University of Albany Geothermal Ground Loop
A geothermal ground loop for a new 500-bed, multistory dormitory for the University at Albany, Albany, New York, was constructed in 2010. The dormitory was approximately 184,500 square feet with an estimated peak heating and cooling load of 355 and 315 tons, respectively.
RESPEC provided construction observation for the geothermal ground loop and was represented on-site by Peter Smith, staff geologist. He was responsible for observing and documenting the performance of the geothermal contractor according to the design specifications, including drilling, looping, grouting, excavation, horizontal piping, and tie-ins to the building.
The drilling and geothermal construction were performed by American Auger and Ditching (AAD), Constantia, New York. The well field included the drilling of 150 boreholes, 450 feet deep, for a total of 67,500 feet of vertical bore. Thick overburden deposits beneath the site were deposited in Glacial Lake Albany. The typical stratigraphic sequence for the site included a surficial layer of sand underlain by varved silt and clay to a depth of approximately 92 feet below ground surface (bgs). Glacial till was present from 92 feet to 200 feet bgs. Glacial till was underlain by bedrock assigned to the Hudson River valley mélange, a sequence of sedimentary rocks composed of shale and greywacke (i.e., dark sandstone) fragments.
Three drilling rigs were used to complete the drilling. Overburden casings were installed to the top of the rock using mud rotary techniques. The bedrock was drilled with an air rotary. Each loop was installed with thermally enhanced grout and individually pressure tested. Circuits were constructed with 3-inch supply and return piping with 15 loops per circuit. Circuits were constructed in a step-up, step-down, and reverse return configuration. Each circuit was individually tested before burial and tied into a central vault. At completion, the system was purged, flushed, and pressure and flow tested with 20 percent ethanol added for freeze protection.
RESPEC worked under contract to Pathfinder Engineers and Architects LLP, a Women-Owned Business Enterprise located in Rochester, New York. The project architect was Paulus, Sokolowski, and Sartor from Warren, New Jersey. The University was the principal investigator for the project, with the Dormitory Authority of the State of New York acting as the University’s agent and providing construction management services.
4. Well Drilling, Resource Production, and Power Plant and Transmission Line Construction