The project is an existing office complex, consisting of two adjacent buildings in Reston, Virginia totaling about 288,000 ft². The two buildings were certified as one project under LEED v3 for Core & Shell. All HVAC systems were replaced as part of the major renovation.
Baumann Consulting was assigned to carry out the energy modeling as well as fundamental and enhanced Commissioning.
During testing the following issues were discovered and corrected:
- Various readings did not match the value shown by the building automation system (room temperature, static duct pressure, etc.), leading to thermal comfort issues
- Non-functioning electric heating coils on fan-powered VAV Boxes
- VAV Box Night Set-Back was not functioning, leading to increased energy consumption
- Air damper did not modulate to control space temperature, leading to thermal comfort issues
- Demand control ventilation not operable due to insufficient airflow from outdoor air fans
JBG Summit achieved 6% energy cost savings compared to ASHRAE 90.1-2007 Appendix G. The design case incorporated the following Energy Efficiency Measures (EEMs) that were considered in the energy modeling:
- Free Cooling by the Cooling Tower
- Increased setpoints of cooling coils
- High-efficiency pumps