In the United States, over 100 million residential refrigerators are in use, and each one can use up to 2 kW of electricity every day. By pumping refrigerants across evaporator coils to maintain low temperatures for fresh and frozen compartments, these refrigerators use compressors that cycle daily and night, increasing energy consumption and carbon emissions.
ORNL scientists have developed a new approach that keeps the food excellent while reducing carbon emissions by 30%.
The technology stores cold energy using sophisticated evaporators with PCMs placed in every chamber. Because PCMs store and release energy when a substance changes from a solid to a liquid or vice versa, they are helpful for heating and cooling. Researchers used direct-contact defrosting technology, porous metals, and a refrigerant with low global warming potential to maximize efficiency and reduce environmental effect.
As ORNL’s Zhiming Gao explains, “By integrating PCMs with evaporator coils to maintain a constant temperature, our technology requires only one operating cycle. This unique feature allows refrigerators to operate almost 100% at nighttime, when energy use is lower. The result? A significant reduction in electricity demand, substantial cost savings, and the assurance of maintaining efficiency.”
