A watermist sprinkler fire engineered for the 21st century
Figure 1: Relatively large droplets are denoted I, medium sized droplets are denoted II, very small droplets are denoted III. The situation denoted IV is when medium sized droplets are following entrained air and combustion products into the fire plume.
It’s often been said that ‘if it’s not broken, don’t fix it’, and, when talking about the fire protection industry, it pays to err on the conservative side.
Since their debut installation in the Theatre Royal, Drury Lane, way back in 1812, the fundamental design of traditional sprinkler systems has remained fundamentally unchanged, until now.
A London company have taken the key attributes of the sprinkler system and turned them on their head. Looking to present an innovative alternative solution that looks to embrace technology and reimagine the fire sprinkler for the 21st century.
Plumis have devised the Automist Smartscan, a device that is already leading the way in how fires can be addressed more effectively, more efficiently, and leaving less damage than was ever thought possible before.
Following in-depth research into both watermist application and ‘means of escape’ particularly in a domestic setting, this fire suppression technology was design led with the intent of meeting the requirements of a fire engineer.
If you ask a fire engineer how best to address life safety in the home, they will of course say, the ultimate aim is to reduce the probability that fires happen in the first place and secondly if fires do occur they want to insure the spread of fire growth and fumes is slow so as to protect the escape routes for as long as possible.
This articles aims to explain the design philosophy behind the product:
- Activation at the earliest possible time
Recent and exhaustive testing by Plumis ensures that the SmartScan can trigger up to two minutes earlier than the traditional sprinkler system thanks to a utilised heat detector as opposed to the customary glass bulb. This is followed by a secondary IR heat detector housed on the spray head itself.
Once activated, in response to the onset of a growing blaze, the scanning technology seeks out the fire with its unique pivoting sensor and water-misting nozzle arrangement. Once the source of the fire is established, a powerful and targeted water mist if directed, rapidly suppressing the flames and keeping both water and fire damage to the minimum.
The company aim to take this further by triggering even earlier with a smoke alarm in the future, and using their secondary heat detector to verify the fire location and avoid false alarms notorious with smoke detection.
Plumis are building up a bank of knowledge into fire growth, allowing them to highlight potential risks before they become problems.
In addition the unit also produces a detailed recording of what took place to help establish what happened in a fire event.
- Efficient use of fire suppressant
Traditionally, sprinkler systems are mounted to the ceiling and as a result, water droplets flow – with gravity and momentum – down against the fire and smoke to reach the source of the fire that naturally moves upwards.
This means that, when activated, the smoke layer on the ceiling is dragged down, reducing overall visibility.
In contrast, through its side wall delivery, the Automist Smartscan is able to utilise the buoyancy of the fire plume to suck the mist in and suppress the fire.
To be most effective in cooling and suppressing flames, a water droplet should ideally evaporate inside the fire plume. If a droplet is entrained and flows upwards, together with the gases inside the plume, it will evaporate quickly when in contact with the hottest part. Upon losing its upwards momentum inside the fire plume, it will fall back, driven by gravity. It is then possible to utilise the unevaporated droplet twice.
Its more effective position and early activation means only 5.6 litres per minute is used to suppress fires which would typically require ten times as much with a traditional sprinkler solution. With easy installation without the requirement of a large tank or water main upgrade, costs, together with the consequences of activation, can significantly be reduced.
- Relentless Testing
The Automist Smartscan is the most comprehensively tested domestic watermist system in the UK. Plumis take pride in the independent third party validation of the Exova Warrington test reports (BS8458/BS9252 Fire Performance for Smartscan).
They are currently the only UK watermist company to have an LABC Registered Detail (EW534/EW171) and a BSi Verification Certificate (VC 656504) – two independent assessments of the fire and product performance against BS 8458:2015. Their systems have even saved at least two lives!
Aware of the need to demonstrate that the Automist Smartscan is suitable and sufficient for the task, Plumis have pushed their system limits beyond the bare minimum; challenging it in many tests to suppress or extinguish fires in any position.
Scenarios tested include difficult fires directly under the nozzle, common chip-pan fires and those hidden by furniture, together with a variety of free and forced draught conditions.
Demonstration tests have convincingly proved the technology’s worth time and time again. The Automist has even travelled to the USA, beginning the process of a UL 2167 listing and where it has favourably impressed fire and insurance authorities in live testing.
Third Party Certification by BRE Global has also established that Plumis have complied with the requirements of ISO 9001:2008 for design, manufacture and supply of water mist fire suppression systems. Plumis are also members of The Fire Industry Association, the largest fire protection trade association in the UK, and members of the International Water Mist Association.
- Homeowner engagement
The final issue the product looks to address is engagement with the homeowner.
Sprinklers can often be forgotten and unmaintained following installation. In many cases, where the system has failed to operate, it has been due to someone inadvertently disabling the sprinkler by perhaps switching off the water or painting over concealed heads. This is, in part, due to people assuming a fire will never happen to them and perhaps not valuing the benefit of fire prevention.
Plumis know they can effectively address this issue. By virtue of being a smart home device and winner of numerous design awards, it is more often than not found that the homeowner is proud of this innovative safety feature in their home and take all necessary precautions to ensure its operative role.
The Automist Smartscan system can communicate when a fault has arisen and the status of the system is demonstrable. It’s this very characteristic that the design team at Plumis are looking to exploit and evolve, with future application in controlling your heating and perhaps providing functionality in your security system.
It’s little wonder they have made a fan of David Purser, CBE for services to Fire Safety and winner of the Rasbash Medal by the Institution of Fire Engineers in 2013 in recognition of his contribution to the advancement of knowledge in fire behavior:
“I could see this system being useful in something like a loft conversion. If you convert your building from a two storey to a three story and you address the main hazard, say a fire in the downstairs lounge, by using the Plumis Automist system, you could hopefully knock down fires at a very early stage and therefore prevent any smoke coming out into the escape route. Should the fire be controlled at least, the volume and energy of the smoke is greatly reduced.”
For more information visit: http://www.plumis.co.uk/
Published: May 2017