Princeton University – Steam to Hot Water Conversion Group 3

To achieve carbon neutrality by 2046, Princeton University will convert all building heating systems from steam to hot water heating, using geo-exchange technology to maximize efficiency. The massive, phased conversion project will reduce total energy consumption, life-cycle costs, and carbon emissions. Buildings require unique conversion plans and are grouped to facilitate ease of conversions.

Princeton engaged Precis for the conversion of Schultz and Moffett Laboratory buildings and the Scully Hall dormitory. The scope involved sizing and specification of systems required to convert existing steam heating and humidification systems to work with new campus low-temperature hot water (LTHW) distribution.

Precis worked with Princeton’s construction management partner under a design-build contract to generate conceptual designs, architectural renderings, a shadow analysis, and cost estimates for various rooftop and mechanical penthouse air-handling and heat-transfer system configurations and options to accommodate construction phasing, energy metering, future system expansion, redundancy, architectural screening of rooftop equipment, and maintenance access requirements. Precis evaluated and performed energy studies and payback analysis on nearly 30 different combinations of equipment upgrade and relocation options to support Princeton’s informed decision-making for this project and future conversions.

Expected to be over five times more efficient, the new system includes heat exchangers for LTHW and domestic hot water along with associated pumps, coil replacements, valence unit replacements, piping distribution, controls, and modifications to existing steam systems. The scope in the Schultz and Moffett Laboratory buildings was coordinated with several other ongoing projects, including enabling work for the new Schmidt Hall and a separate Moffett HVAC upgrade to conceal piping within new exterior building chases. In Scully Hall, the Precis conversion design completely eliminated the need for campus steam and provided improved occupant temperature control and performance monitoring, including window switches that turn off systems when dorm windows are open.