“This store represents another step toward greener supermarkets, and we hope it will continue to set sustainability standards in retail that will be emulated across the country,” said Benny Smith, director of maintenance for Price Chopper.
Part of the process included a decision to utilize secondary coolant refrigeration technology, specifically, a Second Nature medium-temperature system with 35 percent aqueous propylene glycol fluid (food-grade “antifreeze”). A low-pressure chilled-water loop eliminates the circulation of high-pressure refrigerant throughout the sales floor. The technology also allows the store to reduce the initial R-404A charge by approximately 60 percent, according to Hill Phoenix.
Additionally, Copeland smart compressor technology, which has been applied to the design of the primary refrigeration system, enables quick diagnosis of compressor issues and minimizes the use of capillary tubing, further reducing the chance of refrigerant leaks, Smith said.
IMPROVED PRODUCT QUALITYStore and manufacturer officials also noted that a store’s refrigerated display cases and walk-in coolers operate more effectively and efficiently resulting in improved product appearance and shelf life. For example, they said the cases running on Second Nature systems are designed specifically to operate with efficient flooded evaporators, providing better heat transfer and faster pull-down after defrost.
Another benefit of the Second Nature system, according to Smith, is the efficiency of the defrost system. “Product temperatures are better,” he said. “In fact, our VP of operations has already heard the news from the store’s operations team that the cases running on the new Second Nature system maintain better product temperature as a result of this technology.”
The ability to improve product, not just case temperatures, is a real advantage particularly as applied to medium-temperature applications such as meat, seafood, and produce, Smith said.
He noted temperature control is more stable because defrost time is equal to or less than other defrost methods and defrost temperatures are significantly lower. Plus, there is reduced recovery time. The result exceeds the Food and Drug Administration 41°F product temperature requirement. An important additional benefit is improved product quality due to less shock and moisture removal, which in turn yields longer shelf life.
COPPER ISSUESSince the medium-temperature secondary refrigerant is not under high pressure, ABS plastic piping was used at the Malta store. Advocates of this approach argue that by reducing the use of copper, there is a reduction in the amount of mining and smelting and thus a reduction in the amount of greenhouse gases in the production of copper piping materials.
In addition, it was noted that ABS has a lower thermal conductivity rate than copper and a larger wall thickness. Both of these factors lead to lower energy loss through the engineered plastic pipe. The ABS pipe is also recyclable.
The Malta remodel is the first installation in which the Georg Fischer pipe system was utilized by Price Chopper.
According to Mark Hankle, mechanical engineer for Price Chopper, “With this being our first ABS pipe installation, we wanted assurance that the fluid flow and the insulation characteristics would be sufficient. Our engineers were concerned that utilizing traditional copper pipe to transport the secondary coolant glycol would create an opportunity for internal pipe erosion similar to that found in water piping systems. The application of the Georg Fischer ABS pipe eliminated this concern, ensuring a nonturbulent flow of glycol with proper velocity. Additionally, this Second Nature system with ABS pipe has eliminated the potential for refrigerant leaks that typically occur over time in a direct expansion system. We find this to be a significant benefit.”
IN LAYMEN'S TERMSThose involved in the project did some calculations to see how the renovation could be measured and described in laymen’s terms.
A reduction in the amount of HFC refrigerant and tighter leak control method could avoid the release of 2,750 pounds of R-404A into the atmosphere over the next 10 years. This, those doing the calculating said, is equivalent to avoiding the release of 5,160 tons of CO2. It is also equivalent to:
• 103 passenger cars not driven for 10 years.
• 539,000 gallons of gasoline not consumed.
• 24 railcars of coal not burned
• 1,595 tons of waste recycled instead of going to a landfill;
• 61 average households electric use for 1 year.
TRAININGThere is a learning curve for technicians working with secondary loop technology. To that end, “Hill Phoenix offers an extensive training program for customers and contractors that explains how to utilize Second Nature technology to accomplish all of their goals,” says Henry Pellerin, manager of Learning Center Programs for Hill Phoenix.
“Four years ago Hill Phoenix made the commitment to develop an industry leading educational program to support innovative product technologies that we bring to our customers. During 2007, the second year of operation, the Hill Phoenix Learning Center has trained over 600 participants, contributed to the North American Technician Excellence Refrigeration Certification Program, and has contributed to several trade journals.”
For more information, visit www.hillphoenix.com.