Variable Speed Drive (VSD) Applications in Dual-Duct Constant Volume Systems

Models have been developed for static pressure and potential supply fan energy savings by using variable speed drive (VSD) in dual-duct constant volume systems. Experiments have been performed using a full size dual-duct constant volume system installed in a 68,000 ft2 (6,317 m2) office and classroom building. The measured static pressure variations and the energy savings agree with the model projected values. The VSD saves the fan power by as much as 35%, reduces the total airflow by 15%, and decreases the excessive static pressure on the terminal box dampers. This paper presents the systems models, the experimental methods and the results