Recent development on double pass solar thermal collector

The Sun is the star in our solar system that beams solar energy towards the Earth, shining it during the day. The researcher discovered different ways to enhance the use of solar radiation to meet daily need because they are aware of how abundant it is. The thermal performance of double pass solar collector (DPSC) is higher compared to flat plate solar collector (FPSC) when comparing their thermal efficiencies. There have been several studies done on the experimental and theoretical analysis of DPSC, where different kind of tests have been carried out on different aspects. This paper aims to reviews recent development (5 years) on double pass solar collector (DPSC) where it highlights the improvement methods, functioning parameters, materials used, and design configurations. By reviewing experimental and theoretical analysis on the double-pass collector with various thermal transfer enhancement, it can help the researchers to keep updated on new development of the double-pass collector. Several methods to improve the convective heat transfer for the system were adding fins, phase change material (PCM), improved absorbers and porous media to the DPSC. Other important things that require improvement are increasing the outlet temperature, efficiency enhancement for DPSC and pressure drop reduction. The effect of using various mass flow rates, solar radiation, temperatures and working fluid on DPSC are also discussed. We wrap this review by identifying numerous applications that are possible for the solar air heating such as space heating and conditioning, water desalination process and drying agricultural food product. •Adding phase change material (PCM), can enhance thermal efficiency for double pass solar collector.•Fins can increase convective heat transfer.•Porous media can accelerate the performance of double pass solar collector.•Adding tubular on absorber can helps to increase the heat efficiency.•New novelty double pass solar collector has been found for the last 5 years.