Energy — CO2 to the rescue ƒ

Tomorrow’s commercial refrigeration systems – like the ones in supermarkets – could be cooled by carbon dioxide instead of hydrofluorocarbons, a greenhouse gas that is nearly 4,000 times more potent than CO₂. That is important because millions of pounds of HFCs leak into the environment every year, said Brian Fricke, a researcher in Oak Ridge National Laboratory’s Building Equipment Research Group. To address the problem, Fricke and colleagues are experimenting with CO₂ and other refrigerants, including a hydrofluoroolefin called R1234yf. While by definition CO₂ has a global warming potential of 1, the hydrofluoroolefin’s is 4, so both are far less harmful to the environment than HFCs with a rating of 3,900. Still, while CO₂-based systems work well in cold climates, they aren’t as efficient in warmer climates, so Fricke is experimenting with various approaches to address the limitation.