Optimized composite lime cement plasters with phase change materials for enhanced building energy efficiency and comfort

This study investigates the potential of phase change materials (PCMs) integrated into advanced lime-cement plaster composites to improve the thermal performance of traditional building envelopes while preserving their physical and mechanical properties. The research was conducted in two phases, combining microstructural analysis with large-scale field testing to bridge the gap between material development and practical application. Three types of plaster were investigated: a lime-cement plaster without PCM additives and two composites with 20 and 30 percent PCM by volume. The addition of PCM significantly increased the latent heat storage capacity of the plaster and enabled efficient phase transitions within a narrow and practical temperature range. This improvement in the thermal performance was achieved without compromising the structural integrity of the plaster. Cycling tests demonstrated the durability and reliability of the reversible phase transitions during repeated melting and solidification processes. The microscopic analysis confirmed the uniform distribution of the PCM microcapsules in the plaster matrix, a critical factor in maintaining a consistent thermal performance of the material. The study also investigated the effects of the PCM-enhanced plasters on indoor thermal comfort. The results of thermal comfort showed that the studied PCM composites maintained the indoor air temperature within the comfort range for 43.7% of the observation period, compared to 33.9% when using conventional materials. Additionally, the PCM composites used 1.1 times less energy than the reference plaster. Overall, this research highlights the significant potential of the PCM-integrated lime-cement plasters as innovative building materials capable of improving thermal properties without compromising mechanical strength. This study presents valuable insights for the development of sustainable, energy-efficient solutions for traditional buildings that meet modern demands for environmentally conscious and resilient building practices.