Advancing Domestic Freezers With Phase Change Materials: Experimental Study Towards Commercialization

Abstract

The urgency for more efficient and sustainable domestic refrigeration systems (DRSs) is intensifying due to climate change events like more frequent heat waves. Such challenges impose reducing greenhouse gas emissions, increasing renewable energy storage rates, meeting the perishable food needs for cooling, and mitigating food wastage through power outages. While previous investigations contributed to these goals by studying the potential benefits of adding phase change materials (PCMs) to DRSs, our study extends their application to chest freezers: a type of system still underexplored. Additionally, it seeks to enhance industrialization and design decision-making towards tailoring different solutions to distinct markets. Namely, by adopting test procedures closely adhering to the European Standard EN 62552:2013 for experimentally testing four prototypes. The analysis of the novel systems' performance focuses on two metrics internationally recognized but scientifically overlooked by previous peer research: the temperature rise time and the daily energy consumption. A novel approach for filling the top-mounted door with PCMs and an industrialization technique for simultaneous wrapping PCM bags and evaporator tubes around the freezer compartment are introduced to incorporate PCMs, with melting temperatures (T_m) of −21°C and −12°C. Our findings reveal the potential to extend blackout autonomy by 7%–40% and to reduce daily energy consumption by 13%. Furthermore, the results demonstrate that higher T_m values enhance the commercial attractiveness of DRSs in regions with unstable electricity grids where significant autonomy gains are appreciated, while lower T_m values suit sophisticated markets where extended energy storage capacity and compressor lifetime can be prioritized.