The Big Chill
Retailers are steadily embracing sustainability — perhaps none so much as supermarkets, particularly purveyors of natural and organic provisions. In California, the new 28,000-sq.-ft. Sprouts Farmers Market store in Westlake Village has received the EPA’s GreenChill Platinum Award for its state-of-the-art green refrigeration technology. The system is expected to reduce the store’s total carbon footprint by 2,417,000 pounds over 10 years — the equivalent of removing 215 cars from the road for a decade.
According to GreenChill, a majority of the more than 35,000 supermarkets in the U.S. use centralized direct expansion (DX) systems to chill their products. Typically, these refrigeration systems are charged with 3,000 to 4,000 pounds of refrigerant and can leak more than 20 percent of their charge each year.
The Westlake Village location, which opened in May, is Sprouts’ eighth GreenChill-certifed store. Sprouts selected Hill PHOENIX of Conyers, Ga., a designer and manufacturer of commercial refrigeration equipment, to develop a new system for the Westlake store in collaboration with Sprouts’ construction and facilities engineering team.
GreenChill Platinum certification requires that stores achieve an average HFC refrigerant charge of no more than 0.5 pounds of refrigerant per 1000 BTU per hour total evaporator cooling load and a storewide annual refrigerant emissions rate of no more than 5 percent.
“The main goal … was to reduce the risk of leaking harmful HFC into the atmosphere, and secondly, to reduce the cost of our initial refrigeration charge,” says Jerry Stutler, Sprouts’ vice president of construction and facility engineering. “And finally, we wanted to reduce our potential exposure to costly catastrophic leaks in our systems.”
Hill PHOENIX’s solution, dubbed Second Nature MT2LX, features a full CO2 cascade system for both low- and medium-temperature applications. It is one of the most environmentally responsible refrigeration systems available in the industry today, says Henry Pellerin, Hill PHOENIX’s director of marketing programs.
Second Nature MT2LX also represents the next step in CO2 refrigeration technology. CO2 is used as a secondary coolant for the medium-temperature system and as a direct-expansion cascade refrigerant for the low-temperature system. Since the HFC refrigerant is confined to the primary system (located in the machine room), the total refrigerant charge and the potential for leaks are greatly reduced.
Other advantages include CO2’s low cost and wide availability, as well as the fact it’s considered a natural refrigerant with very low global warming potential. Additionally, lines required for CO2 transport are typically one to two sizes smaller than traditional DX piping systems, reducing the weight of installed copper lines by at least 50 percent while also reducing installation costs.
The Hill PHOENIX cascade systems consist of two independent refrigeration systems that share a common cascade heat exchanger. The upper-cascade system is a reduced charge HFC system that cools the CO2 in the lower cascade. The HFC system rejects heat to ambient through an air-cooled, microchannel condenser.
“It was really important that we were able to utilize air-cooled condensers,” says Tom Kilroy, an inside sales engineer at Hill PHOENIX. “Nobody in the industry really thought that you could earn a Platinum Certification with air-cooled condensers. Otherwise you would need a separate condensing loop, pumping station and an expensive fluid cooler on the roof.”
The size of the equipment installed at Sprouts fits in the same area as the traditional systems used in older stores. “We’re containing the refrigerant in the back room [as opposed to the sales floor] where it’s easier to detect HFC refrigerant leaks,” Pellerin says. “This adds up to decreased refrigerant costs, decreased risks and costs associated with refrigerant losses as well as decreased maintenance costs.”
When it comes to ROI, Pellerin says, Hill PHOENIX’s customers “justify the investment in our Second Nature technology by looking at maintenance and installation costs.” With Second Nature systems, he says, “the simplification of the system gained through engineering innovations results in fewer potential mechanical problems.”
“It’s tough to put a dollar value on the potential payback for this investment,” Stutler says. “If we had a catastrophic leak in our old system, we could have leaked 2,000 pounds of refrigerant. …With today’s system, we only have the potential to leak 235 pounds of refrigerant.
“Certainly we’re hoping to save money over the years,” he continues, “but how do you put a dollar amount on the value of being green, reducing your carbon footprint and improving the overall system performance?”
Brand and image enhancement as the result of reducing its carbon footprint, competitive differentiation and being the first store in a market to utilize and leverage new technology are all less-tangible factors operators might want to consider. “Sprouts did a great job communicating these benefits to customers with their in-store marketing initiatives,” Pellerin says.
The Westlake Village Sprouts store “represents many firsts,” says Keilly Witman, manager of EPA’s GreenChill Partnership. “The first CO2 cascade system to achieve platinum, the first platinum store west of the Mississippi and the first time a store was designed from the ground up to achieve GreenChill standards.