Heating Water System

BKM provided prime MEP services for conversion of the Washington National Cathedral (WNC) campus steam heating system and underground piping to a new heating water system. The project scope encompassed over 50 acres of campus ground and connections to eleven (11) separate heating water control piping loops, including the 83,000 square foot main Cathedral.

The project consisted of conversion of the existing garage space into a new boiler plant serving three separate buildings on campus, with provisions for future expansion. Four new 3,000 MBH (nominal) gas-fired condensing heating water boilers were installed to serve the Cathedral and associated buildings. A full boiler plant was created to support the heating system, along with three 20-horsepower pumps for heating water distribution. Extensive piping routing was installed in the sub-crypts below the main Cathedral. Design for this routing was done to accommodate the confined space conditions, with provisions to support project constructability. Connections to eleven (11) heat exchangers and seasonal crossover valves were made within the Cathedral sub-crypt, as well as a replacement of an existing ventilation air handling unit. Piping from the new boiler plant to the connected buildings was accomplished via double-wall insulated underground piping. Detailed coordination was provided as well with Washington Gas to install the necessary natural gas connections for the boiler plant.

The design team participated in extensive coordination with WNC historic preservation council to maintain the aesthetic and grandeur of the cathedral. This included coordination of the new boiler plant gas flues and addition of a 3-foot access door within the historic façade of existing Church House garage door.