Food Engineering

Let There Be Better Light

January 1, 2010
A focus on energy efficiency has produced big improvements in industrial lighting, but other factors also need to be considered, experts say.

High color saturation and sharp contrast characterize foods when illuminated with solid-state lighting. This forkfull of nutrition is lighted with a 12 watt LED, a cell that is highly directional and can be used in place of a 90-100 watt incandescent bulb. Source: Sitka Enterpises Inc.


High-efficiency lamps and improved electronics cut energy costs in half at Inland Cold Storage and qualified the project for a utility rebate that reduced payback to 14 months. Source: Cooper Lighting.

Advancements in lighting technology have made industrial retrofits an easy call in energy-reduction efforts, with utility grants and tax credits accelerating the rate of return these projects yield. The good news for processors considering replacement of obsolete illumination is that there are no bad choices: virtually any of the available options will reduce costs over time. The bad news is that the diversity of choices and continuing change can make selecting the optimum solution a challenge. LED is the elephant in the lighting innovation room, though the consensus among suppliers is that the technology is two to five years away from being ready for prime time, at least in terms of industrial interiors. Some food plants seeking LEED certification already are installing LED lighting, but the economics argue against it. “It’s not fully there,” agrees Gray Sasser, Rig-A-Lite Inc.’s eastern regional sales manager, “but every 30 to 60 days, it’s evolving and changing.” Niche applications like ice cream freezers, where -20° F temperatures cause problems for metal halide and fluorescent lights, and exterior illumination that doesn’t demand a high number of foot-candles, are possible candidates for LED, but otherwise the upfront cost is prohibitive, adds Bob Catone, general manager of St. Louis’s Guth Lighting. Unless it is tied to new construction where lighting represents less than 5 percent of total project cost, LED “feels good, like buying a Prius, but you never get your money back,” he says.

“An early complaint about LED was the lack of warmth of the light,” reflects Brian Roy, cofounder of Sitka Enterprises Inc., an East Texas, PA, supplier. Cree Inc. addressed the color issue by adding more red to the light, helping LED gain a foothold in the retail market for food displays. In food plant applications, the absence of glass makes LED an appealing choice, and sharper contrasts from the light could have a positive impact in controlling the appearance of finished goods and boosting worker performance, Roy believes. A global leader in LED, Cree reflects the melding of mainline lighting technology with electronics. Whether it’s for energy savings or better light quality, solid-state ballasts and other electronic components are creating night and day improvements in industrial lighting.

Fluorescent lamps are appropriate in heavy washdown environments, provided the fixtures include features like fire-rated acrylic tubes and capped and gasketed ends. Source: Gray Sasser, Rig A Lite Inc.

Spotlight on efficiency

More light from less wattage has been the primary focus of suppliers in recent years, notes Michael Vranish, senior electrical engineer at the Jacksonville, FL, architectural engineering firm Stellar. The energy efficiency emphasis plays to the strength of fluorescent, and the development of special fluorescent lamps that closely replicate the warmth of incandescent lighting is encouraging more food and beverage manufacturers to install fluorescents. “For the last four to five years, the use of fluorescents in high mounting areas to save energy has been coming on strong compared to metal halide, which was the only option before,” says Vranish, who recently was honored for his lighting work in the food industry (see related story on page 110).

“Electronics” derives from the Greek word for “something else to go wrong,” and maintenance engineers who prefer to think about their light fixtures every 50,000 hours, when the lamps burn out might prefer electromagnetic ballasts and controls no more complex than an on/off switch. But the reliability of photo sensors, time-of-day controls and other electronic components, “have come a long way and can be very reliable these days,” Vranish reports. “In warehouses, we use motion sensors almost exclusively. You just have to make sure you get the most reliable system, not the cheapest.”

Cycling in an electronic ballast is so rapid that fluorescent flickering is barely perceptible, notes Roy. When equipped with dimmers, the units open the door to, “daylight harvesting,” automatically maintaining a constant level of foot-candles of illumination as sunlight waxes and wanes. Natural light has been designed into several LEED-certified food and beverage facilities, though HACCP considerations and the attendant need to maintain seals around windows and skylights could limit sunlight’s role in food plants, at least in existing buildings.

Natural lighting and automatic dimmers added cost to a 55,000-sq.-ft. expansion at Summer Garden Food Manufacturing, a Boardman, OH, producer of branded and private-label pasta sauces, but the company determined it was essential to boost its green-manufacturing credibility with retail customers. “Natural light was one of the easier ways we could green up the process,” explains CFO John Angelilli. The LEED-certified project, which came on line in January, cost the company $6 million, with green initiatives adding up to $1 million to the total cost.

Upgrading existing systems accounts for the bulk of lighting projects. Regardless of how obsolete the old system is, financial returns usually occur quickly. Tax credits and rebates often push projects into the no-brainer category of capital improvements. Energy savings alone produced a 14-month simple payback for Inland Cold Storage’s 125,000-sq.-ft. warehouse in Riverside, CA. But benefits extend well beyond simple payback, points out Keith Hall, marketing director of Cooper Lighting’s Metalux fluorescents division. Sociological studies suggest an improvement in light quality has a positive improvement on work performance, even when the lamps produce fewer foot-candles of illumination than what they replace. “More and more, you’re seeing a movement to quality of life while also addressing energy consumption,” says Hall.

The old metal halide lights at Inland seldom were off: they operated an average of more than 22 hours a day, 365 days a year. An audit by Senergy Solutions pegged energy costs alone at $66,000 a year. Cold environments are metal halide’s sweet spot and were a challenge for fluorescent, but Senergy consultants recommended converting to T5 hi-bay fluorescents fitted with occupancy sensors. The specialty tubes were rated to perform at temperatures down to -20° F, and the improved color rendering drew positive feedback from workers. The ability to better push the light down and out to where it’s needed is an advantage with hi-bay fixtures, Stellar’s Vranish points out.

