Reports From the Field: Open Controls

Well over a decade ago, concern about the proprietary communications methods for building control systems led the industry to ponder a change. At the time, many building owners—and system designers—felt that they were at the mercy of particular vendors for the installation, maintenance and upgrade of building automation systems.

And while the development process of interoperable control systems has sometimes left much to be desired (see "Diagnosing the State of Interoperability," p. 42), there have nevertheless been a number of projects capitalizing on the "openness" established by products using standard protocols like BACnet and LonWorks.

Two recent projects illustrate how modern controls equipment has the ability to be more open and interactive, and allow facilities options for future system upgrades. The first, a new corporate headquarters for Echelon—the developers of the LonWorks standard—displays a single, sophisticated control system that is comprised of interactive components from a variety of manufacturers. The other project, a retrofit, offers the example of an entire city—Tucson, Ariz.—breaking away from the grips of a proprietary control system and converting to a system that uses a BACnet-based control backbone and also integrates existing proprietary controls into the system. In both cases, "going open" was the only option.

San Jose, Calif.—the cradle of modern computing technology—is now home to another technological marvel of sorts: the new Echelon Corporation headquarters.

Admittedly, it is a showcase for the LonWorks platform of open, interoperable device networks, but that was not the only factor driving the creation of this facility. Echelon was also trying to display how modern controls can minimize energy usage in an expensive energy market, as well as provide comfort for employees.

"We have to work in the building every day, so we wanted it to be a great environment for us," says Steven Nguyen, director of corporate marketing for Echelon. "And we wanted employees to be involved in the energy management program for the building."

As a result, each space within this three-story, 77,000-sq.-ft. building has a programmable room manager controller to personalize light and temperature setpoints for occupied, standby and unoccupied modes. This setup fits Echelon's travel-and-telecommute business style, where approximately 25% of the building occupants are away from the office at any given time.

While the level of control is certainly a key feature of the building control system, the most distinctive facet is the amount of "interoperability" in the design. The facility's building-management network integrates monitoring and controls for HVAC, lighting, security, elevators and many other functions (see Table, p. 43), as well as control components from nearly 20 manufacturers—a project stipulation from Echelon.

Due to the complexity of the project, Teng & Associates, Chicago, was selected as the lead system integrator on the project—a role they fit into naturally considering the firm has been a member of the LonMark Interoperability Association since its inception in 1994. On this particular project, Teng designed the control system, and worked with the contractors on its installation.

According to Tom Lohner, P.E., vice president with Teng, the project did entail a significant amount of time and cooperation.

"For a typical building, the consultant would spend maybe a week to put together a basic performance specification," Lohner asserts. "We went beyond that and designed the physical infrastructure of all the Lon products."

In keeping with the project goals of energy management and interoperability, Teng conducted a detailed analysis using the U.S. Department of Energy's DOE-2 energy simulation software to compare the costs and benefits of a conventional control system to integrated, interoperable controls. By analysis, it was found that the extra money needed to tie the systems together could be paid back through energy cost savings in less than 10 years. And this analysis did even not take into account the cost benefits of competitive bidding for service, maintenance and upgrades.

Because this was a "demonstration" project, many items in the system could have been done more cost effectively. The individual level of control, with over 1,000 governing devices, increased first cost, and the robust control software—although it allows for impressive system displays and maneuverability—was actually more than a similar project would have required. But Lohner agrees that, overall, the new facility can serve as an example of open-control system interoperability and savings for a variety of buildings.

"There is really a lot of standard equipment in the building," he maintains. "Maybe 75% of the equipment is fairly standard. The thing that is unusual is the sheer number of items being monitored and controlled in the system."

The total project has not ended either. According to Nguyen, Echelon has plans for a "twin" facility to be built on a site adjoining their new building. When it is finished, the control system for the new facility will be integrated with the existing facility's system.

In suit with Echelon, many new facilities, learning from the past, are choosing open-protocol control systems. However, there is also a growing number of existing proprietary control systems that are being replaced rather than upgraded. One recent example occurred in Tucson.

During the late '90s, the centralized control system that had managed HVAC for a number of city-operated buildings was reaching obsolescence. As malfunctions occurred within the proprietary control system, city administrators realized that they were losing money with each upgrade by basically being locked into a noncompetitive service contract.

Thus, when the city set out to create their new energy management and control system (EMCS), one of the stipulations was to create a system that had the BACnet protocol coming out of each of their buildings. In addition, the city wanted their building controls to tie into their wide-area network.

The existing control system managed 40 buildings on 20 different sites—which added up to over 7,000 control points. As this control system grew over the years, newer technology was integrated with original controls. As a result, a good number of these buildings were still working on control panels from the 1970s, especially the older buildings in the downtown area.

Palmer Engineers, Tucson, was chosen to design the system in cooperation with ESS Engineering of Tempe, Ariz. Jim Palmer, P.E., principal of Palmer, was involved from the beginning of the process, and helped choose the particular control system and contractor.

"The four proposals [from controls contractors] were reviewed to see how they complied with the spec, as well as the dollar amount," he explains. "Of the two lowest in price, only one offered a completely BACnet solution."

The chosen contractor, Climatec of Tucson, came in with a proposal that allowed the city to keep much of its newer control hardware in place, while still having a "single seat" BACnet interface for all network communications.

So far, the first phase of the project has been finished, with roughly half of the city buildings converted to the new, BACnet-based system. The overall plan for the upgrade involves removing almost all of the old control hardware from the downtown buildings and replacing it with BACnet-enabled hardware, with all of these buildings then connected via a WAN. This was fairly straightforward, with the design reusing as much of the existing cable, wire and conduit as possible.

At the same time, the facilities with more modern, PC-based controls are being converted, via gateways, to a BACnet communications protocol. Using a brand new type of field controller which, according to Palmer, was only introduced during the project's design stage, the new BACnet system is able to communicate over the WAN with the existing proprietary hardware.

The result is a control system that has accomplished the stated goal of freeing the city from the proprietary system.

"The system has gone from 100% sole source to 95% competitive—at least for those that can provide a BACnet solution," says Palmer. "[The control-system vendor] would need to be involved in about 5% of any upgrade project, basically to integrate the points to their front-end [interface]."

Besides being more open for future upgrades and installations, Palmer says that the control system gives system operators a much quicker, cleaner user interface than before, with more specific alarm signals as well. The rest of the city buildings are scheduled to be completed in the next year.