Developing building exergy methods through collaboration in the open-data era

Exergy analysis combines the first and the second law of thermodynamics through a reference state, quantifying energy quality. Although exergy methods are a relatively recent development in applied thermodynamics, many classical engineering fields use them successfully to optimise their processes. A deeper understanding of quality and degradation of energy resources would be beneficial for the built environment too, but designers do not use exergy assessments yet, and building exergy analysis is still limited to research institutions. Classical exergy assessments of buildings are conducted on a steady-state basis, but the building behaviour is intrinsically dynamic in most cases, which means that dynamic calculations are required for exergy to be meaningful in the everyday life of designers. However, there are three major obstacles to the development of dynamic exergy methods for buildings: the controversial definition of the reference state, the unclear usefulness of the analysis and the lack of simulation tools; these problems are deeply interconnected and difficult to address separately. This research attempts to tackle the obstacles simultaneously by proposing a collaborative approach to exergy methods and simulation software development, and open data as the fulcrum of the connection between academia and the real world. An open-source software for the dynamic exergy analysis of the building envelope, with a user-defined reference state, is partially developed and used to illustrate the process with a research case; detailed building exergy assessments give the opportunity to test different definitions of the exergy reference state and virtually experiment various solutions, which are then discussed with building designers and tested in real cases. Calculations are currently focused on envelope exergy storage. Further developments consider model calibration with measurement of the real case, discussion of software tools, modification and addition of calculations, validation and improved user-experience, and require open collaboration with fast feedback loops among researchers and building designers