Level 3 Energy Audit

Architect of the Capitol HOR Office Building | Washington, DC



We recommended 28 ECM and O&M projects for the Rayburn House Office Building. The estimated cost to implement the recommended projects was $17.6 million with an associated savings of $2.4 million annually. 41% of the estimated construction cost, and 33% of the annual savings were attributed to the replacement of the pneumatic HVAC controls with Direct Digital Controls (DDC). This ECM included replacing the controls on 28 air handling units that contributed to a significant amount of cooling and reheating.

Rayburn is currently using three-way control valves on the air handling units and constant speed hot water pumps. A project was underway to replace the existing pumps and install new pumps with VFDs. We recommended replacing the existing, uninsulated three-way valves with two-way valves to repair leaks. This modification allowed the pumps to modulate system flow as the two-way valves closed, resulting in pumping savings and a payback of 1.2 years. Located at the most remote point in the system, one three-way valve would need to remain in place to prevent “starving” AHUs of water. One alternative to the two-way valve replacement included installing bypasses at the three-way valves. The closed bypass would allow the existing three-way valve to act as a two-way valve, and the proposed ECM savings would be augmented even further.

recommended ECMs & O&M
  • Lighting Upgrade all Fixtures - Subway
  • Fixture Retrofit - Bi-level & Occ Sensor - Stairwells
  • T8-32 Watt to T8-28 Watt with H.E. Ballast
  • T12 to T8 Lamp Conversion - Committee Rooms
  • Lighting Recircuiting with Occ. Sensors - Garages
  • Cove Lighting Upgrade - Pool
  • Walkway Lighting Upgrade - Courtyards
  • Dry Type Transformer Replacements
  • Air Locks at RAFs in Sub-Basement
  • Seal Duct Penetrations
  • Partial Pneumatic Control Replacement with DDC
  • Steam Piping Insulation Improvements
  • Constant Volume AHU Conversion to VAV
  • Steam Room Ventilation Improvements
  • Dual Duct Efficiency Improvements
  • VFDs on Hot Water Pumps
  • Pool Humidification Unit
  • Low Flow Shower Heads in Gym
  • Fountain Use Reductions
  • Lavatory and Sink Faucet Flow Reduction
  • Deduct Water Meters for Irrigation
  • Swimming Pool Recirculation
  • Water Harvesting for Fountains
  • Dual Flush Valve Installation
Recommended O&M
  • Steam Room and Sauna Use Scheduling
  • Water Use Survey
  • Occupant Sensor Installation
  • Cove Light Upgrade CFL to LED
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$2.4M annual savings

28 projects developed