invention;

FIG. 7 is a diagrammatic cross sectional view depicting part of a fourth exemplary embodiment for a building envelope part according to the invention.

WAY(S) OF IMPLEMENTING THE INVENTION

FIG. 1 shows a glass pane 1 as a first exemplary embodiment of a building envelope part according to the invention with an outer surface 2 and an inner surface 3 opposite the outer surface 2. The outer surface 2 exhibits outer structures 21 with a fixed width, as well as intermediate outer regions 22 lying between the outer structures 21. The inner surface 3 exhibits inner structures 31 with a fixed width, as well as intermediate inner regions 32 lying between the inner structures 21.

The glass pane 1 is made out of a low-iron glass. The outer structures 21 are formed by etching the glass pane 1, wherein the intermediate outer regions 22 are left unchanged. The inner structures 31 take the form of a mirror coating generated by means of a printed silver layer on the glass pane 1, wherein the intermediate inner regions 32 are also left unchanged.

The following stipulation applies with respect to the entire remaining description. If reference numbers are contained in a figure for purposes of graphic clarity, but not mentioned in the immediately accompanying text of the description, reference is made to their explanation in preceding descriptions of figures. In addition, if reference numbers are mentioned in a text of the description belonging directly to a figure but not contained in the accompanying figure, reference is made to the preceding figures.

FIG. 2 shows the glass pane 1 as viewed from outside. The outer surface 2 and inner surface 3 are here bordered by four side edges 5. The glass pane 1 has a rectangular design. The outer structures 21 as well as the inner structures 31 of the glass pane 1 are configured as comparatively narrow, parallel stripes, which run at differing inclinations depending on the cardinal direction and location of a provided application for the glass pane 1. In other words, tailored to the respective circumstances, the parallel stripes or the outer structures 21 and inner structures 31 define a more or less acute angle co with the side edges 5. The degrees of freedom are essentially as follows when configuring the parallel stripes: The width of the diffusely scattering stripes, i.e., of the outer structures 21, relative to the glass thickness; the width between the diffusely scattering stripes, i.e., the intermediate outer regions 22, relative to the glass thickness; the degree of diffusion for the outer structures 21 that defines the spatial dispersion of the incident light; the width of the mirroring stripes, i.e., of the inner structures, relative to the glass thickness; the relative position of diffusely scattering to mirroring or absorbing stripes or of outer structures to inner structures relative to the glass thickness; and the acute angle ω₁ at which the stripes run relative to the horizontal side edge 5.

FIG. 3 shows how the glass pane 1 functions in winter. As evident, solar radiation 4 strikes the outer surface 2 of the glass pane 1 in a specific first spatial angle of incidence range. The solar radiation 4 is refracted at the intermediate outer regions 22 in a conventional manner in accordance with the refraction index of glass, and then penetrates through the glass pane 1 up until its inner surface 3. The solar radiation 4 is scattered on the outer structures 21, and again penetrates through the glass pane 1 in the direction of the outer surface 2 or to the outside. The outer structures 21 are arranged relative to the inner structures 31 in such a way that allows comparatively abundant solar radiation 4 to penetrate through the glass pane 1 directly through the intermediate outer regions 22 via the intermediate inner regions 32 through the glass pane 1. The scattering effect of the outer structures 21 also causes additional solar radiation 4 to penetrate through the glass pane 1 via the intermediate inner regions 32 in the first spatial angle of incidence range, so that comparatively abundant solar radiation 4 can penetrate through the glass pane 1 in winter.

FIG. 4 shows how the glass pane 1 functions in summer. As evident, solar radiation 4 strikes the outer surface of the glass pane 1 in a specific second spatial angle of incidence range. The solar radiation 4 is again refracted at the intermediate outer regions 22 in a conventional manner, and then penetrates through the glass pane 1 up until its inner surface 3. The solar radiation 4 is scattered on the outer structures 21, and penetrates through the glass pane 1 up until its inner surface 3. The solar radiation 4 is reflected on the inner structures 31, and then penetrates the glass pane 1 through the outer surface 2 toward the outside. The outer structures 21 are arranged relative to the inner structures 31 in such a way that comparatively little solar radiation 4 can penetrate through the glass pane 1 directly through the intermediate outer regions 22 via the intermediate inner regions 32 through the glass pane 1. The scattering effect of the outer structures 21 also causes additional solar radiation 4 to strike the reflecting inner structures 31, so that comparatively little solar radiation 4 can penetrate through the glass pane 1 in summer.

