Advanced building façade design for optimal delivery of end use energy demand
Funded by: EPSRC
University of Nottingham, Loughborough University, University of Exeter
Partners and stakeholders:
Brinell Vision Limited; Couch Perry Wilkes LLP (UK); Elementa Consulting Ltd; MDelta Ltd
Glazed façades play an important role in determining a building’s energy performance and perform a range of, sometimes conflicting, functions. They regulate heat transfer to and from the external environment by radiation (solar and long wave), conduction and convection, allow natural daylight into the space and can improve the way buildings look externally. Improving fenestration energy performance can make a significant contribution to reducing building energy loads.
The aim of this project is to adopt a holistic approach to developing advanced façade technologies to achieve building energy reduction goals. Low cost optical components will be designed and integrated into conventional double glazing, which will significantly increase the thermal resistance of the window, provide control of solar heat gain, and enable windows to perform better than walls on an annual basis in terms of their net energy balance. Building energy loads will be reduced significantly while providing a comfortable luminous environment.
Four types of advanced glazing are to be developed with input from industry partners to ensure the systems developed will be a viable option adopted by commercial building designers. The new products being developed will be suitable replacements for current transparent glazing systems, offering building energy reduction through enhanced thermal resistance and optimised daylight transmittance. By recognising the range of functions played by different areas of the façade, it is possible to tailor systems to match requirements. For example, in areas where view is less important active coatings can be used that vary the transmission and scattering of light to direct daylight deeper into rooms, or solar technologies to generate electricity or capture useful heat can be integrated.
In addition, a system-level optical-thermal-electrical model for advanced glazing systems will be developed and integrated with existing building simulation software in order to more accurately predict the performance of advanced façades and their impact on building energy demand. The developed systems will be installed into existing buildings for long-term monitoring and life cycle analysis. Our target is for a typical commercial building incorporating the proposed advanced glazing façade system to provide comfortable annual daylight levels while achieving over a 20% reduction in annual artificial lighting energy consumption, space heating reductions of over 30% in the heating season and cooling load reductions of 20% in summer. The integration in a façade system of active solar energy technologies with better performing windows may potentially lead commercial buildings to become net energy producers on an annual basis.
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