Fire Detection


In many instances there are numerous opportunities for cameras to be hidden such as above the ceiling with a cut out for the camera lens. A solution that would generally not be possible in a heritage building.


Voluminous spaces: new and old designs The voluminous, often unusual, spaces created by new designs are echoed albeit differently by historic buildings.


Let's first take The Gherkin again as a modern example.


The lobby of this iconic property reaches 6.5 metres and has 6 light wells with a depth of 25m, which are used for ventilation. Such spaces can be challenging for fire detection.


Smoke stratification means that systems that rely on detectors being activated by smoke particles reaching sensors can be compromised.


Heated by the fire, smoke rises. When the smoke cools and comes down to the temperature of the surrounding air, it stratifies – an effect known as The Equilibrium Point.


Systems that are reliant on smoke particles reaching detection points cannot guarantee that stratification will not happen before it rises to trigger the alert. In addition, air flow behaviour can vary greatly, leading to complex and sometimes unpredictable smoke behaviour.


Smoke also takes time to reach point detectors. may never reach them in extreme circumstances.


Indeed, it


Pipes used for ASD can be quite prominent and so for listed buildings the affect on the aesthetics of the building can hinder consideration of the system.


Historic properties share many of these issues.


Spaces can be as large, one only has to think of Liverpool's Anglican Cathedral, the fifth-largest cathedral in the world by volume (with a height of more than 100m) to illustrate that spacial challenges can be as great in historic properties as they can in modern ones. The cathedral is far from an isolated illustration.


Visual Smoke Detection (VSD), Infrared (IR) and Aspirating smoke detectors (ASD).


Advanced fire detection solutions to consider The main fire detection solutions for high value properties are


Each fire detection system offers its particular strengths for the specific requirements of each building, relating to sensitivity, creativity required to meet the demands of legislation or the owners and of course, effectiveness to the particular challenge at hand.


The Solutions While ASD and IR have certain attributes, a VSD solution was selected by London Guildhall and The Gherkin.


VSD offers high value property buildings a system that can detect fire at source, without sensors having to be triggered. Using visual monitoring, large voluminous areas can be surveyed, focusing on areas of particular concern if required. The complexities and challenges of smoke stratification are significantly reduced.


The system works by detecting smoke patterns as well as changes in brightness, contrast, shape, motion, colour matching, content and loss that could indicate the early stages of a fire. Visual verification, on or off site, can determine if the situation warrants further action.


The key to a successful solution is not centred on compromise, but on a creative approach balanced with the most effective fire detection solution for the building in question. Each system offers benefits that can be considered in how best to protect the building. Today's systems offer a range of solutions that can be considered to protect high value property.


Alerts can be studied after the event to improve safety. Conclusion


Mark Tansey business development manager at fire detection solutions provider FireVu www.firevu.co.uk Mark can be contacted on 01928706422 or enquiry@firevu.co.uk


Guildhall's magnificent Great Hall – cameras are located above the stage in the distance (over the statue's hand) and on the balcony the solution cannot be seen at either location by the casual observer


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