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The investment of solar energy in life applications has become mandatory to maintain a clean environment and reduce the use of fossil fuels. This work aimed to improve the performance of solar air heater (SAH) by using evacuated tube solar collectors ETSC integrated with nano-enhancer phase change material (NE-PCM). To achieve this purpose, a system consisting of 5 linked collecting panels was designed, fabricated, and experimentally investigated. Each panel included a glass-evacuated tube with two concentric aluminum pipes installed inside. NE-PCM was placed between the inlet and outlet air paths inside the evacuated tube to enhance the heat transfer rate. The performance was investigated with and without NE-PCM at five mass flow rates (0.006, 0.008, 0.01, 0.03, and 0.05 kg/s). Experimental results revealed that the highest temperature was 116, 108, 102, 95, and 93 °C, respectively, for the above mass flow rates without adding NE-PCM. The outlet temperature was decreased by 6–15 °C when using NE-PCM. The SAH efficiency was increased by 29.62% compared to the system without NE-PCM at 0.05 kg/s. The maximum thermal efficiency for the system with NE-PCM was 62.66% at 0.05 kg/s, and the pressure drop was 6.79 kPa under the same conditions. As well known, the hot air is used for a variety of purposes including space heating, food processing, drying of fruit, vegetables, dairy, and solar cooking.

The investment of solar energy in life applications has become mandatory in order to maintain a clean environment and reduce the use of fossil fuel. In this work, the performance of solar air heater is aimed to be improved with the help of evacuated tube solar collectors. To achieve this purpose, a system consisting of 5 linked collecting panels was designed, fabricated, and experimentally tested. Each panel included a glass-evacuated tube with two concentric aluminum tube installed inside. The system was reinforce by adding paraffin wax as a PCM and boosting its thermal conductivity by incorporating it with copper oxide nanoparticles CuO. The performance was investigated with and without Nano enhancer phase change material NE-PCM at five mass flow rates (0.006-0.008-0.05-0.03-0.01 kg/s). Experimental results revaluated that the highest temperature was recorded as 116°C at a mass flow rate of 0.006 kg/s. The maximum thermal efficiency with storage material was 38% at 0.05 kg/s, and the pressure drop was about 2.2kPa.