Poly2Facade - Innovative thermal self-regulating solar facades by means of functional polymers

Status

ongoing (started: April 2012)

Summary

Utilizing façades for energy conversion, distribution and storage is a major opportunity of increasing the energy efficiency of buildings due to the very large areas available, in particular for multi-storey buildings in “smart cities” of the future. A prototype of such a multifunctional façade is being realized in the course of the Austrian K-Project “Multifunctional Plug & Play Façade” (MPPF) by a consortium of 14 industrial and scientific partners since 2008. A high degree of prefabrication of various functional, inter-exchangeable modules for energy conversion, air conditioning, shading, IT and control ensures economic viability in the long run. However, one year of intense monitoring of the fully integrated solar thermal modules revealed the major obstacle for the widespread use of flat plate collectors in aluminum/steel-glass-façades: In the unavoidable case of stagnation, the temperatures at the room-sided-panel of the façade exceed values that can be considered comfortable for inhabitants.

Thus, this MPPF project aims at developing a technologically and economically sound solution that resolves the overheating problem of fully integrated flat plate façade collectors once and for all. The solution employs highly sophisticated functional polymers that will be integrated into various parts of the solar thermal façade element. The methodical approach includes theoretical modelling as to optimum material parameters and wall settings, development of novel latent heat storages and colored thermotropic layers based on polymeric materials and application demonstrations on a laboratory scale and in the real MPPF test building.

In year 1 a simulation model has been developed which combines CFD and one-dimensional simulations and allows for an automated optimization of the material parameters. Due to the speed of the simulations extensive parameter studies were conducted and optimum material parameters for latent heat storages and thermotropic layers have been calculated. Simulations clearly demonstrate that effective overheating protection is achieved by applying such functional polymers. With optimum material parameters in scope, currently tailor-made, polymeric phase change materials and thermotropic layers are developed. Based on outcomes of subsequent test rig measurements in solar simulators, promising functional materials are selected for a final demonstration of the fully integrated, overheating protected solar thermal façade elements in the real MPPF test building.

Finally, a monitoring of the test façade shall prove the efficiency of the aspired overheating protection devices. After the successful project conclusion comprehensive (theoretical and practical) knowledge on the overheating protection potential of functional polymers for buildings with fully integrated solar thermal modules will be available. Moreover, novel, tailor-made, and coloured thermotropic layers for overheating protection of façade collectors as well as novel, tailor-made polymeric latent heat storages with variable heat conductivity for insulation of buildings with integrated solar thermal modules will be developed. 

Project management

• Materials Science and Testing of Plastics, University of Leoben

Project or cooperation partners

• ÖFPZ Arsenal GesmbH
• Forschungszentrum für integrales Bauwesen AG
• Polymer Competence Center Leoben GmbH
• Polymer Processing, University of Leoben
• Chemistry of Polymeric Materials, University of Leoben

Dr. Katharina Resch
Otto Glöckel-Straße 2
A-8700 Leoben
Tel.: +43 (3842) 402 2105
E-Mail: katharina.resch@unileoben.ac.at
Web: www.kunststofftechnik.at