Keeping perishables cool or cold may seem as obvious as putting them away in a store's many refrigerated or frozen cases. But maintaining those cases at peak efficiency with minimum cost remains a far from trivial exercise.
Fortunately, the technology supporting the in-store refrigeration process continues to improve. From energy-free doors, propylene glycol refrigeration systems and superheat optimizers to scroll compressors and leak-detection kits, retailers have a wide range of tools available to keep perishables fresh, while conserving energy and even helping the environment.
And given the ever-rising cost of energy, these systems play a critical role in maintaining bottom lines -- especially since refrigeration systems account for approximately 50% of utility costs.
Joe Lopez, energy manager for H.E. Butt Grocery Co., San Antonio, said the company is constantly looking into ways of being more energy efficient through new equipment and techniques.
"We're pretty innovative, and we're constantly looking at new technology," Lopez said. "Energy is a huge cost to the operation of our stores, so we've got to look at ways to reduce those costs by looking at new equipment and implementing programs to hopefully reduce electricity use." For its efforts, including work in refrigeration equipment, H-E-B was one of three supermarket chains recognized as an "Energy Star Leader" by the U.S. Envir-onmental Protection Agency (see story, Page 59).
In this special section, SN takes a look at some of the technology that is helping to maintain and control refrigerated and frozen sections.
One refrigeration system that continues to gain traction in the supermarket industry is Second Nature, from Hill Phoenix, Conyers, Ga., which pumps low-pressure propylene glycol to cases rather than the freon used in traditional systems. "We've had an excellent response to it," said Scott Martin, director of advanced engineering, Hill Phoenix. He said the system is installed in 350 locations in the U.S. and Canada.
One of those locations is Howard's Market, Boca Raton, Fla., a 10,000-square-foot, one-store independent that has used the Second Nature system for about a year and a half in lieu of a series of compressors for its refrigerated cases and walk-in cooler. Its Second Nature system supports Hill Phoenix cases, though any cases can be maintained by the system.
Howard Atkins, president of Howard's Market, cited a number of advantages the store has reaped from the system. One is the absence of refrigerant leaks in the store, since refrigerant is confined to the machine room rather than being pumped through the store. Since installing the system, the store has replaced about five gallons of the propylene glycol, which is pumped through the store rather than refrigerants at a much-reduced pressure.
The loss of glycol occurs not from leaks but during cleaning of deli cases. "Compare five gallons of glycol to five pounds of refrigerant -- that's a big cost savings," Atkins said. Without refrigerant leaks, the Second Nature system has not yet required a service call during the installation period, he added.
Atkins also cited the overall energy savings garnered from the system, which he said costs about the same as a traditional system. For example, though Howard's Market has doubled its refrigeration capacity and square footage, its electric bills have increased 60% at most.
In Atkins' view, the main drawback to the Second Nature system is that it is "different from what the market is accustomed to, so some companies may hesitate to consider it."
DEALING WITH LEAKS
Retailers that prefer traditional systems need to have a way to detect and seal up refrigerant leaks. When conventional leak-detection methods are unsuccessful, Super Seal 3-phase HVACR, from Cliplight, Toronto, is a liquid that can be injected into the system. It travels with the oil and refrigerant through the system and forms a crystalline structure at the point of leakage. The seal is compatible with the electrical windings of the compressor motor and does not interfere with compressor valves or impede lubrication.
Hector Delgadillo, president of Pacific Coast Air Conditioning & Electrical, Pasadena, Calif., uses Super Seal in the supermarkets and restaurants that his company serves. When equipment leaks, Pacific Air first tries to fix the leak, Delgadillo said, but then employs Super Seal. "The sealant is the last resort instead of tearing the equipment apart," he said.
Delgadillo first used the sealant for a leaking, 55-foot salad bar at a Souplantation restaurant owned by Garden Fresh Restaurant, San Diego. The unit had a rooftop parallel rack with 180 pounds of R-404a refrigerant, ester oil and three scroll compressors. The unit was leaking upwards of 80 pounds every 30 days, and after several "conventional approaches," Delgadillo used Super Seal.
"We checked the unit afterward and found no leaking," Delgadillo said. "Four months later, there still isn't any leaking." The product cost $50 a can and saved $20,000 to $30,000 -- the cost of taking apart the system and replacement parts.
Delgadillo said the executives at Garden Fresh were ecstatic, and now want to have this product used by all their vendors, due to its cost efficiency and environmental impact.
Cliplight's All-in-One Leak Detection Kit is a newer product that injects a very small amount of dye into a closed system, using a high-powered ultraviolet light to spot leaks. Only a quarter-ounce of dye is needed for every seven pounds of refrigerant.
"This is a fast way to determine if a system is losing refrigerant," said Paul Appler, director of research and development, Cliplight. "And it's good preventive maintenance because then the problem can be fixed before it gets to the point where it loses so much refrigerant that you lose all the food."
To keep its display cases running at maximum cooling capacity, some retailers are using what's called a superheat optimizer system, from Consolidated Energy Solutions, Toronto. For example, Loblaw Cos., Toronto, has installed a superheat optimizer on all low-temperature display cases and walk-in freezers, according to Bryan Elliot, vice president, CES.
This system is essentially a sensor that consists of two copper tubes that can be installed to any refrigeration system that uses a thermal expansion valve, such as refrigerated display cases or walk-in boxes. In such equipment, improper superheat control results in the evaporator not being fully active. This results in a partial emptying and refilling of the evaporator coils and can lead to a reduction in cooling capacity of up to 35%, according to CES.
By contrast, the optimizer system keeps the evaporator fully active so the energy used to constantly fill and empty the evaporator is greatly reduced. The system was first put on the market eight years ago but has since been redesigned to allow for bidirectional flexibility.
