Pump it Up! Accelerating Advanced RTU Adoption in Commercial Buildings

Space conditioning accounts for 40% of United States commercial building energy use (EIA 2023). Next generation rooftop units (RTUs) can increase energy efficiency in buildings and lower energy bills by up to 50% compared to conventional RTUs (PNNL 2013). Recent case study participants reported site energy savings of 17%-70%. However, heating performance of most commercially available and installed RTUs has not improved since 2011, and heat pump and dual fuel RTU technology has low adoption in commercial buildings. As part of the U.S. Department of Energy's Better Buildings & Better Plants Initiative, the Commercial Building HVAC Accelerator (Accelerator) aims to increase adoption of advanced RTUs in commercial buildings through a Campaign to address market barriers. The Accelerator also initiated a Challenge to develop next-generation RTUs with superior performance. This paper discusses the status of these efforts, including updates on 12 prototype nextgeneration RTUs installed for validation in real buildings, and common barriers and takeaways from 9 case studies on advanced RTUs that are commercially available. Adopters faced common barriers to installation that included equipment lead times, permitting delays, and contractor inexperience with both dual fuel and all-electric systems. The paper highlights successful strategies used to overcome these barriers-such as proactive planning, clear communication, and team continuity-and shares lessons learned from the case studies. It will also explore how these findings are shaping future retrofit strategies and building momentum toward a more resilient building stock with lower operating costs.