First Union Tower
THE FIRST UNION TOWER GETS COMFORTABLE IN THE FLORIDA HEAT
Commercial tower in Orlando gains control of its environment through HVAC plant improvements
Located on prime real estate in one of Florida’s largest cities, the First Union Tower in Orlando was a prominent place for business. But even though it serviced high-powered clients, the building contained one very important weakness. The facility’s cooling plant couldn’t keep up with the demand. As a consequence, comfort levels in the building didn’t meet the performance standards expected by its owner, Hannover Real Estate Holdings, or the property manager, CB Richard Ellis. In 1999, plans were initiated to give the building’s HVAC plant a complete makeover.
The original chiller plant for the 292,000-square-foot structure consisted of two TRANE CenTraVac™ centrifugal chillers, Model CVHA, rated at 230 tons each. They provided chilled water to fan-coils on the second floor and to air handlers on floors 3 through 16.
In the original system, chilled water was piped from the chillers at the basement level to the upper floors via a PVC riser in an interior pipe chase.
Up until that time, the strategy had been to pre-cool the building in advance of weekday occupancy. This process meant that on the warmest days, the building became unacceptably hot by mid-afternoon. Despite the fact that there was sufficient chiller capacity, there wasn’t enough cooling tower capability to shed the excess heat. Further, the airside plant couldn’t provide air volume at desirable levels. A solution was needed.
While the entire central system was completely re-piped and the existing cooling tower was replaced, the building management relied on a rental air-cooled chiller from TRANE Chillersource™.
To address the airside problem, all of the air handlers on the upper floors were replaced with TRANE Modular Climate Changer™ air handling units. This posed a challenge that Trane was more than capable of handling. The clearances of the mechanical rooms on each floor were so tight that the new units had to be installed in pieces and assembled in place. The modular design of the Trane air handlers made this possible. To bring all of the pieces together seamlessly, a TRANE Tracer Summit™ system was installed to provide improved control and complete monitoring of building comfort levels.In addition, new Trane UCP2™ controls were installed on the two older centrifugal chillers, which allows more complete unit diagnostics, monitoring and optimization.
As a result of the HVAC plant improvements, the First Union Tower now provides complete control of the building environment, even during the hottest times of the year. With the waterside improvements, chilled water is delivered to the air handlers and fan-coils at 42°F (6°C) and returns at 57°F (14°C).
The new air handlers allow complete environmental control with specified fresh air makeup, even when it’s sweltering. Despite the increases in the size of much of the service equipment, building energy usage did not increase. Precooling of spaces is no longer necessary and tenants can enjoy an optimum office environment.
Air-cooled chiller from TRANE Chillersource™;
TRANE Modular Climate Changer™ air handling units;
TRANE Tracer Summit system;
TRANE UCP2™ controls
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