Dynamic modelling of multidimensional thermal bridges in building envelopes: Review of existing methods, application and new mixed method

This study presents four approaches to model correctly the heat transfer through a thermal bridge and simply introduce it into building energy simulation programs. These approaches are based on the equivalent wall method: defining a 1-D three-layer wall, replacing the thermal bridge, which has the same steady and dynamic thermal behaviours as the thermal bridge. The four methods are tested on 1-D simple cases. However, the best approach is a fifth method, a mix between the principles of the structure factors method and a harmonic method: it leads to very accurate results and a unique solution. This mixed method is tested on a 2-D thermal bridge, junction between floor and exterior wall, and the results are again accurate and much better than a classic consideration of the thermal bridge. (C) 2015 Elsevier B.V. All rights reserved.