Case In Point
University medical center updates HVAC system under tight deadline
June 1, 2013
In the s
pring of 2011, Vanderbilt University Medical Center in Nashville needed to update its HVAC equipment. However, the work needed to be achieved under a very tight deadline.
|Vanderbilt University Medical Center in Nashville successfully updated its HVAC systems with minimal infrastructure changes and without disrupting important research.|
The HVAC equipment update was for a 17,000-sq-ft research facility within the university’s 800,000-sq-ft Medical Center North building. The existing air-handling unit, originally field-erected inside a roof-mounted penthouse, had begun to fail and was no longer providing adequate air flow throughout the facility.
Mechanical systems engineers at the university were primarily concerned with completing the project as quickly as possible, and ideally over the course of a single weekend, as the facility itself supported important ongoing research. Disruptions from prolonged HVAC system downtime and/or an extended construction timeline could present notable and costly setbacks, and the mechanical team became responsible for identifying a solution that would ensure neither issue occurred.
To keep within this project timeline while also minimizing the need for demolition to existing infrastructure, Vanderbilt University’s mechanical team additionally hoped to retrofit a system that could be assembled onsite, with parts that could be lifted via crane through a 6-ft wide opening in the 65-ft by 82-ft rooftop penthouse.
“There were some very specific parameters around this job, including the desire to keep demolition and reconstruction to a mini-mum,” said Michael Gable, P.E. CEM, mechanical engineer at Vanderbilt University. “The HVAC replacement was taking place within a highly active part of one of our medical research areas, and we wanted to avoid downtime as best as we possibly could. Recognizing that this was a challenging timeframe, particularly for a system of this size, we even had some mechanical contractors decline bid opportunities because of it.”
The mechanical contractor, Nashville Machine, accepted the project bid, which was designed by Smith Seckman Reid of Nashville. Gable and his staff were encouraged by the inclusion of a 259-ton, 100% OA, 34,500-cfm ClimateCraft ACCESS knock-down air-handling unit, engineered specifically for final assembly at the job site. The unit, which incorporated foam insulation panels, an IFB Steam coil and a humidifier, would provide more static pressure capability than the existing air handler, and would also include a ClimateCraft FanMatrix™ fan array tower for built-in redundancy.
“The new air handler provided increased load capacity compared to the existing unit, and also provided numerous design and functionality improvements,” said Gable.
“We were glad to now have built-in redundancy, and the vertical discharge design made management of a non-hazardous odor control issue via a high-velocity plume more efficient.”
According to Craig Barbee, P.E., senior mechanical engineer at SSR, the ClimateCraft ACCESS™ process of custom engineering and manufacturing factory-fabricated, field-assembled air-handling units was the reason why the firm identified it as an ideal retrofit solution.
“We were looking at a situation in which the customer wanted minimal disruption to the surrounding infrastructure, with an ideal goal of the only deconstruction being that of the HVAC system we were replacing,” Barbee said. “The ClimateCraft ACCESS custom knock-down air-handling unit, along with the support program surrounding it, seemed like the right solution to achieve this goal.”
Coy Gilland, superintendent at mechanical contracting firm Nashville Machine Co., said the ClimateCraft ACCESS helped achieve the goal of a quick installation.
“We started on a Friday at about 3 p.m., executed demolition of the existing unit by 10:00 that night, and began assembly of the new unit at 6 a.m. on Saturday morning,” said Gilland. “By Sunday night at 7 p.m., after running around the clock, we had completed 450 hours of assembly and installation, and were ready to get the system up and running. This was considerably ahead of the game, as the factory estimated the job would finish Monday or Tuesday.”
Gilland shared that an advance factory tour and training at ClimateCraft’s headquarters facility contributed to the time savings during installation.
“We’d seen how the unit was put together during our visit to the Oklahoma City plant, so we were prepared once it was delivered on the jobsite,” Gilland said. “It was a great help to have the added support of ClimateCraft techs on the site as well, and between the extra help and the advance training we were able to really just motor through the assembly and installation process.”
Gilland additionally noted that replacement preheat face and bypass dampers were shipped directly to the jobsite by ClimateCraft.
“It’s unbelievably helpful when you know you’re working with a manufacturer that understands how best to address unanticipated on-the-job issues, particularly as there’s always something that happens unexpectedly,” he said.
According to Barbee, using ClimateCraft ACCESS was one of the best choices made for the project.
“The trainings and ongoing support provided by the company were top-notch, and everyone was very responsive to any questions or issues we had along the way,” he said.