Thermal bridge modelling, based on conjugated heat transfer and CFD methods

In the building structure, the “thermal bridge” is defined as an isolated zone, where construction elements have higher thermal conductivity, compared with the rest of the building envelope. Thus, a significant temperature difference may exist between adjacent solid and air volumes within the developments, especially in winter conditions. The existence of thermal bridge mostly affects the energy performance of buildings, due to the increased heat losses from the occupied spaces. But also, the decreased surface temperature in these zones, could lead to moisture accumulation and substantial humidity related problems in the indoor environment. Considering these important effects, the presented study describes the development of numerical model of a thermal bridge distribution, based on conjugated heat transfer in concrete external wall section. The thermal bridge distribution is analyzed relative to the indoor and outdoor air parameters, and the envelope thermal properties. The achieved surface temperature sensitivity results may be used for further moisture accumulation model development or enhancements.