New European standards and legislation are among the issues that need to be considered when specifying the most effective evacuation solution for a building, as Adam Bernstein reports.
Evacuating people from a building is a complex operation requiring the input of specialists from initial consultation and design stage through to commissioning and continuing building management.
But only when it is used in anger can the effectiveness of alarm systems be truly evaluated. So what should FMs be aware of when specifying?
Klaxon Signals’ Clym Brown says it is vital to assess the nature and importance of the messages, the type of personnel for whom the messages are intended; and the environment that the system will be installed in. His company differentiates notification system types into three application areas — fire safety, mass notification systems and industrial signalling.
“Each requires a different approach and mindset, and it is equally as important for facilities managers and end users to understand the different philosophies and constraints of each system type,” he says.
It is imperative that there is no ambiguity in messages or system performance requirements. No one fire safety element works in isolation.
Paul Pope, business innovation manager EMEA for Apollo Fire Detectors, says fire detection and alarm systems do provide one method for the early warning and evacuation strategy to begin — “but before this, a lot of work has to be undertaken to ensure that all elements come together so that all occupants are given the best possible chance to exit the premises safely and quickly under a number of scenarios”.
British Standard BS5839 Part 1 is the basic requirement for all fire systems.
Jim Spowart, senior applications engineer at Eaton’s Fire Systems Business, says: “The main requirement is to detect a fire at an early stage to give the maximum available time to enable safe evacuation.”
There are five elements of the standard’s requirement:
- Effective and early detection;
- A method of raising the alarm either by automatic or manual devices;
- A method of alerting occupants, a similar sound audible throughout the building with fixed minimum sound outputs;
- Clearly defined, protected and unobstructed escape routes; and
- A clear evacuation plan.
“Fire alarm systems must be able to warn all occupants of the need for evacuation, assuming that the recipients have no system knowledge nor have any specialist training,” says Brown. “These markets are highly regulated, defining both product and system performance and ensuring that fire systems behave and operate consistently in terms of detection and evacuation.”
Part of the equation means making sure that the fire detection system operates the fire protection measures correctly according to the evacuation strategy. For Pope, such considerations include simultaneous or phased evacuation, closing fire containment doors, grounding lifts to a safe area relative to the fire, fire and smoke damper control.
Everybody out
Legislation has led to fire and security systems with capability beyond that of a basic audible warning. To comply with the Disability Discrimination Act (DDA) 1995 a sounder can now no longer be used in isolation but must be used in conjunction with a beacon. To evacuate everyone from a building, duty holders need to signal effectively using light as well as sound.
Brown and Pope point to standards — as well as legislation — as having made a difference in product design. A new European fire system standard, EN54-23, came into force on 31 December 2013 and it recognises new requirements and specifies the minimum performance requirements for Visual Alarm Devices (VADs), removing any ambiguity regarding the light output requirements or system design parameters involved with using light to evacuate buildings.
The aim of EN54-23 is to enable manufacturers to design, produce and have certified VADs to a specified visual coverage and mounting position to ensure that any person with a hearing impairment — physical, environmental or equipment related — is notified in the event of a fire. “In these situations, audible alarms — sounders — are not considered to be effective as the only primary means of warning device,” says Pope.
The standard specifies the minimum requirements for VADs, providing performance criteria and test methods in a uniform and consistent way.
VADs are particularly useful in areas such as hotels, hospitals, and shopping centres, says Pope, adding that following a site/risk assessment VADs should be positioned wherever hearing-impaired people may be unaccompanied, such as bathrooms, toilets and bedrooms.
EN54 will have big implications for product selection and system design, says Brown. And in the context of EN54-23, generating sufficient light output to meet the new requirements has required advancements in light technology that has increased device costs.
Spowart echoes this, noting that recent changes to EN54 have also prompted changes to panels, power supplies and sounders.
“The challenge created from the introduction of VADs under EN54-23 has been an increased current draw on devices. Previously, manufacturers had been gradually reducing the amount of current through a variety of efficiency savings aimed at reducing the size of backup battery or providing a longer standby period for the same battery capacity.”
More importantly, most conventional and addressable fire alarm systems are dependent on low current devices, allowing numerous system components to be added onto a single loop, where one wire connects all devices to the control panel. Brown says this saves time and cost in wiring, reducing the number of power supplies and aiding installation and commissioning. But EN54-23 demands devices that require additional power to comply with the new light output and system coverage requirements.
One consideration when specifying is that, as Spowart says, most manufacturers use their own communications protocol so only their equipment will work on their panels. “For these applications ease of installation, costs and reliability are the choices of the installer.”
Mass notification
With ever greater numbers of people comes the greater need to devise more efficient methods of evacuation with “mass notification systems” and signalling solutions for large complexes (see FM World, 1 November 2013). Spowart believes that the most effective method of carrying out a mass evacuation is by use of voice commands. “Research has proven that in an emergency people will react without confusion or panic if they receive a clear, intelligible message.”
A well-implemented system, says Spowart, can be used to direct people away from the source of danger or, indeed, to tell them to remain in their current position and await further instructions.
