Emergency Evacuations: Think smart to prepare for the worst

As our buildings and the uses to which we put them become more complex, the challenges of safely evacuating occupants also increase. The latest analogue addressable fire panels give integrators, specifiers and end users more control and peace of mind than ever, delivering unprecedented levels of accuracy, performance and credibility.

The latest panels’ capabilities stretch way beyond ‘detecting a possible fire and letting everyone know’, making evacuations safer and faster by detecting and acting earlier, operating well past the initial activation and integrating with third party building management systems (BMS).

Better By Design

Effective evacuation begins at the design stage of the fire system. If the building is a new-build or refurbishment, things like building use, escape routes and fire compartments should all be considered at this stage, ideally as an integral part of the wider design and specification process.

An in-depth fire risk assessment needs to be carried out and, in the case of larger or more complex buildings, this may include a more detailed evacuation strategy for the site. This should cover important factors such as locations of indicating equipment, escape routes, safe areas and people at risk, as well as identifying and addressing any potential barriers to an effective evacuation.

Avoiding Unnecessary Evacuations

Ideally, we’ll only evacuate a building if it’s a genuine alarm and recent innovations in false alarm reduction are a major advantage. Panels like Advanced’s MxPro 5 combine cause and effect programming with human interventions and intelligent detection to confirm alarm signals. Many modern point detectors are good at false signal rejection. However, when used in conjunction with an intelligent panel, they can operate in different sensitivity modes to confirm an activation (mode change) or in combination with other devices (commonly referred to as co-incidence or double knock operation).

Another area of false alarm reduction is using investigation delays to allow trained personnel to identify the cause of alarm in a given area. After the fire condition is displayed at the panel, the responsible person can physically check if an activated device is a genuine alarm. If no action is taken the delay expires or, if a pre-determined set of conditions are met, evacuation will commence. However, if the alarm was false and the signal has cleared, the responsible person can reset the panel, avoiding an unnecessary evacuation.

New devices like Advanced’s AlarmCalm Button can also be located, for example, in an apartment, allowing a resident to indicate if a local alarm is false (eg due to steam or cooking smoke). If the signal clears within a pre-programmed validation time, the system status returns to normal, but if it continues beyond the preset verification time, or any number of failsafes occur, a full alarm and the next stage of the evacuation programming are triggered.

Responsible people are also able to receive pre-warning of potential alarms, notice of validation periods or investigation delays via pagers. An integrated, secure paging system can provide rapid, detailed alerts of fire system signals, allowing them to be rapidly located and investigated. The same paging systems can also alert people with hearing impairment, using personal pagers, flashing bedside units and pillow vibrators to alert them to a fire alarm and aid evacuation.

Planning for the Worst

When a genuine alarm is confirmed, the evacuation needs to proceed as safely and quickly as possible, ensuring all occupants at risk are alerted and can leave the premises safely. While some buildings are relatively straightforward to evacuate, others are more complex, which is why it is vital to both plan and rehearse emergency evacuations, anticipating multiple fire scenarios.

Evacuation in larger premises can be an operation involving thousands of people. It’s not simply a case of activating the alarm and waiting for everyone to leave. A badly organised evacuation can result in life-threatening delays in the form of queues, clogged evacuation points and even crush situations, especially in an actual fire emergency.

The System is the Key

In a real emergency, the fire system may be managing all manner of devices with involved strategies, including phased evacuation, summoning of the fire and rescue service, smoke control, graphical indication, voice evacuation, door closures, safely shutting down plant, gas suppression, etc. This means that the specification of a suitable fire panel and associated components is vital to an effective evacuation.

A fire system is mandated in a building and the best are highly intelligent, with the ability to control many operations vital in safely protecting occupants and infrastructure. The panel needs to remain operational for long periods in adverse conditions, even as cables degrade (due to fire) or ultimately fail, so that a safe and orderly evacuation can be completed.

The fire system needs to work quickly and reliably, so processing power is an important consideration. On larger sites, seconds count and systems that can convey accurate information about the location of an alarm quickly can make use of valuable extra seconds in maximising the time for investigation, verification, evacuation and firefighting. Panels that are EN54-13 compliant will self-test components to ensure reliability, while also offering the assurance of fast and efficient operation to facilitate a rapid and efficient evacuation.

Get with the Programme

Programming is the key to meeting the full potential of fire system technology. Using cause and effect, modern fire panels can be configured according to usage of the whole building, specific areas or even according to the needs of specific individuals.

A system should also have the programming capability to manage phased evacuation. This uses cause and effect in conjunction with recorded messages, or ‘alert’ and ‘evac’ tones, to facilitate the evacuation of people most in danger from a fire first, whilst keeping the flow of other people in the building at a manageable level and maintaining safe escape routes. Indeed, super-tall buildings may evacuate to safe floors inside the building to reduce the load on evacuation systems and reduce the danger of crushes.

