Mississippi, Alabama, Florida, Georgia Commercial HVAC, Mechanical Systems Projects

Navy Federal Credit Union Building Four

A commitment to excellence was made priority in this project by the owner and was carried out by the construction team. The owner’s vision was 100% employee comfort and overall energy efficiency. Through a detailed design and a thorough construction team the owner experienced immediate return on their investment with low employee turnover and efficient power bills.   It is rewarding to an owner and contractor when a quality product is constructed under a complex schedule all while the visions of the project are embraced and delivered. This project required contractors who understood the owner’s vision and an atmosphere where teamwork between all parties could work towards the ultimate goal. A complete success story for all involved is why we think a National ABC Eagle award is the final compliment to the team’s determination and commitment.

Navy Federal Credit Union Building 4 is a 210,000 square foot general office space including a mail room, warehouse and storage space located in the basement of the building. This building is the most recent addition to the Heritage Oaks campus which is located in Pensacola,  Florida. Building 4 will provide Navy Federal the space they need to expand the data center operations with their growing customer base. Building 4 is one of five structures located on the recently expanded 62 acre campus which consists of four buildings (total of 602,000 square feet) used for credit union operations and one parking structure allotted for the 1,300+ employed at this campus.

ASD, an Atlanta, Georgia architectural firm led the design effort for the campus with Newcomb and Boyd providing the mechanical design. Greenhut Construction (Pensacola, Florida) is constructed the buildings and engaged Comforts Systems USA Southeast as the mechanical contractor for the HVAC system. Jones, Lang, LaSalle provided Construction Management for the team.

Navy Federal Credit Union’s commitment to employee comfort and energy efficiency was a contributing factor to strive for LEED (Leadership in Energy and Environmental Design) Gold status for each building on the campus in Pensacola. The decision to go LEED Gold brought on challenges for the design team to deliver a sustainable design which focused on employee comfort and energy efficiency while creating the smallest possible impact to the environment. This was accomplished through use of non toxic renewable products while focusing on indoor environmental air quality, efficient lighting systems and an energy efficient air conditioning system. Out of this came a state-of-the-art HVAC system that was designed around six custom SEMCO energy recovery units (ERU) that supply air via floor plenum to 3,100 adjustable low velocity floor grilles strategically located near each employees work space. Through a sophisticated energy management system, temperature and humidity levels are strictly maintained for optimum employee comfort and energy efficiency.

Early planning was required before the slabs and structure was erected with our focus on the plan needed to bring the six Energy Recovery Units (ERU’s) into the building. The units came in four sections with a total weight of 36,000 lbs. These units carried a footprint of 40’x16’ and a unit height of 11’. After reviewing the structure clearance of just a few inches it was evident that strict coordination was needed with all trades to allow for this installation. The first obstacle was how to get these large units into the basement of the building. Wanting to protect the equipment as much as possible we found that we could allow the construction of the structure to continue overhead and lower the units into the basement from the exterior stairwell. This task took on time delivery and strict coordination with other trades since the height of the units would not allow overhead work to proceed until the units were resting in the recessed mechanical rooms. We only had 3 inches of clearance between the units and structure while moving them in place with the necessary industrial skates that would handle the unit weight load. The next structure related obstacle with this installation was the mechanical room floor elevation was 6’ below the building slab grade. Incorporating this issue in our preplanning phase we worked with the structural engineer to include weld plates in the overhead concrete structure to allow installation of steel trolley beams. These beams extended over the slab on grade and continued over the recessed mechanical room pits. We used these beams in conjunction with beam trolleys and chain falls to lift the units slightly above the slab on grade which allowed the rollers on the trolleys to move the units over the mechanical room pits. Once the units were over the recessed mechanical room slab in the proper location we were able to lower the units in their final resting place and make the final connections with the other sections of the units.

While the HVAC industry continues with an overall growing knowledge and concern for air quality in finished buildings we found that LEED standards has incorporated this importance into the rating point system. LEED standards require fabricated duct openings to be sealed from contaminants during delivery efforts, on-site storage, and for protection after installation.  We found this to be rewarding to the overall systems performance but also a challenge incorporating this labor intensive task into our shop fabrication standards. The best way we found to combat the labor required for this task was to reduce the open ends of duct there was to wrap. We accomplished this by pre-fabricating multiple sections of duct together in each system. In lieu of wrapping six ends on three separate pieces we could put these pieces together and wrap only two ends. This was also rewarding to the environment in that we had less waste from the plastic wrap going into the trash and ultimately into a land fill. A new onsite challenge we found with protecting duct openings was monitoring the covered ends on the duct systems that were installed daily. With just shy of 300,000 pounds of sheet metal ductwork covering 210,000 square feet of building we found it necessary to increase quality control efforts to monitor duct installations and timely placement of protective wrap. Prior to project completion the ERU’s were put into operation for testing and commissioning. Following LEED guidelines we installed filters at return duct openings and at the units to keep duct systems free of dust and debris. The last step taken to be sure of a clean duct system was a stringent air quality test that was performed by an independent testing facility prior to the owner’s occupancy. It was a testament to all involved during the construction process upon receiving a passing review on the air test prior to owner occupancy.

Every project is unique and keeping the work space open and free of material is always a challenge no matter the project. With a large portion of the air delivery system located under the raised access flooring (RAF) we knew a unique opportunity would present itself during the construction rough-in phase of the building. The project schedule would dictate overhead work to complete enough that man lifts would not be required so that duct, equipment and conduit could be installed on the slab prior to RAF. During our shop drawing process we utilized the shop drawings to coordinate the under floor equipment and ductwork. Crews on site utilized control lines from the shop drawings to locate floor pedestal for the RAF to allow equipment and duct installation to progress. With focus on the building air test at project completion the general contractor followed a thorough cleaning procedure before any RAF was installed to eliminate construction dust and debris.

As systems and installations were nearing completion it was time for the LEED enhanced commissioning efforts to begin.  For this task the owner hired LKPB Engineers located in   St. Paul, Minnesota to lead the process as the Commissioning Agent. LEED enhanced commissioning on the HVAC system started early in the design with a commissioning review prior to publishing completed construction documents. The onsite commissioning started once all of the system installations are finalized and testing is completed. This task would prove to be a large team effort to cover the 215 terminal units, 20 computer room units, 27 blower coil units, 6 custom energy recovery units, 8 smoke exhaust fans, 2 chilled water pumps, variable speed drives and the building pressure control system. Review of these systems included everything from installing the equipment label to the point’s review of the building automation system. After building systems were proven to operate as the design intended the systems manuals were assembled for the owners use over the course of the buildings life.