An external water spray system (EWSS) is a

domestic Domestic may refer to: In the home * Anything relating to the human home or family ** A domestic animal, one that has undergone domestication ** A domestic appliance, or home appliance ** A domestic partnership ** Domestic science, sometimes cal ...

external

fire sprinkler system A fire sprinkler system is an active fire protection method, consisting of a water supply system providing adequate pressure and flowrate to a water distribution piping system, to which fire sprinklers are connected. Although initially used on ...

designed to protect homes from

bushfires A wildfire, forest fire, or a bushfire is an unplanned and uncontrolled fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identified as a ...

and

wildfires A wildfire, forest fire, or a bushfire is an unplanned and uncontrolled fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identified as a ...

. While external spray systems have long been used in fire protection for buildings and facilities, EWSS refers to domestic bushfire/wildfire systems.

Usage

The types of systems vary greatly from a single impact sprinkler placed on a

roof A roof (: roofs or rooves) is the top covering of a building, including all materials and constructions necessary to support it on the walls of the building or on uprights, providing protection against rain, snow, sunlight, extremes of tempera ...

, systems installed during

construction Construction are processes involved in delivering buildings, infrastructure, industrial facilities, and associated activities through to the end of their life. It typically starts with planning, financing, and design that continues until the a ...

with sprays on all

window A window is an opening in a wall, door, roof, or vehicle that allows the exchange of light and may also allow the passage of sound and sometimes air. Modern windows are usually glazed or covered in some other transparent or translucent ma ...

s and

door A door is a hinged or otherwise movable barrier that allows ingress (entry) into and egress (exit) from an enclosure. The created opening in the wall is a ''doorway'' or ''portal''. A door's essential and primary purpose is to provide securit ...

s, and small sprays damping gutters. Some are installed using

copper Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...

piping Within industry, piping is a system of pipes used to convey fluids (liquids and gases) from one location to another. The engineering discipline of piping design studies the efficient transport of fluid. Industrial process piping (and accomp ...

and sprays while others use common PVC piping. Usage depends on type of

risk In simple terms, risk is the possibility of something bad happening. Risk involves uncertainty about the effects/implications of an activity with respect to something that humans value (such as health, well-being, wealth, property or the environ ...

and belief of effectiveness. Copper piping is used to withstand high

temperature Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measurement, measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making ...

s that may be experienced during a fire front or for higher reliability for in

ceiling A ceiling is an overhead interior roof that covers the upper limits of a room. It is not generally considered a structural element, but a finished surface concealing the underside of the roof structure or the floor of a story above. Ceilings can ...

installations. External PVC piping is used where failure with exposure to high

radiant heat Thermal radiation is electromagnetic radiation emitted by the thermal motion of particles in matter. All matter with a temperature greater than absolute zero emits thermal radiation. The emission of energy arises from a combination of electro ...

is acceptable, as at the time the system is considered have "done its job". This is a matter of personal judgment.

Issues

There is a lack of scientific research regarding EWSS. Other issues that may affect the effectiveness of an EWSS: * Sprinkler performance in high

wind Wind is the natural movement of atmosphere of Earth, air or other gases relative to a planetary surface, planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heatin ...

conditions typical in a bushfire * Home design ** High vulnerability areas. e.g. decking **

Garden A garden is a planned space, usually outdoors, set aside for the cultivation, display, and enjoyment of plants and other forms of nature. The single feature identifying even the wildest wild garden is ''control''. The garden can incorporate bot ...

beds near walls ** Window sills ** Large windows (heat radiation) ** Internal furnishings (e.g.

curtain A curtain is a piece of cloth or other material intended to block or obscure light, air drafts, or (in the case of a shower curtain) water. Curtains are often hung on the inside of a building's windows to block the passage of light. For instan ...

s) * Home location **

Slope In mathematics, the slope or gradient of a Line (mathematics), line is a number that describes the direction (geometry), direction of the line on a plane (geometry), plane. Often denoted by the letter ''m'', slope is calculated as the ratio of t ...

** Surrounding

vegetation Vegetation is an assemblage of plants and the ground cover they provide. It is a general term, without specific reference to particular Taxon, taxa, life forms, structure, Spatial ecology, spatial extent, or any other specific Botany, botanic ...

* If defended by occupiers * Preparation (if prepared for defense) * If intended for remote (unattended) defense * Available

water supply Water supply is the provision of water by public utilities, commercial organisations, community endeavors or by individuals, usually via a system of pumps and pipes. Public water supply systems are crucial to properly functioning societies. Th ...

Ember attack An ember attack is when, during a bushfire, embers (also known as firebrands) such as burning twigs, bark fragments, moss or leaf, leaves become temporarily airborne and are carried by winds in a cluster. Fuel characteristics that make plentiful a ...

* Fire front (radiant heat) * Adjacent building or vegetation fire

Types

* Roof impact sprinkler * Gutter sprays * Window spray / deluge Commercial sprays designed for EWSS are available, but most systems use commonly available irrigation sprinklers/sprays.

Research

External spray systems for buildings are well documented for protection from fires in adjacent buildings. However, up there is little published scientific research on scientific information pertaining to the effectiveness of EWSS under varying wildfire conditions.

References

External links