Retro-Commissioning Success in Healthcare

Based in Owatonna, Minnesota, a two-story, 112,977-square-foot outpatient medical facility serves as a crucial part of a large health system’s regional operation. The building serves a wide range of services, including orthopedics, family medicine, pediatrics, dialysis, and MRI imaging. With operations in such a sensitive healthcare environment, energy efficiency projects must carefully balance patient comfort, regulatory compliance, and operational continuity.

Recognizing opportunities to improve performance and reduce energy costs, the clinic hired Michaels Energy to conduct a retro-commissioning (RCx) study in coordination with Owatonna Public Utilities and Southern Minnesota Municipal Power Agency (SMMPA).

The Challenge

Leadership required a trusted expert to identify improvements that could be implemented without compromising clinical operations. Michaels Energy worked to uncover low-cost, high-impact energy conservation measures that could be integrated with existing building automation systems in place. The Owatonna Public Utilities RCx Program funded the initial assessment, with reimbursement contingent on implementation of the low-cost recommendations.

Solutions Implemented

Michaels Energy conducted a comprehensive RCx study and follow-up functional performance testing (FPT). The team identified several Energy Management Improvements (EMIs) that could be implemented at low cost for immediate benefit. The customer implemented the following measures:

• Adjust Space Temperature Set Points in Unoccupied Mode: Reduced heating and cooling loads during unoccupied periods, while still maintaining the required minimum airflows. This saves thermal energy, reducing energy lost or gained through the building envelope.
• Optimize Rooftop Unit (RTU) Schedules: Created schedules for RTU HVAC to operate only in occupied mode and added an optimal start/stop sequence. This change results in less ventilation air in unoccupied spaces, less heat gain/loss through the building envelope, and less fan energy consumed.
• Widen Occupied Temperature Set Points: Programmed a 4°F dead band to reduced cycling between heating and cooling. Introducing a wider dead band causes units to enter cooling mode less often, reducing air volume and saving fan energy.
• Hot Water Reset Strategy: Reprogrammed hot water system to respond to heating demand rather than solely to outdoor temperature, reducing the amount of thermal energy lost through the piping system into areas where it is not necessary.

These measures required collaboration between Michaels engineers, the health system’s facility staff, and vendors. Functional performance testing ensured that systems were operating as intended post-implementation, and corrections were made where needed.

Results

The implemented RCx measures produced exceptional outcomes, including:

• Annual cost savings exceeding $40,000.
• Energy savings of over 312,000 kWh and 24,000 Therms annually.
• Operational efficiency improvements across multiple HVAC systems.

The clinic’s drop in gas usage was so substantial that their utility flagged the account for a potential metering issue, which upon verification was attributed to the successful RCx measures. The most impactful upgrades included optimizing the RTU schedules (estimated $20,662 in annual savings) and widening temperature set points ($14,330 annually).