Tysons II, Building C
Henry Adams designed the MEP systems for this 13-story building with basement and penthouse. The building is 300,000 SF with a 5-story, 400,000 SF, 1170-car, secure parking garage. The 2-story lobby features a 100-foot fountain with cascading pools and ornamental plantings.
This project won a NAIOP Award - Excellence in Best Buildings - Speculative High Rise.
There are two cooling towers on the roof that provide condenser water to one 65-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. All heating is done by electric reheat coils in the perimeter fan-powered terminals. 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. Fire alarm is designed 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 use 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 two 480Y/277-volt switchboards. Switchboard A powers tenant 5000-amp bus ducts. Switchboard B powers cellar and penthouse as well as elevator equipment. The typical tenant situation consists of an 800A fused switch powered from a 5000A 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 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 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. Ventilation is provided for the below grade levels.