FIG. 5 shows a glass pane 19 as a second exemplary embodiment of a building envelope part according to the invention with an outer surface 29 and an inner surface 39 opposite the outer surface 29. The outer surface 29 exhibits outer structures 219 with a fixed width, as well as intermediate outer regions 229 that lie between the outer structures 219. The inner surface 39 exhibits inner structures 319 with a fixed width, as well as intermediate inner regions 329 that lie between the inner structures 219.

The glass pane 19 is essentially designed to correspond to the glass pane 1 shown on FIG. 1 to FIG. 4. In particular, the glass panes 1, 19 described above as well as those described below (see glass pane 18 on FIG. 6 and glass pane 17 on FIG. 7) are here preferably dimensioned and manufactured via the following steps:

The axial rotation ω of any angle-selective outer and inner structures is geared toward the orientation, i.e., the alignment and inclination, of the glass pane 1, 19, 18, 17 in its provided application, as well as toward the latitude of the object location at which the glass pane is being used. If the glass pane 1, 19, 18, 17 can receive direct solar radiation on all days in a calendar year, the longitudinal axis of the outer and inner structures must be aligned parallel to the intersecting line between the solar ecliptic and glass pane 1, 19, 18, 17, and otherwise perpendicular. The latter holds true in particular on the northern hemisphere in winter for glass panes 1, 19, 18, 17 or building envelope parts aligned toward the north. The following relationship applies to glass panes 1, 19, 18, 17: A mathematical expression that correlates the variables ω, β, γ and φ,

$\begin{array}{cc}\omega =-\mathrm{sgn}\left(\phi *\sin \left(\gamma \right)\right)*\arccos \hspace{1em}\left(\frac{\sin \left(\phi \right)*\sin \left(\beta \right)+\cos \left(\phi \right)*\cos \left(\beta \right)*\cos \left(\gamma \right)}{\sqrt{\begin{array}{c}{\cos \left(\phi \right)*\cos \left(\beta \right)+\sin \left(\phi \right)*\cos \left(\gamma \right)*\sin \left(\beta \right))}^2\\ +{\sin }^2\left(\gamma \right)*{\sin }^2\left(\beta \right)\end{array}}}\right)& \left(1\right)\end{array}$

In this case, β is an inclination of the glass pane 1, 19, 18, 17, γ is an alignment of the glass pane 1, 19, 18, 17, and φ is the latitude of the object location.

The angular dependence of the outer and inner structures in a transversal axial direction can be achieved in a variety of ways, for example through the geometric or structural configuration of the glass pane 1, 19, 18, 17. As described above, the angle α₊ at which a maximum or minimum transmittance is to be achieved must first be determined for this purpose given a parallel and perpendicular alignment. These two angles are reached on June 21 and December 21, when the respective solar azimuth and alignment of the glass pane 1, 19, 18, 17 coincide, and described by mathematical expressions that correlate the variables α_±, β, γ, ε and φ, preferably in accordance with the following equations:

α_±=arcsin(cos(φ)*cos(γ))+(β−90°)±ε,  (2)

wherein ε≅23.4° is the obliqueness of the ecliptic relative to the equator, which is also referred to as the tilt of the earth's axis or obliquity. The outer structures and inner structures described above and below will be used in the following to illustrate configurations that yield comparatively high contrast ratios for the angles α₊ (continuous lines) and α₋ (broken lines).

