The great escape
23 March 2020
As our buildings and the way in which we put them to use become more complex, the challenges of safely evacuating occupants also increase. The latest analogue addressable fire panels give fire engineers, specifiers and end users more control and peace of mind than ever, delivering unprecedented levels of performance and accuracy, explains Paul Duffy
The capabilities of latest analogue addressable fire panels stretch way beyond ‘detecting a possible fire and letting everyone know’, by making evacuations safer and faster, detecting earlier, operating well past the initial activation and integrating with third-party building management systems (BMS).
Better by design
Effective evacuation begins at fire system design stage. Whether a new-build or refurbishment, building use, escape routes, fire compartments and false alarm minimisation should all be considered 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 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 evacuation.
Avoiding unnecessary evacuations
Ideally, evacuation only occurs when a building is in genuine false alarm, and recent innovations in false alarm reduction aim to ensure this. Panels like Advanced’s MxPro 5 combine cause and effect programming with human interventions and intelligent detection to confirm alarm signals. Using complex algorithms in conjunction with an intelligent panel, detectors can operate in different sensitivity modes to confirm an activation, or in combination with other devices – commonly referred to as co-incidence or double knock.
Programming of alarm verification and investigation delays is straightforward. 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.
The responsible person is 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, including flashing bedside units and pillow vibrators, can also alert people with hearing impairment, aiding evacuation.
The system is the key
In a real emergency, the fire system may be managing all manner of devices with involved strategies. 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 to 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.
Processing power is critical, particularly on larger sites where systems that can convey accurate information about the location of an alarm quickly can make use of valuable extra seconds for investigation, verification, evacuation and, ultimately, firefighting. EN54-13 compliant panels 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 program
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 the needs of specific individuals.
A system should also have the programming capability to manage phased evacuation. By using cause and effect programming in conjunction with the latest sounders that support recorded messages, or ‘alert’ and ‘evac’ tones, the people most in danger from a fire can be evacuated first. Meanwhile, the flow of other people in the building can also be kept at a manageable level and safe escape routes can be maintained.
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.
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 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 a site to give dynamic information in control rooms.
Evacuate alert systems
Newly introduced, evacuation alert control and indicating equipment (EACIE) that supports the fire and rescue service during firefighting and rescue operations, helps enable the phased evacuation of an area, floor or building in the safest possible way.
BS 8629:2019 is the new code of practice for the design, installation, commissioning and maintenance of evacuation alert systems for use by fire and rescue services in Britain. In place since November 2019, this standard applies to new blocks of flats with a storey located at a height of more than 18 metres above ground level. It recommends the installation of a dedicated evacuation alert system intended for the sole use of the fire brigade and separate from the building’s fire alarm system.
The standard stipulates against this integrated arrangement in order to avoid confusion between fire and rescue service evacuation alert systems and fire detection and alarm systems, and until the concept and management of evacuation alert systems becomes well established and understood.
For maximum ease of use, the evacuation alert panel should provide a simple, at-a-glance overview of the building’s evacuation alert zones along with LED indication and manual controls for operating evacuation alert devices in each zone. The panel needs to be in a suitably rated security enclosure only accessible by the fire and rescue service. Most importantly, the panel has to be designed to support any anticipated firefighting and rescue strategy and must not limit evacuation options. These systems should be planned, designed and commissioned in consultation with the fire and rescue services.
For larger buildings in particular, an evacuation situation can potentially lead to a great deal of confusion.
The intelligibility of mass notification 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 these alerts are highly effective in a fire situation, and the fire system may well be required to integrate with a voice evacuation system. These systems are becoming more widespread as they are more effective in attracting attention, as people hearing a voice message are less likely to automatically suspect a false alarm.
With smoke inhalation killing more people than fires themselves, its flow is a major concern, particularly in larger or complex buildings where it is important to ensure that evacuation routes are kept clear. 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.
In effectively managing how smoke and fresh air travel within a building, sometimes off-the-shelf smoke control panels don’t offer the best solution. In cases such as these, Advanced’s AdSpecials department designs and manufactures custom solutions for the most specific of fire protection challenges. Bespoke fireman’s damper control panels, sprinkler indication panels and custom control interfaces offer a more tailored approach that is often the best way to integrate these critical but complicated systems.
Adequate emergency lighting is a vital aid to 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 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’ to await safe evacuation.
In all cases, the key to safe evacuation is planning. The fire risk assessment, evacuation strategy and specification of a suitable fire system are crucial to success.
Paul Duffy is technical support manager at Advanced. For more information please visit: www.advancedco.com