The Big Chill

Sprouts Farmers Market in Westlake Village, Thousand Oaks, Calif., has joined an elite club: It is only the third store in the nation to achieve the Environmental Protection Agency’s GreenChill Partnership higher honor, Platinum Level Certification.

Sprouts, which specializes in natural and organic foods at affordable prices, joined the EPA program in 2010 and, since then, eight of its stores have earned GreenChill awards. (GreenChill works with food stores to reduce refrigerant emissions and adopt green refrigeration technologies and practices.) With the construction of its Westlake Village store, the grocer wanted to raise the bar and meet the stringent Platinum standards. The Platinum level of certification requires, among other things, the use of only non-ozone depleting refrigerants, and a storewide annual refrigerant emissions rate of no more than 5%.

“The main goal at Thousand Oaks was to reduce the risk of leaking harmful HFC into the atmosphere, and to reduce the cost of our initial refrigeration charge, said Jerry Stutler, VP construction and facility engineering for Sprouts Farmers Market, Phoenix, which operates some 100 stores throughout Arizona, California, Texas and Colorado.

The company also wanted to reduce its potential exposure to costly catastrophic leaks in its systems.

Sprouts selected Hill Phoenix, Conyers, Ga., to design a system that not only would be eco-friendly and energy-efficient, but also cost-effective to install and maintain. The system also had to reduce the store’s use of refrigerants to meet the Platinum certification standards.

In collaboration with Sprouts’ construction and facilities engineering team, Hill Phoenix designed and manufactured an innovative new refrigeration system that met Sprouts’ criteria. Installed in April, the system uses CO2, considered a natural refrigerant with very low global warming potential, as a coolant.

“Before we got involved with GreenChill, we were averaging about 2,000 lbs. of refrigerant in our system,” Stutler said. “We reduced that (amount) by about 60% to 65% with our stores that are GreenChill Gold certified. But this new CO2 design yields an even more significant reduction in HFCs.”

The new solution features a full CO2 cascade system for both low-temperature and medium-temperature applications (the Second Nature MT2LX). It is made up of two independent refrigerant systems that share a common cascade heat exchanger. The upper-cascade system is a reduced charge HFC system that cools the CO2 in the lower-cascade.

The advantages of a cascade system include reduction in the refrigerant charge and a reduced carbon footprint. And since the HFC is confined to the primary system located in the machine room, the total refrigerant charge and the potential for leaks are both greatly reduced.

According to Stutler, it’s not easy to put a dollar value on the potential payback for the Second Nature system.

“If we had a catastrophic leak in our old system, we could have leaked 2,000 lbs. of refrigerant — multiply that by $10 per pound to recharge the system,” he said. “With today’s system, we only have the potential to leak 235 lbs. of refrigerant.”

Stutler added: “Certainly, we’re hoping to save money over the years. But how do you put a dollar amount on the value of being green, reducing your carbon footprint and improving the overall system performance?”