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

HVAC Control in the New Millenniumdard of the American National Standards Institute (ANSI) which has aBACnet device compliance testing facility in Gaithersburg, MD.BACnet was developed as a voluntary consensus standard asASHRAE Standard 135. There are three main parts to the BACnet standard.There is a specification for local area network technologies. A localarea network (LAN) provides a way of moving information among computers.Another part of the BACnet standard provides a way to interconnectmultiple LANs into a wider area network. A third part of BACnetspecifies a standard communications format that can be used by differentmanufacturers to allow their building control systems to work togetheras independent but cooperating systems.BACnet ApplicationBACnet applications include integrating fire detection, protection,and suppression systems with HVAC systems and increased communicationsbetween building control systems and utilities for energy managementand utility load management. BACnet can provide better energymanagement, building performance monitoring, and enhancedHVAC diagnostic capabilities.A consortium of control manufacturers organized by the NationalInstitute of Standards and Technology (NIST) has been testing manufacturers’equipment for interoperability.ASHRAE has been developing an addendum to BACnet thatwould define conformance tests. These tests could provide an industrywidecertification program that would ensure the compatibility ofBACnet products made by different vendors.Manufacturers are applying BACnet for island-to-island, multivendorsystem integration. Communicating through BACnet, these islandsof control allow monitoring and command capabilities from asingle PC workstation. BACnet can also be a vehicle for combiningmulti-vendor campus sites into a single intercommunicating system andmoving existing systems into an open environment.When a building owner buys a building control system, the owneris effectively locked in. Once a specific vendor is selected by the customer,ongoing service, future additions, and changes to the system areavailable only from that vendor. Building owners that find themselveslimited to a single supplier for service and upgrades have higher costs©2001 by The Fairmont Press, Inc. All rights reserved.