No Need to Be So Hot and Cold: Chaska Targets HVAC System Upgrades


by Julia Eagles, Metro CERT Organizer, August 2012
Outside view of the City Hall in Chaska, Minnesota

Located in the Minnesota River valley just southwest of the Twin Cities, Chaska bills itself as “a quality small town.” As the city grows, it is committed to doing so responsibly to improve quality of life for its residents.

Following this commitment, the city took advantage of the 2009 American Recovery and Reinvestment Act’s Energy Efficiency Conservation Block Grant program as a way to make improvements in its public buildings without costing the city money.

Public Works Superintendent Tim Wiebe doesn’t have a lot of extra time for grant writing and management, given his duties of overseeing maintenance for the parks, streets, buildings and stormwater systems city-wide. “I’m a park and street guy, not a grant writer.” said Wiebe. “This is the first time I’d ever done a grant, and you have to do it regularly to be good at it.”

However, with the Chaska City Hall needing several upgrades, Weibe gave it his best shot and successfully secured a $100,000 grant through the MN Department of Commerce Division of Energy Resources, who administered the EECBG funding for local units of government throughout Minnesota.

The City Hall, a multi-use building that houses the administration offices, council chambers, finance, planning and engineering departments, the county library and the police department, had several opportunities for improvement. With the building’s old energy management system, it was challenging for staff to set up the temperature zones and schedules to make everyone happy. The building was also being heated with two boilers that were inefficient and designed to run alongside the air conditioner in the summer, causing unnecessary energy costs.

To address these issues, Weibe proposed two projects: first, to install a computerized energy management system that would allow building managers to program and adjust the comfort settings for different spaces; and second, to update the building’s boilers and heating, ventilation, and air conditioning (HVAC) system.

With the EECBG funding and utility rebates, the old boilers were replaced with 95% efficient units that run only when they are needed based on the temperature outdoors, saving city dollars spent on energy. As part of the HVAC upgrade, a variable air volume (VAV) system and a variable frequency drive (VFD) on the air handler were installed as well. The VAV system balances the amount of cold or hot air entering different rooms, helping to regulate temperatures. In addition, the VFD automatically lowers fan speeds when temperatures are milder, so the system isn’t working harder than needed. As a result of these improvements, the city of Chaska has seen a 15% reduction in electricity usage and a 50% reduction in natural gas usage per year, resulting in $11,631 saved on energy costs in 2012 compared to 2010.

After completing the proposed projects, Weibe is happy with the results. “We never had that flexibility to adjust the temperature like we do now,” he said. “We would just set the thermostat and that was it.” With the new system, comfort levels in the building can be easily adjusted to the satisfaction of occupants.

This project did raise a few challenges for the city, including a lack of staff capacity, and difficulty with managing the reporting requirements and paperwork amongst other duties. At the same time, the process gave Wiebe a crash course in HVAC operations, grant writing and management.

Plus, as a part of the EECBG requirements, Wiebe and other staff members began tracking the city’s energy use in public buildings with the State of Minnesota’s B3 Benchmarking software. Wiebe thinks this will be especially useful in the future: “When it comes time to talk with the City Council about doing other upgrades and retrofits,” he said, “we can use the B3 data as a tool to demonstrate the value of these projects.”

Despite some challenges, Weibe looks fondly upon the project. “At the end of the day, it was a positive project. I know we’re saving energy, we have a better HVAC system at City Hall, and it put people to work.”

Project Profile:

  • Location: City of Chaska, Carver County
  • Types of technology: HVAC; Energy Management System and Controls
  • Description of the project: The City of Chaska upgraded the Heating, Ventilation and Air Conditioning (HVAC) equipment and controls in their City Hall building.
  • Actual savings: Natural Gas 913,400 kBtu/year; Electricity 9,134 kWh/year; Costs $11,631/year
  • Total project cost: $160,000
  • Project funding: American Recovery and Reinvestment Act Energy Efficiency Conservation Block Grant program ($100,000); City funding ($60,000); Utility rebates
  • Organization contact information: Public Works Department, City of Chaska; Phone: 952-448-4335

Data calculations for this article were provided by the Minnesota Department of Commerce, Division of Energy Resources.

The Minnesota B3 Benchmarking tool is available for public buildings in Minnesota, including state, local government, and public school buildings. It provides the tools to manage your buildings, improve your building portfolio efficiently, and monitor the improvements. The B3 tool is provided by the Minnesota Department of Administration and the Minnesota Department of Commerce, with funding from all utilities in the state supporting the effort. To add your building to this benchmarking database, go to and click on “Contact Us.”

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