Assembled cognoscenti; it being the bush-fire season my thoughts turned to the practicability of protecting buildings , using external water-spray systems. My thoughts went something like this 1/ If one knows the air temperature , humidity, wind velocity, distance to, and composition and dryness of surrounding bush . 2/ Can't one calculate the radiant heat in KW/m2 impacting on the building ?; and 3/ the likely duration in the event of a bush-fire ? 4/ Can't one then calculate the minimum spray flow in litres / sec and the total volume of water required ? 5/ Can't one then make an informed decision about, whether such a system is physically and financially practical in a particular situation? Because such systems don't seem to receive much attention from media or insurance companies ; I assumed the answer must be that they are usually not practical. So I was somewhat surprised on reading : http://en.wikipedia.org/wiki/External_water_spray_system to find: "Issues There is a lack of scientific research regarding EWSS..........." I am contacting the CSIRO because I seem to recall they did something on this years ago; but would be interested in actual research if anyone has come across it ; regards Rohan McLeod