U.S. retailer Publix Super Markets, which operates 1,284 stores in seven Southeastern states, has committed to using propane (R290) refrigerant in all of its small self-contained cabinets in new stores as well as in replacement units in existing stores.
That was one of the messages shared by Doug Milu, Manager, Refrigeration & Energy Program for the Lakeland, Florida-based chain, during the end users session at the ATMOsphere America conference, held online on November 3. ATMOsphere America was organized by ATMOsphere (formerly shecco), publisher of Hydrocarbons21.com.
Because of the current 150g charge limit for R290 in self-contained plug-in cases, Publix has limited its use of the refrigerant to smaller cases, including beverage coolers at the registers, soft drink machines at store exits, self-contained cabinets in the lobby, and cases holding fresh organic pet food.
“We really believe that R290 has won that small-cabinet format,” Milu said.
Last month, UL (Underwriters Laboratories) approved a second edition of its UL 60335-2-89 standard, including higher charge limits for hydrocarbon refrigerants. The new UL standard raises the charge limit in commercial plug-in display cases to 13 times the LFL (lower flammability limit) of a refrigerant – or 500g for propane (R290) – for open appliances (without doors). It raises the charge limit for closed appliances with doors and/or drawers to eight times the LFL of the flammable refrigerant (300g for R290). The higher charges approved by UL would still need to be adopted by the U.S. Environmental Protection Agency, and finally adopted by local building codes, before retailers could install cabinets with more than 150g of propane.
Milu said he was open to installing larger R290 cabinets with the higher charges once they become available. “It’s up to equipment manufacturers to design, build and offer these larger cabinets,” he said. “At some point I see that happening.”
Meanwhile, R290 display case companies such as True Manufacturing are providing training for technicians working on their equipment, and RSES (Refrigeration Service Engineers Society) offers “good training” for R290 and R600a applications, he said.
Publix primarily uses centralized rack systems for its refrigeration. The chain has begun to install transcritical CO2 systems in some stores, following its use of a CO2 DX (for low-temperature cases) and pumped CO2 liquid overfeed (for medium-temperature cases) system in about 78 stores, said Milu.
“We really believe that R290 has won that small-cabinet format.”Doug Milu, Publix
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