National Museum of African American History and Culture
Architect: Freelon Adjaye Bond/SmithGroup
General Contractor: Clark/Smoot/Russell
Contractor: Southland Industries
As the National Museum of African American History and Culture rises on Washington, D.C.’s National Mall, Southland Industries has been installing the massive behind-the-scenes HVAC system that will keep thousands of visitors comfortable and historic artifacts preserved.
Slated to open in April 2016, the 410,000-square-foot museum includes five stories of above-grade space (lobby, galleries, offices) and three levels of below-grade space (mechanical, loading dock, support spaces). The stories above ground are supported by four concrete towers. These four cores rise up through the building and encompass shafts, stairwells, elevators, and electrical and storage rooms.
SMACNA contractor Southland Industries Dulles, Va., division, surmounted some daunting challenges that the project presented—from guiding oversize equipment down to the third level below ground to setting large riser ductwork at night, much of the time in the freezing rain.
Forty-two sheet metal workers implemented the project with 12 sheet metal workers handling the night shift. In all, Southland installed 797,000 pounds of sheet metal.
Installing heavy air handling units and equipment three stories down on the mechanical C3 Level was tricky. Workers had to crane in 12 oversize air conditioning units, tilt the huge units to fit through the narrow 16-foot-by-16-foot shaft opening, then lower each one down through the shaft to the third level.
More than 300,000 CFM of conditioned air flow is supplied by the12 custom-built air handlers. The air handlers and associated ductwork were all oversized.
Below grade, multiple layers of duct and pipe were installed inside a space envelope of just 32 feet. The mechanical systems accounted for 20 feet of that space.
One challenge on the upper floors involved installing 28-foot-tall risers at night. Starting work in the chilly February weather, workers installed multiple riser ductwork from 4 p.m. to 2 a.m. during the second shift. With construction taking place both day and night, night-time was the only shift that the general contractor’s tower crane was available.
Specializing in energy efficiency, Southland also installed chilled beams in office spaces on the upper floors including the mezzanine, second, and fifth floors. Variable refrigerant flow systems were also used in the electrical rooms.
All duct, some as large as 6 feet by 14 feet, was pre-assembled in Southland’s shop and delivered to the jobsite on wide-load trucks through Washington, D.C.’s gridlocked traffic. Southland workers installed a massive HVAC system of more than 52,000 linear feet of ductwork and 40,000 linear feet of piping, totaling nearly 800,000 pounds of duct.
Southland also installed a chilled water cooling plant with three 500-ton Trane chillers and six rooftop cooling towers.
In addition, the SMACNA contractor supplied nearly 200,000 CFM of smoke exhaust and additional stairwell pressurization fans for on-site emergency power for life safety.
Occupying the last available space on the National Mall, the National Museum of African American History and Culture is located on 15th St., N.W., near the Washington Monument. The building has been designed to achieve LEED (Leadership in Energy and Environmental Design) Gold certification.
Founded in 1949, Southland Industries is one of the nation's largest MEP building systems experts providing innovative yet practical solutions through a holistic approach to building performance. Advocating a design-build-maintain model, Southland specializes in the design, construction, and service of mechanical, plumbing, fire protection, process piping, automation and controls systems, as well as comprehensive energy services needs.
Photos courtesy of Shawn Cingle, Southland Industries