Minneapolis-based Target Corp. now has self-contained display cases using propane(R290) refrigerant in more than 1,000 stores, and Hannaford Supermarkets is planning to open a small new store that uses self-contained propane cases with water-loop condensing for all low-temperature foods.
Those were among the developments in natural refrigerant systems shared yesterday at a session on alternative refrigeration at the Food Marketing Institute’s Energy & Store Development Conference in Orlando, Fla.
“Target gas been evaluating alternative refrigerants for several years and has determined that R290 is the preferred self-contained refrigeration solution,” said Paul Anderson, the company’s senior director of engineering.
The reasons for this determination include:
Target’s propane cases include larger units it purchases for stores as well as smaller beverage coolers provided by brands like PepsiCo, Coca-Cola and Red Bull.
Anderson also discussed Target’s other natural refrigerant installations, including its prototype CO2 cascade system deployed in 12 stores and two transcritical CO2 stores (in Marin City, Calif., and Minneapolis) opened this year. Target has also converted or built 100 stores using an HFO blend.
Anderson reported that in a study of the energy consumption of the transcritical system in Marin City, Calif., since March of this year, the system consumed 20% more than an HFC system in a nearby store. But he acknowledged that the period measured included the summer months (the average high in June of 2017 in Marin City was about 80°F, with 10 days exceeding that temperature) and did not include the winter months (the average high in Marin City in February 2017 was 58°F). In addition, the store did not employ an adiabatic condenser, parallel compression or an ejector, all designed to improve efficiency in warmer climates or times of the year.
Harrison Horning, director of energy & facility services for Delhaize America (who focuses on Hannaford Supermarkets in New England) noted that the company plans to install self-contained propane display cases for low-temperature foods in a new small-format store. These cases would use a water-loop to remove heat; Hannaford also employs air-cooled propane cases in several configurations in a number of stores.
As propane cases have developed, “they are getting quieter, lower-maintenance and more plug-and-play, so they’re easy to replace,” said Horning. “Will there come a day when we buy self-contained cases for the whole store? I don’t know But I’m excited to see where this is headed.”
Also at the session, Michael Lehtinen, director of marketing for Kysor/Warren, described the energy savings experienced by a Piggly Wiggly store in Columbus, Ga., using the OEM’s ammonia/CO2 cascade system. The store measured a 33% energy savings over nearly two years for the store compared to an HFC store (including all energy consumption) and a 22% energy savings when comparing the ammonia rack and an HFC rack installed in the store for the study.