BBA was hired to document and evaluate the heating, ventilation and electrical systems serving the Bryn Athyn Cathedral complex, which is located within a National Historic Landmark District. As a result of the study, facility improvement goals were established to replace aging equipment, reduce annual operating expenses, provide air conditioning, become more sustainable, and respect the integrity of the original architecture.
Based on these goals and BBA’s recommendations, a ground coupled heat pump system was selected for its comparatively low annual operating cost and 40-year life cycle cost. Other advantages were that it had the smallest carbon footprint, least visual impact on the site and the cathedral, and lowest mechanical equipment and piping space requirement.
Consisting of 80 wells spaced on a 20-foot square grid at a depth of 400 to 500 feet, the system circulates condenser water underground and into individual water source heat pumps throughout the facility. Piping loops are grouted into each well and headered together, using the constant temperature of the earth as a more efficient exchange medium than outside air to maintain condenser water temperature between 45 and 75 degrees Fahrenheit.