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DETECTION AND ALERTING DEVICES (page 2)
“There are two common types of smoke detectors: photoelectric and ionization. Each type has its own weaknesses. Livestock barns are usually not suitable for either type. The ammonia and dust in the air cause false alarms. Of the other types of detectors made, the flame-signature infrared/ultraviolet system works best (except for smoldering, spontaneous combustion type fires, common in barns). This is what the military uses in jet hangers and it’s very expensive. For people who are determined to have smoke detectors installed in their barns, this is how I have handled this problem in the past:
- I warned the customer that this would be a somewhat expensive
and a high maintenance installation, otherwise a high number of false alarms
could be expected. And no other guarantees,
either.
- I used photoelectric detectors with detachable hoods and placed
them in the barn using NFPA and (especially) the guidance of a factory fire
safety engineer (NOT the sales rep). Usually, I spaced them on 20-30
foot centers and was sure to keep them accessible for service.
- I taught the customer to clean the detectors every two to three
months, and made him keep a written record.
- I designed the system with pre-warning: When tripped, a local beep
tone sounds for thirty seconds before the main alarm signals to the central
alarm station. This
allows the cancellation of an alarm locally when caused by throwing hay
bales (dust), etc.
- I made sure the customer was the one who kept the place clean in the first place.
“If you are going to do this installation yourself, be sure ALL components are UL listed for fire alarm use, including the wire (they will be plainly labeled as such) and get decent commercial-rated equipment from a professional company. Get your system designed by an experienced company. A poor installation is worse than no installation at all; it gives you a false sense of security. I don’t wish to sound negative, but fire alarm engineering and installation is seldom successfully done by amateurs, a least without a LOT of help (just talk to your insurance company loss prevention engineer or fire marshal for their ideas on this)."
Another type of detection system is the linear heat detector, manufactured by Protectowire Co., Inc. This is a heat detector in the form of a heat-sensitive wire that can be easily installed in a barn. The wire is available in a variety of operating temperatures that can detect heat at any point along its length. The wire is connected to a control panel that can monitor the alarm status and provide critical functions such as alarm notifications, location of the overheat or fire, sprinkler system activation, and emergency backup power so the system is always functioning (see Products page for website).
Keep in mind regardless of system: Even if the alarm is transmitted to a central monitoring station, without an attendant in the barn, the alerting signal from smoke and heat detectors will not be heard unless there is also an exterior alarm or the signal is picked up through an intercom system and there is someone in the residence to hear it and respond. The siren or bell should be loud enough to be heard from some distance. If alerting of helpers is done by someone in the barn, he or she must have access to a manually-operated farm bell or siren outside the barn. In some areas, such as multi-barn facilities or race track barns, a flashing red light or a strobe light activated by the alerting system is mounted on the roof to attract attention and indicate which building has had an alarm activated.
An intercom system can be helpful when you’re at home. If you are
unaccustomed to continuous use of an intercom, a few days of "training" will
teach your ears to sift out the usual from the unusual and you will no
longer hear the bumping of salt blocks in feed tubs or similar normal sounds. What
you will hear is anything else--a horse in difficulty, intruders, frightened
neighs. An intercom system doesn't have to be elaborate or expensive. It
is a valuable instrument for "seeing" your barn when you're in
your house.
I probably should issue a warning here in case you have a built in intercom with a speaker in your bedroom and you have one or more barn cats who hunt at night while everyone in the house is asleep. It’s hard to say this nicely—if the demise of the prey occurs near the intercom speaker, you will hear your cat’s cute purring turn into the snarling growls of a jungle cat and the intercom may magnify the sound so you think you’re in the middle of a horror movie! Amazingly, in my house, I seemed to be the only person who heard those bone-chilling screams that caused me to leap out of bed, ready to scream myself. Well, enough of the nightmare stuff. What’s important here is that you have the intercom speaker(s) placed where you can hear any abnormal barn activities clearly.
It's frightening to consider that a fire might start when no one is home
or near the barn, so an alerting system tied through phone lines to a central
monitoring station can bring great peace of mind. The fire department
will be notified immediately, even if you are unavailable. The Yellow
Pages of your telephone directory lists, under the heading, Fire Alarm
Systems, firms who install alerting devices.
