Georgetown University’s Yates Field House, located in Washington, was in need of an overhaul. The 30-year-old building received a new HVAC system, including a separate dehumidification unit for the indoor swimming pool area. The natatorium portion of the building covered approximately 10,000 sq ft and included a six-lane pool with diving bell.
KTA Group was given responsibility for the building’s mechanical systems. KTA was familiar with aquatic facilities. “We are very sensitive to pools because of the humidity control problems, especially when you have additional humidity from the outside air used to ventilate the structure,” said Rick Eudy, director of mechanical engineering for the firm’s institutional division. Eudy said a PoolPak dehumidification system was specified because of prior successful installations, and because it offered features like dual-fan operation for ventilation control requirements and heat recycling for energy efficiency.
Eddie Xue, the project’s engineer for KTA, also liked the PoolPak unit because it satisfied the air temperature requirements before the water. “The Yates pool was equipped with a separate pool heater, and we wanted the recycled heat to satisfy the space before the water,” Xue noted.
The unit specified had a capacity of 50 tons, capable of removing 260 lb/water/hr. It was also equipped with a mixing box, which, when working in conjunction with PoolPak’s ECC controller, maximizes cooling in the economizer mode and heating when in the “smart economizer” mode.
Too large to fit through the doorThe biggest problem facing the design team was how to get the extra-large dehumidification unit into the utility room. The facility was built with an athletic field situated on its roof at ground level. As such, all mechanical equipment was located below grade. To make matters more complex, the foundation was constructed of poured concrete with only a single 6-ft-wide access doorway.
The usual approach to a problem like this would be to remove the existing wall, thereby providing an opening large enough to slide the unit into position. The wall would be rebuilt after the installation. This was not an option because to remove part of the wall and replace it later would be a costly undertaking for the school, and it would add valuable time to the project. The university was also concerned the finished appearance would not match the remaining structure when completed.
Other problems included a large flagpole situated near the entrance that had to be removed to facilitate the demolition. And the grounds surrounding the proposed entrance area were too confined for allowing a large flatbed tractor-trailer to deliver a completed unit.
PoolPak, working in conjunction with their regional representative Havtech, decided to build the dehumidification unit on site. “We considered many options from using multiple smaller units to splitting the system once it arrived, but each posed a size issue,” said Dick Shaffer, Havtech’s manager for the project. “Besides a very narrow entrance area, the size of the utility room did not allow ample clearance for ducting if the units were stacked. The unit alone measured 25 feet long by 8 feet wide by 7 feet high.”
Employing old fashioned muscle powerTo prepare for the project, PoolPak completed several small subassemblies at the factory to reduce the assembly time on site. The subassemblies were trucked to the job site along with a team of six employees to begin the assembly process.
The component parts had to be manually carried in, and the utility room had no overhead lifting system for placing the heavy components. Working in conjunction with the university staff and contractor, the PoolPak assembly team rigged a temporary lifting system from a wall to position the unit’s frame for piping and insulation. Components such as the heavy compressors and all-copper coils were methodically moved into position inch by inch using blocks and raw muscle power.
It took the PoolPak crew a total of six days working more than 12 hours each day to completely assemble the unit. The actual assembly time took only slightly longer than if the unit had been manufactured at the factory, and the mechanical contractor was able to connect the ducting and power with very little loss of time.