FAIRFIELD, Iowa – Hy-Vee opened a 64,000-square-foot store here last month that uses secondary loop refrigeration systems to reduce refrigerant usage and cut emissions, earning the store Gold-Level certification from the Environmental Protection Agency's GreenChill program. It is also the chain's second LEED-certified store.
Hy-Vee chose the Second Nature Medium-Temperature Secondary System from Hill Phoenix, Conyers, Ga., for its meat, seafood and deli cases. The system circulates propylene glycol fluid throughout the sales floor to refrigerate product displayed in the medium temperature cases and coolers.
Because its R404A refrigerant only chills the glycol, the system uses 1,397 pounds of R404A charge — a 50% reduction over a standard direct expansion system. It also uses 1,600 gallons of glycol. "This system offers a significant reduction in refrigerant charge," said Jon Scanlan, director of refrigeration and energy management for Hy-Vee, West Des Moines, Iowa, in a statement. "It's extremely important to us and it goes back to our objectives with the EPA GreenChill program to reduce refrigerant charge and emissions."
In addition, the Fairfield store is using the Second Nature Low Temperature Secondary system for its cases and walk-in freezers. The system employs carbon dioxide fluid as a secondary coolant in a loop piping system. It requires 303 pounds of HFC refrigerant charge — about one-fourth as much as a typical direct expansion system — as well as 1,030 pounds of carbon dioxide, which has excellent thermodynamic properties and can reduce energy consumption by as much as 5%.
Overall, the systems offer a 14% reduction in leak rates over a standard DX system, saving more than 883 pounds of refrigerant per year; said Hill Phoenix.