However, systems can be multi-purposed. Most large enclosed areas such as shopping centres, football grounds and theatres already use public address systems for announcements. These can be used to convey safety messages. But, says Spowart, if this is the case, then fire-rated cable (FP200 type) must be specified for the speaker circuits. He adds that the use of speakers for fire safety messaging is regulated by BS5839 Part 8, which indicates the type of speakers, sound pressure levels and intelligibility. This means that the terminal blocks (usually ceramic) need to be able to withstand a similar temperature for a similar duration to that of the interconnecting cable (fire rated 830C — PH30 standard cables/930C PH120 enhanced cables) and recessed ceiling loudspeakers (when used) need to be fitted with a protective, non-combustible fire dome capable of withstanding a temperature of 850C.
“Each solution must be bespoke for the location and environment. It’s not a case of applying standard products in a standard configuration,” says Brown.
Mass notification system design generally falls into four discrete stages:
- Strategic assessment: Initial enquiries are assessed for mass notification suitability to ensure that the aims of system performance are clearly defined.
- Physical location study: The properties of the application site, taking into account its size and location, population density, special factors and communication requirements.
- Acoustic analysis: A background acoustic survey is conducted and major sound path restrictions identified, leading to the development of a sound plan based on a computer simulation.
- Solution design: Different designs are computer modelled and evaluated. Procurement specifications are then produced.
Part of the modelling process involves inputting the physical dimensions of the site and modelling all elements that affect sound propagation, including outbuildings, terrain, and other environmental factors. Also, by taking on-site background ambient noise readings and including them in the model system, designers can assess performance based on volume differentials and message intelligibility.
Industrial signalling
While fire and mass notification are obvious targets for notification systems, industrial signalling applications can take many forms. Brown details how they can notify that a machine is operating, automate production and indicate that a room is occupied — “what will be interesting for industrial markets is the potential effect EN54-23 may have on product selection and availability,” he says.
But products used for generic industrial applications are derived from products aimed at the fire market that have been adapted to industrial use by converting to work with AC-based power supplies.
External areas also require protection. Consider that in the case of educational establishments, large industrial and Control of Major Accident Hazards sites the duty to protect extends not only to site personnel or students outside the buildings, but also members of the public.
Systems need sirens that use a clear voice and tone signal communication above local background noise across a wide area. These must be supported with beacons, display messageboards and GSM messaging facilities.
Brown says it can be argued that for people working in a facility — and those contracted to it — only a simple tone warning signal is required as they will have been trained in the appropriate response. But the general public will not recognise the meaning of the signal. And there may be more than one form of incident to be communicated. Examples of this include warning of a fire — when people are required to remain outside buildings — and incidents when terrorism is involved and staff need to stay inside in a ‘lockdown’. It is important to be able to be able to use a public address system or a large-screen display for messaging in a fast-changing situation.
“A pre-recorded message facility could be useful to communicate to people who do not speak English as a first language, or at all, as the messages could be broadcast in several languages,” says Brown.
But one issue creates more difficulty and confusion in open-air, wide-area signalling: No national standards apply to a certain signal type and its meaning, so the general public and visitors to a site cannot automatically recognise it or understand the meaning of the signal and react accordingly. Brown says that this extends to site personnel whose site adjoins another facility where a particular warning signal heard on either side means different things on the two sites.
Each installation needs its own bespoke evaluation and set-up as the building layouts, the audio paths, the people to be communicated to and the hazards specific to that building all differ. There is, therefore, no ‘one-size-fits-all’ solution. Buyers need to seek good advice, involve the professionals and buy according to the standards that exist; there really is no other way out.
Escape equality – fire safety legislation
The The Disability Discrimination Act (DDA) 1995 played a key role in developing the fire industry. Employers, organisations and businesses must now have fire procedures in place that take account of the requirements of the DDA, including warning systems catering for both the hearing and visually impaired.
The act was extended by the Disability Discrimination (NI) Order 2006. But, says Eaton’s Fire Systems Business’s Jim Spowart, there are other laws and codes of practice to bear in mind such as Building Regulations Approved Document M, covering disabled access to and use of buildings while Section M1 includes schools, maintained schools and purpose-built student accommodation; the Building Regulations Approved Document B (Fire Safety) Volume 2, Section 4 covering designs for vertical escapes in buildings other than flats, all commercial buildings and housing association properties; and British Standard 8300:2009, covering the provision of disabled facilities within a building.
There’s also the Regulatory Reform (Fire Safety) Order 2005 (RRO). It says the responsibility for fire safety lies with employers, who have a duty to safeguard all who use their premises, including those in the immediate vicinity. In essence, the RRO requires any person who exercises control over premises to take reasonable steps to make sure occupants can escape safely if fire breaks out. The RRO was made under the Regulatory Reform Act 2001 and combines previous fire safety law into a single piece of law.
Although a fire risk assessment was necessary under previous legislation, the RRO requires the responsible person to make a suitable assessment of the risks to identify the general fire precautions needed. The RRO is enforced by county fire and rescue services, who can offer informal advice on improving fire safety provisions, issue a Notification of Deficiencies advising of shortfalls on fire safety provisions, issue an Enforcement Notice detailing requirements and setting timescales, and issue an Alterations Notice if required to prevent changes to provisions already in force.
But, says Spowart: “It’s the power to issue a prohibition or restriction notice to restrict use of all or part of a building or their ability to bring prosecutions through the courts for persistent or extreme non-compliance that should concern duty holders the most.
“These policies have not only forced employer accountability, they’ve have changed the way the fire industry has developed. Technology has moved on from the simple fire bell and is making use of combined sounder-beacon technology and pre-recorded voice messaging.” – See more at: http://www.fm-world.co.uk/features/feature-articles/gone-in-60-seconds/#sthash.EVebB9C9.dpuf