Dynamic simulation and analysis of ancillary service demand response strategies for variable air volume HVAC systems

Output variability and low generating inertia associated with solar and wind electric power generation resources increase the requirement of grid-scale ancillary service capacity and add strain to existing firm generators that provide these services. Buildings consume the majority of electricity in the United States and can play a significant role in helping to meet these challenges by using their HVAC systems as a link to thermal energy storage. However, predicting a building's ancillary service demand response performance continues to be a challenge, particularly for complex multi-zone systems, such as the variable air volume. A dynamic model of a representative variable air volume system was developed and simulated to investigate the response of the system to implementation of four common demand response strategies over a range of cooling loads and implementation intensities: zone air dry-bulb temperature adjustment, duct static pressure adjustment, supply air temperature adjustment, and chilled water temperature adjustment. Curves are presented that map power reduction as a function of cooling load and implementation intensity on a 10-min spinning reserve timescale. A study of these maps along with simulated data reveal that terminal unit damper position is a significant determining factor of performance effectiveness for each strategy.