PHOENIX — In the wake of the merger that nearly doubled its store count to 102, Sprouts Farmers Market, a chain of natural and organic stores based here, is pursuing a green agenda aimed at making its refrigeration systems among the most environmentally friendly in the industry.
Since acquiring 34 Henry's and nine Sun Harvest stores from Los Angeles-based Smart & Final in April, Sprouts has added to its list of stores receiving certification from the Environmental Protection Agency's GreenChill Advanced Refrigeration Partnership. In April and May, two Sprouts stores earned silver GreenChill certification awards, and in April a store in Thousand Oaks, Calif., received platinum certification — the highest level of certification, given to only two other U.S. stores, operated by Price Chopper and Star Market.
Sprouts now has a total of eight GreenChill-certified stores, including one with gold and four others with silver, across its four-state chain. Only one other food retailer, Fresh & Easy Neighborhood Market, El Segundo, Calif., has more GreenChill-certified stores, with 13. All told, there are 61 GreenChill-certified U.S. supermarkets (three platinum, 24 gold and 61 silver). GreenChill certification must be renewed annually to remain current.
More GreenChill stores are in the works for Sprouts. “We're planning 10% growth in the number of stores every year going forward,” said Jerry Stutler, vice president, construction and facility engineering for Sprouts Farmers Market, in a statement. “Our goal is to have every one of the new stores GreenChill-certified.”
GreenChill was established in 2007 as a voluntary program to help food retailers reduce the quantity (charge) of refrigerant used in their stores, as well as reduce the leakage of refrigerant into the atmosphere, transition from R-22 refrigerant to non-ozone depleting variants, and test so-called advanced refrigeration systems that serve all of those goals.
GreenChill established best-practice metrics by which stores could receive silver, gold or platinum certification. To earn platinum status, for example, a store must either use refrigerant with a very low global warming potential (GWP) of lower than 150, or, more commonly, use HFC-based refrigerant that meets very strict leak and charge requirements (a leak rate of 5% or less and a charge equal to or less than 0.5 pound of HFC refrigerant per 1,000 BTUs per hour total evaporator cooling load).
Sprout's Thousand Oaks store met GreenChill's platinum-level requirements by installing a carbon dioxide-based “cascade” refrigeration system for both low-temperature and medium-temperature cases — the Second Nature MT2LX system from Hill Phoenix, Conyers, Ga. It is one of a handful of U.S. stores employing a cascade system in place of a conventional DX (direct expansion) refrigeration system, and the first to be platinum-certified. Other chains testing cascade systems include Food Lion, Price Chopper, Stop & Shop and Fresh & Easy Neighborhood Market. Cascade systems are widely used in Europe.
“We challenged Hill Phoenix to come up with a design that would reduce our use of refrigerants by an amount that would allow us to meet GreenChill platinum standards,” said Stutler.
“The platinum award is hard to achieve,” said Henry Pellerin, director of marketing programs, Hill Phoenix. “Using the right technology is a key part, but also designing it at the store level.” Hill Phoenix also installed the unit and continues to service it.
LIMITING HFC
The key to the Thousand Oaks store's cascade system is that it relies on carbon dioxide to cool all refrigerated and frozen cases, not HFC refrigerant, which is confined to the machine room and condenser.
For medium-temperature cases, the system uses liquid carbon dioxide as a secondary coolant; for low-temperature cases, it employs carbon dioxide as a direct expansion (liquid to gas) refrigerant. The system also incorporates an air-cooled microchannel condenser that is energy-efficient and helps to reduce refrigerant charge.
Carbon dioxide, though the most common greenhouse gas, has a very low GWP (1) compared with conventional refrigerants, and is far less expensive than conventional refrigerants. The lines required for carbon dioxide transport are typically one to two sizes smaller than traditional DX piping systems, thereby reducing the weight of installed copper lines by 50% and cutting installation costs.
By limiting the scope of HFC refrigerant, Sprouts' cascade system reduced the amount of HFC needed in Thousand Oaks by 72% to 235 pounds (it also uses 900 pounds of carbon dioxide). “Since we joined GreenChill in 2010, we've been really working hard to reduce the amount of [HFC] refrigerant in our stores,” said Stutler. “That's not only good for the environment in terms of less leak potential, but also makes sense financially.” Sprouts also wants to be prepared for stricter regulations, particularly in California, on greenhouse gas emissions, he added.
The average Sprouts store, which is about 25,000 square feet, uses a DX refrigeration system containing about 2,000 pounds of [HFC] refrigerant. In about 20 stores, the chain has installed “distributed” refrigeration systems with 600 to 800 pounds of refrigerant. Sprouts is now working with Hill Phoenix on developing an ammonia-based refrigeration system, expected in 18 months to two years, that would eliminate HFCs altogether. Ammonia, like carbon dioxide, is an all-natural refrigerant.
The HFC refrigerant chosen by Sprouts for the platinum-certified store is R-407A, which has one of the lowest GWPs (2,107) of any HFC refrigerant. About 1½ years ago, Sprouts began replacing R-22 refrigerant in five stores with R-407F refrigerant, which has an even lower GWP (1,824). Sprouts is one of a small group of food retailers using R-407F, said Stutler, because major compressor manufacturers are not offering warranties for its use. Sprouts has started to employ a compressor from the German manufacturer Bitzer, which does warranty R-407F.
Sprouts is now committed to using R-407F in every new store and all R-22 retrofits over the next two years. “The R-407F is so close to R-407A that we're confident in using it,” even with compressors that don't warranty it, he said.
Sprouts is embracing the challenge of being among the first to test a cascade system in a live setting. “We wanted to be a GreenChill partner that would participate in alternative refrigeration systems and be somewhat of a testing or proving ground,” he said. The more retailers that conduct such tests, the more likely the technology will be understood and widely used, reducing its cost, he noted. Meanwhile, at the Thousand Oaks store, “we have not had one issue or service call on this system to date; it's still running perfectly,” he said.
Stutler acknowledged that Sprouts paid a 12% to 15% premium on the cascade system compared with a conventional system, including installation. On the other hand, the system is designed to cut leaks by 11% compared with a standard DX system, and replaces HFC refrigerant with cheap carbon dioxide. Hill Phoenix estimates that the system will yield a 5% reduction in energy consumption; Sprouts is in the process of measuring that energy usage.
“It's tough to put a dollar value on the potential payback for this investment,” Stutler said in a Hill Phoenix document on the Thousand Oaks store. “Certainly we're hoping to save money over the years, but how do you put a dollar amount on the value of being green, reducing your carbon footprint and improving the overall system performance?”
