Gas & Water Suppression
NEFP now offer water mist fire suppression sprinkler installations to BS8458 along with our established gas suppression systems.
We are helping this fledgling field of fire protection to establish safe designs and working practices to develop a practical and functional water mist fire suppression installation suitable for domestic and residential requirements.
Benefits of water mist systems may include a lower water flow requirement where we can prove that water mist nozzles can actually perform against the fire loading. Customers should note that water mist nozzle manufacturers make certain claims about performance which when tested by independent test houses such as the BRE can be found to not perform as expected.
Where we can make water mist effective as a suppression system, there is a benefit in stored water volumes being reduced which helps offset the higher cost of high pressure pumps that are required.
With the introduction of the DD ( Draft Document, which is a trial version of a forthcoming standard) from the British Standards Institute we now have a document to measure the performance of our product against and to give our customers the comfort of knowing their water mist installation has been designed and fitted correctly.
How Water Mist Fire Suppression Systems work.
In water mist systems, water is forced through micro nozzles to form a water mist with the most effective firefighting droplet size.
The water mist can give optimum protection by its cooling effect and by the "inerting" or elimination of oxygen effect as water expands by a factor of 1700 when it evaporates.
Thus when water mist comes into contact with the fire - heat and oxygen, 2 of the essential ingredients of fire are much reduced or eliminated.
Less water is required in water mist systems than with conventional fire sprinklers systems.
Water mist systems are almost like the spray from an aerosol where conventional sprinklers are more like the water coming from a domestic shower.
Water Mist systems are not ideally suited to all applications.
Summary of UK Gov Building Research Establishment on commercial applications for water mist fire suppression systems.
"Overall, the full scale test results were of concern. Most water mist system arrangements were not able to provide expected levels of fire protection for the tested scenario (open plan office areas with a high ceiling). Or, in terms of the design of the tested systems, the spacing between nozzles was too great and the quantity of water discharged too low, to provide effective fire suppression."