Energy Efficiency in Buildings through the Application of Phase Change Materials: An In-Depth Analysis on the Integration of Spent Coffee Grounds (SCG)

The energy demand in the building sector has drastically increased due to the increase in occupant comfort requirements accounting for 30% of the world's final energy con-sumption and 26% of carbon emissions globally. Thus, to improve building efficiency in a matter of heating/cooling applications, a phase change material (PCM)-based pas-sive thermal management technique has been considered due to its characteristics for energy storage. This study hands over a comprehensive review of research works for PCM applications, types and encapsulation forms. Various solutions were proposed to enhance PCM performance. In this review, the authors suggest new methods to improve PCM efficiency by using the multilayered wall technique which involves employing two layers of hybrid bio-composite specifi-cally hybrid hemp/wood fiber-reinforced composites with Polypropylene (PP) matrix along with a layer of PCM made from Spent Coffee Grounds (SCGs). Previous studies proved that oil extracted from SCGs have demonstrated good thermal and chemical stability since it contains approximately 60–80% of fatty acids with a phase transition temperature of approximately 4.5 ± 0.72°C and latent heat values of 51.15 ± 1.46 kJ/kg.