Dive Brief:
- Just in time for its eponymous day, St. Patrick’s Cathedral has been updated with a 10-well geothermal heating and cooling system to update the New York City landmark with 21st Century building technology, according to Building Design + Construction.
- Wells drilled down to 2,200 feet will regulate temps via a "Dedicated Heat Recovery Chiller," and can heat and cool different portions of the 76,000 square foot building simultaneously.
- Started in June 2015, the geothermal plant came online in February 2017 and is capable of 2.9 million BTUs of AC and 3.2 million BTUs of heat per hour when running at full capacity.
Dive Insight:
Opened in 1879, the century-plus old St. Patrick’s is one of New York City's oldest surviving buildings and historical landmarks — meaning construction of the geothermal system required special attention to the preservation of its historical details. Similar MEP upgrades across the country are seeing contractor teams leverage laser scanners and total stations for incredibly accurate as-built point clouds to insure maximum preservation of historic facades and building systems.
The geothermal plant is designed to achieve efficient temperature regulation while reducing CO2 emissions, and is an add-on to the $177 million modernization of St. Patrick’s completed in 2015 in advance of a papal visit. That renovation included glass-blasting the building’s four different types of primary marble and replacing cement joint seals used to patch cracks in the 1970s, as well as the installation of a fire suppression system. Due to its softness, cleaning and restoring marble remains a challenge in historic renovation, leading researchers at the Department of Civil and Environmental Engineering at Princeton University to recently propose a hydroxyapatite clear coat — using the same calcium base found in human teeth and bones — to protect the material from environmental decay.
