To assist in the design of a new Addition at the University of Pittsburgh, a close examination of the mechanical exhaust and intake systems was undertaken to help avoid undesirable re-entrainment issues and assist in establishing acceptable turn-down operating conditions for energy savings.
Novus worked closely with Renaissance 3 Architects and Wilson Architects providing consultation and detailed evaluations to assist in identifying and mitigating potential exhaust re-entrainment issues. The assessment involved:
- Initial design guidance and on-site consultation;
- Local site conditions and meteorological review;
- Numerical and Computational Fluid Dynamics (CFD) modelling; and,
- Detailed wind tunnel tracer gas testing of problematic emission sources.
Through an initial on-site consultation and review of early architectural and mechanical design drawings, Novus highlighted positive features of the designs as well as identified exhaust sources (both on-site and off-site) that could be potentially problematic. Numerical modelling and CFD simulations were performed to gain a more in-depth understanding of expected wind flow patterns around the building accounting for local site conditions and meteorology. This also provided a first-level estimate of exhaust dispersion and re-entrainment quantities and air-sensitive locations of the building. Detailed wind tunnel tracer gas tests were undertaken to finalize design recommendations for exhaust stack and fresh air intake configurations. The assessment provided detailed guidance to the design team regarding stack location and stack height, as well as minimum exhaust flow rates and exit velocities for maximizing energy savings during turn-down conditions.