The facility at 8954 Rio San Diego Drive in San Diego, CA is a six story building on a braced steel structure with a curtain wall of mixed stone tiles, polymeric wall panels, and insulated glass providing the decorative exterior finish. The building was built in 2001 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 taken from the US DOE’s Energy Information Administration CBECS energy use Table for office buildings located in the Pacific. Their number is 65.1 kBtu/ft2/year. This building has an EUI of 60.6 kBtu/sf/year indicating that this building has an EUI slightly below the average, indicative of the energy conscious practices and upgrades in the building.
EE&D engineers identified 7 Low Cost / No Cost Measures and 8 Capital Improvement Measures. Added together the overall annual kWh reduction is estimated at 347,779 saving approximately $59,966 per year. The total estimated implementation cost of the identified measures is $138,173 with a simple payback of 2.3 years.
All floors except the 6th are cooled by a 60-ton McQuay packaged self-contained water-cooled air conditioning unit. Each of these five units has four scroll compressors in four stages to provide direct expansion cooling for the unit. The 6th floor is cooled by a 90 ton McQuay air-cooled rooftop air conditioning unit
Five of the units are water cooled via two 400-ton Marley cooling towers. Condenser water from all five of these units is pumped constantly to the cooling tower by one of the two 50 HP condenser water pumps, each of which have new VFDs
The heating and ventilation for each floor is provided through a variable air volume (VAV) air distribution system served by the five air-handling units (AHU) and single rooftop unit for the 6th 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. All heating for the facility is provided through the hot water reheat coils installed within the perimeter terminal boxes. Hot water for the heating VAVs is provided by two Rite cast iron boilers,
The Building is equipped with a Building Automation System (BAS) with custom built graphics. This system allows you to set schedules, program equipment and control set points for temperatures and starting and stopping equipment. Additionally, extensive energy use monitoring of the buss duct taps allows the engineer to monitor and reduce electric demand throughout the day. All major equipment in the building is controlled with start/stop/status and temperature set points for AHUs, pumps, and terminal boxes.