The increasing use of ventilation systems in buildings increases the associated energy and environmental challenges. The aim of the research project "Efficient ventilation systems for the energy and heat transition (ELAN)" is to develop more efficient, quieter and energy-optimized ventilation systems. The project focuses on optimizing reversible fans and analysing interactions between different components. A test rig will be set up to analyze the behavior of fans in combination with various components such as ducts, covers, heat exchangers and sound insulation elements. Both experimental investigations and accompanying numerical flow simulations will be carried out. Prof. Dr. Daniel Möller wants to use the "ELAN" project to develop new modelling approaches and optimization concepts for fan geometries and sound-insulating elements and thus improve the energy efficiency, user satisfaction and environmental compatibility of ventilation systems.