U.S. Engineering Construction, LLC (USEC) partnered with Adolfson and Peterson Construction and Colorado State University (CSU) on a design-build project: the campus’s largest Geo-Exchange (GeoX) system. The system serves the heating and cooling needs of the Moby Arena Complex. Reducing the carbon footprint of the nearly 400,000 SF athletic complex was critical to reaching CSU’s goals of achieving carbon neutrality by 2040 and moving to 100 percent renewable electricity by 2030.

CSU’s new GeoX system is currently the largest ground-source heating and cooling system in Colorado and one of the largest in the western United States. It is an on-site renewable energy system that utilizes a large closed loop well field to provide cooling  and heating for up to five buildings in the Moby athletic complex. In this video, CSU and USEC team members talk about the complexity of the project and the sustainable payoffs. Read more about the project below.

For the Moby Complex project, USEC installed the GeoX system in tandem with five, six-pipe heat pumps and two new central plants that include the heat pumps, geothermal pumps, heating and chilled water (CHW) distribution pumps. We reused or replaced select heating and chilled distribution piping and some heating water and CHW coils; we also added new piping as needed. The completed project has 70 miles of u-shaped condenser water piping and 342 wells that are each 400-feet deep.

Results

With the new GeoX system, CSU retired the steam system from not only the Moby Complex, but also this entire side of campus. Total energy usage in 2021 has been reduced in this five-building complex by 56 percent on average compared to 2018 and 2019.  A large portion of this savings can be attributed to the mechanical system upgrade. As a result, CSU has decreased their energy costs by 28 percent.

A Complex Process

In the past, Moby Arena relied on heating from a steam system that was built in 1960. It had significant leaks and returned minimal condensate back to the central plant. This system was carbon-intensive, and heating capacity was needed elsewhere to support an aggressive expansion program on campus. 

CSU aspired to disconnect the campus steam system from the sports complex completely. As the design-build mechanical contractor, we chose the entire design team – mechanical engineer, electrical engineer, structural engineer, geothermal engineer and architect. Our approach allowed us to work directly with the design team from the beginning. This early involvement enabled us to steer the design, lending our construction expertise throughout the process.

Keeping the budget top of mind, we reduced the number of costly, time-consuming changes. Additionally, our field crews had access to the site from the beginning, providing them with the opportunity to thoroughly investigate the site and offer valuable insights that could be immediately incorporated into the design. As the top research institution in the country for sustainability, named by the Association for the Advancement of Sustainability in Higher Ed (AASHE), CSU is already known for its academic and research efforts. But its commitment extends beyond the classroom. Our work together is an exciting example of how our industry is innovating alongside our customers and partners to design and more sustainable practices.