In the glass pane on FIG. 4, stripes are applied as the outer structures 219 to the outer surface 29 (air side) parallel to the longitudinal axis through printing, etching, sandblasting, roughening or in some other way, and diffusely scatter the incident light or incident solar radiation 49. The sections between the stripes, i.e., the intermediate outer regions 229, are left unchanged. Stripes are also applied as the inner structures 319 on the inner surface 39 of the glass pane parallel to the longitudinal axis through printing or in some other way, and reflect or absorb the incident light or incident solar radiation 49. The sections between the stripes, i.e., the intermediate inner regions 329, are left unchanged. The width and relative location of the upper and lower stripes, i.e., the outer structures 21 and inner structures 31, of the glass pane must be selected in such a way that the light falling through the clear sections, i.e., the intermediate outer regions 229, from outside or above, in turn passes through the clear sections below, i.e., the intermediate inner regions 329, at the angle α₊ and the light falling through the clear sections, i.e., the intermediate outer regions 229, from outside or above, in turn strikes the reflecting sections below, i.e., the inner structures 319, at the angle α₋. The respective light refraction of the glass must here be taken into account by a mathematical expression that correlates the variables r, d, α_± and n, preferably in accordance with the equation

$\begin{array}{cc}\frac{r}{d}=\frac{\sin \left({\alpha }_{+}\right)}{\sqrt{n^2-{\sin }^2\left({\alpha }_{+}\right)}}-\frac{\sin \left({\alpha }_{-}\right)}{\sqrt{n^2-{\sin }^2\left({\alpha }_{-}\right)}},& \left(3\right)\end{array}$

wherein d [mm] is the thickness of the glass or glass pane 19, r [mm] is the width of the reflector or inner structures 319, and n is the average refraction index of glass. The second summand in the above equation indicates the offset in outer and inner structures x/d. The scattering effect of the diffuse stripes or outer structures 219 with width m [mm] must be selected in such a way as to widen the incident light band by about a factor of three as it passes through the glass thickness.

FIG. 6 shows the glass pane 18 as a third exemplary embodiment of a building envelope part according to the invention with an outer surface 28 and an inner surface 38 opposite the outer surface 28. The outer surface 28 exhibits prismatic outer structures 218 with a fixed width. The inner surface 38 exhibits inner structures 318 with a fixed width, as well as intermediate inner regions 328 that lie between the inner structures 218. The outer structures 218 designed as flat prisms on the outer surface of the glass pane guide the light bands or solar radiation incident at angles α₊ or α₋ in the direction of the reflectors or inner structures 318 via light diffraction to a maximum or minimum extent.

FIG. 7 shows a glass pane 17 as a fourth exemplary embodiment of a building envelope part according to the invention with an outer surface 27 and an inner surface 37 opposite the outer surface 27. The outer surface 27 exhibits outer structures 217, as well as intermediate outer regions 227 that lie between the outer structures 217. The outer structures 217 protrude through the glass pane 17, and extend from the outer surface 27 up until the inner surface 37. The inner surface 37 exhibits inner structures 317 with a fixed width, as well as intermediate inner regions 327 that lie between the inner structures 217. The outer structures 217 are each joined with one of the inner structures 317, so that they together each exhibit an essentially L-shaped cross section.

The outer structures 217 and inner structures 317 designed as L-shaped lamellae allow the light bands or solar radiation 47 incident at angles α₊ or α₋ to be maximally passed through or reflected by the construction or glass pane 17 owing to reflections. In the case of

α₊=−α₋  (4)

where x=0 mm, the contrast ratio is maximal (full transmittance or full reflection). At

$\begin{array}{cc}\frac{x}{d}=\sin \left(\left({\alpha }_{+}+{\alpha }_{-}\right)/4\right)& \left(5\right)\end{array}$

an optimal contrast ratio is reached for α₊≠−α₋.

Even though the invention was depicted and detailed based on the figures and accompanying specification, this depiction and detailed description must be regarded as illustrative and exemplary, and not construed as limiting the invention. It goes without saying that a person skilled in the art can introduce changes and modifications without departing from the scope and spirit of the following claims. In particular, the invention also encompasses embodiments with any combination of features mentioned or shown above or below in relation to various embodiments. For example, the invention can also be realized by the following additional variations in structural design:

• • Given an analogue construction as described above with respect to FIG. 5, using light-polarized stripes as outer structures and inner structures that are complementarily polarized for c and r, the transmittance can be maximal at an angle α₊ and drop off approximately or entirely to zero at an angle α₋.
  • The disclosed arrangements and configurations of outer structures and inner structures, in particular those described above on FIG. 5, FIG. 6 and FIG. 7, can advantageously also be arranged in such a way as not to form an acute angle with one of the side edges. They can also be situated horizontally.

