Since February 2008, the Desmond Tutu Center and the Kohne and Dodge dormitories have been heated and cooled by the Seminary's cutting edge, Earth- friendly geothermal system. The system is an important step in the Seminary's goal of a carbon-free, green Close and stands witness to the Episcopal Church's longstanding concern for environmental stewardship.
Geothermal: How it works
Geothermal heating and cooling systems use the steady temperature found below ground as a source for heat transfer. These systems are nonpolluting, practically hydrocarbon free and need little maintenance. When fully operational, the GTS Geothermal System will eliminate the 1,400 tons of hydrocarbon that were emitted annually by the Seminary's boiler while providing a modern, efficient heating/cooling/hot water system for the Seminary's buildings.
With a steady temperature of 55°F, the water found deep below Manhattan's granite base is an excellent source for a geothermal system. Using this naturally occurring source, the Seminary's new system uses standing column wells drilled into the sidewalks surrounding the Seminary Close. Steel casing runs from the ground surface to the Manhattan bedrock where an unlined bore hole will descend further to a depth of 1,500 fee—a distance roughly equal to the height of the Empire State Building. Water is pumped from the wells into a basement room containing heat pumps.
Using heat transfer technology similar to that found in air conditioning units, the pumps transfer heat into rooms that need to be warmed or from rooms that need to be cooled. After running through the Seminary's heating/cooling system, the water returns down the wells, where heat transfer will equalize the temperature of the returning water to the groundwater constant of 55°F.
In addition to replacing the heating that was provided by the Seminary's boiler, the new GTS Geothermal System is designed to provide 850 tons of cooling for 260,000 square feet of buildings on the Close, a first for the Gothic Revival buildings that previously had to make do with inefficient and ungainly window air conditioning units. The geothermal system has no need for cooling towers, yet another way the system helps preserve the beauty and architectural integrity of the Seminary's historic buildings.
When fully operational, the system will be the largest heating/cooling system of its kind in New York City, a trailblazing effort that will encourage future retrofitting efforts. The system is an efficient, economically sensible way for the Seminary to do its part in the struggle against global warming.