Rabu, 17 Februari 2010

New fire alarms for old buildings

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This is an existing system that was going to be upgraded. This whole panel is filled with relays to get certain functions accomplished such as releasing security doors, roll-down shutters, and smoke control systems. This type of panel is replaced by smaller devices or can be integrated with the building management system (BMS) such that the fire alarm only provides an output to the BMS and the BMS triggers all these functions. All photos: Arup
The prospect of retrofitting an existing fire alarm system can be very troubling to building owners and facility managers because of the many possible pitfalls. Apart from potential interruptions to normal business operations, upgrading a fire alarm system can cause a great deal of anxiety regarding design and installation costs.
Because building owners and operators are understandably concerned about the value that they are getting when upgrading their fire alarm systems, they naturally opt for curtailing planning to get an expedient installation. However, well-executed due-diligence planning not only has the potential to save substantial sums of money on first costs, but can result in significant long-term savings associated with reduced upkeep and maintenance.

To upgrade—or not

There are many reasons why a building owner or facility manager may want to upgrade or even replace an existing fire alarm system. A few of the more common reasons are discussed below.
Code compliance—The need to comply with federal, state, and municipal codes or requirements is perhaps one of the most common motivations for replacing or upgrading fire alarm systems. Although buildings that undergo a change in use or occupancy would certainly be expected to comply with the current requirements for the design and installation of fire alarm systems, even fairly minor renovations to a building can trigger fire alarm upgrades. Specifically, compliance with state and federal accessibility requirements may necessitate that notification appliances be brought up to current code even in areas that are not directly being altered.
Furthermore, accessibility upgrades are not only triggered as a result of voluntary alterations or additions, but also can be required during the course of repairs to a building following a fire, earthquake, or similar catastrophic event.

Wear and tear—Older high- and low-voltage systems that have been in operation for many years may start to show their age through an increasing number of system troubles, false alarms, or system down-time events. These occurrences reveal more fundamental underlying reliability concerns associated with aging or poorly maintained system components. Some of these components, such as power supplies, tend to wear out quicker than other installed elements of hardwired systems.
Other components, such as smoke detectors, may start to malfunction because they become dirty or damaged from the normal wear and tear that occurs in a lived-in building. Although many manufacturers recommend replacement of detection devices every 10 years, it is not uncommon for smoke detectors to be in service for more than twice as long. Over the span of many years, tenant improvements and other building alterations or system adjustments may have been performed, resulting in subpar performance.
Obsolescence—System obsolescence is another factor that may influence the decision to replace an existing fire alarm system. With older systems that did not rely as much on integrated circuit technology, a fire alarm system would last for 30 to 40 years. However, as the capabilities of fire alarm systems increased over time (and the reliance on proprietary technologies), the useful life span of the systems diminished. In much the same way that consumers have opted for newer, faster computers in the past two decades, so has the fire alarm industry become more reliant on rapidly advancing technologies that are not always backward-compatible or cross-listed for use with available equipment. The net result was that fire alarm systems that used to last three or four decades were now becoming obsolete in 10 to 20 years as manufacturers stopped making parts, opting to create ever more versatile systems. The lack of parts availability and associated compatibility challenges have led many owners to simply upgrade rather than deal with a perpetually outdated system.

Integration with other systems—A newer, more versatile fire alarm system may be required to more efficiently integrate fire alarm functions with other building systems such as security, access control, or BAS. Newer codes allow for greater integration of the fire alarm system with other building systems. The form of integration may simply consist of monitoring other building equipment and controls, or it may entail the development of a common communications infrastructure to serve multiple building systems.

The cost of keeping an old system

Apart from the increased flexibility associated with newer components, one of the most compelling reasons to retrofit an older fire alarm system is the cost of keeping the outdated system intact. Aging and obsolete systems are subject to a number of pitfalls that can manifest as a slow but steady trickle from the owner's coffers.
False alarms—Older systems may not be able to take advantage of new technologies such as self-adjusting intelligent detectors that use alarm verification functions or integrate several detection technologies into one device to read “fire signatures.” As a result, the occurrence of false alarms may be greater, potentially resulting in fire department fines or increased fees from third-party alarm monitoring/service companies.
Maintenance costs—Existing infrastructure may require more frequent cleaning of sensing devices, as well as repair of wiring and notification appliances due to vandalism, age, or poor-quality changes made to the system. The normal wear and tear associated with even the small changes related to tenant fit-outs can add up to large service bills. Additionally, because older fire alarm systems cannot readily be combined with other building systems, disparate infrastructure and multiple vendors become necessary, and with them, multiple service contracts.
System downtime—For obsolete systems in particular, there can be significant delays in getting replacement parts. If the system becomes partially or totally nonoperational, the authorities having jurisdiction may require a fire watch or otherwise limit building occupancy until the fire alarm system is functional. Clearly, such outcomes can be very costly to any business.


