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EP-3535611-B1 - DAYLIGHTING ILLUMINATION SYSTEM

EP3535611B1EP 3535611 B1EP3535611 B1EP 3535611B1EP-3535611-B1

Inventors

  • HINTERMANN, TOBIAS
  • BUJARD, PATRICE
  • KOSTRO, ANDRE
  • VON MUEHLENEN, ADRIAN
  • GARRIDO SEGURA, Cristobal

Dates

Publication Date
20260506
Application Date
20171102

Claims (14)

  1. Daylight illumination system for integration into a building or a vehicle, the daylight illumination system comprising a translucent façade element (800) or wall element containing a glass sheet and a light redirection element (302 or 708), and a light transport channel (801) for guiding light about horizontally into an interior of the building or vehicle, the light transport channel comprising one opening attached to the interior side of said facade element or wall element and at least one opening towards the interior of the building or vehicle, wherein the light redirection element (302 or 708) is formed as a structured polymer film or sheet attached to a glass sheet of the façade -element (800) or wall element and is configured for changing the direction of incident light into the about horizontal light transport channel, wherein said at least one opening of the light transport channel towards the interior of the building or vehicle is equipped with a light distribution element (807) allowing the guided light to leave the channel into the interior of the building or vehicle, characterised in that the light transport channel contains an air or gas filling being sealed against the ambient atmosphere.
  2. Daylight illumination system of claim 1 for integration into a building, the daylight illumination system comprising said translucent façade element (800) containing said glass sheet and said light redirection element (302 or 708), and said light transport channel (801) for guiding light about horizontally into an interior of the building, the light transport channel comprising one opening attached to the interior side of said facade element and at least one opening towards the interior of the building, characterised in that the light redirection element (302 or 708) is formed as a structured polymer film or sheet attached to said glass sheet of the façade element (800) and is configured for changing the direction of incident light into the about horizontal light transport channel.
  3. Daylight illumination system of claim 1, or 2, wherein the openings of the light transport channel for light entry and equipped with the light distribution element (807) are arranged about rectangularly to each other, wherein preferably the light transport channel's opening for light entry, and said attached façade element (800) or wall element are mounted with the light redirection element (302) about vertically, and the opening equipped with the light distribution element (807) about horizontally.
  4. Daylight illumination system of claim 1, 2, or 3, wherein light guiding inner walls of the light transport channel (801) are covered by a reflective layer, preferably a reflective silver or aluminum layer or a reflective multilayer polymer film, most preferably providing at least 95% directed reflection and less than 5% diffuse reflection.
  5. Daylight illumination system according to any of claims 2 to 4, wherein the translucent façade element (800) comprises an insulating glazing unit containing at least 2 parallel glass sheets and at least one polymer film, wherein the total thickness of the façade element (800) preferably is from the range 10 to 1000 mm, especially 15 to 50 mm.
  6. Daylight illumination system according to any of claims 2 to 5, wherein the translucent façade element (800) comprises at least 2 parallel glass sheets, and the light redirection element (302) is attached to an interior surface of one of the glass sheets suitable for forming a section of an outer surface of a building envelope.
  7. Daylight illumination system according to any of claims 1 to 6, wherein the cross section of the light transport channel (801) has a height from the range 8 to 50, especially about 10 to 35 cm; has a width from the range 20 to 300 cm, especially about 30 to 120 cm; and a length of the light transport channel (801) is from the range 500 to 2000 cm, especially about 600 to 1200 cm.
  8. Daylight illumination system according to any of claims 2 to 7, wherein the translucent façade element (800) comprises a light collector (100, 200, 700, 800), the light collector comprising at least one waveguide layer (301), said at least one light collection and redirection element (302) which is configured for coupling sunlight (303) into the waveguide layer, and at least one outcoupling element (304) configured for outcoupling light from the waveguide layer into the light transport channel (801) of the daylight illumination system.
  9. Daylight illumination system according to any of the preceding claims, wherein the light redirection element (302 or 708) is embodied as a plurality of grating couplers and/or holograms and/or mirrors and/or micromirrors and/or reflective microstructures.
  10. Daylight illumination system according to any of the preceding claims, wherein the light redirection element (302 or 708) comprises a metal and/or a material of low refractive index such as air, each embedded in a polymer film.
  11. Daylight illumination system according to any of the preceding claims further comprising an artificial light source, preferably a LED light source.
  12. Daylight illumination system according to any of the preceding claims wherein the light transport channel's cross section narrows down by a factor 1.2 to 5 over a distance of up to 2 m from its opening attached to the interior side of said facade element or wall element.
  13. Building or vehicle comprising a daylight illumination system according to any of claims 1 to 12, and an envelope with a façade or outside wall in which the light redirection element is integrated in the translucent façade element or a wall element or a window.
  14. Method for improving the light quality in a building or vehicle by increasing the amount of daylight brought into the building or vehicle, characterized in that a daylight illumination system according to any of claims 1 to 12 is integrated into a building envelope or vehicle wall, with its light transport channel aligned about horizontally away from the building's façade or outside wall of the vehicle.

