Alexander Schmitt

This project is the first to build, measure and optimise a recyclable asphalt collector for the regeneration of geothermal probes.

The background to this pilot and demonstration project is the increasingly dense use of geothermal probes, which leads to long-term cooling of the subsoil. Studies show that there is a considerable need for regeneration, particularly in urban areas. Asphalt collectors, which use heat from solar radiation on asphalt surfaces, are a potential cost-effective heat source for this regeneration. Initial pilot projects have shown that promising yields can be achieved with collector pipes embedded in asphalt. However, in these cases the asphalt was no longer recyclable. Based on simulations, it is assumed that it is also possible to lay the collector pipes in the underlying clean layer (separating layer between the subsoil and the asphalt surface) for the application of geothermal probe regeneration, thus maintaining the recyclability of the asphalt. This will be implemented and investigated in this P&D project.

Reducing heat losses from existing residential buildings by refurbishing the building envelope is an important step to reduce the heating demand of buildings. In the EU project PLURAL, prefabricated façade modules are being developed and tested, which enable novel possibilities for energy generation, heat/cold supply and ventilation with the façade. The prefabrication of the façade modules is intended to enable rapid and cost-effective refurbishment in an inhabited state. Three field installations will be used to demonstrate renovations in different European climates. Simulations will be used to analyse components and buildings, and a Big Data management platform and decision-making tool for component selection and integration will be developed.

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under Grant Agreement No. 958218.

This pilot and demonstration project shows new ways for the cost-efficient renovation of multifamily houses to «nearly zero energy» buildings. The core components are multifunctional facade elements which, in addition to thermal insulation and windows with integrated comfort ventilation, contain both power generation with photovoltaics and the distribution of space heating. In a first phase of the project, the building physics fundamentals are analyzed and the feasibility is demonstrated with a prototype and simulations. In a second phase, a multifamily building in Bern will be renovated with this new concept.

For the new building of Oblamatik AG in Chur, a heating and cooling concept that is unique in Switzerland was developed. Using the foundation slab as a heat sink and heat source represents an alternative to the current heating systems for office buildings. The regeneration of the foundation slab in winter as well as in summer is mainly guaranteed by PVT collectors. The HVAC concept is designed to use as much of the internal heat (servers, commercial refrigeration, etc.) as possible directly for heating purposes.

In this P&D-project a highly efficient heat supply for residential buildings in Obfelden was realized with new technologies. The combination of a low-lift heat pump with a deep membrane geothermal probe and a new type of control of the heating distribution system enables efficient heating in winter and cooling in summer with the lowest electrical energy consumption. The evaluation of several years shows how important monitoring and operation optimization are to realize efficient systems in the field. In addition to many valuable field experiences, the project has shown that a holistic concept can make a significant contribution to the stabilization of the Swiss energy supply.