Thermal and mechanical performance of a novel 3D printed macro-encapsulation method for phase change materials

The mechanical and thermal properties of a novel 3D-printed macro-encapsulation method for Phase Change Materials (PCMs) was investigated and compared to mixtures that contain commercially available micro-encapsulated PCMs. Two types of cement-based mixtures, a mortar mix with a density of 2,161 kg/m(3) and a lightweight mix with a density of 1,351 kg/m(3), were utilized for both the micro- and macro-encapsulated samples. The micro-encapsulated mortar and lightweight samples contain 0 vol%, 10 vol%, and 20 vol% of PCMs with a melting point of 28 degrees C. The macro-encapsulated samples contain 20 vol% of the same PCMs but in this case the PCMs were incorporated into a hollow 3D-printed polymer lattice which is embedded in the cement-based matrices. This lattice not only serves as macro-encapsulation but also as reinforcement to enhance the ductility of cement-based materials. The results reviled that the lattice specimens developed the lowest panel temperature during heating and showed a significant reduction of the indoor temperature. The mechanical properties of the lattice specimens were improved and resulted in a change from a brittle to strain-hardening behavior. This research shows the potential of the developed system to be uses for thermal retrofitting or as wall elements to lower the indoor temperature and save energy in tropical climates.