This cause and effect programming, alongside the latest sounders, voice alarms and beacons allows the residents in most need and in most danger to be evacuated first, minimising the possibilities of jammed and dangerous evacuation routes. Importantly, the panel and its programming must be able to manage this process in dynamic fire conditions with spreading fires and smoke in multiple areas simultaneously.

In more complex sites, custom interfaces can be developed to control the fire system, addressing the unique requirements of the building and integrating third party systems, such as sprinklers and the wider BMS. This helps to simplify what can become a very complicated process by bringing together all of the individual elements and helping to streamline the evacuation process.

Managing the Evacuation

All staff should be trained to operate and monitor the fire system, with regular update sessions and fire drills to ensure the effectiveness of the procedures put in place.

Providing clear, precise information to those responding to a fire signal in a building is key, which is where graphical repeater panels such as Advanced’s TouchControl can help. These use touchscreen technology to display dynamic maps of sites. Many systems will also link with PC graphics systems including diagrammatic representations of the site to give dynamic information in control rooms, and new technologies are allowing fire and rescue services to see this information before they arrive on site.

Some panels have provision for manual control of the system so that a firefighter or operator can take actions as the fire situation develops. For example, they may want to evacuate a particular area of a building, make live ‘voice’ announcements or manage the smoke control system. This facility is particularly advantageous in large or high-rise buildings where there can be a multitude of processes all going on at once.

Consideration also needs to be given to modern day threats with some sites. Traditional muster stations may be vulnerable to terror attack, so occupants are told to move away from the building and the traditional fire count is abandoned in favour of ‘clear floor’ surveys by marshalls. When safe to return, occupants can be informed by SMS messaging. Even the simple task of getting people out of the building can quickly become complicated, and the system configuration must be able to cope.

Communicating

For larger buildings in particular, an evacuation situation can potentially lead to a great deal of confusion due to large crowds of people and a profusion of different signals from the fire system. Voice alerts, tones, bells and strobes, especially if a mass notification system is in place that is warning of more dangers than a fire.

The intelligibility of these warnings is very important as potentially life-threatening situations can occur where messages are unintelligible or misunderstood. Fire system installers need to ensure that any messages are clear and audible, remain synchronised and properly indicate the nature of the incident, while also providing clear evacuation directions where necessary.

Research has shown that smart audio alerts, providing voice guidance and description, are highly effective in a fire situation. These systems have been used effectively in the USA for many years and are now becoming more widespread elsewhere. Not only are they more effective in attracting attention, with people less likely to automatically suspect a false alarm, they are also less likely to be ignored. Advanced’s unique PerfectSync systems effectively ensures audio and strobe synchronisation over any site.

Smoke Control

Another threat to safe evacuation is smoke, with smoke inhalation killing more people than fires themselves. The flow of smoke is a major concern, particularly in larger or complex buildings, where it is important to ensure that evacuation routes are kept clear of smoke. This can be managed via fans and dampers, using either the building’s HVAC (heating, ventilation and air conditioning) system or using a dedicated smoke control system to manage airflow through the building in the event of fire.

Modern smoke control is an active and dynamic tool. The best fire systems can manage smoke and airflow through a building both automatically and if needs be manually, and can help keep evacuation routes clear of smoke by pressurising stairwells, for example. They can also exhaust smoke from an area, help contain a fire in an area or clear smoke from a building after a fire is extinguished.

The operation of such systems is highly complex, with many layers of detection, cause and effect and interlocking required to guarantee safe operation, so the speed and power of the fire panel, and the ease with which it can be programmed and controlled are vital.

Emergency Lighting

Adequate emergency lighting is a vital tool in a successful evacuation. Modern emergency lighting panels, such as Lux Intelligent from Advanced, can self-test each luminaire and ensure they work when they need to. The range of luminaires, both traditional and LED is now huge and environmental lighting can be converted to emergency use, delivering compliance and performance benefits.

In the future, we are likely to see a move towards even more intelligent systems that focus on directing the public towards a specific exit route, as opposed to simply lighting up the area. The technology to do this does exist, but with limited guidance legislation, the jury is still out on whether the public will take notice, or simply follow the crowd.

In more complex or high-rise buildings, you also need to provide standby or ‘stay-put’ lighting to allow for non-evacuation if it is not deemed the best course of action, or where occupants are marshalled on ‘refuge floors’ and awaiting safe evacuation.

The key to safe evacuation is planning. The fire risk assessment, evacuation strategy and specification of a suitable fire system are vital.

For more information, go to www.advancedco.com