The United States Navy in 2011 enlisted the help of Southland Industries in constructing a 40,000 square foot aircraft hangar along with a 35,000 square foot office building at the Patuxent River Naval Air Station in Maryland.
In partnership with a general contractor and an electrical design-builder, Southland designed and installed the HVAC system and its controls, and also carried out testing, adjusting, balancing and commissioning of the system. Southland also installed all plumbing and sheet metal, and performed energy modeling to meet and exceed ASHRAE 90.1 energy efficiency standards, helping to earn a Silver LEED certification for the project.
The project required significant discipline in planning and execution not only because the client was a military installation with strict security practices, but also because of the project’s proximity to an active runway, which remained open during construction.
To ensure a structured and coordinated approach, Southland employed a variety of methods:
- Lean planning and pull schedules to track field progress and commissioning activities.
- REVIT for design, coordination and fabrication and to implement multi-trade modular construction. REVIT also was used to create a coordinated design model for all the trades that was used for spool drawing, eliminating the need to re-draw the designs, as is typically done during the coordination process.
- Multi-trade modular racks engineered and fabricated by Southland. The racks included HVAC piping, ductwork, and plumbing, in addition to ductwork and piping thermal insulation. Conduit and cable tray were installed at an electrician’s fabrication facility. The use of modular racks reduced the overall installation time by four weeks when compared with traditional installation practices.
- Close coordination with the logistics team to ensure materials arrived on time from the Southland fabrication facility, which was located two hours from the project. Deliveries were just-in-time and closely coordinated with the strict access procedures required by the Naval facility.
This approach enabled the Southland team to seamlessly integrate field input into the design model, allowing for the inclusion of constructability comments in the 100 percent design documents. This integrated process allowed the designer and builder to work together earlier in the process to account for safety, equipment procurement, and logistical concerns much sooner than in a traditional plan and spec type procurement.
The team’s methods also yielded unexpected benefits as the mechanical system exceeded client requirements for energy efficiency and reliability. Southland also performed energy modeling for the project and developed a comprehensive measurement and verification plan that the owner can use to track energy consumption and compare it to estimated energy use.