Laboratory for the thermal physics of buildings
In the Building Physics Laboratory technological solutions are developed for the construction of energy-efficient buildings with high indoor comfort. Research undertaken here deals with investigation into the dynamic behaviour of opaque and transparent building envelopes and building services installations, in particular mechanical ventilation systems, with the aim at the same time of improving the comfort, physical health and energy efficiency of buildings. For this purpose, field tests are supplemented by laboratory experiments with computer simulations. The researchers analyse the energetic performance of each component of the building envelope, they examine its impact on living comfort and its interaction with the rest of the building and its facilities. They further examine the effectiveness and behaviour of different technical solutions for building envelopes, not only under planning conditions but also under practical conditions in summer and in winter. For this purpose, the corresponding climatic conditions are reconstructed in the laboratory or experiments are carried out outdoors.
The laboratory is able to measure the thermo-physical properties of building materials, above all insulating materials. The calculated values for thermal conductivity, temperature conductivity and specific heat capacity can be used in energy models for the detailed performance evaluation of buildings and building envelope components, but also for the theoretical or experimental analysis of opaque components. The researchers use and develop instruments and methods for on-site measurement of the most important thermo-physical and environmental properties of building envelopes and buildings. This enables them to measure directly both on and in existing buildings the energetic performance of the building, its thermal/hygrometric comfort, its indoor air quality, and its acoustic and visual comfort.
To evaluate and optimise building performance, highly sophisticated calculation tools such as numerical models with finite elements (FEM), fluid dynamic models (CFD) and codes for dynamic simulation are available. Researchers use these tools, individually or in combination, for simulations which take into account various physical aspects simultaneously (multi-domain and multi-physics). By numerically modelling thermo-physical processes in the various components of the building envelopes and in the individual rooms, the technicians are able to determine the energetic and acoustic behaviour and lighting effect of the building and its facilities, both at the level of the component, as well as at the building and urban planning level. By using multi-criteria optimisation techniques, the most efficient planning configurations can be determined.