Partner Energy completed a retro-commissioning study for a 1.2 million SF building in River North Chicago for a leading institutional real estate owner. Partner Energy identified retro-commissioning measures that produced over $100,000 annually in energy savings, with a simple payback of less than 6 months. Measures included supply air temperature setpoint resets, reduced outside air flow during off hours, reduced supply air flow, reset supply air static duct pressure setpoint, chilled water temperature setpoint resets, condenser water setpoint resets, chiller variable flow sequencing, cooling tower fan sequencing, and reduction of off-hour operations of the air handlers.