A comparison of energy behavior of a sunspace through EN ISO 13790 methods and dynamic simulation tools

The increasing of insulation levels both of opaque and transparent building envelope and the consequent rising of the gains to losses ratio make solar gains becoming essential in influencing the thermal energy balance of building, both in summer and in winter season. For this reason, as passive solar applications, such as attached sunspace, are becoming important, it is therefore of great importance to properly evaluate the solar gains entering the conditioned space through sunspace, in order to better consider the advantages of such passive solar systems. This paper presents a comparison between simplified and detailed methods in order to calculate solar heat gains entering a conditioned space through sunspace. A case study has been analyzed through EN ISO 13790, assessing energy performance both with monthly quasi steady–state calculation and simple hourly dynamic calculation method, and through a detailed dynamic simulation tool (EnergyPlus). In order to investigate the effect on the energy performance of the sunspace, the same building has been analyzed both with and without the attached sunspace.