the water drops to the temperature of vaporization (sensible heat) and continues to provide heat for the change of state from liquid to vapor (latent heat of vaporization). As the water drops change the phase as they extract the heat, their volumes expand for about 1700-fold upon evaporation (at temperature 95 oC and 1 atm pressure) [6]. The rapid expansion of the water vapor forces the oxygen away from the fire source. Therefore, from some researches view, WMFSS has a better heat extraction capability than the sprinkler system [7].