Originally Posted by
MaMa Mount
I SAW THAT PICTURE TOO BUT I DON'T THINK THAT THE WATER SPRAYED THAT FAR OUT. LOOK AT THE GREEN TREES A BIT AWAY FROM THE HOUSE. NO WAY THAT WATER REACHED THAT FAR.
Did you read it too? (underlining is mine)
Unlike the sprinkler systems found inside buildings, these outdoor units
are not intended to put out a fire. Instead, they work in the following manner:
- Sprinklers are used to thoroughly wet down an area. This results in cumbustibles (buildings and landscape) being much less likely to ignite due to flying embers and the intense heat of a nearby fire.
- The soaked landscape releases moisture into the air. This lowers the ambient temperature and increases the humidity level of the immediate area. These effects extend some distance above ground level. The result is that the advancing wildfire will tend to be deflected by this less supportive enviromnental pocket and pass by the protected property.
- Sprinklers are most effective when in continual operation for 2 or more hours prior to the arrival of the fire. However, any operational time, even as little as an hour, will increase chances of a successful defense of the property.
And this further down below:
A rooftop sprinkler system is not just for fire protection. Because it is designed to provide gentle water distribution
over a large area, it is a perfect means of
keeping your landscape green and lush. On a hot summer day, it will even provide natural cooling - no need for an air conditioning system.
Not only will your surroundings look attractive (when everything around you is dried and brown) but it will be fire safe.
You don't need a fire pump pumping into a 1-1/2" fire hose, you are not "fighting the fire", you are "preventing the fire". It takes a lot less water, but for a longer time, to prevent a fire than it does to put one out.
Thus having it come on and run a long time, just keeping everything wetted down, and keep wetting it down until you either run out of water to pump or run out of gas for the generator. Most small generators are not designed to run for long periods of time, their gas tanks are small for that reason, so you would need a longer run-time supply of gas.
As with a fire pump in a building, you do not protect the circuit to save the fire pump, you allow the fire pump to burn itself up to save the building.
With a smaller generator, who cares if the generator freezes up after two days of continuous running because it was only designed to run 4-6-8 hours, be shut off, cooled down, re-filled (you should never re-fill a hot generator due to risk of flash fire/ignition/explosion), instead you let that little bugger run, and run, and run, and run, and ker-klang it dies.
Now, you could also buy a larger, more powerful generator which IS designed to run longer. Say something like a 12 kw propane fueled whole house generator. Install a 250 gallon buried tank and let that sucker run for 4-5 days before running out of fuel.
The cost of those is negligible compared to losing your house. I installed a 16 kw one on our house in South Florida for hurricane power outages. Less than $6,000 to install it myself (for the generator and electrical) and including what I had to hire out - the gas tanks, gas lines, and the propane. Ran for 4 days on about $500 of propane, had 10% left when power came back on. And that was powering our entire house, and 4 neighbors to give them lights, refrigerators, and microwaves.
For that pump? It would run a lot longer on the same fuel as it would never get off idle. Probably use about 1.2 gallons per hour at idle, 250 gallon tank gives about 200 gallons usable fuel, that's 200 gallons divided by 1.2 gallons per hour or about 167 hours, which is right at 7 days.