U.S.-based supermarket chain Hannaford has equipped the entire frozen section of its new store in Brunswick, Maine, with propane (R290) self-contained cases, according to a recent presentation by Harrison Horning, Director of Maintenance, Retail Business Services – Hannaford and Stop & Shop, part of Ahold Delhaize.
The presentation was made during the End User and Contractor Panel at the ATMOsphere (ATMO) America Summit 2022 on natural refrigerants, which took place June 7–8 in Alexandria, Virginia. The conference was organized by ATMOsphere (formerly shecco), publisher of Hydrocarbons21.com.
In addition to the 120 doors of frozen food and ice cream R290 display cases, the setup includes a water-cooling loop that contains a 35% propylene/glycol mix and removes condensation heat from the freezer units. This heat can either be transported to the store’s rooftop where the it is dispersed to the air in a fluid cooler, or it can go via the loop’s diverting valves for heat reclamation. The overall system, called Micro DS, is provided by U.S. manufacturer Hussmann.
Hannaford’s Brunswick store, which opened in June 2021, is the fifth of the chain’s new stores to adopt this frozen-food refrigeration architecture. It demonstrates how R290 cases can be used across in large sections of a store, or an entire store, as opposed to individual spot units.
Hannaford is planning to adopt a similar approach in existing stores for the first time in two projects later this year.
The retailer has the distinction of being the first chain in the U.S. to install a CO2 (R744) transcritical system in 2013 at its store in Turner, Maine.
When asked whether there was a preference between CO2 and R290, Horning said that both refrigerants have their advantages and disadvantages.
“CO2 tends to be complicated in remote areas where technician support is limited,” said Horning. “With R290, you can lose one condensing unit and it still holds temperature, so it’s not an emergency call and might be a better bet from a reliability point.”
“I don’t think there’s a right or wrong,” continued Horning. “You can [use] either of these solutions in an existing store; both are compatible with medium-temperature glycol, and you can do CO2 for low temperature.”
“With R290, you can lose one condensing unit and it still holds temperature, so it’s not an emergency call and might be a better bet from a reliability point.”Harrison Horning, Hannaford
During Horning’s presentation, he looked at four aspects of the store’s R290 setup: cost, reliability, sustainability, and maintenance and training.
For new stores, Horning said that costs are either the same or lower, than a rack system, depending on freezer design. Despite the R290 cases being more expensive, retailers save costs by not needing a rack. Horning also pointed out that some retailers may be willing to spend more money “if it’s an effective way to reduce greenhouse gas emissions.” This is the case with Hannaford’s Retail Business Services, which is striving to achieve net-zero greenhouse gas emissions by 2040.
Reliability is the most important thing, according to Horning. He rated system performance as “generally acceptable,” with lower than 7% failure during its first year. Emphasis was placed on not cutting any corners during installation – flushing, filling, venting, flow balance etc. – to reduce risk.
In terms of sustainability, refrigerant emissions are negligible for this part of the system, and gas heating requirements can be reduced through heat reclamation. Electricity demand may increase slightly due to the system’s pumps, but this is also negligible, according to Horning.
The system requires R290, water/glycol and on-board controls training.
While many stores in Europe are demonstrating a wider adoption of R290 across frozen units, medium-temperature units and cold rooms, this is relatively rare in the U.S. However, a growing number of retailers are starting to opt for more extensive use of R290. This is particularly relevant with the higher charge limits on R290 that have recently been approved, potentially creating a more competitive landscape between R290 and R744.
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