Supermarket chain Ukrop’s and refrigeration equipment manufacturer Hill Phoenix have taken another step in getting more secondary loop technology into food stores.

A new 55,000-square-foot store in Williamsburg, Va., is the first Ukrop’s store to use Hill Phoenix’s Second Nature® technology, which replaces a portion of HFC-404A customarily used in supermarket units with 35 percent aqueous propylene glycol fluid (a food-grade antifreeze). A low-pressure chilled-water loop eliminates the circulation of high-pressure refrigerant throughout the sales floor.

Ukrop’s is headquartered in Richmond, Va.; Hill Phoenix relocated its display case manufacturing operation to the Richmond area in 1995. “Richmond is a key Hill Phoenix manufacturing hub, so we are especially proud to partner with Ukrop’s, another Richmond company, to create a more environmentally friendly store,” said Ray Hoglund, president and chief executive officer of Hill Phoenix.

“This store marks a big step forward in environmental technology, and we hope it will help set new sustainability standards that will be emulated throughout the state and across the country,” he said.

Those involved in the project said that by applying the new technology, the store has been able to reduce an initial typical charge of R-404A by 40 percent, or about 1,500 pounds. According to Ukrop’s officials, “The ongoing savings that will result from the elimination of refrigerant circulating between the display cases in the store and the mechanical room, and the subsequent leaks that would occur over time, will be significant.”


Since the medium-temperature secondary refrigerant - the propylene glycol - is not under high pressure, like primary refrigerant in a direct expansion system, an ABS plastic piping system was able to be used in the store. This resulted in an overall lineal footage reduction of installed copper piping of 60 percent.

According to officials, the ABS piping has a lower thermal conductivity rate than copper and a larger wall thickness. Both of these factors lead to lower energy loss, they said. The ABS pipe is also recyclable. Ukrop’s officials said they anticipate reduced maintenance costs as a result of the design.


The refrigerated display cases are designed to benefit from the latest advances in secondary refrigerant technology. Temperature control is said to be more stable because defrost time is equal to or less than other defrost methods, and defrost temperatures are significantly lower. The result is reduced recovery time after defrost, as well as less shock and moisture removal for better product quality, which in turn yields longer shelf life.

The case design has medium-temperature evaporator coils engineered for 25°F secondary fluid. Typically, display cases are designed to operate with a fluid temperature of 15° to 20°. The flooded evaporators are said to provide better heat transfer and faster pull down after defrost.

High-efficiency fan motors have been added to the cases. Where applicable, electronically commutated motors (ECMs) are used. These solid-state, variable-torque, electronically controlled fan motors are said to reduce energy demand on motors by more than 50 percent.

Brad Schwichtenberg, vice president of business development for Hill Phoenix, said, “The service meat department at the new store features our Prestige service cases for both meat and seafood. The proprietary Coolgenix technology was chosen not only for its design, but also for the extended product life that is achieved. Red meat is brought to a beautiful bloom and is maintained longer; seafood shelf life is extended and color is maintained better than anything the company has experienced in the past.”


Although some supermarket chains are still specifying HCFC refrigerant R-22, Ukrop’s has not used HCFCs for more than three years. The chain has also employed the use of variable-speed drives to control motors in its HVACR systems for many years to reduce energy.

It has also started controlling unnecessary exhaust and makeup air in the kitchen hood systems. In addition, waste heat from the refrigeration system is used to preheat hot water for the store, and will supplement the space heating system in winter and dehumidification during summer, reducing the use of natural gas.

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Publication date:01/29/2007