Using smoke and heat detectors

Ira

Active Member
Before I do the final installation for my 4-wire smokes, I want to make sure I don't cause problems for adding heat detectors next.
 
Using ELK M1G and System Sensor I3 sensors (everything hard wired)...
 
Is the best practice to have the heat detectors on their own zone(s), and define the zone(s) as Fire Alarm? Then if a heat detector triggers, since it is defined as a fire alarm, it will trigger the same M1G output used by the smokes/RRS-MOD (i.e., whenever any fire alarm turns on, turn on output 3), which will cause the smokes' integral sounder to sound. Is this the best way to do it?
 
Read your documents.
 
Any mechanical device that places a short on the fire alarm circuit should not be placed on the same zone as a detector that has a reversing relay installed.
 
The rules would determine the output to be driven on FA and that must trip for every FA.
 
HelenHill said:
Why do you need both heat and smoke detectors. Isn't one enough? I have installed a smoke detector in my home that is all. I saved the amount on heat detector and invested it in security alarms. I now have a personal emergency response system because I am old and staying alone. And I will not have felt this safe if I had a heat detector instead of this emergency system.
 
I used a heat detector in a utility room that has laundry equipment, as I was worried humidity, dust, etc. might cause false alarms.   Often the common advice is just not to put anything there, but I figure it is the second most probable room in the house to see a fire start, and not having it alarmed was a bit silly.  Same for a garage, a regular smoke may give too many false alarms.
 
It sounds as though you have a single detector, and yes, a smoke detector is better than a heat-only detector in that case (though many smoke detectors are combined rate-of-rise + smoke detectors).  But if you have a larger house, and the fire starts in an unlucky spot screened off from your single detector, it can let the fire get very advanced before it signals.
 
HelenHill said:
Why do you need both heat and smoke detectors. Isn't one enough? I have installed a smoke detector in my home that is all. I saved the amount on heat detector and invested it in security alarms. I now have a personal emergency response system because I am old and staying alone. And I will not have felt this safe if I had a heat detector instead of this emergency system.
Heat detectors and smoke alarms are not interchangeable.  Smoke alarms work great inside your house where you go, but heat detectors work great in attics (near where furnace fires can start, near the hot water heater, in a basement, in a laundry room, etc.  Its much better to catch a fire from a furnace in the attic, for example, then wait until your house fills with smoke.  My house has fire sprinklers, but that doesn't do you much good in an attic fire. (They are discussing adding the attic to fire sprinkler requirements, but we aren't there yet.) 
 
Smoke alarms are great for saving lives, but heat sensors (including rate-of-rise) are cheap protection for things you know might catch on fire.
 
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