Dock shelters save energy

Energy loss has been cut by 85% at the docks of mattress manufacturer Select Comfort Corp.

By Sara Pearson Specter, Editor at Large -- Modern Materials Handling, 2/1/2006

Select Comfort Corp., manufacturer of adjustable firmness mattresses, couldn't keep its workers comfortable. The company, which operates a manufacturing and distribution facility in Irmo, S.C., was experiencing "white space" at its dock doors—spots of open air around parked trailers—due to 20 years of battering by semi-trailers to the shelters and seals.

Darin Swiger, order fulfillment manager, noticed that the air conditioning system just couldn't keep the loading dock at an even temperature throughout the day. That increased the company's air conditioning costs. And, considering that the suburban Columbia facility's 18 loading docks handle about 20 semi-trailers daily, seven days a week, that energy loss added up.

"The dock seals we had were in very bad shape," Swiger says. "You could see sunlight through them, and some days the heat would make work conditions very uncomfortable for those loading and unloading trailer."

The exposed space created by the hinge gaps of open swing-out, semi-trailer doors posed another problem. The 1.5- to 2-inch gaps on either side of the trailers produced the equivalent of a 2.5-square-foot hole in the wall. These gaps allowed air—and expensive energy—to freely flow in and out.

Swiger's suspicions were confirmed by a custom energy loss analysis. The analysis showed that the old loading dock shelters were contributing to a potential energy loss of hundreds of dollars for each of the 18 dock openings—as much as $40,000 for the entire facility.

To solve the problem, Swiger installed soft-sided dock shelters (Rite-Hite, 800-456-0600). The shelters' side curtains seal the trailer door hinge gaps to prevent airflow in and out, reducing energy loss by 85%. Sealing the gaps also minimizes the infiltration of dust and pests. Additionally, the seals feature a fabric-wrapped rain gutter to divert water, keeping the dock area, workers and materials dry.

Select Comfort is installing the dock shelters in two phases, replacing the 12 most worn first. Swiger immediately noticed a comfort difference, particularly as the energy-robbing trailer door gaps disappeared.

"For now, our electricity savings are $1,000 to $1,100 a month. We're anticipating even better savings as we add more new shelters—and as we watch the price of energy rapidly rise," he says.