This study designed and investigated a system that used a latent heat thermal energy storage (LHTES) system and a heat pipe solar collector (HPSC) along with a gas backup system and air heating system in a single unit. The nanofluids used in the solar cycle of this system include TiO2, MWCNT, CuO and water-propylene glycol (70:30 volumetric composition), were used in the system of air heating. In latent heat thermal energy storage system, the phase change material used is calcium chloride 6-water. The maximum outlet air temperatures recorded for the air heating system were found to be 47.2, 46.1, 48.3 and 43.9 ◦C in August and 43.2, 41.7, 44.2 and 40 ◦C in November for CuO, TiO2, MWCNT and water respectively, indicating better performance of MWCNT working fluid in comparison with other working fluids. Comparing the amount of energy consumed in this system with the package, the results show that energy consumption decreased by 67.7% in August and 42.2% in November.
