NBP 300The National Business Parkway Building 300 (NBP 300) project involved a $3.8 million construction of a seven-story, 175,000 sq. ft. core and shell office building in Annapolis Junction, Maryland which will be LEED®-certified for Core and Shell. Mechanical Engineering & Construction Corporation (MEC²) was the mechanical contractor responsible for the plumbing, heating, ventilating, and air conditioning systems. The project is a new facility with air-handling units mounted in the Penthouse and also in a first floor mechanical room. The cooling in the building is provided by (2) 260-ton centrifugal chillers and a roof-mounted cooling tower. The heating in the building is generated by electric heating coils located in the air handling units. The plumbing systems were installed for the core toilet areas.
Construction was an intense coordination process with the Owner, COPT, the general contractor, Riparius, the Commissioning Agent, and the sub-contractors to build a state-of-the-art office building that maintained site cleanliness, safety and environmentally-friendly impacts to the existing area.
The HVAC system serving the NBP 300 facility provides year-round temperature and ventilation that meets or exceeds all applicable code and industry standards as defined by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE). The system utilizes (6) existing variable volume central station air handling units with electric heating coils for heating and ducting supply air to fan powered variable air volume terminals. The fan powered VAV terminal units are equipped with electric heating coils to maintain space temperature. The scope of the project called for MEC² to provide medium pressure insulated sheet metal ductwork and 279 fan-powered VAV terminals for the shell building. The chilled water plant consists of (2) 260-ton machines, (3) 780 gpm condenser water pumps, (3) 620 gpm chilled water pumps and 12″ piping mains extended throughout the building to provide the required cooling. Refrigerant safeties are in place as required by ASHRAE. The overall heating, ventilating and air conditioning system serving the building is monitored and controlled by a direct digital computer-based control system. The control system automatically coordinates the function of all mechanical components to assure economical and reliable operation. The system may be monitored within the building and remotely for failures of equipment or operating criteria outside of pre-set levels.
The building automatic temperature control system by CES monitors and controls every HVAC component in the building and also controls the building lighting system scheduling. The air handling units and terminal units work in sequence to minimize energy usage while providing the required air conditioning capacity. Innovative control strategies for static air pressure recalculation were implemented for the control of the variable frequency drives to minimize fan power usage and save energy use and costs.
The plumbing installation work consisted of providing stacked toilet facilities in the core of the building. The building utilities were coordinated with the site work to provide a seamless transition to the interior distribution piping.
Challenges to this $3.8 million mechanical undertaking included precise coordination with Commissioning Agent to verify that all of the requirements of the contract and of LEED® were being met and to provide this verification in a timely manner to keep our scheduled milestone dates. Multi-story construction is always challenging with the coordination of the bulk materials storage and coordination with the multiple trades occupying the same building space. During the construction process, it was discovered that the air handling units required changes to major components, MEC² was on the forefront to correct these issues and not delay the final building commissioning.
LEED® requirements added additional tasks to the construction process including storage of materials off of direct contact with the floor, temporary capping of ductwork and terminal units to minimize debris entrainment, providing required filtration over the return openings, and specific leakage testing of our systems. Close coordination with all trades was critical to minimize dust and debris in construction practices.