Conversion of 2 Dormitory HVAC Systems from Two-Pipe to Four Pipe Systems


Marymount University | Berg Hall & Rowley Hall

Arlington, VA

Berg Hall and Rowley Hall are both dormitory buildings located at Marymount University in Arlington, VA.  The existing dorm rooms in each building were served by fan coil units supplied by a two-pipe heating and cooling system.  The scope of the project was to replace the existing fan coil units, greater than 270 individual units, and upgrade the existing two-pipe system to a four-pipe system in each building.  Work in Berg Hall also included replacement of the existing air-cooled chiller with two new 35 ton water-cooled heat recovery chillers, and the addition of a dry cooler.  The existing boilers were also replaced with a new 600 MBH boiler, and new pumps were provided for the heating system as well as the cooling system.   

SSM performed a detailed field survey of each building.  The existing fan coil units were located in extremely tight spaces above the ceiling.  Converting the system from a two-pipe system to a four-pipe system required detailed coordination with existing architecture and other utilities. 

This project was more complex due to the expedited design and construction schedule.  SSM conducted the field survey over the Winter break while students were not on campus, and then quickly completed the design to meet the aggressive permit submission deadline.  During the construction phase, SSM worked closely with the owner and the contractor to facilitate completion of the project.