Giant Goes Green
Giant Food Stores’ supermarket in Harrisburg, Pa., was designed green from the ground up. At 97,000 sq. ft., the Giant Super Food Store is the company’s largest and most eco-friendly location yet.
One of the key elements contributing to the store’s energy savings and reduced carbon footprint is the use of cutting-edge refrigeration technology in the medium-temperature display cases and walk-in coolers.
The technology—Second Nature refrigeration systems, from Hill Phoenix, Conyers, Ga.—is designed to keep refrigerated foods at optimum temperatures. It replaces R404A, a halogenated fluorocarbon (HFC) and contributor to greenhouse gases, with a 35% aqueous propylene glycol fluid and R407A, a non-halogenated refrigerant with less than half the global-warming potential of traditional HFC refrigerants.
The system uses a low-pressure chilled-water loop to circulate the refrigerant. This eliminates the circulation of high-pressure refrigerant throughout the store floor, allowing the system to achieve a 50% reduction in refrigerant charge.
“The 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,” said Tharon Gilreath, manager of energy and mechanical design, Giant Food Stores, Carlisle, Pa., a division of Ahold USA.
Less piping, fewer joints and the elimination of subsequent leaks that normally occur over time not only reduce the store’s refrigerant charge, Gilreath explained, but will also lower costs due to fewer maintenance calls.
Also, temperature control is more stable with the Second Nature system because it uses the warm-fluid side for defrost, which makes the defrost time shorter and eliminates large temperature swings. Plus, there is reduced recovery time. All of this will result in improved product quality for customers, Gilreath said.
“With the warm-fluid defrost, there is less shock to the product as compared with electric or hot-gas defrost systems,” he added.
According to Hill Phoenix, the Second Nature system will provide Giant with a number of environmental benefits, including a reduction in its annual carbon footprint on 29,125,999 lbs. of CO2. The reduced refrigerant charge and leak rate will lead to a carbon emissions savings of more than 14,653 tons of CO2 over a 10-year period.