If you’re like most supermarket owner/operators, selecting a sustainable refrigeration technology is a key component in your long-term operational strategy. Whether you’ve made a public declaration of sustainability commitments or you’re prioritizing steps along the path to Net Zero operations, migrating away from hydrofluorocarbon (HFC) refrigerants is essential for achieving your goals.

Navigating a sustainable path forward requires a clear understanding of a refrigeration system’s total equivalent warming impact (TEWI), which includes both the direct carbon emissions from refrigerants and indirect emissions from energy consumption. And as always, refrigeration selection criteria must be considered within the framework of the total cost of ownership (TCO).

Among emerging refrigeration architectures, CO₂ transcritical booster systems address many key points on retailers’ sustainability checklists. CO₂ (refrigerant name R-744) is a natural refrigerant with zero ozone depletion potential (ODP) and a global warming potential (GWP) of 1 — characteristics which have long made it a leading alternative to higher-GWP HFC refrigerants. Today’s CO₂ transcritical booster systems are simpler to deploy, maintain and operate than ever — all while approaching TCO parity with legacy HFC systems.

Although CO₂ refrigeration has been widely used in Europe for decades, applications are now flourishing around the globe. Today, nearly 1,000 CO₂ transcritical booster systems are installed in the U.S., while adoption is projected to increase more than 50 percent by 2025.

Retailers who are now looking at CO₂ for the first time will benefit from years of trials that have significantly improved upon equipment technologies — especially those designed to enable system efficiencies, even in the warmest climates within the continental U.S. Refrigeration system designers, original equipment manufacturers (OEMs) and component manufacturers have made tremendous strides in developing smart CO₂ solutions that mitigate high ambient challenges, optimize performance, and simplify system management.

Case in point: A recent collaboration between Copeland and OEM partner Zero Zone demonstrated the potential for CO₂ transcritical booster systems for a new supermarket in Joplin, Mo. Due to the warm climate, Zero Zone and Copeland would need to install a CO₂ transcritical booster system that leveraged an adiabatic gas cooler — an emerging design optimization strategy designed to maximize the efficiency of CO₂.

The climate in this location averages more than 2,500 annual hours above 75 °F — the temperature at which a CO₂ transcritical booster system transitions into transcritical (aka supercritical) mode. The adiabatic gas cooler ensured that system efficiencies achieved the retailer’s energy targets in these high ambient temperatures. This approach effectively delayed transcritical operation by 1,729 hours and limited the use of the adiabatic gas cooler to 864 hours per year.

Zero Zone’s energy-efficient system design featured Copeland’s integrated approach to CO₂ refrigeration compressors, controls and components, including:

• Copeland™ CO₂ transcritical semi-hermetic compressors (3), with the lead compressor equipped with a Copeland variable frequency drive (VFD), EVH/EVM Series
• Copeland ZO scroll compressors (2), one of which is a digital scroll compressor
• E3 supervisory control for CO₂ system applications

Copeland is committed to developing CO₂ transcritical booster system technologies that help retailers to meet their sustainability goals.