Description

Field of the invention The present invention relates to daylight illumination of interior rooms with insufficient daylight, typically in buildings. In particular, it relates to a mirrored light transportation channel suitable for horizontal mounting under the ceiling, whose front end is sealed to the interior side of the building's façade and comprises a structured polymer film or sheet functioning as a light redirection element and/or light collector. The transportation channel's other end extends into the interior of the building; its side wall, especially the side wall facing the floor, comprises one or more openings equipped with luminaires. The invention further relates to a daylight illumination system comprising such components, and to a building with such daylight illumination system. Background of the invention The long-distance transport of visible light through a building can use large mirror-lined ducts, or smaller solid light guides which exploit total internal reflection. Mirror-lined ducts include advantages of large cross-sectional area and large numerical aperture (enabling larger fluxes with less concentration), a robust and clear propagation medium (i.e., air) that leads to both lower attenuation and longer lifetimes, and a potentially lower weight per unit of light flux transported. Solid light guides include the advantage of configuration flexibility, which can result in relatively tight bends with low light loss. While the advantages of mirror-lined ducts may appear overwhelming, solid light guides are nevertheless frequently selected because of the practical value of assembling light conduits in much the same fashion as plumbing. Regardless of the technique used to transport light effectively, a practical and efficient daylight collector that is adapted to the transport system is needed. Fiber optics based daylighting systems collecting light outside a building and transporting it over long distance through optical fiber cables to the interior have been described e.g. in US 4389085 and US 5581447. These systems can collect and concentrate large quantities of direct sunlight with a high concentration factor for coupling into a fiber optic cable. Their sun acceptance angle is however very small and they need thus bi-axially sun tracking mechanic devices which are expensive to produce, require intense maintenance in use, and are very bulky which makes integration into the facade of a building extremely challenging. In DE 3604269, US 5709456, and US 6059438 a fiber optic system that uses a static (non sun-tracking) collector based on light absorbing and re-emitting dyes is proposed. Such a system can be flat and thus easily integrated into the facade or the roof of a building. It suffers however under very low optical collection efficiency, a low light concentration factor, and a non-natural light spectrum. US patent application US 2010/0172147 describes another type of fiber optic system consisting of a static collector with macroscopic prism array modules to collect light and coupling it into a solid light pipe for transport into a building. Patent application WO 2015/098209 describes yet another fiber optic system based on a flat multilayer micro-optic prism film collector design. DE 3522717 describes a fiber optic system with a flat lens based static concentrator element. All these static collector systems are flat and can in principle easily be integrated into the facade of a building or its roof. They do however not allow a high light concentration factor and a large amount of optical fiber (light pipe) is thus required to transport the light over long distances into the building, which makes the systems extremely expensive and heavy. Daylighting systems based on mirror lined duct light transport elements are well known. Vertical light tubes for light transport from the roof to the upper floors of a building are described e.g. in US 8955269, WO 2011/022274, US 2014/0160570, or EP 1306606. Systems of this class are of only minor interest for multistory office buildings, where distances from the roof to the offices are mostly too long to provide the required light intensity of 500 Ix in the central working region (DIN EN 12464-1, office illumination).They are thus limited in their light transport distance to about 5 m or do require a very large cross-section area for transport of light over longer distances, thus occupying a large proportion of the available building volume. For higher light collection efficiency, the systems often comprise a dome covering the light transport duct which may comprise additional optical structures such as Fresnel structures or laser cut panels (LCP). The cover is thus bulky and does make integration of the system into the building envelope challenging. Horizontal light tubes for building illumination with daylight from the facade have been suggested in CN 102305380 and WO 1998/028645, a system combined with laser cut panels as collector (LCP) was descri