Choosing the right equipment and honing maintenance procedures will help to significantly reduce energy expenses.
By: Erin Rigik, Associate Editor.
Convenience stores looking to save money on operating costs should start examining their cooler and lighting expenses, in addition to the lighting inside the coolers—for simple ways to save big bucks.
Canastota, N.Y.-based Nice N Easy Grocery Shoppes, which has 85 stores in upstate New York, has been including LED lighting inside its stores, as well as in the forecourt, under the canopy and inside the cooler doors, as it adds new locations.
“We’ve added LEDs outside to the last 3-4 new stores, and we’ve gone back to a number of older stores and updated the cooler door lighting with LED fixtures to eliminate the florescent bulb— it puts a nice light on the cooler,” said Nice N Easy’s Executive Vice President Peter Tamburro. “I haven’t been real pleased with the interior lighting capabilities with LED, but we’re very pleased with the LEDs on the outside of the stores. There is definitely some energy savings.”
In a number of newer stores, Nice N Easy installed a protocol unit, which is a stacking compressor rack that controls the entire store’s refrigeration needs. “Instead of having a compressor for each unit, this is an on-demand system. If there’s a low demand, the smaller horsepower compressor on the first shelf runs the equipment,” Tamburro said. “As the demand grows, the next level will kick on, which is a higher horsepower compressor. As a result, you don’t have multiple compressors running at the same time, which saves money and energy.”
Instead of using heated doors to control fogging, Nice N Easy partnered with Emerson Climate Technologies to control the relative humidity within the store. Air conditioning or heat kicks on when necessary to eliminate high humidity levels, so the doors don’t sweat and become fogged.
Rob Webster, a Pick‘n Save franchisee in Ripon, Wis., has been beta testing Clean Light Green Light LED lighting for more than 10 months in one of his freezers. Pick’n Save as a whole operates a total of 155 stores.
“The LED lighting itself is, at least in the frozen case, actually a nicer, more consistent lighting,” Webster said. “It holds up better over the long term, and it’s also a cooler lighting. Not only are we saving on the fact that the LED isn’t using as much energy, but the freezer doesn’t have to work as hard to offset the heat the light is producing.”
The lighting has its challenges, though. “In the summertime, most freezers will ice up,” Webster said. “If we’re not adding as much humidity with the heat of the light bulb this should offset the coldness of the air, allowing the defrost cycles to operate more smoothly.”
Webster also put anti-sweat heaters with a timed program on the store’s frozen cases, so they’re not running continually, which is expensive. He expects to roll out LED lighting in all of the coolers and freezer cases soon, and anticipates a five-year return on investment.
Like Nice N Easy, Webster is waiting for LED technology to advance a little more before adding the lighting inside the store. “The advantage isn’t quite as big outside the cooler because you don’t have the added component of the heat fighting the cold,” he said.
Tips on Efficiency
Jerry Lawson, national manager of the Energy Star Small Business & Congregations Network for the U.S. Environmental Protection Agency (EPA), said that when it comes to controlling cooler costs, the first line of defense is keeping the heat out of the building, while the second defense is using efficient equipment that’s well maintained.
To keep heat out of the c-store, look to the windows. Coolers with glass facing west are going to have to work harder to stay cool if nothing is done to shade the glass from the sun in the afternoon, or on a summer morning if the glass faces east. Solar film can be added to windows to shade the sun and assist energy efficiency, which will not only help the coolers, but the air conditioner as well.
Add plastic strip curtains to the rear doors of the large walk-in coolers, so if the back door is left open as products are being unloaded less cool air will escape.
Also consider energy efficient-lighting and occupancy sensors to ensure lighting isn’t on while no one is in the cooler. This is another waste of energy.
Nice N Easy has added sensors to 80 points throughout its stores. “We have done some daylight energy harvesting around the window area, so when the sun is shining those fixtures close because the light isn’t necessary,” Tamburro said.
The chain also has two walk-in coolers with motion sensors that flip the lights on when someone walks into the cooler. As a result, the lights aren’t on when no one is in cold vault.
Having energy efficient equipment and buildings is important and fundamental, but the way you operate and maintain your equipment is just as critical to store operations. For example, maintaining the seals around the doors to avoid losing cool air and taking care of the motors that drive the HVAC units are often overlooked by store operators, especially at smaller chains without a maintenance crew.
“Equipment these days is pretty maintenance free, but there’s a time in a motor’s life where it may need to be cleaned and rewound,” Lawson said.
It also helps to keep the coils on the chillers cleaned regularly as well, which is something that can be added to an employee checklist. If refrigerator coils get dirty and dusty they won’t be as efficient at cooling.
“It’s a learning process for us, Tamburro said. “We continue to learn more, and more energy-efficient products are becoming available, so we continue to research them and figure out what’s best. We’re not the experts on energy efficiency yet, but we’re definitely keeping an ear to the ground.”
Energy Efficient Checklist
Federal law outlines the steps retailers can take to improve the efficiency of walk-in coolers and freezers manufactured after Jan. 1, 2009. The federal regulation only applies to walk-in coolers and freezers with a total chilled storage area of less than 3,000 square feet. Regulated coolers must achieve temperatures above 32 degrees and regulated freezers must achieve temperatures at or below 32 degrees. While it does not apply to units manufactured prior to Jan. 1, 2009, retailers interested in boosting the efficiency of older walk-ins can use the checklist to identify opportunities to make energy-saving improvements.
• Doors. Automatic door closers should be inspected to ensure they shut to within one inch of the closed position. This requirement does not apply to doors wider than 3 feet 9 inches or taller than 7 feet. Minimize air infiltration when doors are open with strip doors, spring-hinged doors or other measures.
• Insulation. Walls, ceiling and doors should be insulated with at least R-25 for coolers and R-32 for freezers. Floor insulation should be at least R-28 for freezers.
• Lighting. Look for bulbs with an efficiency of 40 lumens per watt or more, including ballast losses or occupancy sensors that turn lights off within 15 minutes if the walk-in is unoccupied.
• Glass. For coolers, use double-pane with heat-reflective treated glass and gas fill or triple-pane with either heat-reflective, treated glass or gas fill. For freezers, use triple-pane with either heat-reflective treated glass or gas fill.
SOURCE: THE AIR-CONDITIONING, HEATING AND REFRIGERATION INSTITUTE