Performance of a collector/storage solar water heater

This communication presents an improved analysis of a collector/storage solar water heater, proposed by Garg [1], which is in close agreement with the experiments of Garg [1] and the authors. The heater consists essentially of an insulated rectangular tank whose top surface is suitably blackened and glazed. After collection of solar energy during day the heater can store a substantial amount of heat for an appreciable time if the top glass is vovered by adequate insulation (assumed to be of the same thickness as the insulation below the tank) during the night. Expressions for the transient temperature of the water in the tank have been derived. The authors have recorded the hourly variation of temperature of the water in the tank. These experimental results as well as those of Garg [1] have been found to be in close agreement with the theory presented in this paper.