Thermo-active Ground-Source Structures for Heating and Cooling

Energy foundations and other thermo-active ground structures, energy wells, and pavement or bridge deck heating/cooling represent an innovative technology that contributes to environmental protection and provides substantial long-term cost savings and minimized maintenance. The paper focuses on earth-contact concrete elements that are already required for structural reasons, but which simultaneously work as heat exchangers. Absorber pipes filled with a heat carrier fluid are installed within conventional structural elements (piles, barrettes, diaphragm walls, basement slabs or walls, tunnel linings), forming the primary circuit of a geothermal energy system. The natural ground temperature is used as a heat source in winter and for cooling in summer. Hence no additional elements have to be installed below surface. The primary circuit is then connected via a heat pump to a secondary circuit within the building. Benefits of energy foundations are also listed in this paper.