Solar water heater is a devise which is used to heat the water. Solar water heater plays a role in energy conservation. Solar water heaters are characterized by its thermal performance that depends on the transmittance, absorption and conduction of solar energy and the conductivity of the working fluid. Because its efficiency is more than the electric conversion. In conventional solar water heating system, the water flows in laminar regime. A Solar radiation is the heat input to the collector; water is used as the working fluid. The overall thermal performance and efficiency is higher in variable header due to uniform velocity one of the biggest uses of electricity, gas and oil is the heating of water home, and in offices, schools and hospitals etc. Solar water heating is a very simple and efficient way to grab energy from the sun and use it. Solar water heaters concentrate diffused solar radiation into thermal energy. The objective of this project is to create uniform velocity in solar water system by using variable header. The solar water heater is designed with a larger diameter of the header with a length of 100 cm. The existing solar water heating systems the overall thermal performance reduces due to non-uniform flow in riser tubes. The overall thermal performance and efficiency is higher in variable header system due to uniform velocity. The experimental results are analyzed with CFD analysis software and the results are compared with the existing solar water heating system[1].

Key words: Variable header, Solar water heating, riser tubes, CFD