AI-optimized biochar–PCM composites for passive building cooling toward sustainable and net-zero energy pathways via Lévy-flight ant colony optimization

Biochar phase change material (PCM) composites have emerged as promising passive cooling materials for sustainable building operations due to their high latent heat storage capacity and carbon sequestration potential. Biochar pores are inherently hierarchical and irregular, exhibiting complex thermo-physical behavior that limits the capability of traditional optimization methods. To address this challenge, current study proposes a novel prioritized Ant colony optimization (ACO) with Lévy flight fine tuning which incorporates pore thermal interaction memory for enhanced global exploration and avoidance of local optima. The developed framework achieved rapid convergence with a fitness value of 0.88 by iteration 27. Thermophysical analysis revealed latent heat storage ranging from 160–185 J/g, melting temperatures between 21 and 63 °C, and thermal degradation onset at 150–180 °C, confirming effective thermal stability and energy storage performance. Correlation analysis indicated strong dependence of storage efficiency on PCM loading and nonlinear pore-controlled thermal interactions. The optimized composite exhibited latent heat of 183 J/g, storage efficiency of 87%, and melting temperature of 45 °C. These findings demonstrate the potential of AI-optimized biochar–PCM composites for sustainable passive cooling.