Abstract

Environmentally friendly technology provides sustainable solutions to reduce non-renewable energy use and carbon emissions. This study investigates efficiency, optimal flow rate, and environmental impact of solar water heater with serpentine configuration. Data were collected during summer in Solo, Indonesia. Inlet and outlet water temperatures, wind speed, and solar radiation intensity were measured from 9:00 AM to 3:00 PM (Western Indonesian Time) at flow rates of 60, 120, 180, and 240 L/h. The optimal flow rate was 180 L/h, thermal efficiency of 57.02%, heat absorption efficiency of 81.93%, and collector efficiency of 69.60%. High flow rates caused too short contact time, while low flow rates increased heat loss. Life cycle assessment showed usage phase dominated energy consumption and significantly reduced carbon dioxide emissions, whereas materials and manufacturing impacted costs and emissions. The serpentine solar water heater offers highly sustainable, efficient, and eco-friendly heating solution by optimizing energy efficiency and production process.