[SML] Smoke vs Heat vs Rate of Rise detectors

[Dale Farmer]

According to everything I've read about them. they work great in large 
spaces.  Here is a video link to testing of the system in the 
engineering spaces on a cargo ship.  (caution, loud fire alarms and 
machinery noise in sound track)   The first space is the main engine 
room, which looks like it's at least three decks above the top of the 
engine, and there likely is another two or three decks down to the base 
of the engine.

https://youtu.be/urZVDTkZXdE
You notice that they are not bothering to de energize any of the 
electrical equipment either.

Dale

On 3/9/2022 7:55 AM, Bill Conner via Stagecraft wrote:
> I have no expertise on mist fire protection systems but have to wonder 
> if they are as effective in the tall spaces in a theatre as they are in 
> the very low floor to floor spaces of cruise ship.
> 
> On Tue, Mar 8, 2022, 9:37 PM Dale Farmer via Stagecraft 
> <stagecraft at theatrical.net <mailto:stagecraft at theatrical.net>> wrote:
> 
>     On 3/8/2022 9:29 PM, Dale Farmer via Stagecraft wrote:
>      > On 3/8/2022 9:35 AM, Dougherty, Jim via Stagecraft wrote:
>      >> I'll second the recommendation to include your AHJ, your alarm
>     system
>      >> contractor, and your Powers That Be early in the process. 
>     Demonstrate
>      >> the atmospheric effects that you use in your space - fog and
>     haze will
>      >> false trip many systems.  We underwent an upgrade some years ago
>     and
>      >> the decision was made to try a camera-based system; it was meant
>     to be
>      >> able to detect fire and flame by analyzing the video image (not
>     a fire
>      >> system engineer, don't know the details) specifically to avoid
>     false
>      >> activations through what we do.  It was pricey, we were early
>      >> adopters, and it was a big investment.  Long story short, it didn't
>      >> work.  It thought moving draperies/fog/a patron fanning themselves
>      >> with a program were all flame and we experienced many false alarms,
>      >> mid-show.  However, because communication was good throughout we
>     ended
>      >> up with a solution that works.  They were able to pull that
>     system out
>      >> and replace with other compliant equipment - primarily heat and
>      >> rate-of-rise based.  The!
>      >   o!
>      >>   nly trips we've had since were faulty sensors that were
>     replaced and
>      >> the troubles ceased.
>      >>
>      >> Regarding the mist systems mentioned, I like the idea but why
>      >> distilled water? Is there a large reservoir somewhere in the
>     building
>      >> to draw from? I'd think any benefit of it being distilled might go
>      >> away over time in storage.
>      >>
>      >> - Jim Dougherty
>      >> Middlebury College Theatre Dept.
>      >>
>      >> _____
>      >    the reason for the distilled water, and yeah there is a
>     storage tank
>      > that has to be periodically drained and refilled, is to make the
>     system
>      > safe for use on energized electrical equipment.  Once the tank is
>      > drained, it switches over to regular water supply.   Regular
>     water mist
>      > will have enough trace chemicals in it to cause short circuits in
>      > energized electrical gear. Especially if your area has hard water.
>      >
>      >    The systems are sized such that it will extinguish expected
>     fires, or
>      > contain them long enough for fire response to show up.  The huge
>     benefit
>      > is that unlike halon systems, it is perfectly harmless to the meat
>      > machines that are also in the space, so you don't need to wait
>     for the
>      > people to evacuate and the fire to get worse before release.
>      >
>      > There is a video from a cruise line that was retrofitting these
>     into all
>      > their ships.  They had engine room fires on a ship with a
>     conventional
>      > halon system and one with the water mist system installed. Both very
>      > similar causes, a leaking diesel fuel spraying inside the
>     engine.   The
>      > halon sysstem worked, and the fire was put put.  The ship needed
>      > emergency dry docking and was out of service for three months
>     while the
>      > contents of that engine room got replaced.   Several millions in
>     direct
>      > damage repairs, tens of millions of refunds of cruise tickets for
>     that
>      > three month period.   The ship with the water mist system.  Fire
>     was out
>      > before the firefighting team made entry.   Damage was confined to
>     one
>      > cylinder of one of the two engines in that engine room, cleanup and
>      > repairs were completed at the next port call, mostly because they
>     had to
>      > order the parts.  No lost time, repairs cost a few thousand bucks,
>      > cleanup was done with mops, buckets and rags by ships crew.
>      >
>      > Here is the video.  They had a camera in the engine room that
>     showed the
>      > fire breaking out and being extinguished by the HI_FOG system.
>      > https://www.youtube.com/watch?v=tKXiNdJMhgA
>     <https://www.youtube.com/watch?v=tKXiNdJMhgA>
>      >
>      > Also here is an article about a system installed in a historic
>     property
>      > in the US.
>      >
>     https://www.securitysystemsnews.com/article/thomas-jefferson-s-home-gets-marioff-water-mist-system
>     <https://www.securitysystemsnews.com/article/thomas-jefferson-s-home-gets-marioff-water-mist-system>
> 
>      >
>      >
>      > Dale
>      > _____
>     Memory fail.   only two weeks out of service and only eight million
>     dollars in damages.
>     Dale
> 
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