6.3 System design
A single Automist Smartscan Hydra spray head has a maximum 6m range in front and 4m range either side along the wall depending on the spray heads location. The spray pattern acknowledges it is easier for us to address fires in front of the spray head as opposed to alongside it.
The spray head must therefore have an approximate line of sight of any possible fire hazards within this range and be positioned at least:
- 1.5m away from any hob
- 1.5m away from any oven (if in direct line of sight)
- 3m away from any log burners or small fireplaces
Visibility extends radially from each mist head and ends wherever there is an obstruction. If an obstruction is fixed and equal or more than 0.9 m high (standard worktop height), it must be regarded as blocking the line of sight from any spray head positioned within 3m and reflected in the layout drawing. For example, bookshelves, wardrobes, large fridges, or vertical radiator covers. Obstructions higher than 0.9 m and wider than 0.3m must be regarded as blocking the line of sight at any distance. This does not relate to a householder deciding to disable the suppression system; full obstruction of the spray head or the creation of de facto room partitions with bookcases are akin to willfully removing fire doors, decorating over sprinkler heads, or removing detectors and are beyond the scope of this recommendation.
Automist is a dry pipe system. The system has been tested considering the time taken to fill the hoses did not impact the ability of the system to suppress the fire during the tests. A dry pipe system avoids escape of water claims from tampering, legionella, corrosion and clogging risks.