Sentry Equipment Corp., Oconomowoc, Wis., never intended to build a sustainable facility when company growth required a larger headquarters. “We didn’t set out to be green,” says Michael Farrell, chief executive officer. “It just turned out that way.”
Located about 30 miles (48 km) west of Milwaukee, Sentry Equipment is employee owned. In recent years, it has experienced unprecedented growth internally and from acquisitions. With 140 employees, the company outgrew its building. When the time came to build an expanded facility in March 2006, Sentry Equipment implemented innovative building solutions in many areas and updated its lighting system. “When we were building, we were using a lot of new technology,” Farrell remembers. “When we got down to lighting, it seemed like we were stuck using old technology.”
Farrell was aware that light-emitting diodes were an up-and-coming lighting solution. He called an acquaintance in the lighting business to ask where the market was with regard to LEDs. The outlook was positive and Farrell pursued LEDs as the new building’s primary light source because of energy efficiency and longevity.
As it happened, Sentry Equipment was on the bleeding edge of commercial LED installations. “We moved in August of last year,” Farrell says. ”Some of the lights didn’t arrive until the week after we got here and that was the first production run.”
With the exception of the flagpole, all the exterior lighting is made up of LEDs. Inside, about 90 lights in the aisle-ways are LEDs, as well as the secondary spotlights in the conference rooms. “In the whole building, we have probably two or three small incandescent decorative lamps and everything else is either fluorescent or LEDs,” Farrell says.
At 55,000 square feet (5110 m2) Sentry Equipment’s headquarters is relatively small, but its cost savings from using LEDs are significant. The final building design allotted 40 to 45 kilowatts of demand, which was whittled down to 30 kW by using LED technology, about a 25 percent reduction. Assuming the lights are in use for 6,000 hours per year at a cost savings of $1.14 per hour, Sentry Equipment will save almost $7,000 per year on lighting alone.
Initial installation costs were about $12,000, so Farrell expects to regain the costs in less than two years. The energy savings, however, account for only part of the return on investment. Maintenance savings are more difficult to calculate. LEDs have an average lifespan of about 50,000 hours, as opposed to incandescent or high-intensity-discharge lights that have lifespans of 3,000 hours or less. Not only does that translate into savings from not having to buy replacement bulbs, but Farrell also saves on the cost of renting a bucket lift to change lights in tall lamp posts. “LEDs may cost a little bit more, but if you look at the energy and maintenance savings I think they’re pretty easy to justify,” he remarks.
Farrell also notes the intensity of the lights. “The light is very white and easy on the eyes. It’s amazing,” he says. “You can really see it in a smaller space like in our bathrooms, where there are six LEDs, about 66 watts total, to light the whole bathroom. If we had put one 60-watt incandescent bulb in there you would probably think you were in the dark ages. The light is really nice and spreads out.”
Sentry Equipment’s building also features natural daylighting. The front of the building is shaped like a triangle with 10-foot- (3-m-) high glass on the southeast and northeast walls to maximize eastern and southern sun exposure. Eight- by 10-foot (2.4- by 3-m) clerestory windows line the top of all four sides of the factory, and interior walls are painted white to reflect light. The glass contains a special solar component to control glare. “I forget to turn the lights on in my office sometimes; that’s how bright it is,” Farrell says. “Employees really enjoy it.”
Although Farrell never intended to go green, he’s proud of the decision to use LEDs. “We just said we wanted to build a new building and make it nice,” he says. “It turned out that it was easy to green our space. We just thought it was nice to have light in the building because it makes people feel good.”
Light-Emitting Diodes from CREE INC. / Durham, N.C. / www.cree.com