TI - Water heater employing granular coal photothermal absorber and solar thermal collector combination AU - SARIFUDIN, A. AU - YANINGSIH, I. AU - KRISTIAWAN, B. AU - WIBAWA, A. AU - FUDHOLI, A. AU - AZIZ, M. SO - Journal of Thermal Engineering 2026;12:610-634. DO - 10.14744/thermal.0001104