The demand for sustainable and viable drying technologies has risen continuously in response to the growing energy costs and emerging environmental decline. The study designed and evaluated the operational efficiency of a counter-flow heat recovery fish drying kiln at a uniform temperature (55 $^\circ$C), varying air velocities (1.0, 1.5, and 2.0m/s), and batch sizes (15, 20, and 25kg) of catfish using an eco-thermodynamic approach embodying energy, exergy, environmental, and economic assessments. The findings indicate that heat transfer was greatly improved with higher air speeds and batch sizes, which also reduced charcoal consumption from 22.18kg to 18.85kg and shortened the drying durati... More >