An approximate analytical solution for dynamic heat transfer of building walls

The present work deals with an approximate analytical solution for the dynamic temperature field due to the coupled effect of building walls to the adjacent environment. The solution is derived within the framework of weighted residuals and can be used as a handy tool to realize a reasonable estimation of the building thermal performance and to elucidate the dependence on the room descriptive parameters. Results from the present model are compared with predictions arising from both a commercial FEM code and the analytical solution from the standard EN 13786, showing satisfactory results. This conclusion is not surprising since it is demonstrable in view of the characteristic-time responses of the climatic forcing and the building walls. Finally, as an example of application of this approach, the model was focused on describing the thermal response of an open-loop regulated indoor environment.