Review on enhancement methods for phase change materials

Nowadays a mayor aspect for reducing the carbon footprint focuses on the reduction of the heating and cooling and the incorporation of energy efficient systems. It is in this regard, innovative technologies such as thermal energy storage (TES) can help boost the energy efficiency systems. Phase Change Materials or PCMs are substances that can absorb, store and release a large amount of thermal energy at relatively constant temperatures and are well suited for heat transfer and energy conversion applications where the state of the material normally varies from solid-liquid or vice-versa. The thermal performance of PCMs depends on their melting temperature, thermal conductivity, and energy storage density. The principal drawback for the PCMs application is the low thermal conductivity; to overcome this problem many researchers have focused their investigations to enhance the thermal conductivity in organic PCMs by adding nanoparticles such as carbon nanofillers, alumina and graphite. This review presents different enhancement methods to increase the thermal conductivity of the PCMs depending on the base fluids. Parrafins appear as the most common material; nevertheless further investigation is required regarding lower melting points for building application.