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

The increasing demand for energy and the greenhouse gas (GHG) emissions resulting from the use of conventional fuels are directing humanity towards renewable energy sources, in this case solar energy, and towards increasing investments in research and improvement of solar systems that produces both electricity and heat. For household consumers as well as for some industrial ones, the large volume of energy consumed is due to space heating, ventilation and drying. The availability of solar energy can contribute to reducing this consumption utilizing solar air heater systems. In the presence of solar energy, reducing the household energy consumption also depends on the thermal performance of these systems. Recent studies focus on improving these performances by modifying the components so that there is as much absorption of solar radiation as possible and as high a thermal transfer as possible between the absorption surface and the existing air flow through the system. The objective of this paper is to review different forms of the absorption plate and the different obstacles (roughness’s) used by researchers to refine thermal performances of solar air heater systems. The role of obstacles is to create swirlers that favor heat transfer. The results presented briefly refer to thermal efficiency, thermo-hydraulic improvement factor and friction factor. The final remarks propose observations and proposals for further improvements to solar air heating domain.