Design and Feasibility Assessment of a Sewage Heat Exchange System for Smith College

Salas O’Brien Team: Lanzhao Cheng, Emma Lesser, Rose Sears, Lesly Kemboi

2021-2022: In collaboration with Salas O’Brien, this student team designed and assessed a sewage heat exchange system for Smith College. Smith is pursuing ground source geothermal heat exchange to meet the campus heating and cooling loads as part of its District Energy Master Plan. Implementing sewage heat exchange (SHX) could potentially reduce the number of geothermal wells needed to support the thermal loads. The goal of this project was to assess the technical and economic feasibility of a SHX system for Smith.

The team reviewed SHX technology and case studies, investigated site options and thermal data from Smith, and determined key requirements. The team determined a location, selected a SHX manufacturer, and developed two SHX designs: in-line and sidestream. Using load coverage and life cycle cost calculations, the team analyzed both designs and demonstrated that the in-line design would be economically feasible. The team delivered their schematic CAD drawings, system flow diagrams, and feasibility analyses to their liaisons to inform further planning.