When the problem was pressure

Three-quarters of a million square feet. Sixteen stories. A $365 million total construction budget.

That’s CDC Building 23, the largest lab facility at the Atlanta headquarters of the U.S. Centers for Disease Control and Prevention. When Batchelor & Kimball was hired to install the HVAC mechanical systems, we knew the building’s size would be a major factor.

“It was so large that just keeping track of all the workers could be a challenge,” says Bill Doty, project executive. “The team could be spread up and down across five or six floors at once.”

Outside the facility, we faced the opposite problem: no space at all. Rubbing shoulders with sprawling Emory University and bustling Emory Hospital, the CDC’s crowded main campus is already densely built. That meant no staging area to store supplies or organize materials for the next day’s work. Nowhere to route trucks, and no way to bring in big equipment.

“You’re in a little postage-stamp area,” says Trent Strine, project manager. “And the only thing that will fit on the job site is a crane.”

With all of the supplies stored off site, each day’s work depended on a complex choreography of just-in-time deliveries — the right materials, for the right workers, at the right moment. And a day of bad weather, a malfunctioning crane, a misfiled form or any other small mishap could bring a domino effect, requiring the reworking of numerous interlocking schedules.

So we worked hard to stay one step ahead. Each day, we reviewed the schedules, adjusted timelines, proactively contacted vendors, and made lots and lots of phone calls. All to ensure that everyone was perfectly synchronized, keeping that choreography as fluid as possible.

But then a problem surfaced: Unforeseen pressure on the water loop system.

When completed, Building 23 would be the tallest on the CDC campus. Its height meant higher pressure would be exerted on the water loop than the Central Energy Plant could handle.

To replace all flanges and devices inside the plant would be far too costly – not only for added construction, but because of a clause in the overall project contract.

Built into the CDC’s agreement with contractors was a scheduled start-up date for the building’s cooling system, which was B&K’s responsibility. If we didn’t start up that system by the deadline, the CDC would be required to pay more in construction costs. A lot more, all funded by the taxpayers.

We helped the team develop a solution to the pressure problem: Adding flat plate heat exchangers, pumps, pipe and controls to Building 23, so that water from the loop would stop at the third floor and keep pressure manageable. Then we would build a second – and independent – loop of pipe from the new heat exchangers to serve the upper floors, thus keeping those from adding to the pressure in the system.