Bowen Science Building Retro-Commissioning Study

The Bowen Science building, a mixed use teaching and research facility, underwent construction of numerous renovation projects over the years that have failed to holistically evaluate their effects on the overall building HVAC system. Consequently, the building experienced significantly higher-than-benchmarked utility usage and poor ventilation control. This nearly 400,000 square foot lab building was the biggest energy user on the University of Iowa campus. The university initiated a retro-commissioning project to define problems and recommend solutions that focused on improving pressure control in the building, improving occupant comfort, decreasing maintenance effort, and reducing energy usage.

NV5 conducted a study including benchmarking energy usage, understanding existing systems, functional performance testing of existing systems, energy modeling, defining energy savings opportunities, and quantifying potential savings. Systems involved were HVAC, chilled water, and lighting. The team identified multiple energy savings opportunities that together represented potential savings of more than 35% of the total energy usage, with an average payback of approximately 2 years. Following the study, NV5 was engaged to upgrade the variable air volume (VAV) boxes, adding ventilation control to building corridors and atriums.

The university then engaged NV5 to develop a planning study with concrete actions and financial information based on our retro-commissioning recommendations. As they implemented this plan, NV5 served as the commissioning agent. Our team performed a baseline survey of the entire building and identified a significant list of flaws and problem areas that were integrated into the design documents. During the process of inspecting the building, the NV5 team simultaneously corrected the discovered problems, saving the University over $100,000 immediately in unanticipated annual energy costs.

The completed project is expected to reduce the building’s energy use by over 25%, in this, the most energy intense building on the University of Iowa campus.


Iowa City, IA


University of Iowa



Key Facts

  • 375,000 SF
  • $440,000 VAV