Metal halide's challenge

Lighting specialists are passionate about the technology, and sharp differences of opinion are evident when discussing the best options and the impact of regulations, particularly in specialized applications such as food and beverage. One of the more contentious topics is the future of high-intensity discharge (HID) lighting.

High-intensity discharge fixtures can operate with mercury-vapor ballasts, which were banned by the Energy Policy Act of 2005; high-pressure sodium, an efficient light source with a yellow hue that relegates it to outdoor use; and metal halide. Like T12 fluorescent, metal halide is still serviceable technology but not the best energy-efficiency option, Sitka’s Roy believes.

Guth’s Catone staunchly defends metal halide. “There is a time bomb on mercury and probe-start metal halide, but high-pressure sodium and pulse-start metal halide have no problem,” he insists. Newer metal halide lamps also produce excellent color rendering. Citing a lamp his firm introduced a year ago that approaches the rendering of an incandescent bulb, Catone says, “The color is just gorgeous.”

“The hazard of metal halide is a real risk,” disagrees Rig-A-Lite’s Sasser, and the mandated switch to pulse-start lamps, “has increased the risk factor three or four fold.” With a probe-start, the bulb won’t come back on once it burns out. “Pulse-start forces the issue,” Sasser says, “and there is no safety mechanism to prevent an explosion.” Anticipating the problems posed by the probe-start ban that went into effect this year, he asked Rig-A-Lite’s engineers two years ago to design a NEMA 4X rated fixture that accommodates T8 and T5 fluorescent lamps.

The switch to electronic ballasts is another nail in HID’s coffin, he believes. While electronic HIDs are available, he dismisses them as too expensive and impractical. HID hi/lo systems still are used extensively in warehouses, but the inventory costs for multiple lamps and components is an argument for all-fluorescent lighting in food plants. “Hi/lo is still a consideration,” Sasser concludes, “but it’s been blown away by fluorescent.”

The washdown requirements and contamination issues in food production environments argue against standard lighting systems, according to Tamar Williamson, product manager at Grandville, OH-based Holophane. Fixtures also need to slope to eliminate harborage points and aid water runoff. Although Holophane’s acrylic shields are UL-tested to ensure that glass from an exploding lamp won’t breach them, Williamson says some food clients specify coated lamps, as well as a fail-safe.

Specialized fixtures make retrofits more expensive in food and beverage processing areas. To minimize the cost, Sitka Enterprises developed a fixture-in-fixture solution. The package bypasses an existing T12 or T8 ballast and converts the lighting to T5, “and it takes it from a job for a skilled electrician to something a lower-skilled person can do,” says Roy.

While some lighting specialists believe T8 fluorescents are as good or better than T5, Roy takes a contrary view. Missing in many efficiency calculations is the heat generated by the lamps. In refrigerated environments, removing the heat is a big issue, and that gives the lower wattage T5 a big advantage. For each 4 kilowatts of installed lighting, 1 kilowatt is needed to remove the unwanted heat in a refrigerated area, he says; in a freezer, the cost is even greater. After a recent audit of a 500,000-sq.-ft. refrigerated food facility, Roy concluded lighting and heat removal accounted for about 25 percent of total electric cost.

When weighing the pros and cons of various lighting options, Cooper Lighting’s Hall advises plant engineers to look beyond energy consumption and consider lamp life, color, maintenance requirements and other factors. “Have you taken into account everything you can before the product is installed?” he asks rhetorically. A 60-day trial installation in a work area is advisable to determine if enough light will be delivered and whether or not people like the hue. While technological advances will continue, once a lighting system is overhauled, organizations and the people in them are going to have to live with it for awhile.  For more information:

Keith Hall, Cooper Lighting, 770-486-4785
Bob Catone, Guth Lighting, 314-533-3200, bob.catone@philips.com
Tamar Williamson, Holophane, 740-349-4241, tamar.williamson@acuitybrands.com
Gray Sasser, Rig-A-Lite Inc., 919-524-8766, graysasser@azz.com
Brian Roy, Sitka Enterprises Inc., 610-393-6708, bcmproy@ptd.net
Michael Vranesh, Stellar, 904-899-9256

Warm lighting that enhances the look of food was essential in the award-winning design of the Nestle Professional Customer Innovation Campus in Solon, OH. Source: Nestle Professional.

Spotlight on appetizing food

People eat with their eyes, it’s been said, and the first impression a meal makes is largely dependent on the light cast upon it. When managers at Nestle Professional set out to build the Customer Innovation Campus in Solon, OH, they conducted detailed discussions with the designers of the 67,000-sq.-ft. facility to ensure that the culinary center would put new foodservice products in the best possible light.

“Early on, we talked about concepts and what they were trying to accomplish,” remembers Michael Vranish, senior electrical engineer at Jacksonville, FL-based Stellar. “They wanted a building they can be proud of and show to their foodservice clients and others in the Nestle organization.”

Marble and other architectural accents, combined with stainless steel-equipment, posed challenges of reflected light, requiring glare-free illumination schemes. A wide assortment of light sources came into play, including fluorescent, halogen and incandescent bulbs. In the tasting area, “lights that you use in a jewelry store” add warmth to the food, says Vranish.

Special care was taken to blend light sources into the architecture, and sophisticated lighting controls sense the amount of available sunlight, automatically dimming and raising lamps’ wattage as necessary.

The project recently was honored with an award from the Northeast Florida section of the Illuminating Engineering Society. Nestle opened the R&D center in November 2008.