Improper installation of a smoke detector is shown. Also note: Over time, the detector has been painted and no longer mounted in the proper orientation. Use of wire and nail as conduit strap is not an acceptable mounting technique.
   
 Planning for a new system
The first step in evaluating an existing fire alarm system is to pull together a team that knows code requirements and design approaches, inclusive of how fire alarm systems are installed. Typically, such a team consists of the owner or owner's representative, an engineer or fire alarm system designer with good working knowledge of fire alarm systems and the associated scope requirements, and a general contractor that can simultaneously direct the efforts of fire alarm contractors and service personnel.
Next, the team should undertake a due-diligence exercise to identify the relevant code requirements. It is critical to research basic code requirements to understand precisely how they pertain to the building occupancy and type. Although this might seem like an obvious task, it is often overlooked in favor of making assumptions about the existing uses that may or may not be true. Jurisdictions often allow a fire alarm system to be maintained in the arrangement in which it was originally approved, but many have different trip points as to when fire alarm maintenance becomes an upgrade that would require the entire existing system to be brought up to current code. A small investment in time to research the building occupancy and corresponding requirements early on can save huge sums of money and eliminate nasty surprises later during the plan review process.
After the basic code parameters have been identified, the team should do a bit of research about the system by examining drawings, interviewing maintenance personnel, and even reviewing available specifications in some instances. Such research might involve these types of questions:
  • Was the system well-maintained and was maintenance documented, or are there potential unknowns that could impact cost, schedule, and operational integrity?
  • Where the old and new systems are proposed to interface, will there be issues associated with strobe synchronization or the joining of other system components? Will information need to be shared between the two systems? It should be noted that most codes do not allow two systems to be permanently installed in a single building.
  • Where the fire alarm system is integrated with other building systems, is the extent of the integration understood? Or are there potential gaps in knowledge or scope that can result in costly additions later? Systems that may be interconnected to the fire alarm system include building automation, smoke control, sprinkler (e.g., pre-action releasing valves), gaseous suppression, security, door unlocking or releasing, and elevator recall.
  • Will the system likely be upgraded to include mass notification capabilities in the future?
  • Are there requirements associated with the new system that could cause complications for the existing system? For example, if a voice alarm system was not required at the time of original system installation, but is now required, how does this impact the existing panels and speakers?
  • Were there changes in related systems (e.g., fire sprinklers) that could cause complications? Would the changes in the new fire alarm system impact these systems, or vice-versa?
  • Are accessibility requirements along the path to the modified areas from the building entrance also being addressed? What changes do potential accessibility upgrades necessitate?
  • Are there any special occupancy requirements that would impact the contractor's ability to perform the work? For example, if the facility has to remain open during replacement, more costly measures should isolate building occupants from the construction.

The survey

Once the potential design (and cost) impacts have been identified, and the basic code research has been completed, it's time for the survey. The purpose of the survey is as much to identify existing conditions that will have an impact on the extent and constructability of any new fire alarm infrastructure, as to learn how much of the existing equipment can be reused. The survey can be framed in terms of the key system elements, including the backbone, initiating devices, and notification appliances. At a minimum, the following elements should be examined:
Fire alarm control panel—The manufacturer and model number of the panel are of equal import to the availability of expansion slots (the means by which additional appliances or devices are added). With this information in hand, it is possible to determine not only the technical capabilities of the system (e.g., is voice alarm an option with the existing panel?), but also the practical capabilities with respect to expansion of the fire alarm system.
Consideration must also be given to the existing system's manufacturer. Proprietary systems often require that the same manufacturer be used if parts of the system are to be reused. Also, if the system is part of a larger campus or site-wide system, the proprietary nature of the components will need to be addressed to maintain full functionality of the campus-wide system.


