The use of adequate thermal energy storage (TES) systems is an opportunity to increase energy efficiency in the building sector, and so decrease both commercial and residential energy consumptions. Nano-enhanced phase change materials (NEPCM) have attracted attention to address one of the crucial barriers (i.e. low thermal conductivity) to the adoption of phase change materials (PCM) in this sector. In the present study two PCM based on fatty acids, capric and palmitic acid, were nano-enhanced with low contents (1.0 wt.%, 1.5 wt.% and 3.0 wt.%) of copper (II) oxide (CuO) nanoparticles. Copper (II) oxide (CuO) was synthesized via coprecipitation method obtaining 60⁻120 nm diameter sized nanoparticles. Thermal stability and high thermal conductivity were observed for the nano-enhanced phase change materials (NEPCM) obtained. Experimental results revealed remarkable increments in NEPCM thermal conductivity, for instance palmitic acid thermal conductivity was increased up to 60% with the addition of 3 wt.% CuO nanoparticles. Moreover, CuO nanoparticles sedimentation velocity decreases when increasing its content.
Keywords: DSC; buildings; energy efficiency; fatty acids; hot wire; nano-enhanced phase change materials (NEPCM); nanofluid; thermal energy storage (TES).