Development of Integrated Solar Water Heater Using Phase Change Material

Abstract

Main barriers for installation of conventional solar water heating system (SWHS) are requirement of large installation area and heavy weight of the heat storage tank consisting water. A storage tank with minimum capacity of 230 liters are needed for household usage and this tank when empty can weigh up to 100 kg while a filled tank could weigh up to 400 kg. In reality, installation of this conventional system require more space and heavy structural support on the roof, which is not available in most houses. As a solution, a form stable light harvesting phase change material (FSLHPCM) integrated compact system is proposed. This new SWHS consists of glass - topped collector cum storage tank filled with FSLHPCM. This new FSLHPCM is form stable, does not leak and exhibit stable latent heat when tested to 1000 thermal cycles. It is capable to not only store heat but can improve the collector efficiency by harvesting the visible light and converting it to heat. The additional light to heat conversion efficiency was 22%. In the new system a maximum 75 liters' glass-topped collector tank is sufficient to substitute a 230-liter tank. This will reduce installation, renovation and maintenance costs for the SWHS.