The Pentagon, completed in January 1943, has seen numerous additions and modifications during the past 60 years, but no major renovations. In September 2001, Southland Industries was awarded the contract for the design-build mechanical services for the renovation of Wedge 2, and subsequently awarded the contract for the renovation of Wedges 3, 4 and 5.
During this design-build project, Southland Industries proposed the use of fan-powered induction units (FPIU) to meet the environmental, indoor/outdoor ventilation, and energy efficiency requirements put forth by the Pentagon Renovation Office. Using fan-powered terminals with the addition of chilled water-cooling coils, and an air valve to supply a constant volume of conditioned outdoor air, several aspects of the system make it truly distinctive and appropriate system for the Pentagon.
The building itself provided a unique challenge, with low floor-to-floor height, making any system relying on air delivery through ducts difficult to fit. Southland was able to reduce the required amount of mechanical ductwork by almost half, which allowed the ceiling to be raised 23 inches and substantially increased natural lighting.
The scope of this renovation was to fully decommission, demo, and replace all existing mechanical and plumbing systems within Pentagon Wedges 2 through 5 without impact to the tenants as the building remained occupied.
- By using chilled water piping to deliver most of the cooling, Southland saved a considerable amount of above-ceiling space and enabled the architects to provide higher ceilings in the exterior zones with the systems hidden in bulkheads.
- This project illustrates Southland's ability to overcome the challenge of working inside an existing structure to modernize the facility with sitting tenants, without disrupting the main nerve center for our military.
- This project also utilized short interval production schedule, which is a lean construction method.