The invention also encompasses individual features in the figures, even if they are there shown in conjunction with other features and/or not mentioned above or below. In addition, the subject matter of the invention can exclude the alternative embodiments described in the figures and specification, and individual alternative features thereof.

Furthermore, the term “encompass” or “comprise” and derivations thereof does not preclude other elements or steps. Likewise, the indeterminate article “a” or “an” and derivations thereof does not rule out a plurality. The functions of several features enumerated in the claims can be satisfied by a single unit. In particular, the terms “essentially”, “roughly”, “approximately” and the like in conjunction with a property or value also precisely define the property or precisely define the value. A computer program can be stored and/or run on a suitable medium, for example on an optical storage medium or a fixed medium, which is provided together with or as part of other hardware. It can also be run in another form, for example via the internet or other wired or wireless telecommunication systems. In particular, for example, a computer program can be a computer program product that is stored on a computer-readable medium, and designed to be executed to implement a method, especially the method according to the invention. All reference numbers in the claims are not to be construed as limiting the scope of the claims.

Claims

1. A building envelope part (1; 17; 18; 19) for angle-selective irradiation insulation, wherein the building envelope part (1; 17; 18; 19) comprises an outer surface (2; 27; 28; 29) with outer structures (21; 217; 218; 219), an inner surface (3; 37; 38; 39) opposite the outer surface (2; 27; 28; 29) with inner structures (31; 317; 318; 319) and a side edge (5) that borders the outer surface (2; 27; 28; 29) and inner surface (3; 37; 38; 39), wherein the outer structures (21; 217; 218; 219) and inner structures (31; 317; 318; 319) are arranged relative to each other in such a way that the translucency of the building envelope part (1; 17; 18; 19) varies as a function of the spatial angle of incidence, characterized in that the outer structures (21; 217; 218; 219) and inner structures (31; 317; 318; 319) are arranged at an acute angle to the side edge (5).

2. The building envelope part (1; 17; 18; 19) according to claim 1, in which the outer structures (21; 217; 218; 219) are arranged as light diffusers, and the inner structures (31; 317; 318; 319) are arranged as optically opaque.

3. The building envelope part (1; 17; 18; 19) according to claim 1, in which the outer structures (21; 217; 218; 219) are prismatic, and the inner structures (31; 317; 318; 319) are optically opaque in design.

4. The building envelope part (1; 17; 18; 19) according to claim 2 or 3, in which the inner structures (31; 317; 318; 319) are designed as light reflectors.

5. The building envelope part (1; 17; 18; 19) according to claim 2 or 3, in which the inner structures (31; 317; 318; 319) are arranged as light absorbers, wherein the light absorbers are photovoltaic light absorbers.

6. The building envelope part (1; 17; 18; 19) according to claim 1, in which the outer structures (21; 217; 218; 219) comprise parallel stripes arranged in a common plane, and the inner structures (31; 317; 318; 319) comprise parallel stripes arranged in a common plane.

7. The building envelope part (1; 17; 18; 19) according to claim 6, in which the outer structures (21; 217; 218; 219) are arranged parallel to the inner structures (31; 317; 318; 319), wherein the common plane of the outer structures (21; 217; 218; 219) and the common plane of the inner structures (31; 317; 318; 319) are different.

8. The building envelope part (1; 17; 18; 19) according to claim 1, in which the outer structures (21; 217; 218; 219) are arranged in a direction perpendicular to the outer surface (2; 27; 28; 29) and to the inner surface (3; 37; 38; 39), offset in relation to the inner structures (31; 317; 318; 319).

9. The building envelope part (1; 17; 18; 19) according to claim 1, in which the outer structures (21; 217; 218; 219) and inner structures (31; 317; 318; 319) are essentially lamellar in design.

