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

HVAC Control in the New MillenniumThe city of Memphis, Tennessee has installed new control systemsas well as upgrading and expanding its Fairgrounds Complex. The retrofittedcontrols are BACnet-compatible, and will be networked into acentrally monitored system via the city’s existing municipal stages. Theflexibility offered by BACnet appeals to city managers.BACnet is being used in thousands of building automation systemsoperating around the world but that is only a small portion of allcontrols projects being done. One of these projects is a centralized networkof BACnet-based building automation systems in Tucson, Arizonafor about 25 municipal facilities. The new system replaces a group of 5-to 10-year-old direct digital control systems. The city was concernedabout their existing control systems, and were expecting to see majorsystem failures if they did nothing.The project uses BACnet at the head end and the main distributedprocessors, connecting all of the buildings into a single centralized system.This will allow flexibility to allow true competitive bidding forcontrol system additions in the future.As more control vendors offer BACnet products, the dream ofinteroperability through BACnet will be put to the test. The projects thatare being planned and executed will be watched closely. One way oranother, the era of proprietary BAS protocols is coming to a close.The U.S. General Services Administration (GSA) is using BACnetcontrols from Alerton Technologies and the Trane Company at its 450Golden Gate Building, located in San Francisco. This is the first largescaleimplementation of the BACnet open communications protocol. Thebuilding is the first large demonstration of BACnet among multiplevendors.The building houses several government departments and agencies,including GSA and federal courts. It has 22 floors with 1.4 millionsquare feet and is one of the largest buildings in the San Francisco skyline.Each floor is bigger than a football field. The building has seenextensive renovations, including asbestos removal and mechanical systemupgrades, while maintaining its pneumatic control system.The new building-wide energy management control system cost$3.5 million and should save over $500,000 in energy costs per year.The Alerton system is based on the company’s BACnet systemcalled BACtalk[R], and the Trane system is based on the Trane Tracersummit system. The building owners workstation network uses aBACtalk for Windows NT server with an Ethernet 10Base2 LAN to con-©2001 by The Fairmont Press, Inc. All rights reserved.