By Fred Leber
We have requirements in the Building Code for testing fire protection systems and ensuring they are properly supplied and installed. We have additional Building Code, Fire Code, Electrical Code, Plumb...
We have requirements in the Building Code for testing fire protection systems and ensuring they are properly supplied and installed. We have additional Building Code, Fire Code, Electrical Code, Plumbing code, Elevator code (and so on) requirements to verify the proper supply and installation of other systems in a building.
Surely all these laws ensure that life safety sytems will function properly? Well maybe they do, but we should consider the term “Life Safety Systems” a little more carefully.
The fire alarm system in a building is generally called a life safety system. The sprinkler system is also referenced as a life safety system. The heating, ventilating and air-conditioning (HVAC)equipment may have a life safety function, and its components such as fans and dampers may have dedicated life safety functions.
Each of these systems are really part of the building’s overall “life safety system” because they generally interact with each other.
The construction industry might benefit if it were to make a clear distinction by referring to individual systems as “fire protection or other equipment,” while using the term “life safety system” only in the context of the interconnection and interoperability of the fire protection and other equipment installed in a building.
In many cases, different equipment components are linked together and orchestrated to be activated or deactivated based on various sequences. Consequently, while each of the components may be relatively simple to implement individually, when one considers the number of them, and the various engineering disciplines that are involved, it becomes obvious that the integration of these controls and related equipment is critical to life safety. Therefore, the integration of fire protection equipment to provide a building’s life safety system must be a focus for those commissioning a building.
What can go wrong
The commissioning of a building is done once construction is completed but before the occupants take over. It is done to ensure that all the systems are in working order and so is of critical importance to the success of a project, to ensuring the building owner and occupants are happy and safe once they move in.
As buildings become more complex, the commissioning process becomes more of a challenge. The technologies of fire protection equipment are changing, and those responsible are becoming more specialized within their own fields. Someone with a specialized expertise designs each piece of equipment. A different specialized contractor may install each system. Someone with the appropriate skills verifies each of them.
Our experience in the field has shown that the integration of the different systems often results in major deficiencies during the final testing. This is the time when the individual fire protection components and other equipment have already been tested and when the building’s “life safety system” should be fully operational.
However, we have found recurring deficiencies in many areas, such as:
• Insufficient fire alarm zones to monitor sprinkler valves. The mechanical designer decides how many sprinkler valves are needed. The electrical designer provides the circuits to monitor these valves. Everyone knows that these people communicate well with each other since they are in adjacent cubicles — Not!
• Failure to detect sprinkler valve closure due to a monitor switch adjustment.
• Failure to operate correct alarms signalling devices due to a programming error.
• Failure to start pressurization fans due to improper system programming. The pressurization fans are designed by the smoke control system designer, but controlled by the fire alarm system via the electrical designer’s program sequence.
• Failure to stop recirculation fans due to unconnected wiring.
• Failure to properly orient smoke control dampers due to a programming error.
• Failure to home elevators due to unconnected wiring.
These deficiencies may seem relatively easy to repair. However, they usually aren’t identified until the building is moments away from occupancy.
Last minute scramble
What happens during a typical building commissioning?
All the specialists and contractors have been busy tying up the loose ends of their own equipment. Last night the fire alarm equipment verification company tested the fan shut downs. Today, the HVAC equipment is being balanced. The continuing fire alarm bell tests are driving everyone nuts, and the fans keep turning on and off.
It may be understandable that the HVAC contractor disconnected his fans from the fire alarm equipment in order to do his own testing. But who knows if it will ever be connected again?
Many deficiencies occur because no one has ever identified the correct sequence of operation. There was always something else more important to do and as a result there was a lot of guessing and assumptions. At this point the wiring is in place and the software programs are fixed. Now we’re into the last minute scramble. People are asking questions:
Have you heard any of these typical conversations at a job site? — “O. K., so the fan doesn’t turn off. Do we really have to do it?” — “If the code doesn’t require it, why are we doing it?” — “We don’t have to worry about that because it didn’t work on the last job either and nobody said anything.”
