[SML] Smoke, heat, fire sensors for HVAC systems

[Dale Farmer]

These used to be a feature on some fire alarm systems.  The intent is to 
delay the call out to fire department and to delay building wide alarms 
from disturbing the occupants.  Were quite common in hotels and such. 
the intent is to allow the trained building staff to go to the location 
and do a quick determination if it was a valid alarm or another damned 
hotel guest smoking a joint in the linen closet, again.
   The problem is that over time, the understanding that the button was 
only supposed to be used for a short time tends to fade away as staff 
turn over and the training of seldom used procedures evaporates.

Time for the Discwave story.  Hotel in suburban DC, has a convention in 
it.  One sub group at the convention is a BDSM group, and they decide to 
use as a ceiling attachment point the handy sprinkler head right over 
the bed.  Much later that evening, around 3amish, the activities and 
weight on the sprinklerhead pulled it right out of the ceiling. 
Depositing the lady in question abruptly onto the bed as a stream of 
water from the broken off sprinkler piping starts pouring out.

   This sets off the water flow alarm in the fire alarm system.  Front 
desk clerk, young and inexperienced, hears the alarm, vaguely remembers 
that he is supposed to press the shut up for a couple minutes button and 
call maintenance.  So he does this. Unfortunately the only maintenance 
guy is sound asleep and not answering his radio.  The only other hotel 
staff person on duty is the contract security guard.  He has no idea 
what to do either.
    Sprinkler water is flowing out at a great rate and spreading around, 
and eventually starts a waterfall into the elevator shafts.   Front desk 
clerk, clueless, one each, is continuing to press the silence button 
every few minutes, until the steadily growing tide of phone calls from 
guests wondering why it is raining in their hotel room distract him from 
pressing the button in time, and finally the alarm sounds and the 
notification to the fire department went out.  After something like a 
half hour delay.
    Bottom line, six figure damage bill from the water, and a five digit 
fine from the fire department for the blocking of the alarm.   Now 
imagine if it had been a real fire in a fully booked hotel.  That's why 
that feature is disappearing from fire alarm building codes.
    I can vouch for this story, as many good friends of mine were at 
that convention.  I would have been there, but had another commitment 
that weekend.

Dale

On 1/25/2021 2:07 PM, Richard Niederberg wrote:
> Why can't they install a 'push to silence alarm' switch on the wall and 
> have a crew member keep their thumb on it during the effect or have a 
> device that only detects heat rise?
> /s/ Richard
> 
> On Mon, Jan 25, 2021 at 10:57 AM Dale Farmer via Stagecraft 
> <stagecraft at theatrical.net <mailto:stagecraft at theatrical.net>> wrote:
> 
>     I was peripherally involved with getting such a system working many
>     years ago.  It involved getting a fire engineer study of the building
>     and alarm systems.  The eventual outcome was that the sensors in the
>     air
>     ducts and auditorium were able to be selectively disabled, and we
>     had to
>     hire a fireman on detail duty to be on site whenever they were disabled.
> 
>     One kind of smoke detector is beams of light up near the ceiling
>     shining
>     across the room to a detector on the opposite wall. They detect
>     balloons
>     just fine. surprise!
> 
>     Dale
> 
> 
>     On 1/25/2021 1:21 PM, Ben Thoron SML via Stagecraft wrote:
>      > Our 10-year-old theatre was installed with sensors in the HVAC system
>      > that are easily set off by theatrical smoke and haze, to the extent
>      > that we can’t use either, at all.
>      >
>      > I’m looking for a source that knows more about the options and
>     devices
>      > than I do.
>      >
>      > Any suggestions?
>      >
>      >
>      >
>      > Ben
>      >
>      >
>      >
>      > Ben Thoron | Production Manager | the old globe | 619-684-4105 direct
>      > | 619- 846-9529 cell | he him his | bthoron at theoldglobe.org
>     <mailto:bthoron at theoldglobe.org>
>      >
>      > ____________________________________________________________
>      > For list information see <http://stagecraft.theprices.net/
>     <http://stagecraft.theprices.net/>>
>      > Stagecraft mailing list
>      > Stagecraft at theatrical.net <mailto:Stagecraft at theatrical.net>
>      > http://theatrical.net/mailman/listinfo/stagecraft_theatrical.net
>     <http://theatrical.net/mailman/listinfo/stagecraft_theatrical.net>
>      >
> 
> 
>     ____________________________________________________________
>     For list information see <http://stagecraft.theprices.net/
>     <http://stagecraft.theprices.net/>>
>     Stagecraft mailing list
>     Stagecraft at theatrical.net <mailto:Stagecraft at theatrical.net>
>     http://theatrical.net/mailman/listinfo/stagecraft_theatrical.net
>     <http://theatrical.net/mailman/listinfo/stagecraft_theatrical.net>
> 
> 
> 
> -- 
> /s/ Richard
> _________