Built in 1967, Hillcrest High School is a comprehensive public high school with a student population of approximately 1,230 students in grades 9-12. Located at 17401 South Pulaski in Country Club Hills, Illinois, Hillcrest serves four communities: Country Club Hills, Hazel Crest, Markham, and Homewood. A typical school year spans from mid-August to the first week of June.

In addition to classrooms and offices, the school has various athletic-oriented spaces, including a swimming pool, basketball courts, and a fieldhouse. The largest portion of the school building is conditioned with hot water heat and chilled water cooling. There are two air-cooled chillers and two boiler plants, one significantly larger than the other.

Nineteen air handling units (AHUs) deliver conditioned ventilation air to the building; seven are variable air volume (VAV), while the rest operate on a constant volume (CV) basis. Rooftop units (RTUs) provide additional conditioning to spaces in the main building, such as the main office, the coaches’ office, and the driver’s education room. The connected south building of the school also has three dedicated RTUs. Additionally, each classroom has a univent that provides mechanical ventilation, heat, and cooling.

The fieldhouse is conditioned by a DX cooling, variable air volume RTU for the office area terminal units. That unit also houses a third boiler plant, which serves the fieldhouse. Three heat-only RTUs provide ventilation air to the fieldhouse athletic space. Prior to the project, the school was performing above average in energy efficiency, as indicated by an Energy Star score of 66.