Low Exergy Systems for High Performance Buildings and Communities

Completed (2005 - 2010)


Exergy expresses the quality of an energy source and quantifies the useful work that may be done by a certain quantity of energy. The exergy content required to satisfy the demands for heating and cooling of buildings is very low, since a room temperature level of about 20°C is very close to the ambient conditions. Nevertheless, high quality energy sources like fossil fuels are commonly used to satisfy these small demands for exergy. An aim of this project is to promote rational use of energy by means of facilitating and accelerating the use of low-valued and environmentally sustainable energy sources for heating and cooling of buildings.

The main objective of the project is to use exergy analysis as a basis for providing tools, guidelines, recommendations, best-practice examples and background material for designers and decision makers in the fields of building, energy production and politics. Another important objective is to promote possible energy/exergy and costefficient measures for retrofit and new buildings, such as dwellings and commercial/ public buildings, and their related performance analyses viewed from a community level.

The major benefit of following low exergy design principles is the resulting decrease in the exergy demand in the built environment. By following the exergy concept, the total CO2 emissions for the building stock will be substantially reduced as a result of the use of more efficient energy conversion processes. This new concept will support structures for setting up sustainable and secure energy systems for future building stock. The strategies developed for a better and exergy optimised building design, aiming at a future of clean, clever and competitive energy use, will help to pinpoint specific actions to reach this goal. Additionally, the exergy demand of buildings will be reduced due to enhanced new heating and cooling systems.

Participants will carry out the project in the framework of four Subtasks:

  • Subtask A : Methodologies
  • Subtask B : Exergy efficient community supply systems
  • Subtask C : Exergy efficient building technologies
  • Subtask D : Knowledge transfer, dissemination

Operating Agent

Dr. Dietrich Schmidt
Head of Power-Heat-Systems Department
Fraunhofer Institute for Wind Energy and Energy System Technology Kassel
Gottschalkstrasse 28a
D-34127 Kassel
Tel: +49 561 804 1871


Austria, Canada, Denmark, Finland, Germany, Italy, Japan, Poland, Sweden, Switzerland, the Netherlands, USA