This allows the central plant to meet a peak cooling demand of 3,000 tons or 6,000 gpm of chilled water flow for a maximum period of six hours. The chilled water thermal energy storage tank must be re-charged with cold water at night for the next day s use. Most of the campus buildings have secondary chilled water pumps with variable frequency motor speed controllers and two-way modulating temperature control valves. The campus hot water utility distribution piping delivers 120 to 180 degrees F. hot water to the buildings based on a hot water reset schedule inversely with outdoor temperature.
Some buildings utilize a reheat process to maintain space temperature and humidity control.
An industrial grade heat pump chiller produces low temperature hot water for heat and reheat requirements. The system is tied into the existing condenser water piping and existing hot water piping.