advanced building skins 14 | 15 June 2012 - lamp.tugraz.at - Graz ...

Advanced Building Skins
energy use, they function as transparent sun protection while also using daylight. For one thing, the
mounting of vacuum tubes outside the facade (consent has already been granted by the Office of
Building Technology) has had to be adopted for architectural and energy considerations, and the
collector pipes installed behind protective glass panes, on the grounds of safety and cleaning issues.
2.1 Multiple functions of the integrated system
Energy
A facade integrated solar collector provides absorbed heat and energy gain for the different
uses such as domestic hot water for sinks and kitchen, solar cooling, and can be used to
support space heating or the like.
Sun protection by reflection and / or absorber plate and heat dissipation
The trapped heat from the sun is dissipated by heat transfer. Through the vacuum insulation of
the tube, the heat absorbed by the tube is not released again, since the surface of the vacuum
tube is not warm.
Daylighting
With proper arrangement of the tubes or corresponding perforation of the absorber panel,
daylight is streamed into the interior, despite the sun protection properties.
Maintenance of transparency
By keeping the necessary distance between the tubes, through the transparent construction and
/or perforation of the absorber panel, the view out of the interior is maintained.
Figure 1: multiple functions of the integrated system
2.2 Multiple positions of the system
In the current research projects, two of the four scenarios examined with regard to the installation
position of the facade collector and thermal level have proved to be useful.
Installation position of the external facade collector before insulation glazing:
This achieves the highest energy returns, architecturally structuring the outer skin of an building. Their
weak points are in the difficulty of cleaning due to the outlying tubes, and in the area of safety, where
approval is still required in individual cases. For the actual installation in the planned pilot project
SOLPOWER1 consent has already been granted. Installation position of the collector behind a facade
glazing: This nets about 30% less energy than vacuum tubes installation position outside the front
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