A secondary loop system is being used in a new Giant Food Store in Harrisburg, Pa. The state-of-the-art store also includes increased focus on nutrition.

When Giant Food Stores opened the doors to its new Harrisburg, Pa., store last fall, the company unveiled 97,000 square feet of modern technology and convenience, including some of the latest innovations in refrigeration.

According to a statement from the company, the store is the largest supermarket operated by Giant, generating 250 more jobs than the supermarket it replaced. There is a nutritionist to conduct one-on-one consultations by appointment, and, within the store, a community center with a lobby and meeting rooms, designed to be the site of healthy living and wellness classes as well as being able to be reserved by community groups.

The technology includes skylights and LED lighting as well as the mechanical refrigeration.

“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 Giant.

The store, which opened in October, chose Hill Phoenix Second Nature refrigeration system to provide cooling for the medium temperature display cases and walk-in coolers.

The refrigerant configuration combines 35 percent aqueous propylene glycol fluid and HFC-407C, the manufacturer said.

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 system to achieve a 50 percent reduction in refrigerant charge.

“The 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 explained. “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.”

The systems also use variable-speed drives. By incorporating the drives on the compressor of each system, capacity control can be achieved throughout the operation and thereby improve energy efficiency, said Tom Kilroy, industrial systems engineer for Hill Phoenix.

“Using VSD 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. By eliminating excess cooling, this technology provides an energy savings of 40 percent over traditional pumping systems.”


The chilled glycol system was cited for its ability to control product temperatures, especially as applied to medium-temperature applications such as meat, seafood, and produce. They said 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.

“With the warm fluid defrost, there is less shock to the product,” Gilreath noted. “This will result in improved product quality for customers.”

Additionally, according to Clyde Miller, director of construction for Giant, “The installation went very smooth and the setup of the system and case temperatures were relatively simple.”

Because the medium temperature secondary refrigerant is not under high pressure, the store was able to use Georg Fischer-engineered ABS piping for construction. ABS pipe has a low thermal conductivity rate and a large wall thickness, for better insulation, and provides energy efficiencies, it was reported.


According to Hill Phoenix, the system at the Harrisburg store is in keeping with Giant Food Stores’ green philosophy and will provide benefits for the environment. Among the statistics cited:

• The total annual carbon footprint will be reduced by 29,125,000 pounds of CO2, which is equivalent to removing 242 passenger cars from the road annually for 10 years.

• The 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.

• The amount of installed copper piping is more than 5,500 feet less than a traditional direct expansion refrigeration system, equating to a total savings of more than 7,300 pounds of installed copper tubing. This will result in a further carbon footprint reduction of more than 18,900 pounds of CO2 emissions.

Scott Martin, director of sustainable technologies for Hill Phoenix, summed 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. Hill Phoenix and Giant Food Stores share a commitment to sustainability and we look forward to more partnerships and even greater innovations in the future.”

Publication date: 06/07/2010