Integrating BAS with Life Safety
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 MethodsIn 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 ComplexityIntegrating 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."
One of those expenses is an additional workstation. When both life safety and automation workstations are required, one workstation can often be completely eliminated by using a single integrated workstation. Even if multiple workstations are still required, graphics creation, and operator training can be significantly reduced.
Another expense that can be reduced, noted Rule, is when remote notification (paging or e-mail) is required. "Configuring and maintaining one common notification system can be far less expensive than configuring and maintaining two."
When smoke control is required, an integrated system can also significantly reduce the redundancy between systems. In many cases, the automation system is used to control fans and dampers during normal building operation. If the life safety system is used to perform smoke control, then redundant fan and damper controls have to be installed in parallel and in series with the BAS controls so that these devices can be overridden on or off.
"Through integration, these two additional contactors can often be eliminated for every fan and damper in the facility," said Rule. "But before going forward with this type of control strategy, it's important to make sure that the automation system is UL listed to perform smoke control with the fire and life-safety system installed at the facility under UL 864 category UUKL."
When fire alarm annunciation and control are required, then UL 864 category UOJZ, Protected Premises, is required. "When desired, the BAS graphical user interface may be listed by UL for both fire alarm annunciation and commands back to the fire panel. In this case, the BAS software must be installed on UL-listed PC hardware, and additional software may be required to manage the fire alarm bypass groups and commands," said Focke.
ConcernsEnsuring proper UL listings adds to the complexity of an integrated system, and there are numerous codes to be aware of in the fire alarm world. Once installed, the AHJ must ensure that the life-safety system is sound and functioning properly. Those people (hopefully) look for anything that's tied into the fire alarm system and make sure everything is listed for its intended purpose. Unfortunately, sometimes the AHJ doesn't always know as much about the BAS as the fire alarm system, so they may not be checking that the devices on the automation side are listed.
This is one of the biggest reasons why system designers often prefer to keep the systems separate: It is a challenge to understand the agency listings and code requirements associated with fire alarm systems. When fire alarm systems are introduced, restrictions on what components can be used and how they are installed become a concern that they don't have to consider otherwise. If designers are not confident in their knowledge of the listing and code issues, they sometimes avoid the situation all together.
Focke said that system designers require special training for smoke control, including the fundamentals of smoke control, how to layout the system according to code requirements, and special programming required for smoke strategies. And when implementing fire alarm annunciation, the BAS designer has to consider alarm priorities.
"Fire alarm must be the top priority, fire supervisory number two, and fire trouble alarms number three. When using the BACnet open standard with smoke control commands, the command priority structure must be understood and used," Focke noted. "Life safety commands are generally reserved for command priority level 1. Done this way, a subsequent command to the same point, at a lower priority, will not affect the output."
Another concern is that through integration, the systems become interdependent and less reliable. It's important that integrated systems be designed and implemented in a way that both the fire alarm and automation systems run as independent and autonomous systems that do not rely on each other for basic operation. For example, if the BAS is disconnected from the fire alarm system for maintenance purposes, it is still necessary for the fire alarm system to detect and annunciate emergency conditions.
It's also important that integration requirements are well-established up front, and that the life safety and automation supplier have a good relationship and work well together. Successful integration requires clear communication and cooperation between both parties. "The last thing anybody wants to deal with is a bunch of fingerpointing at the end of the project," added Rule. ES
The second part of this article, which will appear in the March issue, will focus on the benefits of integrated systems as well as the various protocol issues.