Tempering of water storage tank temperature in hot climates regions using earth water heat exchanger

In hot climate regions, outdoor domestic water tank is directly exposed to high solar intensity in addition to hot summer wind stream. The storage water temperature increases above 50 °C. In order to overcome this problem, time dependent analysis of cylindrical domestic storage water tank that exposed to high solar radiation is performed. The analysis includes energy balance for the water tank as well as to an earth water heat exchanger used to reduce the water temperature in summer months. The governing equations are solved numerically using fourth order Runge-Kutta method. It is found that using earth water heat exchanger reduces the water temperature by about 16 °C. A comparison of the numerical results with experimental data showed a good agreement.