Water is applied to fire as either a spray from a sprinkler head or spray nozzle, or in a straight stream from a nozzle. When considering this, one must remember that fire suppression is a very inexact science at the time of an emergency.

Laboratory testing and controlled situations indicate that very little water is typically required to suppress the generation of heat in substances. The low amounts required for suppression may well surprise most fire officials and fire protection people, but the nature of a hostile fire is quite different than the fires used in laboratory research.

In a well developed structure fire, it is not uncommon to have to apply up to 100 times the flow rates derived in research to be able to "control" and extinguish a fire.