VRF System Keeps the Past Alive on the USS North Carolina
The USS North Carolina Battleship in Wilmington, North Carolina, is one of the state’s most prominent World War II memorials. And, it was also overdue for some much-needed comfort.
The battleship’s new HVAC system needed to preserve the historical accuracy of the decommissioned ship, and it needed to deliver comfort across a variety of load requirements while blending into the background.
The system was also required to heat and cool simultaneously to account for wide temperature differences on different sides of the ship. Ceiling cassettes shallow enough to fit unobtrusively into overhead spaces were necessary as well as longer piping runs to keep outdoor units away from the touring public. Also, the ship needed flow selector boxes in overhead spaces without running separate power.
The solution was to combine two heat recovery outdoor units and 14 indoor units with system management provided by Lite-Vision Plus Remote Controllers. The Toshiba Carrier VRF heat recovery system was an ideal fit to deliver comfort to a battleship designed and built in the late 1930s. This floating relic of the Pacific theater includes a meeting space and museum area along with employee offices, a catering space, and public restrooms, all in need of cooling and heating.
The individual fan coil units — evenly split between ceiling cassettes and high wall indoor units — provided a balance between unobtrusive installation for aesthetics and quiet comfort for hard-to-reach individual work spaces.
Designed and installed by Jacksonville Heating Contractors, company officials said this system has helped bring a welcome breath of fresh air to the monument. Preserving the historical accuracy of a World War II battleship while providing comfort for tourists proved to be a delicate balancing act.
“People are quick to point out non-World War II equipment,” said Terry Kuhn, maintenance director, USS North Carolina. “‘Oh, they didn’t have that in the war!’ they’d say. But, on the other hand, they are happy to have the air conditioning.”
Requirements for the installation included converting the ship’s Ward Room into a meeting space and museum and making sure it retained a number of the ship’s original features. It also needed to provide heating and cooling for a catering room, the guest bathrooms, and individual office spaces. The system had to be versatile, unobtrusive, and offer the ability to handle a variety of heating and cooling loads simultaneously.
Adam Slusher, VRF sales engineer, Carrier Enterprise, explained the choice of Toshiba Carrier VRF Ceiling Cassettes for the meeting space/museum.
“We went with the cassettes because of aesthetics,” he said. “Ours are not as deep as our competitors, so they are more pleasing to the eye.”
Another advantage was the ability to put the Y-pipes in a central location and make longer pipe runs throughout the ship. This allowed technicians from Jacksonville Heating Contractors to install both of the outdoor units on the starboard side of the ship in an area not seen by its visitors.
The ship’s physical constraints and the fact that it sits in water created additional challenges that played into the advantages of the VRF systems.
According to Slusher, the VRF flow selector boxes for the heat recovery system provided a distinct advantage over other systems because they were small enough — about the size of a toaster oven — to fit into the overhead spaces. They also were installed without running additional wiring because they could be powered by the nearest head unit.
Regarding the physical challenges of the ship, Jacksonville’s Randy Ramsey indicated that, “dealing with condensate was a bigger issue than refrigerant.” So a number of condensate pumps were installed.
Glenn Davis, one of Jacksonville’s lead technicians, described an unusually heavy amount of drilling needed to run refrigerant piping and difficulty leveling the ceiling cassettes due to the ship’s motion. To account for the ship’s port holes and other interior obstructions, custom-fabricated mounting brackets were needed to install the high wall units in their optimal locations.
Now that the installation is complete, employees of the battleship say they are more comfortable and more productive.
“These new units make almost no noise whatsoever,” said Kuhn. “I don’t really know if we’ve had to run heating and cooling at the same time, but I really don’t have to worry about it. If my office is too hot, I turn it down. If I’m too cold, I bump it to heat ... the system just takes care of it.”
For Ramsey, who remembered the grassroots fundraising campaign that saved the mothballed battleship from being scrapped in the late 1950s, it was an emotional journey as well.
“To walk on this ship and see what other guys did in 1943, 1944 — they had no air conditioning. They were in the South Pacific, and they only had ventilation,” he said. “And, for me to have the pleasure to work on this ship, it was a great honor. The whole team felt the same way.”