A novel PCM-based foam concrete for heat transfer in buildings -Experimental developments and simulation modelling

Foam concrete is renowned for its lightweight and versatile properties, such as good thermal insulation, airborne sound absorption and adequate compressive strength. Phase change materials are recognized for their heat storage characteristics. The current study investigates the enhancement of building envelope thermal performance by integrating phase change materials in foam concrete composites. The phase change material (PCM) developed using exfoliated vermiculite impregnated with capric acid and absolute ethanol demonstrated optimal thermal stability. Among the various foam concrete mix composites, PCM in addition to the nano silica and coconut fibre (PNC) mix showed improved mechanical and thermal properties. Test results showed that optimum mix (PNC-5 %) possess a compressive strength of 7.96 MPa, with a thermal conductivity of 0.15 W/mK. The nano silica added in the PNC mix reacted with C-H rapidly for the formation of C-S-H and filled the pores, which improved the bonding and reduced the brittleness of the samples, which is also evident from the SEM images. The PNC-5 % sample mixture exhibited a melting and freezing point of 31.42 degrees C and 21.08 degrees C respectively, with a latent thermal storage 9.72 J/g for freezing and 17.55 J/g melting. Scanning electron microscopy and thermogravimetric analysis confirmed the compatibility and high thermal resistance of PNC-5 %. TGA results confirmed that the mass loss corresponding to C-H content was slightly lesser for the PNC-5 % mixture than for the PCM mixture, due to the inclusion of nano silica in the case of PNC-5 %. COMSOL Multiphysics (R) software model analysis is implemented for validation of thermal characteristics of the developed PCM-impregnated foam concrete wall panel for insulation in buildings, emphasizing the potential for enhanced thermal comfort compared to that of noninsulated structures. This research proves the efficacy of PNC insulated foam concrete composites for sustainable and energy-efficient building solutions, paving the way for advancements in building applications.