ECBCS Annex 37 - Low Exergy Systems for Heating and Cooling in Buildings

Logo Annex 37 Low Ex
Logo Annex 37 Low Ex.

There is an obvious and indisputable need for an increase in energy efficiency in buildings. Until now, so called “energy savings measures” and analyses of energy flows in buildings have commonly been based on the energy conservation principle, the first law of thermodynamics. An exergy analysis which combines both the first and second law of thermodynamics allows a better understanding and more effective design of energy flows in buildings. That way a more holistic view on the calculations is gained for all processes involved.

In accordance to these findings, new innovative heating, cooling and ventilation appliances have been developed within the framework of a German national collaboration project. This short introduction describes both the structure and work plan of the German alliance project on low exergy systems and the achievements in the development of innovative systems brought about by this close collaboration between leading German industry and research institutes.

The German alliance project

The German alliance project “LowEx” has been initiated to enhance the development of new and more efficient heating and cooling systems for buildings, which are also able to use more renewable and natural energy sources.


The general goals of the project are specified in detailed objectives and fields of activity to be conducted during the course of this project.

Development of systems to use low exergy sinks and sources (e.g. ambient air, ground, and water).

Development of efficient heat carriers and transport systems, which consume low amounts of exergy.

Development of LowEx transfer systems in rooms that are able to operate with small temperature differences.

Development of thermally active façade constructions.

Development of LowEx storage systems.

System integration and operation of LowEx systems.


Annex 37 summary report: Heating and Cooling with Focus on Increased Energy Efficiency and Improved Comfort    

Annex 37 guidebook: Heating and Cooling with Focus on Increased Energy Efficiency and Improved Comfort           


This project has been financially supported by the German Federal Ministry for Economics and Technology.