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

Advanced Building Skins
Figure 9: Views of on-site usually procedures to replace sealing elements
Dismantling: the proposal was to redesign the glazed panels with air chambers in order to be
completely disassembled and recycled. Currently, waste management is complex for various types of
glass including glazing with air chambers, laminated glass, and printed, inked, coated and silkscreened
glass. The composition and type of joints between the different types of glass that make up
the panels are not reversible, which means that the original materials cannot be recovered in a state
that enables them to be recycled in a technically and financially simple manner. Consequently, much
of the glass that is used in construction is not recycled but downcycled (it is ground up and used as a
component of lower quality compounds). The aim of the proposed measure is to avoid two
environmental impacts: that due to downcycling (which could be avoided by dismantling and selective
separation of the glass components) and that due to the production of new materials (which would be
avoided if the existing glazing could be reused or recycled). Even when we take into account that most
of the materials would be recovered to be reused or recycled, the environmental impact of disassembly
in terms of energy is 10.99 MJ/m2. If we exclude the operations of disassembly, loading and transport
to a recycling centre where the panels would be taken apart, the environmental impact that could be
avoided with this measure is 0.15 MJ/m2 corresponding to waste management at a dump (the joints
and the glass panels with an air chamber) and 0.25 MJ/m2 corresponding to transport from the site
where the façade module is disassembled to the dump. In addition, up to 204.5 MJ/m2 would be saved
due to the reuse of the glass (assuming 50% of the total is reused), as this would reduce the need to
produce new material.
Sheets of glass
Air chamber
Spacer bar
First seal
Drying molecular sieve
Second Seal
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2
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Figure 10: Detailed view of glazing with an air chamber and the process of removing a seal
Impact of the proposals to improve the life cycle: figure 11 shows the combined positive impacts of
the different proposals to improve environmental performance, in absolute and relative terms (taking
into account total energy consumption for the FB720 façade of 2,278.08 MJ/m2 throughout the entire
life cycle).
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