Cast-in-place concrete, ventilation system
make research center's design unique

Forms were set into place (top) or built (center) before concrete was poured into them build the Durham Research Center.

By Bill O'Neill

Drivers who commonly commute on Saddle Creek Road or Farnam Street may have noticed that steel – a material normally associated with multi-story structures – was absent during most of the construction of the Durham Research Center.

That's because many of the highly precise research experiments in the DRC will permit only a very small amount of structural vibration. Constructing such a structure using steel would require significant reinforcement to reduce vibration. Instead, architects and structural engineers chose concrete as the framing material for the building.

"Cast-in-place concrete has natural characteristics and mass advantages for vibration reduction," said Project Manager Craig Ellis of HDR Inc., the Omaha-based architectural and engineering firm. "The roof of the auditorium is steel, and there's some miscellaneous steel throughout the rest of the structure, but primarily, it was built using concrete. For scientific laboratories, concrete is the material of choice."

Concrete alone, however, doesn't guarantee adequate levels of non-vibration. Designers needed to minimize vibration through proper air-handling ductwork design. In addition, the supply and exhaust fans, compressors, pumps and other noise and vibration-producing equipment were situated in mechanical rooms with protective wall/floor construction.

The location of the mechanical equipment in the Durham Research Center is unique to the UNMC campus. Instead of placing the equipment at the top of the 10-level building, it is on floor 2. The location actually saves square footage for the equipment, as smaller ducts are needed when air is pumped in both directions.

Because of the scientific nature of the building, it has higher-than-average ventilation flow rates. At least 15 air changes per hour are required in each animal room space.

"The building requires a lot of exhausting and a lot of fresh air," Ellis said. He noted that the fresh-air intake is located on the second level, while circulated air exits through rooftop exhausts.

Like most research facilities, the DRC laboratory space requires that 100 percent of its air come from the outside during each cycle, said Nick Combs, manager of maintenance and utilities at UNMC. Most buildings recycle some of their cooled or heated air, and the DRC will do that in its office spaces and the auditorium.

"When you put in 100-percent outside air, it all requires conditioning, whether it's hot, cold, humid or dry," Combs said. "Most of the buildings recycle some air, but we can't with this one, because of the specifications needed for research."

Combs said water source heat pumps will be used throughout the building, which helps UNMC with its energy bills and assists OPPD, which uses less generating capacity because of the heat pumps.

Still, the DRC is as energy-efficient as possible because of several design features, said Mike Faber, manager of major construction projects at UNMC.

• All the windows are insulated glass units that include UV protection, which reduces temperature loss and protects equipment.
• The building has extensive "heat recovery" systems. These systems range from the small – allowing such things as the building's icemakers to be cooled – to the bigger transfer units in the exhaust air system on the roof to capture heat or cooling from the air before it is exhausted to the outside.
• The building also utilized renewable resources whenever possible.

John Cameron, HDR design manager for the Durham Research Center, said having the mechanical equipment on the second floor of the structure offered designers an opportunity to transition from the concrete base of the building to the brick that adorns the outer walls of the research lab areas.

The building uses the palette of materials prescribed in the UNMC master plan – materials that have been used in other recent UNMC construction projects such as the Lied Transplant Center and the Durham Outpatient Center. These materials, including green glass, masonry and light precast or limestone, indicate that although the DRC is part of the UNMC campus, it also has its own uniqueness.

"Literally, we want to tie the campus together, and we want to do it with material selection," said Ron Schaefer, director of facilities planning and construction at UNMC. "The materials are a strong unifying factor in the campus architecture."

Though the laboratory spaces are all rectangular in nature, offices and other common areas have curved, glass walls.

"We realized that the laboratories needed to be efficient, and basically all the same so they would be adaptable to whoever was using them," Cameron said. "We were able to be more playful with the offices and the other areas."

Chris Barnwell, the DRC's project designer, said that because of the size of the building, the distance between 45th Street and the entrance to the building is developed as a "transition area." Landscaping and the 319-seat auditorium provide a pedestrian-scaled, transitional space to the DRC, he said.

A lobby area near the auditorium could provide a space for the university to host small receptions and celebrations. "There's a nice skylight in there," said Barnwell. "I think the space will evolve into other uses."

In addition to the scientific and educational elements of the DRC, the building should also produce some outstanding views of the UNMC campus and city. Glass-fronted elevators will run along the east side of the building, and stairwells will run along its northern and southern ends.

"No one has ever seen Saddle Creek from that altitude," Barnwell said. "I look forward to seeing that."