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SUSREF
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Image 40. Solar heating wall with transparent insulation (IEA
The system can be applied on south-facing massive walls without existing insulation. This
means that in many renovation cases, the outer layers of external wall would need to be
removed before applying this system. (IEA 1999)
This kind of system can cause overheating in summer conditions. Without any shading, the
maximum coverage of this type of wall is 30% of the south façade. If the surface area is
limited, this limits the potential solar gains in the winter time. The system can be improved by
using simple overhangs that block sunshine in the summer, but allow it to pass in the winter
time. By using overhangs, the area covered with TI can be extended to 40 % of the façade
with the same heat load in summer. (IEA 1999)
Commercial systems are already available, which do not need additional overhangs. An
example of this kind of system is StoSolar panel, which incorporates translucent capillary
panels covered with a transparent glass render finish. The glass render helps to reflect the
excessive sunlight in the summer, thus preventing overherheating. (Sto 2011b)
Image 41. Solar heating wall with transparent insulation (Sto 2011b)
Example uses of PCM’s –Solar wall with PCM
Typical wall structures may lack the sufficient thermal mass required for storing the solar heat.
Increasing thermal mass may also prove difficult with normal wall structures, since it would
require significant wall thicknesses. Image 42 shows the cross-section of a solar wall with
PCM (Mehling and Cabeza 2008).