As part of the effort to adapt St Patrick’s Cathedral in New York to the structural and environmental standards required of the 21st century, the building has been integrated with a state-of-the-art geothermal plant. The new plant allows the cathedral and adjoining buildings to regulate temperature with increased efficiency and a reduction in CO2 emissions.
In order to accomplish this task, the project’s design team - featuring Murphy, Burnham, & Buttrick, Landmark Facilities Group, and PW Grosser - repurposed the existing infrastructure to harness clean, renewable power from an underground system of 10 wells. Four wells on 51st Street and six wells on 50th Street were drilled to a depth of up to 2,200 feet.
A Dedicated Heat Recovery Chiller extracts thermal energy from the wells and distributes it throughout the campus for heating and cooling purposes. Working in conjunction with the Dedicated Heat Recovery Chiller to accomplish this task is a column hybrid open loop system made up of heat exchangers, air handlers, and fan coils. This system extracts and redirects heat throughout the 76,000-sf building.
St Patrick’s Cathedral’s geothermal plant differs from most in that it is designed to automatically split its cooling and warming functions in order to simultaneously heat or cool the varied areas it services. Most geothermal plants alternate between their warming and chilling functions. The Cathedral’s new plant is capable of generating 2.9 million BTU’s per hour of air conditioning and 3.2 million BTU’s per hour of heating when fully activated.
An additional challenge faced when installing the system was maintaining the standards set for the historic preservation of one of New York’s oldest landmarks. “At the outset, we evaluated a conventional HVAC system, but determined it would pose too many challenges for this historic building,” says Richard A. Sileo, Senior Engineer with Landmark Facilities Group, in a release. “We conducted a feasibility study and found that a geothermal system let us meet our goals with the smallest impact.”
Initial drilling of the wells began in June 2015 and the plant was finalized and ready to launch by February 2017.