Engineers Week: GZA helps with first state-owned zero net energy building
The architect and GZA GeoEnvironmental, Inc.'s client for the project was DiMella Shaffer Architects (DSA) of Boston. The Commonwealth of Massachusetts, Division of Capital Asset Management (DCAM), was the end client that managed the design and construction of the building on behalf of the college.
GZA guided other members of the project team through the geothermal design and construction. GZA provided comprehensive geothermal services in five distinct phases of work: geothermal feasibility study, geothermal test well installation and testing, geothermal design, geothermal construction observation and geothermal loop water quality improvements.
A large portion of GZA's initial work was to educate the team on the various geothermal options and recommend the type of geothermal well to be used, based on an evaluation of the risks inherent in both closed-loop and standing-column systems and the estimated costs. The end result was that geothermal was determined to be a major and essential component of the project's zero net energy goal and energy efficiency strategy to reduce the college's dependence on fossil fuels.
A highly efficient geothermal heat pump system was selected to heat and cool the building. This proven technology, which uses the steady 55-degree temperature of the earth as a primary heating or cooling source instead of fossil fuels, has been successfully employed for over 40 years and is becoming a standard consideration for heating and cooling in most new and renovated building construction.
The design team initially considered utilizing a hybrid system where a more conventional fossil fuel boiler/cooling tower would augment the geothermal system during peak load conditions. By increasing the number of geothermal wells by 15 percent, the geothermal system could provide 100 percent of the building's heating and cooling loads and thereby eliminate the need for reliance on fossil fuels (with the exception of emergency back-up).
GZA observed the construction of the well-field on a full-time basis to confirm construction adhered to the design plans and project specifications. Services included review of the contractor's geothermal submittals; observation of the drilling and grouting of individual boreholes, well construction, header and manifold piping, and pressure testing.