Description: Das Projekt "Daylighting systems for student quarters based on fluorescent concentrators and light pipes" wird vom Umweltbundesamt gefördert und von Norbert Kaiser Consulting and Controlling, Ingenieurbüro für Bauwesen durchgeführt. Objective: Demonstration of innovative day lighting systems for the illumination of dark floors of a students quarter in Stuttgart-Hohenheim. Such systems, when installed in large buildings, could considerably reduce the energy demand for electrical lighting. General Information: The student's living quarters comprise six buildings, 2 to 3 storeys high, of interesting architecture. They are built against earth hills on their north sides and they have grass covered roofs. The students' rooms face almost due south, and on the northern side of the buildings there are rooms for recreation, cooking and eating. These northern rooms have little daylight, the only light sources being light transmitted through the glass roof over the staircase, through the glass doors of the students' rooms (if not darkened by shutters or curtains) and through the entrance door. One building is equipped with a fluorescent planar concentrator (FPC) another one with a light pipe. The systems collect the light near the glass cover of the staircase and then reflect it into the darkest kitchen, about 6 to 7 m below the roof. The FPC-system collects the light with an FPC (yellow fluorescent dye BASF 241/PMMA) forming the surface of a truncated cone, the light is then guided down within the wall of a transparent pipe of PMMA (diameter 30 cm, wall thickness 0.6 cm) by total internal reflections and is then reflected into the kitchen by a mirror. The mirror light pipe is of triangular cross section (with side length about 70 cm), made from Alucobond material (aluminium laminated onto plastic) which is covered with 3 M Silverlux film on the inner surface. The output mirror has a special shape in order to reflect as much light as possible into the kitchen to be illuminated. The estimated light transmission efficiency of the FPC-system is 2 per cent and that of the light pipe is 40 per cent. The integrated light flux is estimated with 1.7 Mio Lmh/y and 5.2 Mio Lmh/y. Achievements: The light pipe system has a light transmission efficiency of 23 per cent for diffuse light. The output light flux, integrated over one year, amounts to about 4 mio Imh, and the cost of one substituted electrical kWh can be DM 2.14, under ideal conditions. The system enhances the illuminance level in the kitchen by a factor between 2 and 5, depending on location (within the kitchen) and weather conditions. The FPC system has a very low efficiency of only 0.2 per cent (compared with the 2 per cent estimated before), due to a number of loss mechanisms which could not be taken into consideration. The contribution to the illuminance level in the kitchen is therefore not significant. Whereas mirror light pipes operating on this or another principle will soon arrive at applications which can be economically meaningful, the FPC system needs further development. Even if this development is successful, day lighting applications of the FPC will be found only for special cases; short distances for the light guiding...
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Stuttgart ? Fluoreszenz ? Kunststoff ? Weiterverwendung ? Aluminium ? Öffentliches Gebäude ? Beleuchtung ? Farbstoff ? Wohngebäude ? Beschichtung ? Elektrizitätsverbrauch ? Gebäude ? Licht ? Ökologisches Bauen ? Architektur ? Gebäudetechnik ? Energiebedarf ? Energieeinsparung ? Energiekosten ? Innovation ? Reflexion ? Wirtschaftlichkeit ? Witterung ? Lichtfalle ? Ökoeffizienz ? Beleuchtungsstärke ? Rohrleitung ? Innenraum ? Bauen ? Physikalischer Vorgang ? Planarkonzentrator ? Wetterabhängigkeit ? renewable sources of energy ? Tageslicht ? Lichtröhre ? Tageszeitabhängigkeit ?
Region: Nordrhein-Westfalen
Bounding box: 6.76339° .. 6.76339° x 51.21895° .. 51.21895°
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 1985-03-01 - 1987-12-31
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