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BACnet Systems Offer Many Opportunities to Improve Sustainability
OTHER PARTS OF THIS ARTICLEPt. 1: This PagePt. 2: BACnet Connectivity and InteroperabilityPt. 3: Interoperability and Green BuildingPt. 4: Controls: Real-World SavingsPt. 5: Why BACnet?
At the heart of an effective green design strategy is the notion that a building is a single entity, not a collection of disparate elements. To maximize the efficiency of the HVAC system, for example, the selection of glazing and the building orientation should be integrated with the design of the mechanical system.
As powerful as that idea is, it's not new. There's no better demonstration of the power of the idea of integration than BACnet-based control systems. These systems not only tie together diverse elements of the building, but also link systems made by a variety of manufacturers.
"Controls are one of the easiest, most immediate and effective ways to improve energy efficiency and affect sustainability," says Larry Haakenstad, director of sales at Alerton. "With proper BACnet control strategies, and system maintenance, it's possible to enhance energy performance and maintain IAQ and facility comfort."
A solid understanding of the range of ways to use controls to improve sustainability is essential knowledge for facility managers these days. But while there are many different strategies, at bottom they come down to using the power of the building automation system to make operating decisions for the major mechanical and electrical equipment in the building, says Jay Garbarino, U.S. sales manager at Delta Controls. "This is where the rubber meets the road," he says.
"A well-engineered system can balance energy performance, IAQ and occupant comfort quite effectively," says Chris Hollinger, senior product manager at Siemens Industry.
The idea that an interoperable control system offers many benefits is catching on.
"Many proactive and strategic-minded building owners and facility managers are recognizing the inherent benefit of intelligent, interactive buildings," says Levi Tully, DDC instructor and application engineer at Reliable Controls.
As popular as the topic of green design has become, the economy can make it difficult for facility managers to get buy-in for sustainable building initiatives.
"While some people are doing their best to be energy-conscious, their budgets limit their capabilities," says Rocky Moore, director of business development for American Auto-Matrix. "No matter how much it might save you in the long run, the up-front cost can immediately kill the desire for long-term gains. Facilities professionals with limited budgets considering upgrading their building should look at ways to integrate their systems with open protocols, such as BACnet, which can guarantee interoperability and mean less cost in future revisions."
Long-term costs are lower because, as a worldwide standard, BACnet's open communication technology can be implemented on many hardware platforms and enables facility professionals to select best-of-breed control system devices on a common network.
There are three levels of applications where controls can help improve energy efficiency, comfort and IAQ, says Andy McMillan, general manager, Philips Teletrol and president of BACnet International. The first level is optimizing specific devices. The second is to optimize management of different components of a system so that they're not fighting with each other. A third level is to systemize the enforcement of standards across one or more buildings.
As Terry Hoffman, director of BAS Marketing for Johnson Controls says, there are hundreds of control applications that can improve energy efficiency and other aspects of sustainability. But among the most powerful are those that involve more effective use of information from control systems.
"If you are looking for the two or three applications that have the greatest impact on the systems we are installing today, I would have to say that energy reporting is right at the top," Hoffman says. "Our customers are looking for a way to get essential information they need to manage their energy spend, as well as carbon emissions."
This is where the concept of "dashboarding" is becoming popular. "While the controls can compensate for comfort issues, they may increase energy consumption to do so," says Garbarino. "By monitoring a carefully designed energy summary for the building — part of a dashboard — the FM can ensure that the performance doesn't degrade over time. The dashboard can't fix the underlying problem, but it can help pinpoint where the problem is occurring in the facility."
A BACnet-based system is well-suited to the task of gathering data. "There's a tremendous amount of pressure to design and operate efficient buildings," says Mike Olson, manager of HVAC applications at ABB. "Building owners and designers are obliged to ensure all the data about energy consumption is collected at a central point. What better way to do this than connecting it all together with BACnet controls?"