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

1 Introduction
Advanced Building Skins
In recent years, solar thermal systems have established themselves on the market, mostly to augment
domestic water heating. In 2006, about 1 million square meters of collection panels were established
in the sector. On the whole, collectors are mounted on or integrated into rooftops.
Given around 5 square meters of collector area, solar water heating systems cover between 5% to 12%
of the total heating demand of a single family home. To increase the solar thermal percentage further,
combination boilers are used. For this purpose, collection panels larger than 10 square meters are
required, which, based on levels of sunshine and the required amount of heat in office buildings, are
best integrated into the façade, since roof space is rarely available. The only systems on the market are
façade mountable, adaptive systems.
Till now, only thermal insulation manufacturers have developed products, such as flat plate collectors,
which can be integrated into their systems.
Non-residential building, particularly office and administration construction, is only now beginning to
take an interest in solar thermal systems -- not least because of the associated positive image. Since in
such buildings roof spaces are in short supply, solar thermal systems must be integrated into the
facade. In the façade, the solar thermal system is visible from outside and in certain cases may also be
visible from the inside and can be used to enhance image. The reticence of office and administration
construction in using solar thermal energy for heating water, for in-house canteens or cafeteria, for
solar cooling, or possibly also for heating assistance, is among other things largely due to the fact that
there is no system on the market which integrates them into conventional façades. Photovoltaic
systems have a similar developmental history. Originally either roof mounted or roof integrated, they
have, unlike solar thermal energy, managed the leap into architectural realization. Meanwhile, there
are a large number of award-winning buildings (mostly administrative buildings), where this
technology is successfully used in the building envelope. Photovoltaics enjoy clearly signaled support
at the political level, which encourages the active use of solar energy use in building envelopes. Thus
the current draft of the EEG (Renewable Energy Sources Act) states that integrated systems will
receive increased financial support and facade integrated systems, the maximum rate. The EEWG
(Renewable Energies Heat Act) has already been adopted. As with the modules of a photovoltaic
system, with solar thermal systems the collection panels are the eye-catching element. They occupy
roughly the same areas of the building envelope, although a partial shading of the panels is less
important than with photovoltaic modules. For flat panels, there are already systems that allow
integration into the building envelope. Currently there is no integration of vacuum tubes. However,
thanks to their aesthetic structure and geometric advantages, they offer great potential benefits for
building facades.
2 Research project
Integration of solar thermal systems in facades of office buildings. The promotion of renewable energy
sources by the BMU seeks to lead long-term development towards economic alternatives to the
primary energy supply in Germany. The aim of energy research programs, besides ensuring security
and efficiency of supply, is environmental sustainability, which means meeting future energy demand
in Germany in an environmentally friendly and cost-effective manner via exploitation of all
technically and economically viable options, replacement of limited resources of coal, oil and gas and
prevention of environmental and climate-related emissions, above all CO2.
The overarching goal of the project is reducing the use of finite energy sources for the supply of
offices buildings with heat and hot water, thereby minimizing the emission of greenhouse gases,
particularly CO2. For the development of a broadly applicable system, scientists, along with FGHK,
TU Munich, IBK2 and Solites, Stuttgart, supported by the industrial firms Frener + Reifer Metalbau,
Metalbau Früh and Hydro Building Systems will work on technical implementation in the facades area
based on the general relevant details. Support with respect to issues concerning collectors has been
taken over by Paradigma of Ritter-Solar. In the research project for the integration of vacuum tubes
into facades of office buildings, two different facade panels with multiple functions, which differ in
terms of their position to the thermal level, were developed. In addition to their ability for active solar
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