The system, running in a Food Lion store in Southport, North Carolina, that opened last fall, “has met our needs,” said Wayne Rosa, at a sustainability session at the Food Marketing Institute’s Energy & Store Development Conference in New Orleans on 12 September.

“We’ve had no issue associated with the CO2 in any shape or form. It’s kept food integrity where we need it,” he said.

Rosa described the transcritical system as being “very close to a traditional refrigeration system”. A lack of understanding of CO2 can cause technicians to be “gun shy” about the technology, but upon learning about “two or three items to stay away from,” they see it’s the “same system” they’ve been accustomed to.

However, Rosa acknowledged that Food Lion is “still investigating” the energy performance of the system, especially given its location in a southern U.S. climate, where it’s more exposed to warmer temperatures that reduce its efficiency.

“We’re trying to get more data – we want to run it a little more than a year,” he said. “Our hope is energy parity [with an HFC system] at worst, and energy savings to help fund the technology.”

Food Lion did not opt to install technology, such as an adiabatic gas cooler, that would help the transcritical system operate more efficiently in warmer ambient temperatures.