Abstract
This paper reports a theoretical study about the thermal performance of the new design of solar water heater with a latent heat storage unit. The new design is a solar water heater system consisting of an array of evacuated tube heat pipe solar collectors connected to a common manifold filled with phase change material and acting as a latent heat storage tank. Solar energy incident on the evacuated tube is collected and stored in the latent heat storage tank. The stored heat is then transferred to the domestic hot water supply via a finned pipe placed inside the tank. The performance is analyzed based on an accurate set of mathematical equations. The various climatic conditions of a tropical region are considered as operating environment of the device. The thermal performance of the new design is compared with the conventional evacuated tube heat pipe solar water heater to have a better observation about the differences and advantageous of the new design. The results showed that the thermal performance of the proposed system is higher than a conventional system at certain conditions, which depend to the weather conditions and flowrates, but the sensitivity of the efficiency of the proposed system to the supply water flowrate is less than the conventional system.