Effects of Al₂O₃ and TiO₂ nanoparticles in order to reduce the energy demand in the conventional buildings by integrating the solar collectors and phase change materials

The solar source, although it can reduce energy consumption (EC) for buildings on cold days, in the summer, its presence on the envelopes intensifies EC. In this study, two techniques were used to make better use of solar energy. In the first method, phase change material (PCM) was used on the envelopes to absorb the sun's rays, thus eliminating summer radiation problems. The second way is to rely on absorbing the sun's radiation and turning it into a heat source to produce sanitary hot water (SHW). In the first method, for hot days, EC declined by 44% which is equal to a 267 kWh drop in EC. For cold days, this figure was 48% and 2419 kWh. Extending the analysis to the whole year, it was observed that EC dropped by 2686 kWh. In the second technique, EC in SHW dropped by 36.6% which means that to supply SHW, as much as 6302 kWh lower EC is required.