On Thu, 31 May 2012 00:59:40 -0700 (PDT), Jonathan wrote:

Our smoke detectors are very sensitive. Would sprinklers be triggered
by the same mechanism, resulting in a wet house whenever the toast is
burnt!

Unlikely. They are a small glass bubble holding the water back, this
bubble is full of a liquid that expands when it gets hot shattering
the bubble and thus letting the water out. From the films I've seen
of commercial sprinkler systems the fire has to be quite large (in
domestic terms) before they go off and when they do it will be new
furnishing and decorating for at least that room. Possibly
replastering and new floor as well if it's chipboard...

http://www.staysafeuk.com/domestic-sprinklers.html

"... activate within four minutes ..."
"... about 150 liters/min ..."

A domestic fire will have quite a hold within four minutes, there
will be a lot of smoke about. A typical smoke alarm will have gone
off a lot earlier to alert any occupants to "Get Out, Stay Out, Get
the Brigade out". Buildings and contents can be replaced you don't
need to "save" them. Educating people to have a "fire plan" and to
get the F out when the alarm sounds be that in the home or work
place.

150l is a large bath full of water, every minute... I wonder where
this water comes from? Most domestic supplies can't deliver that sort
of flow, so how effective at extinguishing a fire large enough to
trigger the sprinkler is a domestic sprinkler?

One also assumes that these sprinkler systems will have an external
water flow driven bell and a link to a service centre that can call
the Fire Brigade out. If you did have a fire that triggered the
sprinklers just after you gone on your two weeks to Malaga, without
such systems there wouldn't be much, possibly no, indication that the
inside is being drenched....

Then of course how vulnerable will they be to being knocked?
Sprinklers are normally installed high up not the relatively low 8'
ceiling of a house.

Strikes me of politicians/bureaucrats reacting to "some one died"
with "we must do something". Personally linked smoke/heat alarms are
enough, along with decent public education. That would have far
greater benefit to society but far harder to measure so the
bureaucrats won't like it as they can't justify their existence.

Do any of the Fire Services still have the chip pan fire demo
vehicles that they used to take around Fetes, Gala Days and County
Shows? It's no use telling people how to safely deal with a chip pan
fire it'll just go in one ear and out the other. Show 'em, in quite
dramatic terms, what happens when you do it wrong. OK I guess the
open chip pan is getting to be a thing of the past these days but it
will still highlight the dangers of fire. Most people these days do
not have any real experience of fire, most homes no longer have open
fires, people don't have bonfires to dispose of waste (garden or
otherwise), kids don't make camp fires.

--
Cheers
Dave.