DESIGN AND CONSTRUCTION OF A SOLAR COLLECTOR WATER HEATER

Abstract

This thesis presents the design and construction of a solar collector water heater system utilizing low-cost materials and passive solar heating principles. The system was developed using homemade heat pipes fabricated from 3/8" copper tubes filled with ethanol and sealed with an oil separator as a condenser unit. These heat pipes were housed inside cleaned fluorescent light tubes to create a simple and effective thermal insulation shell. The heat pipes transfer solar heat to a horizontal HDPE header pipe, which is connected to an insulated plastic tank using 3/8-inch flexible hose pipes. A 12V DC water pump, powered by a 30W solar panel, circulates water through a closed loop whenever sufficient sunlight is available, eliminating the need for external power or controllers. Additionally, a 6-channel temperature monitoring system was developed using Arduino UNO and 104 NTC thermistors, enabling real-time monitoring of system performance at key thermal points, such as the header, tank, and ambient air. All major components, including the heat pipes, tank, header, and control system, were assembled into a single functional unit supported by a custom-built frame oriented for optimal solar exposure. While the current design meets small-scale hot water needs, this paper also proposes future enhancements, including evacuated tubes, automated control, IoT integration, and hybrid heating capabilities. The result is a cost effective, scalable, and sustainable solution that has the potential to serve as a practical water heating system in rural, off-grid, or educational settings.