Performance prediction of single-pass and multi-pass low-cost solar air heater

This study introduces a mathematical model and experimental evaluation of solar air heating utilising an absorber surface constructed from low-cost upcycled materials. The research presents a solar air heater prototype, suitable for applications such as space heating and agricultural drying. The solar heating system was modelled using upcycled beverage aluminium cans, considering both single and multi-pass flow configurations. Performance in terms of useful heat was determined through both mathematical model simulations and experimental methods. The multi-pass system demonstrated superior performance, delivering increased usable heat at elevated temperatures compared to the single-pass system. A comparative analysis and validation were conducted between numerical investigations with natural and forced convection on the five-pass solar air heater and experimental test outcomes. This research highlights the potential of utilising waste materials to develop cost-effective, solar heating solutions, contributing to energy management and waste reduction strategies. The findings can be explored for future explorations into sustainable and renewable energy solutions, particularly beneficial in regions with constrained economic resources.