"Room-temperature fire?! Egads man, what's the point?"
The Tick

Scientists have created a new type of water... that isn't wet. Supposedly it's going to help fight fires without damaging fragile property -- like art and books -- but I'm not sure how it's going to work.

Water fights fire in two ways, and both depend on getting stuff wet. First, water has a high specific heat capacity, which means it can absorb a lot of energy and heat up only a little. When the water used to fight a fire heats up enough it will evaporate and carry the energy it has absorbed away, up into the air. Secondly, water helps douse a fire by engulfing it and restricting its access to oxygen.

Water that isn't "wet" won't stick to things and won't be where it needs to be to absorb heat and block oxygen. Fire is lighter than air and tends to move upward in a structure; water is heavier than air and moves downward. Regular water wets everything it passes as it moves down, but this "new and improved" pseudo-water won't be effective anywhere but at its initial point of delivery (if applied in a continuous stream) and at its final resting place where it pools.

Ray points to a New Scientist article that explains how the chemical works around my objections.

The fluid, produced by 3M, has weak molecular bonds and vapourises at just 49° Celsius, half the temperature at which water boils. It stops fires before they get out of control by soaking up heat from the nascent blaze.

"This is a chemical agent that absorbs heat and vapourises better than water," says Joe Behnke, a manager at Tyco Fire & Security. According to 3M's web site, Novec 1230 requires 25 times less energy than water to evaporate.

So it evaporates more quickly and absorbs less energy in doing so, which is a weakness and would indicate that the chemical can't fight fire as well as water can.
The enclosed spaces are also necessary to corral the gas in the concentrations needed to extinguish a fire. Tyco launched its first fully engineered systems in January, but on Wednesday the company released new information about the system.
The need for an enclosed space wasn't revealed in the original article, and this restriction changes everything. It sounds like the gas that results from the chemical's evaporation is a key component to its fire-fighting ability.

The chemical still sounds neat, and will likely be useful in some limited applications, but it won't be nearly as effective as plain old water for the vast majority of fire situations.



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