NREL – Solar Energy Research Facility (SERF) – Chiller Replacement

The Solar Energy Research Facility (SERF) at National Renewable Energy Laboratory (NREL) serves as a state-of-the-art laboratory building for photovoltaics research. 360 Engineering has led architectural and engineering design teams on over fifteen projects at SERF for various upgrades and modifications.


This project’s mechanical scope of work involved replacing the three failing chillers with two new energy-efficient chillers. These variable speed chillers utilize an internal free-cooling sequence, delivering a high leaving water temperature to provide more tonnage in the same footprint as other systems, plus the intelligently controlled free-cooling bypass valves reduce pump energy when free-cooling is not beneficial. The upfront cost is more, but there is long-term value in efficiency due to the chiller’s ability to move from mechanical to hybrid to free-cooling modes automatically, further minimizing energy use.


Our engineers walked NREL through the decision-making process, outlining the different options and pros and cons of each one, so they could make an informed decision. We also coordinated with the electrical engineering consultant, AE Design, to ensure proper electrical power connections were in place for the new equipment. An upgraded refrigerant monitoring and mechanical exhaust system was required to provide safe operation of the equipment and to meet NREL Safety Guidelines. We coordinated with the structural engineering consultant, Martin/Martin, to place the equipment on the busy roof and provide new openings as needed for the exhaust and makeup air system.

For Construction Administration, we attended the pre-bid walkthrough, OAC meetings, performed site observations with reports, and provided a final punch report. Also, a 360 Engineering Commissioning Agent, who was not involved with the design, provided additional reviews of system verification checklists, functional performance test results, commissioning logs, and site observations for pre-functional installation, equipment start-up, and functional performance testing.



Golden, CO




In Progress/Recently Completed