Review of thermal performance enhancement of Solar Air Heater using baffles on absorber plate

Of all renewable energies, solar energy is abundantly available and can meet current energy requirements if captured and used wisely. Solar hot air heaters are used to capture suns thermal energy and release it to a fluid present in the system. Most often this fluid is air, which after the heat transfer made between it and the absorption surface, it’s used either to heat spaces or to dry various farming products. For high efficiency the absorber plate of the system must capture solar energy in as much as possible and retain energy in the presence of sunlight and release it in the absence thereof. The indoor environment to achieve a greenhouse effect without energy loss and a complete heat transfer through the absorption surface and the fluid are desirable to achieve better performances. Improving heat transfer is achievable by using obstacles on the absorber surface that break the present laminar flow and creates vortexes or eddy currents that take over a greater amount of thermal energy from the absorption surface. This work presents various investigations carried out on solar air heaters with deflectors on the absorber plate. The results obtained are summarized and referred in the paper.