Laboratory and in-situ assessment of thermochromic coatings for building application: Testing on dynamic properties and photodegradation

Thermochromic (TC) coatings for buildings represent a promising solution for temperate climates to reduce the cooling energy need without occurring in heating penalties in wintertime. Nevertheless, only few solutions able to cope with rapid photodegradation are available. For this reason, in the last few years, a growing interest in the development of TC solutions unaffected by photodegradation was reported, and new products are expected in a short period. In this study, a TC coating based on Leuco dye was applied on a flat-roof and the variation of the outer surface temperatures and solar reflectance was monitored for three days. A spectrophotometric characterization of the thermochromic samples was conducted in their coloured and colourless phases, before and after the outdoor exposure. The results of the study provide insights on the energy saving, on the urban climate mitigation potential of TC coatings and on the photodegradation occurring when exposed to solar radiation.