So today we had a Full Evacuation of my high school… Fire Department came. But what caused the system to go into alarm is just…
So I was shooting some hoops with a friend. We shall call him “Billy” for the purposes of this topic. I do admit it was kinda hot in the gym. But about 10 minutes after we started. (Here comes the onomatopoeia)The Simplex TrueAlerts start doing their temporal (Eh-Eh-Eh_ Eh-Eh-Eh.) So we all go to the exit and we evacuated onto the basketball courts near the football field. Our teacher checked roll and then dismissed us to go chat with our friends. (Yes I did bring the basketball with me.) So me and my friend start shooting some more hoops in the outdoor court. About within 2 minutes of the alarms going off, the fire department was in the front parking lot of the school. My gym teacher yelled at us to get back and stand in line so we look good for the firemen. (FFS…) Needless to say about 15 minutes after the alarms went off, they were silenced. 10 more minutes and they sounded the all clear and the firemen were wrapping it up. I went to go ask them what was the cause. They said it was a heat detector in then gym.
Long story short, how does a heat detector that is set for 135°F trigger an alarm when it was nowhere close to that temperature in the gym? The firemen said it was a genuine alarm as where the detector really did report 135°Fahrenheit. :?
I mean I expect this stuff to happen in The locker room where the showers are. (Yes we do have hot water.) But I didn’t think that it could go off in a gym that’s like 72 ° when the basketball team is playing. Could it have been a false alarm?
It doesn’t seem very far-fetched to me. It was stated before, but heat does rise. I remember many times in my old school how hot it would get in the gym sometimes, especially when it was full of people adding all that body-heat to the air (it sounds ridiculous, but its true). That was at ground level…imagine how much more heat accumulates up near the ceiling.
I’m assuming the detector was a combination fixed/rate-of-rise detector? If it’s a fixed-temperature 135-degree detector, the only way for it to activate is if the gym got up to 135 degrees, which I’m pretty sure didn’t happen. Even though I haven’t been in a school gym since middle school, I don’t ever remember the gym being much hotter than 90 degrees or so. (our gyms were air-conditioned, so they usually were cooler)
Rate-of-rise detectors work differently. Instead of detecting a fixed temperature like, well, fixed temperature detectors, they detect how quickly heat rises in the building (usually about fifteen degrees per minute is what it takes to activate an alarm, which, in a normal room, doesn’t usually happen). If the fans or air conditioner shut off in the gym there’s a chance the temperature in the gym, for instance, went from 75 degrees to 90 degrees in the space of a minute. Far-fetched, yes, but certainly possible on a hot day.
How hot was it that day, and is your gym air-conditioned?
Was it mounted to the deck? Roofs get hot with the sun blasting on them, it’s a reason this section of the code exists:
17.6.2.3* Ambient Ceiling Temperature. Detectors having
fixed-temperature or rate-compensated elements shall be se-
lected in accordance with Table 17.6.2.1 for the maximum
expected ambient ceiling temperature. The temperature rat-
ing of the detector shall be at least 20°F (11°C) above the
maximum expected temperature at the ceiling.
135 is standard for heat’s, but in unconditioned attic spaces we normally put 174’s or 200’s and I’m quite a bit further north than you. Just because air temp is below 135, doesn’t mean the ceiling the detector is actually mounted on is below it.
I have a dumb question - how do you know it was a heat detector inside the gym itself? The only reason I throw that out there is it could have been a heat detector in a gym mechanical room that was activated, and any number of reasons could set it off (worker in the area, malfunctioning equipment, etc). All the FD sees when they pull up on the panel is “Heat Detector Gym Mech Rm” and simply asking one of them they might say “It was in the Gym” without giving you a specific location. Just throwing that out there!