A detailed review of various types of solar air heaters performance

Solar energy is an endless and environmentally benign renewable energy source. Among all the forms of solar thermal energy systems, solar air heater is the major system which is used for heating of air. As it is simple in construction and cheaper in cost, it is of main interest for the researchers. There are various techniques to increase the performance of solar air heaters such as: roughened surface, extended surface, packed bed, porous bed, circular turbulators and phase change materials collector etc. Using these techniques, various types of solar air heaters have been designed by many investigators. The concept of thermodynamics laws i.e. Ist and IInd laws are used for the study of the energy as well as exergy analysis. The energy analysis is critical for determining the efficacy of a process, but the exergy analysis is also important for examining the real behaviour of internal irreversibility and processes involving diverse energy losses. The exergy analysis is very essential means for optimal design of solar air heaters which leads to efficient utilization of solar energy. The major goal of this study is to evaluate previous work on energy and exergy investigations into various forms of solar air heaters, as well as to identify research gaps for future research.

Automated summary

This study evaluates the energy and exergy investigations into various forms of solar air heaters and identifies research gaps for future research.