CO2 as a refrigerant has been a part of the refrigeration landscape for close to a decade. From early efforts combining it with ammonia in cascade systems for industrial plants to cascade and other approaches with hydrofluorocarbon (HFC) refrigerants in supermarkets, ammonia has established itself in the HVACR landscape.
The most anticipated next step was running CO2 as a stand-alone refrigerant in a system, which is being done in Europe in more and larger applications. This approach finally crossed the Atlantic and made a high-profile debut just a few months ago in Brooklyn, New York. And it continues to gain more and more attention in the states in refrigeration applications. Most recently, CO2 was showcased as a hot topic at the Food Marketing Institute Expo in Chicago.