Grocery store finds going green is second nature
When Giant Food Stores opened the doors to its new Harrisburg, PA, store last fall, the company wowed customers with 97,000 sq ft of modern technology and convenience. Attention has been paid to every detail, including many aspects customers can’t actually see but that make the store a front-runner in green supermarkets. A large part of the store’s energy savings and reduced carbon footprint comes from the state-of the-art refrigeration systems by Hill PHOENIX, a designer and manufacturer of commercial refrigeration products.
“We’ve been building green technology into our stores for years because it not only makes sense financially, but it reduces the environmental impact of our operations,” said Tharon Gilreath, manager of energy and mechanical design for Carlisle, Pa.-based Giant Food Stores. “We expect the Hill PHOENIX Second Nature system to play an important role in enhancing our green technology package.”
Eliminating Leaks and Maximizing SavingsThe Giant Super Food Store, which opened last fall, chose Hill PHOENIX Second Nature refrigeration systems to provide environmentally friendly refrigeration to the medium temperature display cases and walk-in coolers.
Second Nature Medium Temperature systems - designed to keep refrigerated foods at optimum temperatures - replace R404A, a halogenated fluorocarbon (HFC) and contributor to greenhouse gases, with a 35% aqueous propylene glycol fluid and R407C, a non-halogenated refrigerant with less than half of the global warming potential of traditional HFC refrigerants. By using a low-pressure chilled water loop to circulate the refrigerant, the system eliminates the circulation of high-pressure refrigerant throughout the store floor, allowing the Second Nature system to achieve a 50% reduction in refrigerant charge.
“Hill PHOENIX’s Second Nature technology lets us contain refrigerant charge within the machine room and condenser circuit where it’s exposed to substantially fewer pipe joints and potential leaks,” Gilreath explains. “Less piping, fewer valves, and elimination of subsequent leaks that normally occur over time will reduce the refrigerant charge at the store. It will also lower costs with fewer maintenance calls.”
Another distinct advantage of the Second Nature medium temperature technology is the system’s VSDs. By incorporating the drives on the compressor of each system, Hill PHOENIX can provide precise capacity control throughout the operation and thereby improve energy efficiency.
“Using VSDs with end-of-loop pressure controls on the glycol circulating system allows the system to optimize the flow rates at each display case and walk-in cooler,” adds Tom Kilroy, industrial systems engineer for Hill PHOENIX. “By eliminating excess cooling, this technology provides an energy savings of 40% over traditional pumping systems.”
Optimum Temperature ControlManagement at Giant Food Stores is also optimistic about the use of the chilled glycol system and its ability to control product temperatures, especially as applied to medium-temperature applications such as meat, seafood, and produce. With the Second Nature system, temperature control is more stable because the system uses the warm fluid side for defrost, making the defrost time shorter and eliminating large temperature swings - plus there is reduced recovery time after defrost.
Because the medium temperature secondary refrigerant is not under high pressure like primary refrigerant, Hill PHOENIX was able to use Georg Fischer-engineered ABS piping for construction of the Harrisburg store.
Copper mining and copper smelting are large producers of greenhouse gases in the production of copper piping materials; however, using engineered ABS pipe lowers a store’s environmental impact. In addition, because it has a significantly lower thermal conductivity rate than copper and a larger wall thickness, it is a much better insulator and provides energy efficiencies.
A Reduced Environmental FootprintAccording to Hill PHOENIX, the Hill PHOENIX Second Nature Medium Temperature system at the Harrisburg Super Food Store is in keeping with Giant Food Stores’ green philosophy and will provide impressive benefits for the environment, including reducing the total annual carbon footprint by removing 29,125,000 lbs of CO2, which is equivalent to removing 242 passenger cars from the road annually for 10 yrs. A reduced refrigerant charge and leak rate leads to a carbon emissions savings of more than 14,653 tons of CO2 over a 10-year period, reducing the amount of copper tubing required by 5,500 ft less than a traditional direct expansion refrigeration system, equating to a total savings of more than 7,300 lbs of installed copper tubing. This will result in a further carbon footprint reduction of more than 18,900 lbs of CO2 emissions.
Scott Martin, director of sustainable technologies for Hill PHOENIX, sums up the partnership this way: “This store is yet another example of how the industry is changing the way supermarkets are constructed, in a manner that benefits everyone - the company, the customers, and our planet.” ES