Experimental assessment of energy storage in microencapsulated paraffin PCM Cement mortars

Thermal Energy Storage (TES) methods have gained significant importance in reducing the energy demand of buildings. Among various TES methods, the use of Phase Change Materials (PCM) has emerged as a promising approach to store energy in latent form and enhance the thermal capacity of buildings, thereby improving thermal comfort. This study aims to evaluate the sensible and latent energy accumulation in cement mortars by incorporating microencapsulated phase change materials (10-20% by weight) as a substitute for fine aggregates. The experimental investigation involved density measurements, differential scanning calorimetry (DSC) analysis, and accumulated energy tests. The results indicate that the PCM content increases, the heating and cooling rates are lower, and the temperature difference between the ambient exposed face and the not-exposed face of tested slabs increases. Additionally, the latent heat energy contribution increases when the material is exposed to lower temperature gradients, coinciding with the temperature range at which phase change occurs. The total energy accumulated in mortars with 10% and 20% PCM content increases in 238% to 330%, respectively, for a 5 ºC temperature gradient. However, when a 15 ºC temperature gradient is used, the accumulated energy increases at 70% and 88%, respectively.