Comprehensive Energy Efficiency Treatment
Designated "Energy project of the year" by the Association of Energy Engineers.
EF Education First, a company that provides educational travel and cultural exchange programs throughout the world, was experiencing out of control energy costs at its 200,000 sq. ft. headquarters building at One Education Street, Cambridge MA (across from the Museum of Science). EF was also having difficulty maintaining comfort levels in the relatively new (eight year old) building, and the problem was getting worse as EF’s business was expanding and employee levels were increasing.
The existing systems consisted of air handling units (AHUs) on each floor equipped with direct expansion (DX) cooling coils and compressors that reject heat to a condenser water loop/cooling tower system. The OpTerra upgrade consisted of converting the DX cooling to central plant chilled water cooling by changing out the AHU DX coils to chilled water coils, converting the condenser loop piping to chilled water piping and adding two (2) efficient variable frequency drive 300 ton centrifugal chillers to the system. Other changes included the installation of Electronically Commutated Motors (ECM motors) in place of the inefficient fractional horsepower motors in the 250 fan-powered boxes throughout the building, Building Automation System (BAS) upgrades, and variable frequency drive installations on pumps and fans. Ventilation air was controlled through the use of a building wide CO2 monitoring system and the addition of restaurant hood controls that reduced exhaust and makeup air during periods when the grills and ovens weren’t being used. With the new HVAC systems and free cooling controls, for the first time in the life of the building, space temperature was maintained in the comfort zone without mechanical cooling.
OpTerra qualified the projects for $600,000 of NSTAR incentives and completed the installation of the system improvements. In addition to significantly reducing energy consumption, the system upgrades also solved a number of comfort and operational issues – systems were balanced, appropriate ventilation was provided to each space and hot spots/cold spots were eliminated.
The environment was also served by the upgrade as the energy savings provided a significant reduction in pollutants – both at the building from reduced gas use and area wide from the reduced electricity production at the power plants serving the electricity grid.