Bloomington-based Thermo King has found a cool way to boost fuel economy in trucks that haul refrigerated food.

The company, which makes temperature-control systems for the transportation industry, is pioneering a truck-refrigeration system that draws its energy from the truck engine, eliminating the need for a second diesel just for cooling.

Eden Prairie-based Deli Express, a sandwich maker that is now running six of the trucks, says the technology boosts fuel economy by up to 50 percent and improves fleet productivity over routes that range from dozens to hundreds of miles each day.

Tom Sween, president of E.A. Sween, the corporate parent of Deli Express, said it will replace most of its 240 trucks with the new model over time. They cost less, are more aerodynamic and more efficient.

Thermo King developed the next-generation refrigerated trucks with Isuzu, which supplies the diesel chassis; Johnson Truck Bodies, which produced the lightweight shell, and Automotive Resources Inc., which provided the expertise and analytical tools to calculate the cost and fuel savings.

This truck is smaller, more flexible and economical while being big enough to carry the load for Deli Express. Each truck also emits 4.2 tons less carbon dioxide annually.

"For us it's a big win on many fronts," said Gregg Hodgdon, fleet manager for Deli Express. "We're pleased that we could significantly improve our fleet's carbon footprint through an innovative solution that uses a traditional fuel source and also saves money without sacrificing customer satisfaction.

"In this case, the new trucks cost $19,000 or $20,000 less [than the old trucks], so there is no payback period as we replace old trucks that need to be replaced," he added. "Then we're gaining 6 to 7 miles per gallon. We'll see thousands of dollars per truck in fuel savings and savings in operations."

Bump up in mileage

The mileage went from about 9 miles per gallon on the old trucks to as high as 15 miles per gallon for the new, 12,000-pound trucks.

Hodgdon said the new heating-and-cooling system is far more efficient and runs off the engine. The old trucks needed a second diesel engine to run a separate refrigeration system, plus two power-sucking evaporators.

Doug Lenz, director of product management at Thermo King, said the new system also changed how Deli Express handled thousands of frozen sandwiches it delivers to stores. Under the old system, sandwiches are moved from a warehouse to a thawing area each night and then loaded onto trucks in the morning.

The new technology, which offer a range of temperatures, allows Deli Express to load frozen food onto the truck, thawing it en route, he said.

"They wanted a solution that is multi-temperature and gives them more flexibility," Lenz said. "We were able to drive down weight, go to smaller trucks and expand options from all-frozen to multi-temperature ... and now the thawing is done on the truck."

Thermo King is a 500-employee unit within the Climate Solutions division of $14 billion-revenue Ingersoll Rand Co. that includes Wisconsin-based Trane, the maker of heating-and-cooling equipment for buildings.

Martin Duffy, vice president of sales at Thermo King, said the new truck represented leapfrog thinking that started with ideas on how to "leverage a platform that we had developed for airport shuttle buses, an entirely different application." The new approach should bring opportunities for Thermo King "across the nation and globally," he said.

"We believe we've created a unique segment" for the refrigeration market," Duffy said.

Sween, founded in 1955, employs 900 employees and supplies hot and cold sandwiches to 26,000 grocery, convenience and other stores in 26 states.

Neal St. Anthony • 612-673-7144