"The retailer's energy costs are reduced, and the most important impact is the intangible improvement in retail product integrity," Elliot said.
TRANSITION TO SCROLL
The compressor is a key part of a refrigeration system, and the industry is seeing a slow transition from discus to scroll compressor, said Don Newlon, market manager for supermarket and industrial at Copeland Technologies, parent company for Emerson Climate Technologies, Sidney, Ohio.
Currently, 20,000 scrolls are being used in more than 1,000 locations throughout the U.S., he said. Copeland's medium-temperature scroll was launched in 2003, and its low-temperature scroll was introduced in 2004.
"Going forward, the scroll will grow to be a bigger part of compressor technology," Newlon said. "The newer scroll technology, if you apply them right, gives really outstanding [energy] efficiency."
Though the initial cost of the scroll is higher, retailers will see payback quickly in their energy bills, he said. A few retailers are doing head-to-head comparisons between discus and scroll compressors to prove it to themselves before going ahead with entire scroll installation, he added.
"This new scroll is kind of like turbocharging an automobile. When you turbocharge an automobile you just cram a lot more gas and air into the cylinder, and it gives you a lot hotter explosion," Newlon said. "This is similar because you are cramming a lot more refrigerant into the scroll, and you get a whole lot more cold out of it."
Another important energy factor in refrigerated cases is lighting. At the Food Marketing Institute's annual show in Chicago last month, Zero Zone, North Prairie, Wis., introduced fiberoptic lighting that brings light into cases via fiberoptic cables.
With this lighting, the refrigeration system does not have to remove the heat generated by the light bulbs, resulting in energy savings, the company said. In addition, fiberoptic lighting is able to provide "more even" product temperature inside the case, avoiding "hot spots," the company said.
Power Zone also introduced LED lighting for refrigerated cases. This lighting also offers reduced heat input in cases, while lasting as long as 100,000 hours, the company said.
To prevent condensation from building up on the inside and outside of cooler doors, most doors have a heating mechanism built in. However, one company, Anthony International, San Fernando, Calif., has designed an energy-free door called the E2, which uses plastics instead of aluminum to keep the doors clear without using energy. Safeway, Pleasanton, Calif., is retrofitting some vintage 1994 cases with the energy-free door, said Steve Foege, director of sales and marketing at Anthony International.
"Energy has hit the forefront, and now there is increased focus and interest on energy-free products," Foege said. "It preserves the environment, it reduces the need for power generation, and it's just good business to be as efficient as you possibly can."
An average heated glass door could cost about $125 a year to operate, so removing the heat significantly reduces energy consumption, Foege noted. For its door, Anthony International reports a return on investment period of one year.
There is a catch, however, in regard to energy-free doors. The success of the product is dependent on the temperature in the store. The doors are designed to work only if the store maintains a 75-degree temperature at 55% relative humidity, making a controlled store environment extremely important.
Another trend driven by the high price of energy is that retailers want to put sliding doors over their open cases, Foege said. A reach-in cooler or freezer with a door consumes 50% less energy than an open case without one, he noted.
Another Emerson Climate Technologies offering that helps retailers monitor their entire store operations, including facility maintenance and performance, is the Intelligent Store. Integrating individual system components into a single architecture, it enables electronic control and monitoring of refrigeration systems as well as heating, ventilation, air conditioning and lighting, as well as other store systems. It also uses predictive intelligence to improve store systems' performance.
"When we're able to connect all of the devices with the [Intelligent Store] control system and use that control system to get information into an enterprise management tool, it may offer a lot of access to information that you've never had before," said Matt Lauck, marketing manager for Emerson.
The Intelligent Store architecture can help retailers decrease energy costs by 10%, increase reliability and broaden their understanding of operations. Lauck said Emerson Climate is positioned to offer this system because of the number of components it provides and its ability to make the components "talk" to one another.
Going Above and Beyond
Among the companies recognized for energy conservation efforts by the U.S. Environmental Protection Agency's Energy Star program, three food retailers -- H.E. Butt Grocery Co., Food Lion and Giant Eagle -- have been selected as "Energy Star Leaders."
They achieved this status in October along with 16 other organizations involved with Energy Star, the voluntary program introduced in 1992 by the EPA to reduce air pollution through energy efficiency.
The Energy Star Leader's program was created last year to recognize the companies that have gone beyond improving the performance of individual properties and have improved energy performance across their entire portfolio, according to Stuart Brodsky, national program manager for commercial property markets at Energy Star.
"Like most organizations, the challenges are being able to manage, measure and track their performance over time and recognize where there are opportunities to improve," Brodsky said.
H-E-B was recognized specifically because the company was able to show that its average company score was at 75 or higher on a specific Energy Star rating system. Susan Ghertner, environmental affairs manager for H-E-B, said the San Antonio-based chain, which operates more than 300 stores in Texas and northern Mexico, has made environmental awareness and energy savings a companywide initiative. In addition to using energy-efficient equipment in refrigeration cases, H-E-B employs skylights and LED bulbs instead of fluorescent lights.
"This is a priority for our company because it's the right thing to do," Ghertner said. "We don't want to cause any damage to our environment, and we want to make sure that we are being good citizens and doing everything in our power to create a sustainable future for our community. Another reason we do these things is because it saves us money. It's really good in both aspects."
Food Lion, Salisbury, N.C., was also recognized as a leader because of its results under the Energy Star label. Since it joined Energy Star in 1998, the chain, which operates 1,214 stores, has reduced its energy usage by more than 25%.
Giant Eagle, Pittsburgh, which operates 221 stores, uses EPA's performance rating system to find out which of its stores is in need of environmental improvements. The re-commissioning of some of its stores has resulted in a 12% improvement in energy management. -- RENEE LUCAS