Geothermal Wells at Phillips Exeter Academy
05.07.12 / Peter Reiss, AIA, LEED AP & James Meinecke, Assoc. AIA, LEED AP
How do you add cooling to an eighty year old building while decreasing dependence on fossil fuels?
And what if that building is on the National Register of Historic Places and has no space for traditional rooftop chiller units, even if they could be used in an aesthetically sensitive setting?
Add to that a need for similar conversions at two other equally historic buildings and a classroom building that houses 40 classrooms which must be available during the academic year and you will start to get a sense of the complications faced by the design team at the Phillips Exeter Academy’s (PEA) Phillips Hall Restoration.
In 2007, ARC was retained by PEA to study options for the renovation of the 40,000-square-foot historic Phillips Hall, which in addition to classrooms, hosts all weekly faculty gatherings and is the home of the school’s English and Modern Language departments.
ARC’s planning study explored options for upgrading the mechanical systems in Phillips Hall and three neighboring academic buildings. The study called for the installation of 49 wells in 2012 to provide heating and cooling for Phillips Hall and allows for the installation of 42 additional wells in 2015 to heat and cool the Academy building, the Mayer Art Center and the Lamont Art Gallery.
The closed-loop pump system, originating in and controlled from the mechanical room of the school’s Academy Building, will be heated in the winter (or cooled in the summer) by the earth’s temperature, which remains a constant 55 degrees Fahrenheit at depths of 10 feet or more. The geothermal system is expected to be as much as 30 percent more efficient in energy use than conventional heating and cooling and it will produce minimal air pollution, as no fossil fuels are burned in the process.
In addition to the geothermal wells, ARC’s renovation plan for Phillips Hall includes the creation of five new classrooms carved out of underutilized attic space, a new elevator, improved accessibility for all building users regardless of physical ability and installation of a new fire alarm and sprinkler system to fully protect the building. Careful integration of these new systems is essential to preserving the building’s historic character.
Those attending commencement this year may find it interesting that the lawn they will be sitting on, including about three feet of soil, will be completely removed after commencement. The 49 wells will be installed 400 feet deep into the ground, along with some innovative water catch-basin solutions to help manage the up to 16,000 gallons of water that may be tapped each day during the drilling. Completion of the well field will see all of this tied into the new Academy building mechanical space. This work will provide half of the final well field design and will be completed in time for the return of students in September.
The geothermal wells are only one segment of a plan carefully crafted by ARC and The Green Engineer (sustainability consultant) to integrate sustainable design principles into the project. ARC and The Green Engineer worked closely with Phillips Exeter Academy personnel to develop a set of goals that blended elements of the U.S. Green Building Council’s LEED (Leadership in Energy and Environmental Design) guidelines for schools as well as the National Institute of Building Sciences “Guiding Principles for Sustainable New Construction and Major Renovations” to fulfill PEA’s objectives for environmental stewardship. Sustainable features of the project include energy-efficient mechanical systems and lighting, as well as use of local, renewable materials.
Special thanks to our consultants: GZA, ALTUS Engineering, RFS