False alarms from fire systems are one of the biggest issues in fire today. They have severe financial implications, can impact the effectiveness of fire planning in any building and cause widespread inconvenience.
he good news is the latest developments in fire system technology offer a number of solutions that can drastically reduce false alarm occurrences. This has been led by the development of a new generation of fire panels and high performance detection methods, which use cause-and-effect programming and human input to directly address the issue of incorrect activations.
The primary aim of these new innovations is to confirm the existence of a genuine incident prior to the next stage of the building evacuation strategy being implemented. The secret to successful false alarm reduction is to get the strategy right, which can then be used to develop the optimum configuration options for the system. This comes from the risk assessment and should be considered long before any specification is released.
Each building will have different users and specific circumstances that may require very different verification and investigation processes, as well as unique requirements for evacuation. They can all impact the other. Factors might include the design of the building, its purpose, the location, and the number of floors, so flexibility is key to an effective strategy.
The industry has adopted two primary approaches to address false alarms. Some systems are more focused on technology in the detector heads that works to identify false signals, while other systems concentrate on processing and interpreting signals from loop devices and making decisions in the fire panel. Some progressive manufacturers, Advanced being one, are combining the two into an integrated approach, attacking the causes of false alarms from many directions.
The development of intelligent detectors, which use advanced detection methods and smart algorithms to help differentiate between real fires and false signals, perhaps caused by steam or cooking smoke, has led to a real reduction in false alarms.
However, detectors do not need to be state of the art to make a real difference when married to an intelligent panel. Multimode detectors, for example, can be used to great effect. If the panel will support mode switching, the operating modes of these detectors can be switched between heat and smoke in order to confirm the validity of a signal.
Detectors can also be combined to work together using double-knock or coincidence detection to confirm a genuine alert. While modern detectors offer a superb solution, the best systems use both detection and fire panel technology to address false alarm challenges.
Automatic, addressable fire systems can take detector signals and use them to trigger a range of confirmation and verification procedures. The power of the integrated approach is that it develops and shares more information and allows many more inputs and outputs. These can be combined, usually automatically, but in certain circumstances manually, to significantly reduce false alarms.
Modern fire systems are highly efficient, with loops and networks having the power to cover large distances, allowing a single configuration programme to cover a whole network and site. The configuration options on a network can be huge, so simple programming methods are important. If it’s complicated, the chances of errors may increase.
This comes with a downside; the larger network allows genuine site wide coverage, but the specified system must also allow very fine control of false alarm verification, often by point or collection of points, and will probably require the sub-division of a system beyond simple zones.
Equally, a large network must not suffer from slower speeds. One of the key aspects of a false alarm management system is speed. Fast information from and response to inputs is vital, and on large sites the network speed has the potential to seriously inhibit the false alarm management strategy.
The key time periods to consider in false alarm management are verification times, which occur before a latched Fire signal, and investigation delays to outputs that occur after the latched signal. Both include scope for human intervention – indeed the latter has been a mainstay of alarm management for many years.
The new area of work on verification times has been controversial because, if handled incorrectly, it could potentially delay a full and valid fire condition. The good news is that, in recent years, panel manufactures have launched a range of methods that allow verification to be successfully and safely managed, and these are now widely specified.
The most common model uses a loop input device or dedicated repeater to extend the verification time, or to confirm that a local signal is not due to a real fire (eg. It may be due to burning toast).
The AlarmCalm Button, part of Advanced’s AlarmCalm solution, allows the panel verification time to be extended (once only) by the occupant of a room if they believe the signal in their area to be false. If the signal clears, the system will reset to normal, or if it persists beyond the pre-allotted verification time, the system will go into full alarm and the next stage of cause end effect will be activated. Options for this next phase may include further investigation or phased evacuation, critically this will usually be after a latched fire condition.
When people are introduced in to the equation, failsafe procedures must be strong. The AlarmCalm button can only be pressed once before a system reset, and times are programmable. If an alarm signal has been verified by the panel, or if a manual call point is activated, the system will enter a full fire alarm condition immediately, which is why failsafe options are key, and also why the system should cater for various potential evacuation strategies.
Once a signal has been confirmed and latched on the fire system, users then have investigation delay options. Again, these must not inhibit safe evacuation, but rather enhance it.
Phased evacuation allows the fire system to be programmed dynamically to evacuate those most in danger first, sometimes to a safe area, unlike a traditional ‘all out’ system, which offers only single stage evacuation. The industry has also developed two stage alarms (alert and evacuate), local (staff) sounders, beacons and pagers, and panel notifications that will alert trained staff and sometimes residents to potential issues before signalling a zonal or full evacuation. Alarm signals to other output devices, such as any automatic door release, will work independently of any evacuation delays.
Planning and thought should also be applied to how the system will be monitored, serviced and maintained. An increasing number of solutions are available that allow fire systems to be remotely monitored and controlled, which means an engineer can arrive with a plan agreed and all spare parts required, minimising disruption to the building’s users.
Another key aspect to consider when specifying a false alarm management system is the ease of management. Can the system be divided precisely into different areas? Can points be managed singly or grouped – as in an apartment – and is it easy to programme and install? On big sites, wiring and configuration can add much complexity and cost, so they should be treated as an integral part of the design process.
Equally, priority should be given to selecting a system that is acceptably intuitive for staff and designated users to operate. The ability to share information in dynamic fire conditions has also developed rapidly, for example some touchscreen displays are a key tool that can make it easier to identify the location and status of an alarm. TouchControl from Advanced is a touchscreen repeater and remote control terminal that includes Active Maps and zone plans.
Another tool to consider, particularly across larger sites, and those with residents or overnight guests, is an automated paging system, such as Advanced’s own Lifeline panel. Linked to any new or existing fire system, these can be used to ensure DDA compliance for the hearing impaired (via a bedside unit or pillow vibrator), to pass live fire system information to staff pagers, and to send pre-programmed messages to users.
These systems have a key role to play in false alarm management because they offer the potential to provide detailed information from the fire system in real time, thereby giving them the tools they need to respond and confirm the alert as rapidly as possible. They work on a secure localised UHF radio network that allows increased signal penetration for optimal building coverage.
In summary, false alarm management is not only about detector technology and selection, but also about specifying the right system to suit each site-wide strategy, which is why it should be an integral part of the design and specification process on all new and refurbished buildings, involving all key stakeholders.
The fire system requirements of any public environment, be it business or residential, are demanding, but the fire industry continues to deliver innovation with a wide range of systems and solutions to address the issue of false alarm management.
For more information, go to www.advancedco.com