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When Hunter’s Shop 'n Save grocery store in Wolfeboro, New Hampshire, burned to the ground in January 2023, owner Dan Craffey vowed to rebuild. True to his word, on June 20, 2024, he proudly opened the new store, which is now 25% larger at 16,000 square feet and features a brand-new refrigeration technology called the FlexCube Supermarket Refrigeration System.

Invented by Jim LaBrecque, an energy engineering expert and 50-year veteran of the supermarket industry, the FlexCube modular system consists of identical 2- by 2-foot cubes that are easy to install and take up no floor space. Suitable for both low- and medium-temperature applications, the cubes contain about 25 pounds of refrigerant each and, according to LaBrecque, are virtually leak-proof. The distributed module design allows store owners to easily add more FlexCubes if they expand their space or need additional refrigeration, and by using the A2L refrigerant R-454C, FlexCube complies with federal regulations requiring lower-GWP alternatives.

NO FLOOR SPACE: One FlexCube can run 84 feet of multi-deck produce cases and take up no floor space. (Courtesy of Gunner Found,Wolfeboro, NH)

Love at First ‘Site’

Craffey considered using the unique refrigeration technology in his rebuilt store after learning from LaBrecque that the FlexCube system had been installed in a 26,000-square-foot Gowell’s supermarket in Greene, New Hampshire. Craffey subsequently visited the store and was impressed by what he found.

“I've been doing supermarkets almost 40 years in Maine and New Hampshire, and my experience is those big mechanical rooms with gas leaks, expensive repairs, and huge energy costs,” said Craffey. “I walked into the Gowell’s and saw that the amps for the whole store were about 230 amps, which is just a little bit bigger than a house. Then I walked around and looked at these little 2- by 2-foot cubes.Instead of a mechanical room, you can put them up above coolers, freeing up square footage on the sales floor. That’s huge, because every square foot in the store should produce money. Then I checked the case temperatures, and they were perfect. Within 45 minutes, I said, ‘this is it.’”

Craffey’s new store required six cubes with small-capacity compressors to service the various low- and medium-temperature cases located on the sales floor. Eight heat pumps, each with a capacity of either 1.5 or 2 tons, handle the store’s HVAC. While the cubes are all identical, they can use three different capacity compressors, in order to vary the load as needed. The FlexCube system incorporates Copeland’s refrigeration scroll compressors, which have been optimized for A2L refrigerants and are integrated into the design.

“The FlexCube system using Copeland’s compressors is a neat little package you don’t see in food retail today,” said Joe Summers, senior product manager of scrolls and drives at Copeland. “It is innovative, compact, and designed to be serviceable. The potential for reduced total cost of ownership is compelling.”

Contributing to that lower cost of ownership is the fact that the reclaimed heat from the cubes can be used to heat the store. In Craffey's case, there was enough capacity to heat the next-door Walgreens as well.

“One PVC pipe runs around the perimeter of the building, and the compressors reject heat into that water loop 24/7,” said LaBrecque. “The refrigeration units or heat pumps grab the water from that pipe and run it to the heat exchanger. One evaporative fluid cooler sits on the ground and rejects all the heat for the building, whether it's refrigeration or air conditioning.”

To prevent leaks, the cubes use bendable, half-hard, copper tubing — unlike traditional air conditioning and refrigeration tubing, which is rigid. This eliminates the need for hundreds of elbows, traps, and couplings in a conventional refrigeration system, said LaBrecque. During the manufacturing process, digital pipe bender technology is used in conjunction with a phone app. The app takes measurements and calculates where to mark the pipe and set the digital bender, which eliminates many fittings and brazes. As LaBrecque is fond of saying, “non-existing pipes and fittings will never leak.”

REFRIGERANT SENSOR: James LaBrecque shows how each FlexCube A2L system incorporates an R-454C refrigerant sensor. (Courtesy of Gunner Found,Wolfeboro, NH)

Inside the Hunter’s Shop 'n Save, the six cubes hang from the bar joist above the coolers, so they’re easy to access for service, filter changes, etc. In fact, making them easy to install and service was one of the key reasons for developing the FlexCube system, said LaBrecque.

