Replacement of a university's 22-year-old chiller brought numerous challenges to contractor.

WICHITA, Kan. - When building owners suffer the catastrophic loss of the single chiller serving a structure, decisions have to be made quickly and correctly.

That was the situation facing Brian Leabo, director of facilities management at the University of Kansas School of Medicine in Wichita, in April 2002.

The 34-year-old University of Kansas School of Medicine is housed in a 150,000-square-foot complex in north-central Wichita. About 100 third- and fourth-year medical students study each year at the facility, and unlike many traditional school settings, students spend much of their time outside the classroom working under the supervision of physicians in the community's hospitals.

Each of the school's two buildings has a central cooling system, with chilled water being supplied to the air handlers. In the older, three-story section, chilled water was produced by a 275-ton water-cooled centrifugal chiller. This high-pressure gear-drive machine was 22 years old and located in the center of the older building's basement. It started up normally in March 2002, but a few weeks after, it failed. Preliminary indications were that there had been serious damage to the chiller. The breakdown occurred during a period of unusually warm April weather.

Leabo turned to Craig Singer, an existing-building sales representative with the Trane Co.'s Wichita sales office. When Singer received the call to evaluate the school's ailing chiller, he sent Curtis Beauchamp, a Trane service technician, who had overhauled the machine 10 years earlier.

Beauchamp opened the chiller and his suspicions of major damage were confirmed.

"We got it opened up and it was really torn up inside," he said. "Those are real high-speed machines.

The University of Kansas School of Medicine in Wichita, Kan., suddenly lost a chiller in April 2002. Trane workers installed a temporary chiller to cool the building until a permanent unit could be put in place. Image courtesy of Trane.

Damage

"It had just disintegrated," he added. "Things were so badly damaged we would have had to replace elements that you don't normally have to replace."

Singer suggested that Leabo instead consider replacing the machine with a new 280-ton Series R Model RTHC screw chiller, also from Trane. After comparing the costs of both options, Leabo decided to replace the damaged machine.

His relationship with Singer, he said, and the urgency of the situation played a significant part in his decision.

"I've dealt with Craig long enough that I believe he'll shoot straight with me. He's very up-front and truthful. If he promises to deliver it, it's done. That's built my confidence," Leabo said.

Singer immediately contacted Trane officials in Pueblo, Colo. A new machine could be delivered within a week.

Meanwhile, the building still needed cooling, so Singer contacted the company's temporary-cooling division to secure a rental to serve the building until the new chiller was operating. ChillerSource delivered a 200-ton Trane Series Model RTAA air-cooled chiller, which was quickly connected to the school's chilled water lines using temporary hose connections. This solution prevented several weeks of discomfort.

"It was a lifesaver," Beauchamp said.

The new chiller being installed. Image courtesy of Trane.

Deadlines

With the rental unit cooling the building, much of the pressure was off the service team. However, Beauchamp and Trane service technician Brad David still faced a one-month deadline to install the new machine. Since the old chiller sat in the center of the building's basement, it had to be disassembled and carted out, while the new machine was disassembled, carted in and pieced together. Both old and new pieces would have to be lugged across a 100-yard path that included steps, inclines, declines, narrow doorways and numerous turns.

"We had a lot of pieces and parts," Beauchamp said. "It was stripped down as far as they had it at the factory." While Beauchamp and David took apart the new machine, Richard Caywood, vice president of American Mechanical Inc., a mechanical contractor in Wichita, and his team disassembled the old machine and hauled it out.

"You've got to be creative getting them out," Caywood explained. Several doors had to be widened and glass windows removed to get the chillers' barrels in and out of the building. Both crews used a forklift, winches, carts and rigging techniques to complete the job, which lasted a week. Beauchamp said the new chiller was re-assembled at the final location in four days.

Leabo said he had never seen anything quite like it.

Since it was in the building’s basement, removing the broken chiller proved difficult. The old chiller and its replacement would have to be hauled 100 yards over a path that included steps, inclines and turns. The basement’s stairs are shown here. Image courtesy of Trane.

New piping required

"It was phenomenal, just the amount of work to get the thing in place," he said. Next, Trane and American Mechanical changed the piping system that would feed the new machine. The old chiller had run inefficiently, partly because of a three-way condenser water valve that had pulled air into the pump, causing it to lock, Beauchamp said. He fixed the problem by redirecting the condenser water bypass line to the holding basin. The new chiller was also equipped with an additional condenser water-line valve located at the chiller operated by refrigerant pressure differential, Beauchamp said. This regulates the pressure between the vessels to ensure proper oil return and chiller operation.

"What seemed like a little change is going to be a huge money saver down the road," Leabo said.

On a warm June evening less than a month after the procedure had begun, Beauchamp and David started the new machine for the first time. It ran smoothly.

"It was a good feeling," Beauchamp said. "You get them off the rental chiller and they're back in normal operation."

Leabo said he immediately noticed a difference in the new chiller.

"It's much quieter," he said, adding that people on the building's first floor once complained about the old machine's noisy operation. "We have no complaints from them now. That's an added bonus we didn't plan on."

(This article was supplied by the Trane Co.)