The $30M project will supply energy to 15 campus buildings and the campus chilled-water system, which serves much of the university. Initially, the system is projected to save more than $1 million in energy and operational costs annually, and is expected to grow to $2.8 million annually in future years. The system will include approximately 600 geothermal wells with pipes creating closed geothermal loops serving the three campus geothermal plants. Each of the three plants will contain heat pump chillers, supplemental cooling towers and gas-fired boilers to provide geothermal energy to surrounding areas of campus.
System selection: The first challenge faced by McClure Engineering was choosing the type of system to best suit the campus’ heating and cooling needs, as well as their desire for energy efficiency, minimal carbon footprint, and reduced energy costs. To find the best solution, McClure created an hour-by-hour energy model of the campus and modeled various options. The model was compared to metered data to verify its accuracy.
Existing systems: The project includes removing the old steam system and connecting 15 campus buildings to one central heating system. The challenge was the conversion of all of the existing buildings to the new heating system (a low temperature, 120 degree system) as they were originally designed with other operating parameters. Because each building is unique, McClure examined them individually (on paper and on site) to determine the optimal ways to make the systems all work together.
Construction coordination: McClure is currently facing the ongoing challenge of phasing the construction of the entire project which includes work in existing buildings, construction of new heating/cooling plants, and miles of geothermal piping. Complications include coordinating the work of several subcontractors, minimizing the disruptions to the campus and building occupants, weather delays, and keeping as much of the campus with heating and cooling as possible while installations are completed.
System selection: To find the best solution, McClure created an hour-by-hour energy model of the campus and modeled various options. The ground source heat pump system was chosen for its ability to store rejected heat in the ground during the summer and use that heat for building heating during the winter. A unique feature of this design was the decision to utilize a hybrid system (with gas-fired boilers and existing electric chillers to shave the peak loads), which greatly reduced the number of wells required, enabled the project to fit within the University’s budget, and provided redundancy in both the heating and cooling systems.
Existing systems: In many cases, the best solution was to replace equipment in the buildings to work with the new, low temperature heating system. This allowed the design to maintain high water temperature differentials, thus keeping flows and pump horsepower to a minimum in the buildings and plants.
Construction coordination: McClure works closely with the Construction Manager (JE Dunn), the scheduler (CCS Group), and the school (Missouri University of Science & Technology) to keep the project on schedule and the occupants comfortable through constant communication with all parties. The project team is utilizing a variety of project management tools (including iPads) to facilitate collaboration, effectiveness, and efficiency.
At Washington University in St. Louis’ Danforth Campus, planned campus growth and desire to maintain redundancy necessitated increasing the substation from 28 MVA (14 MVA firm) to 42 MVA (28 MVA firm). For additional reliability a third feeder from AmerenUE was negotiated to be mostly underground and an independent route from the existing two overhead AmerenUE feeders. The project required designing detailed phasing to keep the campus operational during construction. This project was one of a series of projects McClure designed as part of a $10M investment at the campus to increase electrical capacity, reliability, and maintainability.
This project was the culmination of 10 years of campus infrastructure work to join the operation and control of seven separate chilled water plants (full load cooling capacity of 21,000 tons). The work included replacing the building automation system on more than half of the seven separate chilled water plants, designing programming logic to facilitate optimized control, and making piping and pumping modifications to improve redundancy and decrease energy usage.
We also provided mechanical and electrical systems commissioning of the campus chilled water system. As part of this work, our technicians worked closely with the installing contractor to prepare and configure all customized programming for each of the chilled water plants (21 chillers). Additionally, our technicians worked with the facility staff to repair and replace existing components that had failed or fallen out of calibration, in order to ensure project success.