Solar heat energy, one of the typical renewable energy absorbs radiation energy from the sun and converts it into
heat energy. Since it is sustainable and eco-friendly, it can be a good alternative to solve the problem of the depletion of fossil fuels. But it has low density. So, solar collector is very important to use more efficiently. There are some possible approaches to scaling-up the effectiveness of a collector by re-thinking of using the collector as a heat exchanger. In the design of dual-purpose collector with rectangular fin (DPCRF), can be used for heating air and water simultaneously using incident solar radiation resulting in optimum usage of energy and space.