Experimental assessment of fanless thermoelectric cooling using a folded aluminum plate under natural convection

This study experimentally investigates the performance of a fanless thermoelectric cooling system operating under natural convection conditions, with particular emphasis on simple and cost-effective hot-side thermal management. A commercial TEC12703 module was integrated into a miniature refrigeration system consisting of a Styrofoam enclosure, where heat rejection from the hot side was achieved using a folded aluminum plate without any auxiliary cooling components such as fans, pumps, or heat pipes. The aluminum plate was geometrically modified to enhance heat dissipation while maintaining a small footprint and to reduce thermal interaction with the refrigerator wall by increasing the effective separation distance. Experiments were conducted at six different input voltages (3, 4, 5, 6, 7 and 8 V) to evaluate the voltage-dependent cooling behavior and overall system performance under passive cooling conditions. The results demonstrate that even with a simple plate-type heat spreader, stable operation of the thermoelectric module can be maintained, although hot-side temperature rise significantly influences cooling capacity and coefficient of performance (COP) as the input voltage increases. The folded plate configuration achieved up to approximately 2–3 °C lower cold space temperatures and about 15–20% higher COP values compared to the flat plate, particularly within the optimum operating voltage range of 5–6 V. The findings highlight the critical role of hot-side heat rejection in fanless thermoelectric systems and confirm that appropriately designed folded aluminum plates can provide a viable passive thermal management solution for low-power and compact refrigeration applications where simplicity, reliability, and low energy consumption are prioritized. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2026.