10. A method for manufacturing a building envelope part (1; 17; 18; 19) for angle-selective irradiation insulation, wherein the building envelope part (1; 17; 18; 19) comprises an outer surface, an inner surface (3; 37; 38; 39) opposite the outer surface (2; 27; 28; 29), and a side edge (5) that borders the outer surface (2; 27; 28; 29) and inner surface (3; 37; 38; 39), in which the outer surface (2; 27; 28; 29) is provided with outer structures (21; 217; 218; 219) and the inner surface (3; 37; 38; 39) is provided with inner structures (31; 317; 318; 319), wherein the outer structures (21; 217; 218; 219) and inner structures (31; 317; 318; 319) are arranged relative to each other in such a way that the translucency of the building envelope part (1; 17; 18; 19) varies as a function of the spatial angle of incidence, characterized in that the outer structures (21; 217; 218; 219) and inner structures (31; 317; 318; 319) are arranged taking into account the orientation of a provided application of the building envelope part (1; 17; 18; 19) and taking into account the latitude of the provided application of the building envelope part (1; 17; 18; 19).

11. The method according to claim 10, in which the longitudinal axes of the outer structures (21; 217; 218; 219) and inner structures (31; 317; 318; 319) are aligned parallel to an intersecting line between the plane of the solar ecliptic and the plane of the building envelope part (1; 17; 18; 19) in the provided application if the building envelope part (1; 17; 18; 19) can be reached by direct solar radiation on all days of a calendar year in the provided application.

12. The method according to claim 11, in which the acute angle between the outer structures (21; 217; 218; 219) and side edge (5) or between the inner structures (31; 317; 318; 319) and side edge (5) is established by a mathematical expression that correlates the variables ω, β, γ and φ, preferably according to the equation ω = - sgn  ( φ * sin  ( γ ) ) * arccos    ( sin  (  φ  ) * sin  ( β ) + cos  (  φ  ) * cos  ( β ) * cos  ( γ ) cos  (  φ  ) * cos  ( β ) + sin  (  φ  ) * cos  ( γ ) * sin  ( β ) ) 2 + sin 2  ( γ ) * sin 2  ( β ) )

wherein ω is the acute angle, β is an inclination, and γ is an alignment of the building envelope part (1; 17; 18; 19) in the provided application, and φ is the latitude in the provided application.

13. The method according to claim 10, in which a first projected angle of incidence with a maximum light transmittance through the building envelope part (1; 17; 18; 19) is established.

14. The method according to claim 10, in which a second projected angle of incidence with a minimum light transmittance through the building envelope part (1; 17; 18; 19) is established.

15. The method according to claim 13, in which the building envelope part (1; 17; 18; 19) is configured in such a way that the outer structures (21; 217; 218; 219) comprises parallel stripes arranged in a common plane, and the inner structures (31; 317; 318; 319) comprises parallel stripes arranged in a common plane.

16. The method according to claim 15, in which the building envelope part (1; 17; 18; 19) is configured in such a way that the outer structures (21; 217; 218; 219) are arranged parallel to the inner structures (31; 317; 318; 319), wherein the common plane of the outer structures (21; 217; 218; 219) and the common plane of the inner structures (31; 317; 318; 319) are different, and that the stripes of the outer structures (21; 217; 218; 219) and stripes of the inner structures (31; 317; 318; 319) are established by a mathematical expression that correlates the variables r, d, α± and n, preferably according to the equation r d = sin  ( α + ) n 2 - sin 2  ( α + ) - sin  ( α - ) n 2 - sin 2  ( α - ), wherein r is the width of one of the stripes of the inner structures (31; 317; 318; 319), d is the thickness of the building envelope part (1; 17; 18; 19), n is the average refraction index of the building envelope part (1; 17; 18; 19), α+ is the first projected angle of incidence, and α− is the second projected angle of incidence.

17. The method according to claim 15, in which the building envelope part (1; 17; 18; 19) is configured in such a way that a width of the stripes of the exterior side, a width of the stripes of the interior side, and a respective distance between the stripes are essentially identically dimensioned.

18. A computer program comprising a program code structure configured to implement the method according to claim 10 when being executed on a computer.

19. A computer program comprising a program code structure configured to implement the method according to claim 11.

20. A computer program comprising a program code structure configured to implement the method according to claim 12.