Exergetic and energy economic analyses (ECBCS ANNEX 49)

01.08.2008 - 30.04.2010
Assigned research project
The exergy content required to satisfy the demands for the heating and cooling of buildings is very low, since a room temperature level of about 20°C is very close to ambient conditions. Nevertheless, high quality energy sources like fossil fuels are commonly used to satisfy these small demands for exergy. The new approach is not necessarily focused on a further reduction of the energy flow through a building¿s envelope: when the demands for heating and cooling have already been minimised, the low-exergy approach aims at satisfying the remaining thermal energy demand using only low quality energy. IEA ECBCS Annex 49 (Low Exergy Systems for High Performance Buildings and Communities) aims at improving, both on a community and building level, the design of energy use strategies which account for the different qualities of energy sources, from generation and distribution to consumption within in the built environment. Annex 49 is based on an integral approach which includes the analysis and optimisation of the exergy demand in the heating and cooling systems as well as in other processes where energy/exergy is used within the building stock. It is known that the total energy use caused by buildings accounts for more than one third of the world¿s primary energy demand. There is, however, a substantial saving potential in the building stock. The implementation of exergy analyses paves the way for new opportunities to increase the overall efficiency of the energy chain. The method of exergy analyses has been found to provide the most correct and insightful assessment of the thermodynamic features of any process and offers a clear, quantitative indication of both the irreversibilities and the degree of matching between the resources used and the end-use energy flows.

People

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Project personnel

Institute

Contract/collaboration

  • FFG - Österr. Forschungsförderungsgesellschaft mbH

Keywords

GermanEnglish
GebäudeBuilding
Heizen und KühlenHeating and cooling

Publications