Innovative façade refurbishment with integrated air ducting for the existing building stock

For successful transition of the energy system being sustainable, the energetic retrofitting of the building stock is a crucial factor. About 40% of the current final energy consumption in Germany is caused by the building sector for heating purposes. Energetic retrofitting can reduce the heat demand of buildings considerably but extensive refurbishments often fail due to high costs, leading to only individual measures on the façade being carried out. New retrofitting concepts are required which are both energy efficient and cost-effective to increase the rate of retrofitting significantly. A promising solution, developed by the Fraunhofer Institute for Building Physics, provides the implementation of the air duct system in the building envelope. Hereby, the air ducts for the installation of a central residential ventilation system are integrated directly in the mounted ETICS plate. Such a system has already been successfully tested in one and two family houses. However, the challenge of implementing the system in a multi-storey building is much larger due to structural dependencies on the façade, fire protection regulations and other limiting factors. These constraints have been identified to develop appropriate solutions for the planning of the air ducting on the façade.