Wiring—Noting how the wiring was run, and whether conduit was provided, will go a long way toward informing the cost of adding new devices or appliances. Conduits can make it easier to run new wires through what would otherwise be very challenging post-construction environments. It should also be noted that while it may be attractive to retain existing wiring, it is not always the wisest decision because there may be compatibility issues between the wiring and any new installed equipment. If the existing system has many trouble conditions, they are often due to the wiring. All wire proposed to be reused and determined to be compliant with manufacturer's requirements should be tested for continuity and proper grounding before reuse.
Notification appliances—Speakers and strobes should be examined for quantity (coverage), intensity, and location. Newer codes typically have more stringent requirements for the spacing of notification appliances. Strobes manufactured prior to the Americans with Disabilities Act of 1990 (ADA) may have to be replaced with newer xenon strobes having greater flash intensity. Furthermore, systems installed before the enactment of the ADA may not be located at the proper heights, thus necessitating potentially expensive refinishing work to relocate speaker/strobe appliances. Strobe synchronization may also be of concern, both in terms of the existing system appliances and in terms of interfaces between subzones controlled by distinct panels. If a new front-end panel is being installed, cross-listing of existing appliances will need to be confirmed prior to re-use.
Power supplies—Power supplies should be looked at in concert with the notification appliances. Frequently, upgrades to the existing speaker/strobe system will necessitate upgrades to the power supplies serving a particular fire alarm system.
Detection—Because detectors must be replaced more frequently than other fire alarm system components, their condition and age should be carefully examined. To the extent possible, the surveyor should attempt to understand the history of the detectors to identify if trouble alarms or false alarms have resulted from age or improper application. Newer analog devices often use proprietary communications such that they cannot be re-used with other systems.
Alternatively, where older style four-wire detectors are still in use, the surveyor should be aware of potential cross-listing issues associated with the reuse of old style analog detectors with newer replacement panels. Although technically feasible to couple analog detection devices to newer fire alarm panels, such panels may not have been listed for use with the existing detectors, and thus the integrity of the system could be jeopardized.
Architectural features—The surveyor should take note of any aesthetic or historical architectural features that might require kid gloves. Common examples of features that may seem harmless at first but can result in significant cost impacts later are plaster or stone walls that have the potential to make running new wire very difficult. Similarly, relocating pull stations to the proper ADA height may require extensive stone work or less aesthetically pleasing cover plates. Alternative detection technologies such as air sampling and beam detection should be considered as they may allow the detection devices to be more easily concealed or limited in number, respectively.

Hazardous conditions—The presence of asbestos in the vicinity of fire alarm system components can pose significant cost and logistical challenges. If it becomes necessary to interact with existing asbestos installations, additional specialists will likely have to be hired to safely mitigate potential asbestos exposure.

The meeting of the minds

Because each jurisdiction has different requirements for the extent of work required to integrate system components or to update a fire alarm system, the team should have a meeting to flesh out the details.
For example, the design team will generally have to obtain concurrence that not all existing systems being touched will have to be brought up to code simply because portions of those systems are being upgraded in one way or another. Spelling out exactly what is being done and what is not being done can help to avoid nasty surprises during the inspection process that could impact the successful completion of the project.

Bringing it all together

The final step of the process is developing a fire alarm narrative and associated bid documents. Depending on the scope, scale, and location, these documents may be detailed drawings and specifications, or schematic sketches and performance specifications designed to facilitate the development of competitive bids for the fire alarm replacement or upgrade. In addition to their role in reducing risk to the bidders, excellent narratives, drawings, and specifications can be used to better articulate complex aspects of the desired system design, such as fire alarm integration with other building systems.
These documents can be used simultaneously to address construction phasing, inclusive of the needs of the project if the facility has to remain operational during the installation, as such requirements will have a direct impact on the cost and duration of the installation. Additionally, the bid documents should include an option for ongoing system maintenance and testing to meet local requirements.
Following distribution of the bid documents to qualified companies, a pre-bid meeting should be held with the potential bidders so they can understand the building and what is being proposed to be done, thereby setting the stage to conduct an apples-to-apples comparison of price to obtain the best overall value. Although characterized by a lower initial cost, an inferior installation will result in higher long-term maintenance and nuisance issues. The contactor's ability to perform the installation as well as the level of direct manufacturer support the contractor gets should be considered.
After contractor selection, it is important that the team identified at the beginning be kept in place to provide follow-up throughout the installation process. Inevitably, with a replacement project, unknown existing conditions will be discovered, and thus it is important that this team works with the contractor to ensure that cost-effective and functional solutions are developed. Through this type of cooperation, and with the benefit of clear documents to enhance communication and commissioning efforts, the many challenges of fire alarm retrofit and replacement can be effectively save money for the owner and yield a higher performance system in the long run.
 

 

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