Zafar SaidRahman SaidurM. A. SabihaA. HepbasliNasrudin Abd Rahim2025-10-062016095965260959-652610.1016/j.jclepro.2015.07.115https://www.scopus.com/inward/record.uri?eid=2-s2.0-84959568261&doi=10.1016%2Fj.jclepro.2015.07.115&partnerID=40&md5=0ec6240222aaf55d7d2bf49038f35c0ehttps://gcris.yasar.edu.tr/handle/123456789/9844Application of nanofluid to increase the thermal efficiency of a traditional solar collector is getting tremendous attention among the scientific community. Al<inf>2</inf>O<inf>3</inf>-water nanofluid as a working fluid and its effect on the energy and exergy efficiencies of a flat plate solar collector was examined experimentally. Volume fraction used for this study was 0.1% and 0.3% while the size of the nanoparticles was ∼13 nm. Experiments were carried out using a stable nanofluid which was obtained by controlling the pH of the solution over a period of 30 days. The mass flow rates of the nanofluid varied from 0.5 to 1.5 kg/min. Energy and exergy efficiencies of a flat plate solar collector using water and nanofluids as working fluids were matched. The results revealed that nanofluids increased the energy efficiency by 83.5% for 0.3% v/v and 1.5 kg/min whereas the exergy efficiency was enhanced by up to 20.3% for 0.1% v/v and 1 kg/min. Thermal efficiency of the system was found to be more than 50% compared to the existing system available in the literature. New findings on the stability and exergy analysis of the solar collector system operated with a pH controlled nanofluid are reported. © 2016 Elsevier B.V. All rights reserved.EnglishAl2o3, Efficiency Improvement, Energy, Exergy, Flat Plate Solar Collector, Nanofluid, Aluminum, Energy Efficiency, Exergy, Fluids, Nanofluidics, Solar Collectors, Solar Equipment, Efficiency Improvement, Energy, Energy And Exergy Efficiency, Exergy Efficiencies, Flat-plate Solar Collectors, Nanofluids, Scientific Community, Thermal Efficiency, Collector EfficiencyAluminum, Energy efficiency, Exergy, Fluids, Nanofluidics, Solar collectors, Solar equipment, Efficiency improvement, Energy, Energy and exergy efficiency, Exergy efficiencies, Flat-plate solar collectors, Nanofluids, Scientific community, Thermal efficiency, Collector efficiencyArticle