This now becomes a build/design project. Whatever was built must become the design and everyone has a good reason why it has to be that way. Remember we are now at the end of the project. Everyone is out of time and money.
Technologies: no two are the same
In the area of technologies, we have seen tremendous changes in the last few years. With older technologies there were many similarities among the various manufacturers’ equipment. Likewise, many standardized practices were employed in installation. An engineer or contractor could lay out the wiring routes and circuiting for a building, and most manufacturers’ equipment could be installed with very few changes.
But today, you could almost never use the same riser or circuit wiring for equipment from two different manufacturers. Indeed, one manufacturer’s model of equipment has the potential for being configured in so many different ways you could not identify it as equipment from the same manufacturer when looking at the field wiring. Verifying these systems can send you to another dimension. No two systems are the same.
I’ve been told that there is no difference. They say “just treat it like a black box. Operate the detectors and see if the bells ring.” I think I said that once too. I was wrong!
Software controlled equipment (and even your toaster is now software controlled) can employ a digital communication link. The computers all talk to each other over the link. This means that in many cases when a detector is activated (fire, smoke, temperature, pressure), that specific circuit or detector must be programmed to operate a specific function, such as to turn on a lamp or to activate output circuit “A.” Every action must be specifically programmed in this way. There is not always a common point of initiation that will cause many things to happen at once.
If output circuit “B” is to be initiated by the same detector, in many systems this becomes another specific program statement associated with the detector. If a detector is added, it must be programmed specifically to each of output circuits A and B individually and to an appropriate indicator. In short, every action or reaction may be a specific software instruction that is subject to typos and other human error.
Software programming changes might occur either because of human error, or because someone deliberately wants to bypass an equipment function that is not currently required.
Contractors, for example, love this programmability. After an area is tested it can be byp
assed so that it doesn’t interfere with other work in the building. Those who gain access to the system tend to think it is no different from a personal computer. But we’re not playing games here. This is a life safety system.
Necessary changes to the equipment programming also present opportunities for failure. In most large buildings, changes will be made in the time between the design and final construction, and these will require changes on site. They might mean adding zones for the fire alarm system, or changing auxiliary function operations.
This situation can be deadly! I have had ample demonstration that if one program is changed it can affect other unrelated and previously tested functions. Don’t let anyone convince you otherwise.
These things happen. Loose ends are expected on every project. Construction is complicated. Which is exactly why equipment verification is legislated. When the authorities conduct their final acceptance testing it is expected that all these problems, loose ends and other issues have already been solved.
Unfortunately, I have had first hand experience with all of the examples of deficiencies listed above. They were discovered after all the verification certificates had been submitted following the required equipment tests.
Finally, some good news
Let’s go back to the term “life safety system” and once more consider it in the context of the interconnection and interoperability of a building’s fire protection and other equipment. Once we recognize that there is a “building life safety system,” it becomes obvious that there should be a means to verify that system and not only its individual equipment components.
Well, finally some good news. Underwriters’ Laboratories of Canada is developing a new National Standard of Canada for the commissioning of building life safety systems. This standard is to be identified as CAN/ULCS575, Building/Facility Commissioning. The project has been approved for development under the purview of the ULC Committee on Fire Alarm and Life Safety Equipment and Systems.
The intent of CAN/ULC-S575, Building/Facility Commissioning, is to develop performance based commissioning parameters for integrated fire protection systems testing and verification. These include fire alarm systems connected to sprinkler systems, smoke control systems, ventilation systems, pressurization systems, door hold-open devices, electromagnetic locks, elevator recalls, fire shutters, etc.
A recent ULC standards bulletin indicated that it is the ultimate intention of the ULC committee to work with the National Research Council of Canada’s standing committees to have the CAN/ULC-S575 introduced into the National Building Code and the National Fire Code.
Good news for those of us who have experienced some of the issues described above, and good news for the general public who trust us to keep them safe.
Fred Leber is a principal of Leber-Rubes Inc. (LRI), fire protection and building code engineers of Toronto. www.leber-rubes.com
Underwriters’ Laboratories of Canada is developing a new National Standard of Canada for the commissioning of building life safety systems.