BEM Utility for Simulation of Linear Thermal Bridges

This paper aims to prove utility of the boundary element method for modelling 2D heat transfer in complex multiregions, particularly in thermal bridges. It proposes BEM as an alternative method commonly applied in commercial software for simulation of temperature field and heat flux in thermal bridges, mesh methods (FEM, FDM).The BEM algorithm with Robin boundary condition is developed for modelling 2D heat transfer in complex multi-regions. Simulation is performed with the authoring Fortran program. The developed mathematical algorithm and computer program are validated according to standard EN ISO 10211:2007. Two examples of complex thermal bridges that commonly appears in house building are presented. Analysis of two reference cases, listed in standard ISO, confirms utility of the proposed BEM algorithm and Fortran program for simulation of linear thermal bridges. Conditions, quoted in standard ISO, are satisfied with models of a relatively small number of boundary elements. Performed validation constitutes the base for further development of BEM as an efficient method for modelling heat transfer in building components, and for the prospective application in commercial software.