Enhanced evaporative cooling using additively manufactured PLA–wood composite lattices

• Lattice evaporative cooling pads were manufactured from a PLA-wood composite. • The evaporative cooling pads were fabricated through additive manufacturing. • The octagonal lattice pad reached a wet bulb effectiveness of 0.93. • The energy efficiency ratio of a full-scale prototype ranged between 7 and 87. • Lattice structures provide high contact surface, enhancing cooling capacity. Evaporative cooling technologies are increasingly recognized as energy-efficient and sustainable alternatives to conventional air-conditioning systems. In this study, five evaporative cooling pads, four with lattice geometries and one conventional grid-type reference pad, were designed and fabricated through additive manufacturing using a polilactic acid (PLA)-wood composite, then characterized and experimentally evaluated under controlled inlet air conditions. Material characterization revealed a rough mesoporous morphology and intermediate wettability, favouring capillary-driven water retention. Among the tested designs, the octagonal lattice geometry exhibited the largest air–water contact surface, achieving the greatest temperature drop (19.7 °C) and wet bulb effectiveness (0.93), thereby demonstrating superior performance. This geometry was subsequently scaled up into a full-scale prototype incorporating an integrated water distribution system. Statistical analysis confirmed that both inlet air temperature and airflow rate had a significant effect on cooling performance, with coefficients of determination above 0.98. The energy analysis of the prototype showed that the cooling capacity increased up to 800 W, while the energy efficiency ratio ranged between 7 and 87 depending on operating conditions. The findings emphasize the strong connection between material properties, lattice geometry, and energy performance, supporting this design to optimize sustainable evaporative cooling systems for building applications.