According to the latest UK Fire and Rescue statistics, 40 per cent of all incidents attended by fire and rescue services were false alarms*. In fact, fire and rescue services attended more false alarms than fires in the period from April to September 2015, resulting in the already financially stretched Fire Authorities, having to waste precious resources attending these calls.
The five major causes of false alarms given by fire brigades are:
• Incorrect or poorly designed systems
• Fumes from cooking or burnt food
• Steam, aerosols and other fumes activating the detectors
• The build-up of dust on a detector, caused perhaps by building work or air conditioning outlets
• Accidental damage to a 'break glass' point
So what part can the fire system designer play in reducing false alarms?
Of course, false alarms are not only costly to the Fire Services; there is also a cost to your business in terms of lost production and disruption caused by staff evacuation. According to the Fire Industry Association, it is estimated that false alarms cost UK businesses in excess of £1 billion per annum, so how can the design of your fire system assist in reducing incidents and their associated costs?
Let’s take each of the causes cited in the list above:
• Incorrect or poorly designed system. This highlights the importance of the system being correctly designed at the point of installation. BS 5839-1: 2013 is the current code of practice that makes recommendations for the design, installation, commissioning and maintenance of fire detection and fire alarm systems in non-domestic premises and also includes a section devoted to False Alarm management for reference but reputable fire safety equipment suppliers will also have qualified experts on hand to advise and assist you.
• Fumes from cooking or burnt food. The advent of breakfast at work for those arriving early has brought the toaster into the workplace. This in turn generates a huge amount of false alarms, so the detector within the room needs to perhaps be a rate of rise heat detector.
But what about the corridor outside the room? Corridors on escape routes must be protected by smoke detectors. Look at the corridor - does the detector have to go outside the kitchen door? Many typical corridors are less than 2M wide, so take advantage of the increased spacing allowed in such corridors and assess the best place for the detector, away from door of the room containing the toaster.
• Steam, aerosols and other fumes activating the detectors. Steam from showers in hotel bedrooms is a given, so consider using a CO detector within the room (these are specially designed for fire detection and are not to be confused with those placed near boilers for life safety). Don’t just place the detector in the centre of the room near the shower door, place it at the furthest point from the shower door - even if it is 500mm away from a wall on the other side of the room. Alternatively, take advantage of the many features offered by today’s addressable systems and engineer a solution using multi sensors and output delays to allow search time. Most importantly, don’t forget to have these solutions agreed by all parties and record them on the design certificate.
• The build-up of dust on a detector, caused perhaps by building work or air conditioning outlets. It’s amazing how much dust is created by an air conditioning outlet. Detectors should be located at least one metre from any outlet. Once again look for the best place within the room, as long as it’s over 500mm from a wall or beam and it complies with the general coverage constraints.
• Accidental damage to a 'break glass' point. Consider moving away from detectors and using break glass call points instead. These are normally positioned at all external doors, high risk areas, at internal zonal boundaries etc. Where there is a possibility that the call point might be accidentally activated, why not fit a call point cover, or perhaps in a bar area of a pub, put the call point behind the bar? These will need to be recorded as variations but it does help to reduce false alarms.
In part 2 of this blog, we will explore some of the other common reasons for fire false alarms and what can be done to proactively manage and reduce such incidents.
Tim Mann has more than 30 years’ experience in the electrical industry and has specialised in the fire protection industry for the last 20 years. As Group Technical Manager at Sentura Group, his role is to provide help and advice to ensure that customer’s installations are done right first time and to assist in solving their existing equipment and installations problems.
* The Fire False Alarms information was taken from Fire Statistics Monitor: England April to September 2015 as published by the Department for Communities and Local Government