Overcoming the Market Barriers for RTU Retrofit Enhancements

fixing an RTU

Update: July 2023

In June, the project team hosted a webinar on key findings. They found that RTUs are typically only replaced when they fail, forcing contractors and building decision makers to act quickly to replace. Without adequate information and straightforward rebate incentives, decision makers often choose standard efficiency equipment on unit failure, missing out on retrofit opportunities on existing RTUs. The team determined that contractor and customer engagement and education, prescriptive rebates, and continuing to modify TRM measures can strategically address and overcome the market barriers to RTU retrofits. 

Update: January 2023

The project’s approach pairs market study interviews with short-term field demonstrations to test and compare specific RTU enhancements. The market study component revealed that a major obstacle to RTU retrofitting projects is a lack of education and awareness on the now much wider array of technology available. The project team will use results from the field studies to generate a one-page summary of findings as a helpful reference guide for key stakeholders to increase adoption. The project timeline has been extended and is projected for completion and a final report in 2023.


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.

Project Summary


This project will develop strategies to overcome the market barriers to energy efficiency improvement of existing RTUs by identifying and analyzing market barriers, then suggesting strategies to overcome them.


  • Task 1: Technology assessment
  • Task 2: Utility program assessment
  • Task 3: Local and regional interviews
  • Task 4: Field evaluation
  • Task 5: Data collection
  • Task 6: Energy savings calculations
  • Task 7: Decision support tool creation
  • Task 8: Dissemination of findings

Non-energy benefits

  • Improved occupant comfort
  • Improved indoor air quality