Over the past two years, AHT Cooling Systems USA, Ladson, S.C. (a division of AHT Group, acquired in 2018 by Daikin), has been highly proactive in installing self-contained propane (R290) display cases  that are air-cooled or water (mixed with glycol)-cooled in full-store configurations in the U.S. 

This is a follow-up to supplying R290 cases in partial-store layouts, or in spot merchandising situations. 

Globally, AHT supplies self- contained propane cases in full-store layouts to more than 7,000 stores (many in Europe). In the U.S., AHT has supplied more than 90 stores where more than half of refrigerated load uses propane cases, said Drew Tombs, president of AHT Cooling Systems USA. “We see more [U.S.] retailers engaging in design discussion about R290 water-cooled and air-cooled projects to better understand the advantages first hand.”

AHT USA customer Wild Fork Foods, which offers only frozen foods, particularly meat, poultry and fish, opened three roughly 5,000ft² (464.5m²) stores in South Florida in December 2018, and equipped them each with 40-50 air-cooled plug-in AHT R290 frozen-food cases in a full-store layout. The chain has since installed the R290 cases in six other new stores.

“As each store is unique, the layouts change slightly,” said Tombs. “But, in general, the decision for 100% [air-cooled] self-contained is their only direction forward for their next wave of stores planned for 2021.”

The Wild Fork Foods equipment includes both horizontal chest units throughout  the store and vertical reach-ins that are built into the perimeter wall, overhanging the retail space.

The single-circuit cases all have doors or lids, and do not require floor drains for condensation removal. The stores use an R448A split system in the cold room.

AHT USA, in cooperation with sister company Zanotti, has since developed both air-cooled and water-cooled R290 low-temperature and medium-tempera- ture “Monoblocks” for cold rooms; these packaged units are already installed and planned for several upcoming installa- tions, said Tombs.

Store flexibility

Wild Fork Foods installed the R290 cases to be “more environmental” and because “it was conducive to what we wanted to do,” said Layli Sobhani, head of brand and marketing for the retailer, last year in regard to the first three stores. In partic- ular, the cases “give us the flexibility to build out the stores consistently to fit all of our products.” In addition, she expects the cases to save the stores additional energy because they all use doors. 

Wild Fork does not provide energy consumption numbers, but AHT USA’s R290 cases have been “performing and meeting [Wild Fork’s’] expectations” and providing flexibility to the chain “given the type of retail footprints they are targeting for store growth,” said Tombs.

In addition to Wild Fork Foods, in 2020 AHT has implemented a complete-store R290 configuration for other U.S. chains, including  a Grocery Outlet location in California; four additional Grocery Outlet stores (two in California and two in Pennsylvania) are also getting a full- store R290 installation in 2020, said Tombs. These are all semi-plug-in cases with water-loop cooling.

ALDI US said it anticipates testing AHT USA’s R290 semi-plug-in cases with water-loop cooling, as well as air-cooled R290 display cases and cold room packaged units.

AHT USA is also planning an installation at a Piggly Wiggly store in Georgia in which “our R290 water-loop [cases] were selected over traditional  DX  remote for a multi-use retail project,” said Tombs. 

Air- or water-cooled?

Whether a store would use air-cooled  or water-loop cases depends on its products and layout, said Tombs. “For Wild Fork Foods, it was easier to do a true [air-cooled] self-contained [lineup] with plugs and no drains,” he said.

In general, stores using only propane cases tend to employ a water loop on the perimeter, with air-cooled cases in the center store, where they can be flexibly merchandised, Tombs said. Air-cooled units can also be used to add refrigera- tion capacity to an existing store without expanding the rack.

Globally, there are an estimated 1,900+ stores using hydrocarbon water-loop systems, including about 1,700+ in Europe and 100 in the  U.S.,  according to sheccoBase, a division of Accelerate publisher shecco.

For water-loop R290 units, AHT leverages a dry fluid cooler to move water/glycol through the system and remove heat from the cases; the system maintains an average water temperature of 86°F (30°C), with a range of 62°F-113°F (17°C- 45°C) based on ambient temperature.

This article is included in a special issue of Accelerate focusing on Best Practices for Natural Refrigeration in Food Retail. Read the entire issue here.

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