Stability of Distributed Pump Configuration for Cooling Systems

Hydronic Heating, Ventilation, and Air Conditioning (HVAC) systems, where water is used as a media for cooling energy transport, are often used in large buildings. Distributed Air Handling Units (AHUs) condition the air for the cooling and ventilation needs in the building by controlling the chilled water flow. A distributed pump setup, where local pump controllers control the exhaust air temperature, is considered. Commissioning of HVAC is important for the operation of the HVAC and is the focus of this paper. Specifically, a method for local pump controller design, that enables individual operation of the local control loops, as well as operation of the fully connected system. This controller design is expected to fulfill the need for flexibility when setting the building into operation, and thereby ensure better building performance in the end. The theoretical findings are supported by numerical studies of a chilled water HVAC system.