“There is a lack of human resources in our industry,” he said. “There's nobody coming into the industry, and the quality of the people coming in is diminishing. At the same time, things are getting very expensive and very complex, so I designed the system to be highly standardized and simple.”

The simple design makes Craffey happy, because if something fails, it’s easy to repair. “Everything's monitored — all the cases, temperature, everything,” he said. “If there's a problem, my store manager gets an alert on his phone, and he can immediately get the problem repaired without losing product. In fact, it’s so simple, he could probably do the repair himself.”

Benefits

The system is also appealing because it costs significantly less than a conventional refrigeration rack system and takes much less time to design and install.

“The supermarket business is a penny business, so we want to keep costs down. The FlexCube system cost about one-third of a conventional rack system and took only six months to design and install,” said Craffey. “If I went with a conventional rack system, it would have taken 12 to 18 months for design and installation, and it also would have required a much larger electrical system for my size store. With the FlexCube system, I have a 100-amp load, and there’s absolutely no cost to heat the store.”

Indeed, the electrical system for the Hunter’s Shop 'n Save requires less than half the capacity of a standard store. While typical grocery stores use transformers rated at 600 to 750 kVA, Hunter’s operates on a 300 kVA service with a reduced main distribution panel to power subpanels, said Peter Waning, director of construction at Hunter’s store. He added that the benefits of this setup include:

• Lower costs for owners to purchase the equipment;
• Reduced time for installation and procurement;
• Easier acquisition of load-side gear;
• No need to upgrade low-powered stores that are planning to go into existing malls, saving owners, contractors, and future grocers from additional expenses; and
• Greater flexibility in-store placement, as most stores typically require 480V three-phase power.

According to LaBrecque, there are other cost savings to consider as well, such as less store infrastructure to support a large refrigeration rack system and other HVAC equipment.

“Supermarkets will spend hundreds of thousands of dollars for structural steel and cement floors, in order to hold those big racks, which can weigh 10,000 to 15,000 pounds,” said LaBrecque. “Then there’s all the structural steel to reinforce the roof, so it can hold the condensers and central air conditioning units up there. Plus, the associated costs for the additional electrical and plumbing, along with the significant amount of engineering needed to design a big, complex system.”

With the FlexCube system, all that infrastructure is gone, said LaBrecque.

“We use off-the-shelf, high-efficiency, heat pumps that are distributed among the FlexCubes and operate at a COP of 5, because we have warm water feeding them year-round. Our units are pretty much plug-and-play, and we use the same template over and over. This results in massive cost savings in the construction of the building.”

LOCKED AWAY: FlexCube isolates all electrical components in a NEMA-rated enclosure with lockable metal panels to prevent flame spread of A2L refrigerants. (Courtesy of Gunner Found,Wolfeboro, NH)

Retrofit

The FlexCube system can also be used in retrofit applications. In fact, Craffey has two other stores that he plans to retrofit in the near future.

“I'm going to get rid of the rack systems and put in the FlexCube systems,” he said. “That will save me money in three ways. No. 1, I won't have any heat expense, because there’s no oil or gas. No. 2, my electricity use will drop tremendously. And No. 3, I won't have any equipment outside or up on a roof. I can put those cubes in with short pipe runs, plug them in, and the expense will probably be one-third of what it would cost to redo a conventional system. And using an A2L refrigerant is more environmentally friendly.”

Another benefit is that the FlexCube system can be installed in stages, allowing cases to come online quickly and eliminating the usual delays that are part of many store remodels, said Waning. He added that the permitting process is also easier.

“At the local level — from town inspection services to state fire marshal — the FlexCube system reduces complexity, resubmission, and follow-up inspections during construction, eliminating turnover delays,” said Waning. “This is one of the largest issues for retailers, as downtime is money.”

The FlexCube systems installed so far have been test models, but LaBrecque plans to start production in January 2025.

“You can visit every supermarket from Maine to California, and you won’t find two alike. That's been a really big problem, so we're going to change that,” said LaBrecque. “These modules are going to be put into standard production, and as soon as somebody calculates the load, we can ship them ASAP. Owners won’t have to wait 18 months to engineer, plan, and build a big, complex rack with miles and miles of piping that can leak. It will be a complete paradigm shift in the way we construct supermarkets.”