HVAC Control in the New Millennium.pdf - HVAC.Amickracing

HVAC Control in the New MillenniumFigure 3-7. Supervisory computer and DCS gateway.the nodes of the DCS. Gateways are also used to communicate withcomputers through a local area network (LAN).Old and New Control ConceptsThe software used in modern building control systems can resultin significant benefits. More control in these facilities can minimize expenses.However, the sophisticated building control systems requiresome changes. One change is to avoid implementing direct digital controllersto deal with the same inputs that were used in past generationsof pneumatic controls. A more holistic approach is required in modernbuilding controls.Today’s building control systems are fueled by software. If properlyapplied, this software can deliver powerful results. But, this requiresbreaking down some traditional lines of system separation.Direct digital control can transform HVAC controls. Just a fewyears ago, a building’s HVAC control system might consist of a complexnetwork of discrete electro-mechanical components which were linkedtogether with pneumatic tubing. Each component had a specific function,either serving as a link to the physical world, or being part of thecontrol logic itself.©2001 by The Fairmont Press, Inc. All rights reserved.