External water spray system

An External Water Spray System (EWSS) is a domestic external fire sprinkler system designed to protect homes from bushfires and wildfires. 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, systems installed during construction with sprays on all windows and doors, and small sprays damping gutters. Some are installed using copper piping and sprays while others use common PVC piping.

Usage depends on type of risk and belief of effectiveness. Copper piping is used to withstand high temperatures that may be experienced during a fire front or for higher reliability for in ceiling installations. External PVC piping is used where failure with exposure to high radiant heat is acceptable as at the time the system is considered have "done its job". This is a matter of personal judgment.

Types of risks to be considered include:

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

Home location will greatly affect the type of risk which in turn will affect an EWSS system design.

Issues

The main EWSS issue is the lack of scientific research. Other issues that may affect the effectiveness of an EWSS:

* Sprinkler performance in high wind conditions typical in a bushfire
* Home design
** High vulnerability areas. e.g. Decking
** Garden beds near walls
** Window sills
** Large windows (heat radiation)
** Internal furnishings (e.g curtains)
* Home location
** Slope
** Surrounding vegetation
* If defended by occupiers
* Preparation (if prepared for defense)
* If intended for remote (unattended) defense
* Available water supply

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 to 2007 there is little or no published scientific research on EWSS. In 2000 the Fire Protection Association Australia (FPAA) published a report "External Water Spray Systems to Aid Building Protection from Wildfire". The objectives of this report are summarized by the overview quote:

In light of the inherent lack of scientific information pertaining to the effectiveness of EWSS under varying wildfire conditions, this study aims to highlight the current issues associated with EWSS as wildfire protection measure ...

ee also

* Active fire protection
* Passive fire protection
* Fire protection
* Fire protection engineering
* Architectural engineering

References

External links

* [http://www.sprinkler.sk Short description of sprinkler and other fire extinguishing systems]
* [http://www.olyfire.com/history.html Fire Sprinkler history]
* [http://www.zipworld.com.au/~lnbdds/Boschi/ The History of Mather+Platt]
* [http://www.nfsa.org National Fire Sprinkler Association]
* [http://www.bafsa.org.uk British Automatic Fire Sprinkler Association]
* [http://www.cfa.vic.gov.au/ CFA - Victoria, Australia]
* [http://www.fpaa.com.au/ Fire Protection Association Australia (FPAA)]