Solar thermal activation of rear-ventilated facades for multi-storey residential buildings: Development, integration into the energy supply system and demonstration.

The project aims at the development of solar thermal activated façades for multi-storey residential buildings (both new construction and renovation) as well as the evaluation of their energy-saving potential in the system. The rear ventilated facades, which are optimally suited for activation due to structural, building physics and assembly reasons, are specifically addressed.

The main project approach is to implement three different façade claddings made of glass, concrete and metal as solar thermal absorber without changing their architectural effect, so that an invisible integration and a visually appealing solution can be achieved. For the integration into the energy supply system we investigate low-exergy concepts, which enable an efficient use of volatile low-temperature heat and cold from the façade. For the heat source, the focus is on the heat pump, where different types (one / two-stage pumps) and sources (near-surface geothermal energy, ice storage, etc.) are analyzed and the impact on the electricity grid is taken into special consideration. For the storage, the focus is on the thermal utilization of the building mass, with the option of direct loading with solar heat or cold. The processing of control engineering issues represents an essential task in the development of the energy supply system.

The project is divided into two main phases: In an initial three-year phase, the activated facades, the appropriate system technology and their control strategies are developed and tested by means of theoretical (dynamic building simulations) and experimental investigations. Furthermore solutions for increasing the degree of prefabrication and standardizing the installation processes are conceived and evaluated. In a subsequent two-year phase, promising, successfully tested systems are implemented in real multi-storey residential buildings and subjected to a comprehensive monitoring program.