Aetna Life Insurance Company


Hartford, CT

Project Scale

1,800,000 gsf

Effective. Efficient. Excellent.

As part of Aetna’s participation in the Connecticut Energy Efficiency Fund (CEEF) Retro-Commissioning Program, Colliers Project Leaders was retained to provide Aetna’s Home Office in Hartford, CT with a building survey, retro-commissioning investigation, implementation services, training, and measurement and verification for four buildings encompassing 1,800,000 square feet of office space.

  • The objectives of the retro-commissioning initiative included:
  • Improve overall energy consumption and operating performance
  • Improve the building's ENERGY STAR rating
  • Identify system operation, control and maintenance issues
  • Reduce occupant complaints and improve indoor environment
  • Develop persistence strategies to ensure improvements stand over time

As a result, we proposed the implementation of the following energy conservation measures:

  • Optimization of secondary CHW pumping station
  • Enhance tertiary CHW pumping station
  • Upgrade 8 large AHUs and add pressurization control for the Rogers Building
  • Improve controls for 7 snow melt systems
  • Improve controls & sequences for the steam boiler combustion air system
  • Add DDC seasonal "shut-off" control for existing heating PRVs
  • Enhance existing perimeter fan coil unit operation
  • Optimize 8 atrium building AHUs
  • Modify kitchen and dining area AHUs and correct air pressure imbalances
  • Add O2 control for existing steam boiler
  • Add VFDs to chilled water plant primary chilled water pumps