Cementitious plasters for facąde finishing with phase change materials and thermochromic pigments

Abstract

Exterior building surfaces are exposed to considerable thermal stresses and UV radiations that significantly reduce their durability. Additionally, solar and thermal energy affect energy transfer through the building envelope that impacts indoor comfort and energy demands. Thus, improving the performance of exterior finish materials in regulating exterior surface temperatures would impact the overall performance of buildings. The aim of this research is to develop a responsive cementitious finish plaster for building facąde applications to act as a filter for variable solar and thermal loads. The proposed cement plaster is combined with phase change materials (PCMs) and thermochromic (TC) pigments to control solar radiation and surface temperatures dynamically on the exterior facąde. This paper presents the prototype development and optical characterization of the prototypes. The objective is to investigate the interaction between different PCM and TC pigments in regulating surface temperatures. Three different melting temperatures for the PCMs were tested in consideration of two different colours of the TC paint. Twelve samples were produced with 2.5% mass fraction of PCM and TC pigment each. The emissivity of the samples was measured using infrared thermography. The results showed that a high emissivity in high temperatures and a low emissivity in colder temperatures could be achieved.