Life cycle cost and carbon footprint analysis of CuO–Al₂O₃/water hybrid nanofluids in thermoelectric vaccine refrigerators

This study investigates the application of a CuO–Al2O3/water hybrid nanofluid as a coolant in thermoelectric vaccine refrigerators, aiming to enhance heat dissipation from the Peltier module’s hot side. A 35-L cooling cabinet was utilised, and experimental comparisons were made using water and a 2% CuO–Al2O3/water hybrid nanofluid. Results show that the vaccine cabinet reaches the target temperature of 4 °C in 990 s with nanofluid, compared to 1200 s with water. The system’s energy consumption was reduced by 18.3%, and carbon emissions decreased by 12.3% over a 15-year lifespan, highlighting its environmental benefits. Despite similar coefficients of performance (COP), the nanofluid system demonstrates enhanced efficiency, shorter cooling times, and long-term sustainability advantages. These findings support the adoption of hybrid nanofluids in thermoelectric cooling applications for energy-efficient and environmentally friendly refrigeration systems.