Thermochromic materials for indoor thermal comfort improvement: Finite difference modeling and validation in a real case-study building

In recent years, a huge research effort aimed at developing adaptive materials for improving building indoor thermal comfort has been detected. Yet, only a few analytic and dynamic approaches have been implemented to predict building materials thermal performance. In this study, an analytic model is elaborated to evaluate the thermal performance of a well insulated case study prototype building equipped with a thermochromic envelope, and bench-mark it against cool-only and dark-only applications. Therefore, the effect of the selected thermochromic solutions on the indoor environment of the building in terms of surface and indoor air temperature is evaluated both in summer and winter conditions. Results show that the application of the thermochromic membrane and wall paint represents a win-to-win solution combining the well-established passive cooling effect of high reflectance materials in summer with desirable solar gains produced by dark surfaces in winter. Average indoor air temperature reductions up to 0.2 and 0.5 K were found in summer, while a 0.5 and 0.6 K increase was registered in winter, for the low and high insulation configuration, respectively, when compared to more common dark and cool solution.