Inside out: a shift in perspective for building exergy analysis

Research output: Chapter in Book/Report/Conference proceedingConference contribution book

Abstract

In many countries, our lives are lived under a roof. The indoor space is constantly growing and its thermal conditions are kept relatively stable, within comfort requirements, by a variety of passive strategies and mechanical systems. Despite the many energy-efficiency programmes and conservation efforts, the inevitable consequence of the rise in complexity of the built environment is its increasing energy consumption, which poses urgent sustainability concerns. Within this scenario, many optimisation methods are attempted in building design. Among them, exergy analysis - with its roots in thermal power plants - provides a quantification of energy quality and a deeper insight into the causes of inefficiencies. However, buildings are substantially different from machines and some fundamental aspects of their exergy analysis are controversial, such as the impact of the reference-state selection on a dynamic study, or the practical benefits of achieving high exergy efficiencies. Exergy assessments are complex and do not currently hold a prominent role in building design. Nonetheless, second-law approaches preserve their attractiveness and many possible methods are still unexplored. After acknowledging the thermodynamic differences between buildings and power machines and their particular aims, a simplified theoretical framework (built on the current methods) is proposed and formally compared to a state-of-the-art dynamic exergy analysis. The indoor environment is recognised as the fulcrum of all building energy interactions and the reference to assess energy quality. A case study shows the quantitative differences between the proposed idea and the classical approach for the first fundamental steps of the building energy chain from the exergy demand to the emission system. Keeping the design focus on exploiting the local exergy budget, rather than minimising consumption, contributes towards flexible and low-cost sustainable buildings for integrated energy systems. Substantial further research, assisted by virtual representations and real-world testing, is required to explore meanings and practical implications of the proposed perspective.
LanguageEnglish
Title of host publicationECOS 2018
Subtitle of host publicationProceedings of the 31st International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems
Place of PublicationGuimarães, Portugal
Number of pages12
ISBN (Electronic)978-972-99596-4-6
Publication statusPublished - 21 Jun 2018
EventECOS 2018: 31st International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems - Guimaraes, Portugal
Duration: 17 Jun 201822 Jun 2018

Conference

ConferenceECOS 2018
CountryPortugal
CityGuimaraes
Period17/06/1822/06/18

Fingerprint

Exergy
Roofs
Energy efficiency
Sustainable development
Conservation
Power plants
Energy utilization
Thermodynamics
Testing
Costs

Keywords

  • exergy
  • building
  • reference state
  • dynamic analysis
  • low-cost

Cite this

Bonetti, V. (2018). Inside out: a shift in perspective for building exergy analysis. In ECOS 2018: Proceedings of the 31st International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems [220] Guimarães, Portugal.
Bonetti, Valentina. / Inside out : a shift in perspective for building exergy analysis. ECOS 2018: Proceedings of the 31st International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems. Guimarães, Portugal, 2018.
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Bonetti, V 2018, Inside out: a shift in perspective for building exergy analysis. in ECOS 2018: Proceedings of the 31st International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems., 220, Guimarães, Portugal, ECOS 2018, Guimaraes, Portugal, 17/06/18.

Inside out : a shift in perspective for building exergy analysis. / Bonetti, Valentina.

ECOS 2018: Proceedings of the 31st International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems. Guimarães, Portugal, 2018. 220.

Research output: Chapter in Book/Report/Conference proceedingConference contribution book

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Bonetti V. Inside out: a shift in perspective for building exergy analysis. In ECOS 2018: Proceedings of the 31st International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems. Guimarães, Portugal. 2018. 220