![]() The facility level services connect to the zones through a backbone network, handle supervisory level information and controls, and thus facilitate building-wide scalability. The zone-level service includes the control algorithms described above as well as the corresponding interfaces, profiles, sensors and actuators to realize the zone controller. Three levels of services are defined in the architecture: external services, facility level services and zone level services. To address building-wide scalability, a system architecture was developed for the zone-based control technology. The thermostat control algorithm is based on a well-established thermal comfort model and formulated as a root-finding problem to dynamically determine the optimal thermostat setpoint for both energy savings and improved thermal comfort. It is formulated into an optimization problem with minimizing lighting-related energy consumptions as the objective and delivering adequate task light and preventing daylight glare as the constraints. The lighting load balancing algorithm adopts a model-based closed-loop control approach to more » determine the optimal electric light and venetian blind settings. The control framework contains two key algorithms: 1) the lighting load balancing algorithm and 2) the thermostat control algorithm. The control framework is designed following a modular, scalable and flexible architecture to facilitate easy integration with exiting building management systems. The developed technology is a zone-based control framework that minimizes energy usage while maintaining occupants’ visual and thermal comfort through control of electric lights, motorized venetian blinds and thermostats. This project aims to develop an integrated control solution for enhanced energy efficiency and user comfort in commercial buildings. Additional energy savings due to reduced solar and lighting heat gains were not quantified but will add to the total operational cost savings. The building owner received very competitive bids ($30-75 US/DALI ballast) and was able to justify use of the daylighting control system based on operational cost savings and increased amenity. The DALI-based system exhibited faulty behavior that remains unexplained, but operational errors are expected to be resolved as DALI products reach full maturity. The large savings and good reliability can be attributed to the automatic management of the interior shades. Average savings for the 7-m deep dimming zone were 20-23% and 52-59% for Areas A and B, respectively, depending on the lighting schedule. At 4.57-9.14 m from the window, 5-10% and 25-40% savings were achieved in Areas A and B, respectively. At 3.35 m from the window, 30% average savings were achieved with a sidelit west-facing condition in Area A while 50-60% were achieved with a bilateral daylit south-facing condition in Area B. Daily lighting energy use savings were significant in both Areas over the equinox-to-equinox period compared to a non-daylit reference case. = 6.1% of the day on average over the monitored period, respectively, in Areas A and B.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |