Why not consider a dry means of fire control? I have one using pure, cohesive Nitrogen gas cloud technology.
The Fixed Nitrogen fire control systems store liquid Nitrogen above the system which need refilling monthly with a 1% loss of liquid Nitrogen per day rated dewar. With active smoke alarms throughout the space protected, it releases the liquid Nitrogen in a slow flow to that space. It is released through a trough with perforation into that space making cryorain, liquid Nitrogen falling by the force of gravity raining from the perforated outlet with 1/4" diameter holes spaced 1" center to center over the square foot or so release location. This cryorain falls evaporating into clouds of pure, cohesive Nitrogen gas which starts at cryogenic temperature filling the space 230 times the volume of the liquid Nitrogen released which expands to 250 times at ambient temperatures and 600 - 700 times at inferno temperatures. . Were a fire burning, these clouds are drawn to the fire in the fire draft. The clouds are pure and their unique feature is displacing all but Nitrogen-Nitrogen molecules (N2) taking Oxygen from the fire ending flames instantly. The coldness of the gas cools the fuel reducing re-ignition. There is no need of drains or such since with Nitrogen there is no residual, no electrical conducting, no wetting, no dissolving, and no chemical reaction change. In fact, it cools the situation to below the window of reaction were a chemical explosion a threat to the scene. In fires, ending them with this pure, cohesive Nitrogen gas requires in recovery only replacing what burned away, melted, warped or charred. The evaporated Nitrogen when it matches the air temperature will mix with the air and be removed from the area by ventilation.
A common use for liquid Nitrogen is to make unique desserts - ice creams and cooling to solidify food - offered in up to date ice cream parlors and restaurants. If food preparing people can use Nitrogen so can fire fighters and those installing this alternative to water sprinkler systems.
Having liquid Nitrogen available, were an explosive found before detonation, the coolness of applying freshly evaporated pure, cohesive Nitrogen gas clouds can cool the explosive to below its ingredients' reaction temperature. This could have prevented some of the injuries in the Boston Marathon Massacre April 15, 2013 once they recognized the book bags abandoned held explosives.
The pure Nitrogen clouds move in the air and amounts of liquid Nitrogen released are small so as not to create a flooding of the space until supervision comes, clears the room or other space of life, and, if needed, enables flooding the space with Nitrogen gas. Automated use provides no confined space situations.
Try it. You'll like it. The NFPA has the proposal to include this technology for a new section of the NFPA Code. This includes its many uses. A copy is on page 316 of the textbook, "Nitrogen Pure and Powerful," awaiting printing.
It would help if your local fire department knows of and even uses Nitrogen rather than water to handle crises they cover. That way, were things taken care of, the fire fighters will not do precautionary flooding of the space of the fire causing the wetting of the space, possible mold growth, destruction of porous materials and weakening of wallboard in walls and ceilings, destruction of electronics, ruining of paper products, fabrics and foods, and contaminating sterile tools and materials.
Denyse DuBrucq EdD - NFPA 3019224 - CEO and trainer of CryoRain Inc.