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| January 2010 | |
Advances in Communications Infrastructure Support a Range of Building-Based Systems
By Carlos Petty and Val Loh
The notion of intelligent buildings has changed substantially over the decades. Initially, the focus was on the hardware and software of building systems themselves. Today, however, the objective is broader: to optimize building structures, services and management.
The overall goal is to apply technologies that improve the basic building environment by providing greater comfort, healthier conditions, and enhanced building services and functionality for occupants. That brings many benefits to the owners, managers and occupants of intelligent buildings.
Dynamic feedback about building performance improves HVAC control, bringing better comfort and indoor air quality to occupants. Access to local environmental and temperature controls can boost occupant satisfaction.
What's more, an intelligent building helps control costs. Because it uses energy more efficiently, an intelligent building costs less to operate and emits less carbon. Churn costs are lower because an intelligent building provides flexibility for expanding or reconfiguring office spaces. In addition, security is improved by the use of controlled access or CCTV monitoring.
For building owners, those benefits translate into buildings that are more competitive, profitable and valuable. An intelligent building enables the owner to maximize financial returns beyond energy savings, improving asset value.
Intelligent-building technologies focus on monitoring and controlling systems. It's not just a matter of collecting and processing traditional building data to perform numerical or logic-based analysis. Systems in an intelligent building interpret the collected data automatically, reach viable solutions and implement the appropriate corrective actions without human intervention.
Advances in IT
The common thread in today's intelligent buildings is their ability to capitalize on advances from the IT world — the high-bandwidth cabling practices that allow for information data exchange using a common cabling infrastructure based on Ethernet protocol. The installation of a buildingwide Ethernet communications cable plant allows multiple building-based systems to co-exist and in some cases, share building data.
With this emphasis, it is critical that telecom rooms, cabling routes and building risers be properly sized to accommodate and support the various systems within the intelligent building. Gone are the days when telecom rooms were considered "closets." Today, the size and location of the room should be considered carefully. The Building Industry Consulting Service International (BICSI) design standard manuals offer guidance. For high-rise buildings, a dual building riser is critical to establishing both redundancy and resiliency. Pathways and routes of cabling infrastructure should also follow the BICSI design guidelines where the typical distance of communication cabling does not extend beyond 295 feet or 90 meters, for optimum performance.
The communications infrastructure is the backbone of the intelligent building, spanning the entire building to support a range of building systems.
Building Automation Systems extend energy management capabilities to facility managers. Building automation systems offer the automatic control and reporting of HVAC units and help facility managers optimize the central plant systems responsible for the control and monitoring of refrigeration and heating plant equipment. Real-time monitoring gives facility personnel the tools to make better decisions that can reduce the building's overall energy use.
"Open" system networks using industry standard network communication protocols allow control devices to be easily defined, installed and reconfigured while sharing information in a multivendor environment.
Power Monitoring Equipment and Subsystems also help save energy. These systems have an important role in supporting measurement and verification activities for the commissioning of buildings for LEED certification. Electricity use can also be tracked via a supervisory control and data acquisition (SCADA) system.
Critical Facility/Data Center Systems require greater fault-tolerant features via integration to specialized uninterruptible power supplies (UPS) and dedicated cooling systems.
Multimedia/Audiovisual Systems rely on a microprocessor-based control system with pre-programmed intelligence to distribute building-wide audio and video/graphic information via the digital signage system during certain events. Moreover, use of the systems can be monitored, tracked and controlled remotely with the Internet Protocol (IP) by authorized facility support personnel. The systems can be set to automatically turn off or on based on predetermined schedules with minimal human intervention. Systems can also be integrated into other applications such as room HVAC and lighting controls, video teleconferencing systems, and motorized shades that will enhance occupant comfort and convenience.
Access Control and Security Systems have benefited from integration and software advances that have expanded how security is deployed for intelligent buildings. State-of-the-art security systems provide seamless integration with other systems such as CCTV, pagers, intercoms and digital storage devices for video capture, eliminating the need for multiple software/hardware packages. IP-ready cameras using TCP/IP networking protocols provide connectivity anywhere on an intelligent-building communications network. New security systems allow for direct input of CAD drawings, reducing system setup and commissioning.
Security Systems have also taken advantage of power over Ethernet (PoE) technology. PoE has created a host of new security products for "smart devices" that have IP network connectivity but require low voltage power for operation. Applications include wireless CCTV cameras and access control products. Products that use PoE connectivity at the device level are growing, as they reduce the need to install low voltage wiring traditionally required, trimming overall installation costs by approximately 80 percent.
The Institute of Electrical and Electronics Engineers (IEEE) is currently defining a higher-powered PoE standard which would allow for between 30 and 50 watts to be delivered to smart devices. The ability to provide more power to smart security devices for PoE will lead to even greater interoperability and systems integration applications in the near future.
Lighting Controls are increasingly important in intelligent buildings. The U.S. building industry spends about one-quarter of its electricity budget on lighting. The use of intelligent, automatic lighting control technologies developed during the past decade can help cut lighting costs and environmental impact substantially, while enhancing lighting quality.
Digital Addressable Lighting Interface (DALI) is a bi-directional, digital protocol developed by lighting manufacturers for lighting control. The initial application was for the control of fluorescent lamps, both linear and compact. With DALI, it is possible to easily combine the installation of existing 1-10V interfaces with the advances of intelligent lighting control. This system closes the gap between previous 1-10V technology and expensive bus systems.
Daylighting is a strategy that seeks to maximize natural light into a space through windows, with the goal of reducing or eliminating the use of electric light when possible. It's a natural for intelligent buildings, where daylighting is used in conjunction with automatic lighting and shade controls, photocell daylight dimmers near windows (which control lighting fixtures), and occupancy sensors via a building automation system.