Memorial Health System (MHS) chose Hanson to provide retro-commissioning services for its 97,800-square-foot Koke Mill Medical Center in Springfield, Illinois. The facility, which contains medical offices, outpatient surgery areas, physical therapy, a small pharmacy and an Express Care center, was built in 1998.
The project scope encompassed a comprehensive building evaluation, including heating, ventilating and air-conditioning (HVAC) equipment, air handlers and exhaust, the building automation system, lighting and scheduling. The study was funded through the local electric utility company’s retro-commissioning incentive program, which focuses on low- and no-cost measures with a payback of less than two years.
Hanson used a formal, four-phase retro-commissioning methodology that included planning, investigation, implementation and verification/hand-off. The methodology complied with the requirements of the local electric utility company while furnishing MHS with savings opportunities from electric, natural gas, water and sewer providers.
The retro-commissioning study identified nine energy conservation measures (ECMs) that resulted in a 24.1% decrease in annual utility costs. Highlights of the ECMs included a reduction in HVAC equipment operating hours, the implementation of demand control ventilation, building pressurization sensors and variable-frequency drives on exhaust fans, selective lamp replacement, lighting controls and a partial air rebalance of the building’s HVAC systems. The payback on individual ECMs ranged from 0.3 to 7.8 years, with a total average payback of 1.8 years for all ECMs.
The calculated savings were significant, given that the facility had been constructed with higher-efficiency T-8 lighting, eliminating one of the traditional energy conservation measures. The ECMs that were identified also considered the comfort level of patients and staff using the facility. Hanson’s retro-commissioning efforts combined the owner’s requirements with energy savings opportunities, resulting in significant savings in utility expenditures.