Thermochromic paint solution for buildings - An experimental and numerical study

Buildings represent around 40% of all energy consumption, so reducing their energy demands will be a central piece of any climate strategy. Thermochromic exterior paint can be a promising technology for moderating energy consumption in buildings, but it has not been widely investigated. This study investigates the contribution of a thermochromic painting system to the energy consumption of a single-family building. The present study is divided into experimental tests and numerical simulations. For the experimental analysis, which allowed to collect many parameters for the numerical model, samples of three types of rendering mortar were produced: two based on white cement and one based on hydrated aerial lime. In order to make the mortar more sustainable, wood waste was used to replace traditional sand. The render samples were painted with ordinary paint and with a thermochromic paint (which changes from black to white at temperatures above 30°C). The simulation results indicate that a render with thermochromic paint would provide annual energy savings of around 12%, when compared to an ordinary paint. The render-based on white cement with wood waste and finished with the thermochromic painting system has the lowest annual energy consumption.