Energetic sustainability assessment about passive solar systems by a finite difference code

Bioclimatic solutions in architecture has been for a long time in Europe a consolidated procedure, especially developed in northern countries. In the last years, in Italy too, It has been followed through a good policy to increase the construction of buildings equipped with solar energy harnessing system; many architectural competitions expressly ask for passive solar architectonic solutions. In this study, It has been assessed the energetic performance of a solar passive building by a finite differences code (TRNSYS). Many tests and simulations have been carried out on a residential building, changing the configurations of the building envelope and transparent or opaque surfaces. It has been calculated the thermal performance of a south-facing building, in which the façade, chancing configuration, is made up of opaque wall and windows, or a completely transparent surface, testing many kind of glasses (direct gain sunspace) or small sunspaces against a thermal storage matt wall. Thanks to these final results, It has been possible to make some considerations about different kinds of proposed passive solar solutions, picking out the more convenient ones as to their energy performances and appropriate lighting and thermal indoor comfort. This work would arise a contribution about: a correct way of bioclimatic design, by using transparent insulating materials, new kinds of direct gain sunspaces, that allow energy saving of 50%, sustainable energy use of building envelope.