Interoperable building automation systems (BAS) carry the promise of improved building system performance while reducing operating costs. While the concept of interoperability is still in its infancy, systems have moved from development to application. And even though the systems are more expensive than proprietary systems that lack interoperable capabilities, many maintenance and engineering managers have recognized the benefits of interoperable operation.
Each week, new systems come on line. The installation process is not painless, and requires a significant effort by managers. But those who have gone through the process find that the benefits of installed systems are well worth the pain of the installation process.
What do all of these capabilities mean to maintenance and engineering managers? Interoperable systems will have a major impact on how maintenance and engineering departments operate facilities. Interoperable systems will give managers more ways than ever to operate and manage facilities. They will allow managers to consolidate operations, making them more efficient and effective. And the cost of operating and maintaining the interoperable system will be less than what it was for independent, proprietary systems. While the impact of moving to interoperability will be very broad, the most significant improvement will be felt in five areas.
One of the most significant impacts of interoperability is flexibility. With proprietary systems, managers were locked into dealing with a single system manufacturer. As a result, they were at the mercy of that manufacturer.
If managers wanted to install the hardware and software to perform a particular function but the manufacturer did not offer them, system owners and operators were simply out of luck. With an interoperable system, owners can turn to any vendor that supports the standards for the features they want in their system.
Flexibility in interoperable systems also translates into savings for system owners and managers. Facilities today are in a constant state of churn. Functions being performed within spaces change. People relocate. Whole operations relocate. Facility support needs change.
With proprietary systems, it was difficult and expensive to modify building systems to best support those changes. Owners were at the mercy of the system manufacturer for changes. Each independent BAS had its own communication system that had to be modified and rerouted to support the changes in building operations.
With interoperable systems, only one cable is used. Changes to the system can be made by using products from any vendor that supports the system’s standards.
In addition to savings that will result from vendor independence, interoperable systems will reduce other operating costs. The single-seat interface to all BAS means that departments will have to devote less time to training operators and maintenance personnel. Training time is further reduced through the use of standardized, Windows-based software, whose use almost all operators are familiar with.
Also, data sharing across all areas of the system will improve the efficiency of many tasks. For example, with independent BAS running in a facility, managers had no easy way to transfer data automatically between the independent systems.
To bill different customers in a facility for maintenance work or energy use, managers typically had to run a report in one system, then enter the data in another system, increasing not only the workload, but also the chances for error. With interoperable systems, the necessary data is available to any application on the system.
One of the best ways maintenance and engineering managers can reduce maintenance costs is to implement a predictive/ preventive maintenance program. Scheduling maintenance tasks before equipment breaks down, can reduce maintenance costs and equipment. While programs can be established using set schedules for maintenance, it is far more cost effective to design programs around actual operating conditions and needs.
Interoperable systems give managers operating data to optimize preventive maintenance programs. By monitoring equipment operation, maintenance tasks can be scheduled based on actual run time rather than estimated intervals. Similarly, by monitoring equipment operating parameters, managers can determine when maintenance activities are needed to improve system efficiency.
For example, by monitoring chiller performance, managers can identify when it is time to clean the chiller’s tubes or service the cooling tower. Scheduling maintenance activities on the basis of equipment performance will reduce maintenance costs while increasing the life and operating efficiency of those systems.
BAS provide managers with a wealth of information. The problem with independent automation systems has been that this information, although available, is scattered across various systems. To fully understand what was going on in their buildings, managers had to extract data individually from each system.
Even worse, independent systems have no access to information generated by other systems. Energy management systems could not access building security systems to determine when areas were occupied or unoccupied.
Similarly, lighting control systems could not provide feedback on space occupancy to building security systems or to energy management systems. With independent systems, the only option is to provide duplicate sensors, increasing the cost of the systems.
Interoperable systems, with their seamless access to information across all functions, eliminate this barrier. Not only do system managers have access to all information from one point, but the system itself can base actions on data generated from anywhere within the system.
Occupancy schedules have to be entered only once for all functions controlled by the system. HVAC and lighting systems can be programmed to operate based on the actual occupancy of any given area. With the ability to schedule and adjust building system operation using a much wider source of information from the building, managers can optimize energy use and occupant comfort.
Perhaps the most cost-effective use of interoperable systems is the result of deregulation. Those facilities that can control electricity use effectively will get the most favorable electricity rates. Peaks and spikes will have to be eliminated, producing a relatively flat load profile for a facility. But to effectively control electrical loads, managers must have real-time metering data.
And if meters are located in multiple buildings at a single site or across several remote sites, managers must be able to access and compile data from all of those meters in real time.
Interoperable systems not only make that data available to managers; they also give managers a means of controlling their electrical energy use in real time. As the demand for electricity increases, systems can automatically take control action to shift or reduce electrical loads.
And with the ability to perform complex control strategies that were impractical or impossible with independent BAS, interoperable systems can further flatten a facility’s electrical load profile.
Interoperable systems offer managers the promise of improved system performance and reduced operating costs. Thousands of interoperable systems are up and running today.
But many institutional and commercial facilities have not yet made the move to interoperability. Managers of these facilities are not yet convinced that interoperability is beneficial here and now.
But as more systems come on line, maintenance and engineering managers in these facilities will realize that interoperable systems can deliver tangible bottom-line benefits — making jobs easier, reducing operating expenses and making life more comfortable for building occupants.
James Piper, P.E., is a facilities management consultant based in Bowie, Md., with more than 25 years of experience in facilities management issues.
The two leading routes to interoperability today are BACnet and LonWorks. Although the two approaches to interoperability are different, they should not be thought of as competing technologies. Rather, they are better viewed as being complementary.
Each has its own strengths and weaknesses. The decision on which route to take to interoperability is best made based on the needs of the facility, the ability of the maintenance and engineering staff to support the installed system, the layout of the facility, and the system’s life-cycle costs.
While facilities use both routes to interoperability today, the BACnet standard and the LonWorks protocol are evolving.
BACnet has been working on a standard for conformance testing for system component manufacturers. The second public review of the proposed standard was completed recently, with the completed standard projected to be published this fall. ASHRAE also recently announced the publication of a consolidated BACnet standard that includes all of the addenda to the standard that have been approved since it was first published in 1995. Designed to simplify the use of the BACnet standard, the standard is available in hardcopy and on CD.
LonWorks recently announced that it has started shipping an Ethernet Adapter that will provide a cost-effective way to monitor and control small networks.
Used with cable and DSL modems, or local area networks, the devices will allow managers of remote facilities to gain access to LonWorks devices to perform such activities as monitoring, alarm supervision, remote metering and energy management.
— James Piper