(Editor’s Note: In today’s Thursday Feature, we travel deep underground to a subterranean cold storage facility where operators have been struggling with lighting costs for decades.)
Deep below the surface of Johnson, Arkansas, is a former limestone mine and Cold War fallout shelter called “The Cave”. For nearly 50 years, it has served as a cold storage facility that boasts 280,000 square food and freezer space where temperatures fall below -36 degrees F.
Operated by the Zero Mountain Cold Storage Company, the facility and four other warehouses are responsible for freezing, storing and shipping more than 2 billion pounds of meat and other foods annually for such companies as Wal-Mart, Cargill, Tyson and ConAgra.
The problem with operating a warehouse underground isn’t the cold. Refrigeration units actually don’t have to work as hard as they do at Zero Mountains above-ground warehouses because the ground is a natural insulator.
The problem is light.
Lightless Underground Cold Storage
There is no natural light that deep underground. So every square inch of operating space needs to be illuminated using artificial lighting.
And that can be costly. At both The Cave and Zero Mountain’s gigantic 7 million square foot facility in Lowell, interior spaces were lit by old-school 400 Watt light bulbs in metal halide fixtures. There were 268 in TheCave and another 303 at Lowell.
Not only did these lamps eat up electricity like a fat man eating ribs at a church picnic, but they were constantly burning out, especially at The Cave, where moisture seeping into the facility is a real problem whenever it rains.
Changing out the light bulbs and repairing or replacing the fixtures was nearly a full-time job for the Zero Mountain maintenance staff, costing the company an estimated $5,000 to $10,000 annually in manpower to change out burned out bulbs, not to mention the cost of replacing lamps and ballasts, which require a man lift of bucket truck.
Harsh Subterranean Conditions
Plus, the lamps were more likely to burn out when they were turned off and had a slow warm-up time due to cold temperatures. So the company was forced to leave them on 24/7/365.
Not only was the company paying to light spaces that weren’t being used, paying more for electricity, and burning through their bulbs and lamps at a record rate, but the excessive heat from the metal halide lamps were causing the company’s refrigeration condensers to work harder to hold temperature.
Looking for a solution, the company turned to LED Supply Co., a local supplier of Dialight LED lighting fixtures. It replaced all 571 of its old-fashioned lamps with 456 LED High Bay fixtures in the two cold storage facilities.
Tony Parrish, facility manager at The Cave, said the switch has been welcomed by maintenance crews.
“Our crews were impressed by how quick and easy it was to change out each fixture and they’re looking forward to not having to change light bulbs all the time,” Parrish said in a Dialight news release. “This will definitely free up their time to perform more critical maintenance needs that contribute to efficient facility operation.”
Huge Cost Savings
The new lights cut energy consumption by 70% and are expected to provide a decade of service with zero maintenance. Plus, the feature electronic sensors so they are turned on only when there is somebody working in an area that needs to be lit.
Unlike metal halide lamps, the new LED lights don’t need to warm up. Instead, they offer full lumen output from the moment the motion detectors switch them on. And they provide more light for less money — nearly double the illumination of the old lights.
Due to the improved light output, Zero Mountain was able to cut back the number of fixtures it needed by 20%. Combined with the 70% increase in operational efficiency, the company cut 1.3 million kilowatt hours of its electrical bills at the two facilities, a savings of nearly $86,000 per year.
And because the LED lights run cool, both facilities noticed an immediate impact on the performance of their refrigeration units.
‘Who’s There?’
Tony Nichols, facility manager at the Nichols warehouse, said forklift operators are responding positively to the new motion-activated fixtures.
“The forklift drivers like the sensors because as the lights come on it gives them a heads-up that other operators are in the area,” Nichols said in the Dialight news release. “It’s like an advanced warning system that’s turned out to be a significant advantage when working in tight quarters where visibility is limited.”
As an added bonus, the company that provides electricity to The Cave — Southwester Electric Power Company — gave Zero Mountain a custom rebate incentive for making the switch to energy-efficient LED lighting which paid for about 30% of the total project costs, including installation.
Zero Mountain already has approved plans to install the LED lights at its two other cold storage facilities in Fort Smith and Russellville.