Some studies on the flow passage dimension for solar air heating collectors

The effect of the dimensions of rectangular ducts through which air flows in solar air heaters on the air heater performance has been studied for laminar, transitional and turbulent flows. The collector performance and required pumping power to maintain the flow are assessed from a simple mathematical model. The effective energy collected has been determined for different case studies, and the duct depth has been optimised with respect to this effective energy. That is, an optimum duct depth is determined for different flow rates for collecting maximum energy at minimum pumping cost.