Capitol View facility in Washington, DC
The facility at 425 Third Street SW in Washington, DC is a thirteen story building with a braced steel structure with a curtain wall of concrete panels, and insulated glass providing the decorative exterior finish. The building was built in 2005 and has not undergone any significant modifications since the original construction aside from a few mechanical upgrades
Target energy use for this type of building is 78.0 kBtu/ft2/year. This building has an EUI of 70.2 kBtu/sf/year, which is a little below the average for the area, indicative of the energy conscious practices and upgrades in the building.
EE&D engineers identified 6 Low Cost / No Cost Measures and 2 Capital Improvement Measures. The total installed cost was estimated at $130,980 with energy cost savings of $115,117 for a simple payback of 1.14 years.
In general the building is in excellent condition and is very well maintained and operated. The facilities staff is very conscious of energy efficient operation and has done well to keep energy consumption of the mechanical systems low while still maintaining the comfort of the building tenants. Some examples of their efforts are; air handler fans run at low speed, temperature is well maintained and continually monitored, condenser water temperature is kept low, and time of day schedules are well maintained.
Each floor of the 13 story building is cooled by a 65-ton McQuay packaged self-contained water-cooled air conditioning unit (SCU). Each of these units has four scroll compressors in four stages to provide direct expansion cooling for the unit. All of the SCUs are water cooled via two BAC 1500 Series cooling towers. Condenser water from all of these units is pumped constantly to the cooling tower by one of the two 50 HP condenser water pumps, each of which have VFDs
The heating and ventilation for each floor is provided through a variable air volume (VAV) air distribution system served by the SCU on each floor. Air is distributed through a ducted supply air system to terminal boxes located within the occupied spaces. Terminal boxes are controlled by the BAS, with each box having a dedicated temperature sensor/controller that acts as the control point. The majority of the heating for the facility is provided through electric reheat coils installed within the perimeter terminal boxes
The Building is equipped with a Building Automation System (BAS) with custom built graphics. All major equipment in the building is controlled with start/stop/status and temperature set points for AHUs, pumps, and terminal boxes.