Overcoming the Market Barriers for RTU Retrofit Enhancements

Approximately 80% of commercial buildings in Minnesota are served by rooftop units (RTUs) for HVAC. Retrofit packages and technologies are viable options for existing standard efficiency RTUs and offer a great opportunity for energy savings, as RTUs serve many different building categories and space types — however, retrofits continue to be uncommon. Since RTUs are typically used for more than 20 years prior to replacement on failure, increased retrofits have much larger potential to impact Minnesota’s 1.5% energy savings goal than do replacements. The project will establish the statewide energy savings and carbon reduction potential of proven RTU retrofits. These include controls, variable-frequency drives, high-efficiency motors, improved economizer controls, demand control ventilation, dynamic zone balancing, and automated fault detection and diagnostics. The project will define the barriers that have kept these products from significant market penetration and develop strategies to overcome those barriers based on the features and cost-effectiveness of specific enhancements. The findings, along with stakeholder feedback, will inform utility program approaches.