South Heating and Cooling Plant
Northern Arizona University (NAU) constructed the Central Heating Plant building in 1970 for $973,000. Six years later NAU changed the name of the building to Heating Plant Annex. The plant supplied heat to South Campus buildings from October through May until 2000, when NAU updated the building with a second boiler to deliver heat year-round.
In 2005 the University expanded the plant and added a chiller system to provide air conditioning. It also modernized the architecture by creating a glass exterior wall to allow pedestrians to view the mechanical system. In 2007, the building became the South Heating and Cooling Plant.
The plant uses a system of underground tunnels to circulate hot and cold water throughout the buildings.