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6.3 c) Thermally actuated nozzles

BS 8458 states: 

‘thermally activated nozzles should have quick-response thermal elements in accordance with BS EN 12259-1’

Traditional fire sprinklers are designed to operate when affected by the heat from a fire. When a blaze ignites, the air directly above it heats rapidly. This hot air rises and spreads out along the ceiling. Most sprinkler heads feature a glass bulb filled with a glycerin-based liquid. This liquid expands when it comes in contact with heated air. When the liquid expands, it shatters the glass and the sprinkler head activates. Sprinklers work best on fast-growing fires, like an old sofa fire, as the activation temperature threshold is breached quickly minimising the time for toxic gas production.

Electronically controlled nozzles overcome the constraint of current sprinkler systems that depend on a change of state of an element or the bursting of a glass bulb when it reaches a certain temperature. Our solutions can operate earlier, before the temperature required to burst the glass bulb of a sprinkler, tackling fires before they generate that amount of heat, helping to reduce smoke and maintain survivable conditions. Fire engineering research shows Automist is superior to a conventional glass bulb ceiling-mounted system: 

"the measured activation times of a concealed sprinkler head is 2.0 to 13.7 times slower than those using an electronic nozzle system"

Read more - What is the definition of watermist systems in BS 8458?