Integrating BAS with life safety

Engineered Systems, Jan, 2005 by Joanna R. Turpin

The options for connecting these two important systems vary from old-fashioned hard wiring to a single, integrated workstation. While the latter may offer the appeal of simplified notification expenses or a reduction in necessary parts, integrated systems also bring their own code requirements and a need to balance streamlined performance with an adequate level of system independence.

Integrating fire alarm, smoke control, and other-life safety systems with BAS is not a new concept. Indeed, many facilities already have BAS that incorporate HVAC functions along with security, lighting controls, fire alarms, and other systems. But just how integrated are these systems? That's hard to say, because integration means different things to different people, especially where hardware and software are concerned. To some, integration may just mean being able to monitor a particular building system through the BAS without necessarily controlling it. To others integration may mean the ability to monitor and control multiple building systems through one workstation.

Total system integration can be expensive and complex, which is why many system designers are often more comfortable keeping building systems as separate entities. However, endusers may not be content with this structure for long as they start to hear about the potential benefits of interoperability and shared resources.

AVAILABLE METHODS

in general, there are several ways to integrate life safety and BAS. One method that has been available for a number of years involves the traditional hard-wired connection. Some might argue that this isn't really integration, however, it does provide notification of alarm conditions and allows the BAS to react to fire alarms. This can be a cost-effective way of achieving fan shutdowns and very, basic smoke control.

The hard-wired method--a relay output on the fire alarm panel wired into an input on the BAS--is often used when legacy systems are involved. "This method is cumbersome, though, as it requires a separate wiring connection for every fire zone," said Rick Focke, director of marketing for Tour Andover Controls (Andover, MA).

Tom Rule, product manager for Siemens Building Technologies (Buffalo Grove, IL) agreed, noting that the lack of detail available and the potential need for large numbers of connections are drawbacks. "If you've got 30 zones in a building, then you have to make 30 hard-wired connections and write all the logic on them. It just isn't very efficient compared to just making one digital connection."

Monitor-only digital communication is another method of providing integration between life safety systems and BAS. When a building manager wants detailed information about the life safety system or needs to monitor more than a handful of zones, digital communications are much more efficient than hard wiring.

Digital communication for integration purposes has also been around for a while. Indeed, fire alarm system manufacturers have typically provided an interface to the BAS in commercial facilities in order to monitor the status of the fire alarm system. Some BAS manufacturers build communication protocols for various fire alarm systems directly into their systems, while others rely on third-party integration platforms to translate data between systems.

The third (and most recent) method is the use of integrated workstations that are UL-listed to provide full command and control of both the automation and fire alarm systems. With this level of integration, the life safety and automation field panel networks remain independent, but they share information and consolidate data through a workstation or a group of workstations that can monitor and control both the life safety and automation systems through a common interface.

"This is a newer phenomenon," said Rule. "Endusers are saying they've got a workstation with graphics, paging, and Internet access, and they can use it to run reports and archive information, so why can't they tie their fire alarm system into the automation system? They don't want to just monitor what's going on--they want to control it."

This is the most expensive method because of UL and NFPA restrictions that carry over to parts of the automation system when full command and control of the fire alarm system is allowed.

COSTS, CODES, AND COMPLEXITY

Integrating life safety and automation systems can be an expensive and complex proposition. There are upfront issues including the installation of hard-wired connections or digital communicating drivers, both of which require time and money. Another issue concerns whether or not a building has systems already in place.

"If the building has an existing BAS and fire/life safety systems, then there will be an additional cost to integrate the two (or more) systems," said Focke. "However, over time, the savings in operator efficiency and reduced call-outs will help offset the cost. For new buildings, integrating BAS and life safety beginning with the initial design will save cost."