Experimental validation of a dynamic building energy simulation tool and case study analysis on low-emissivity and high-reflective coatings

This paper presents the experimental validation of a novel in-house building energy performance simulation tool and a case study analysis on low emissivity and high reflectance materials. The developed tool (called DETECt) was conceived for research purposes with the aim to analyze the energy performance of innovative building envelope technologies and plant systems and to predict the whole building thermodynamic behavior. The simulation model, based on thermal network approach and implemented in a computer code written in MatLab, allows one to properly model the emissivity of the indoor surfaces and their spectral solar reflectance, necessary to predict the thermal behavior of low emissivity and high reflectance materials. In order to confirm and ensure the reliability of the in-house developed calculation tool, a suitable empirical validation was carried out. Such procedure was performed by comparing simulation results to measurements obtained from a real test room, built up by standard materials and exposed to natural environmental conditions. Details about the experimental campaign and the successful empirical validation of DETECt are reported in this paper. Finally, to show the potentiality of the building model, a case study analysis relative to different low-emissivity plasters for interior spaces and cool paints for external surfaces is presented. By using the validated experimental model, capable of modelling variable properties of outer surfaces of the building envelope and low-emissivity of internal ones, a comparative analysis is carried out to evaluate their impact on the thermal dynamic behaviour of the test cell and to assess its heating and cooling demands. Both passive envelope strategies, also coupled together, show potential to reduce building heating and cooling demands compared to standard finishing.