Home Sprinklers: Your thoughts.

[Richard B the EMT]

I'm going totally anecdotal, here, as I have no hard facts to refer to.

We've mentioned sprinkler systems that are powered by the water coming into the house from the water main, or from a pressurized holding tank. We've also mentioned dry chemical vapor systems, delivering Halon (a trademark, I think), which displaces oxygen.

Unfortunately, I am aware that Halon systems, due to displacing a normal oxygen atmosphere, require rapid evacuation of all persons and 4 legged pets residing in the area, just like the fire itself, mammals need oxygen to survive.

I think all these systems have some kind of "flow alarm", which at minimum, rings some alarm bell when the flow is detected. In the systems I know about powered by the household water main, the water flow itself powers the alarm bell.

As noted, most systems use a melting head. A soft metal in the head melts from the heat of the fire, allowing the water to start flowing. Hollywood and Bollywood movies show all the sprinkler heads starting up at the same time, for the same reason all car crashes have the vehicles explode, because it makes it more visually entertaining than when they don't.

This is not to say they don't have systems that start water flow to all heads when even one detector is activated. I feel that there are systems that are normally dry, but the valve at the feed point to the system starts water into the pipes, and the sprinkler heads are always open.

As for a centralized system, most house or business burglar alarms call a central station, who, in turn calls the local 9-1-1 system to request the LEOs or the FD (if the alarm is activated for a "B&E" or open door/window, the folks at the monitoring station call up to ask if all is OK, and wait for a prearranged code word before calling off the response). The older systems I am familiar with simply dial 9-1-1, and state via a pre-recorded message, to effect that "There is an emergency at the Jones residence at 123 Fourth Street, between 5th Avenue and 6 th Lane. Send someone immediately".

When my house was wired the first time (we've upgraded) by the alarm service, they offered the automatic call to the monitoring station via landline, dedicated cellphone, or combination, so I know these systems are out there, and have been for decades.

As for the pipe freezing? I have been getting home improvement catalogs from many sources, and most offer a heating element that wraps around pipes. It starts heating up when the built in controller reads ambient room/crawlspace temperatures below 40 degrees, and only heats enough to keep the pipes above 32 degrees Fahrenheit, water's freezing point.

Edited May 22, 2009 by Richard B the EMT