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

HVAC Control in the New MillenniumMultiplexing reduced the cost of wiring from remote panels to thecomputer but did not reduce the cost of wiring the input/output devices.Multiplexed systems have a reduced response time as the systemgets larger. This response time becomes less important as distributedsystems put more computing power out in the remote panels and evenin the input/output devices themselves. The speed of information transfercan be increased by switching from twisted pair cables to coaxial orfiber-optics, however, these types of cables add to the installation costs.In the future, communications between sensors and multiplexboxes and the rest of the system may use a combination of technologiesincluding traditional means such as twisted wire and coaxial and nontraditionalmethods such as infrared or radio wave.Operator InterfacesThe first control panels used individual pilot lights, then camesingle line light emitting diode displays. The next evolution in controlinterfaces came with text only, monochrome CRTs. Today, high resolutioncolor graphics provides users with realistic images that are updatedonce a second.Multimedia computers can combine video, CD-ROM, audio, text,pictures and sound to enhance communications between the computerand operator. The system may customize the interface for each operator,anticipating what the operator wants to know.A combined display/sound interface may be used which maymimic what we call virtual reality. In virtual reality, you can experiencethe environment. Special headsets, gloves and even full body suits areused.The operator can experience the building in operation. After acomplaint of a hot or cold temperature or a draft, an operator can zoomin to the space to feel and measure the temperature.Zooming inside the VAV box, the operator could check the damperposition and view readouts of air volume and temperature. The thermostator damper control could be adjusted while observing the system’soperation. The operator could also check the operation of fans, boilersand chillers using this zoom control.Adding a sensor to a room could be a simple operation. The sensormight have a self-adhesive backing and stick to the wall, where power©2001 by The Fairmont Press, Inc. All rights reserved.