MASTER THESIS Biomimetic potential of sponge ... - IAP/TU Wien

were outperformed by simple tubular daylight guidance systems (TGDS) in all climatic
regions, especially close to the equator.
Additionally, they compared the demands that the different systems made to the
geometry of buildings where they can be installed. Here, the greater flexibility of fibre based
systems compared to TGDS became apparent, although SCIS seems to be difficult to
integrate into existing building. Also, once installed, fibre-based systems can better be
adapted to modifications that might become necessary, e.g. when the building use changes.
Thus, fibre based systems hold great promise and the challenges regarding efficiency
should be addressed. Two problems have been discussed in the abovementioned article.
First, guidance technology should be improved. This might become possible with novel
materials that allow for fewer transmission losses and accordingly the guidance of light to
deeper regions of the building. Secondly, collection efficiency needs to be addressed. All the
hybrid lighting systems presented here concentrate light before guiding it to the interior of
the building. This prevents them from using diffuse daylight efficiently, making a close
tracking of the sun important. Only SCIS can make use of scattered light to some extent,
because it has a lower concentration ratio (Mayhoub & Carter, 2011) (Rosemann et al.,
2008). Thus, the presented hybrid systems rely on expensive sun-tracking mechanisms. An
interesting way around this problem was suggested by Schäfer (2011). Inspired by desertdwelling
Window plants, he suggested dome-shaped anidolic collectors that have a wide
reception angle and can concentrate light. This would accordingly minimize, or even abolish,
the need to track the sun. The lower concentration ratio (Stine & Geyer, 2001) as compared
to the collectors of HSL, Parans etc. could be balanced by coupling light from various anidolic
collectors into one light-guide.
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