Equivalent wall method for dynamic modelling of thermal bridges in low-energy building: application and parametric study

This paper presents a mixed method to determine a 1-D three-layer wall having the same thermal behaviour as a multidimensional thermal bridge. It is based on the calculations of thermal resistance, heat capacity, structure factors and an objective function using heat fluxes in harmonic conditions. The method is applied to five different 2-D thermal bridges. Accuracy of their 1-D equivalent wall is checked in various conditions (solar heat flux, meteorological data, period of the year, constant or variable indoor temperature). Results are very satisfactory since the error on the integral of inner heat flux over the study period is always lower than 0.65% (except in one case) and the average error on inner heat flux is always lower than 1 W/m.