Tysons II, Building E
Henry Adams designed the MEP systems for this 18-story building with basement and penthouse. The building is 430,000 SF with a 5-story, 500,000 SF, 1470 car, secure parking garage.
There are two cooling towers on the roof that provide condenser water to one 60-ton air handling unit per floor. Water is pumped from the cooling tower to a plate heat exchanger and then pumped from the heat exchanger to each air handling unit through a set of risers in the building. Air is supplied by the variable air volume air handling unit on each floor to perimeter fan powered terminal and interior variable air volume terminals. Electric reheat coils in the perimeter fan-powered terminals do all heating. Domestic hot water heaters are provided for each zone. There are connections and wet stacks for future tenant plumbing for each floor.
A fire pump serves the sprinkler and standpipe system. A domestic water booster pump provides water to each floor. There are three domestic water zones in the building to control the pressure. Fire alarm system is ADA and NFPA compliant. A stair pressurization system prevents smoke entering each stair. Also, there is a smoke removal system for the Atrium. Fire alarm design to meet NFPA 101 High Rise Codes including Fire Command Center with remote transponder panels for every third floor. Fire Command Center included air handling control, and stairwell pressurization control panels. Elevator status and recall panels, LED graphic annunciator panel, and a complete firemen’s telephone system were also included. The entire building uses voice evacuation and visual strobe alarms, both NFPA and ADA requirements. The automatic controls are direct digital with communications to the Owner’s other buildings.
A single VEPCO 13.2 kV feed and 3750 kVA pad-mount transformer split service to three 480Y/277 volt 4000 amp switchboards. Switchboards A and B power separate lower and upper tenant 400 amp bus ducts respectively. Switchboard C powers cellar and penthouse as well as elevator equipment. The typical tenant situation consists of an 800A fused switch powered from a 4000A bus duct. The fused switch feeds an 800 amp distribution panel which has its own tenant meter and powers the entire floor, except for emergency systems. Dedicated panelboards are provided to separate HVAC, lighting and receptacle. The emergency system consists of one 800 kW diesel driven engine generator feeding a building distribution panel through a bypass-isolation automatic transfer switch.
Lighting was designed for all public spaces as well as exterior building and site lighting. Provisions were designed into the project for future tenant communication systems and a security system with CCTV for building and garage. A conduit system was designed for the future add-ons to the security system.
Utilities for the garages are fed from the office building. A dry standpipe system was designed for the garage. A connecting link between the office building and to Tysons Mall is air conditioned and sprinklered. The garage lighting was designed to meet ASHRAE Standard 90.1. Special systems include FAA approved aircraft warning lighting, TVSS systems on incoming switchgear, rooftop window washing receptacles, and lightning protection.