Author Topic: Can a fire alarm sounder be TOO LOUD?  (Read 816 times)

Offline bigblockofcheese

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Can a fire alarm sounder be TOO LOUD?
« on: February 03, 2024, 10:05:21 AM »
Can a fire alarm sounder be TOO loud?

I'm at a school in the UK, and there's a small staff bathroom (2.5m x 4m) that contains a toilet, cubicle shower and a sink. This room has a Banshee Excel sounder on the ceiling, positioned around 1 metre from the ears of a person using the toilet.

https://hbl.co.uk/app/uploads/2022/07/IS62-Banshee-Excel.pdf

The other day there was a fire alarm, and a person had literally just "committed" on the toilet when the alarm sounded. This meant they needed to spend 1-2 minutes finishing the "job" / cleaning up before being able to leave the room, during which time they were subjected to the full power of the alarm sounding 1m away from their ears.

They've subsequently pointed out that the sounder itself, at this close proximity and in this small a room, could represent its own risk of auditory injury and I think they may have a point.

The UK regulations recommend sounders are a minimum of 65db or 5db above ambient room noise (though apparently running water from showers can be disregarded).

I cannot work out what the sound level from this sounder would be at a 1m distance, for 1-2 minutes, and if this could indeed be dangerous. Can anyone advise?

I note that the RNID state that "for sounds of 110?120dB, even a very short exposure time can cause hearing damage."

Any thoughts appreciated!

Online AnthonyB

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Re: Can a fire alarm sounder be TOO LOUD?
« Reply #1 on: February 03, 2024, 07:17:57 PM »
BS 5839-1 states sound pressure levels should not "not greater than 120 dB(A) at any normally accessible point"

Many current 24V sounders are usually in the 85-95dB @ 1m range. The Banshee Excel, like some, can (depending on which of the 32 tones is used) be up to 110dB but the DIL switches include volume settings where you can reduce the dB by 10dB or 20dB id required.

Excessive sound was an issue when 240V fire alarm systems were common using motor driven sirens blasting out 127dB (you'd often see single sirens covering whole floors where you might have 2-4 or more now)
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Offline bigblockofcheese

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Re: Can a fire alarm sounder be TOO LOUD?
« Reply #2 on: February 04, 2024, 10:05:00 AM »
Thank you, that's really helpful.

I do think there may be valid reasons not to install super-loud sounders in locations where users cannot immediately easily leave.

It will be worth looking at the DIL switches to see if the volume can be reduced slightly, to prevent aural pain.

Offline lyledunn

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Re: Can a fire alarm sounder be TOO LOUD?
« Reply #3 on: February 12, 2024, 09:08:10 PM »
I have seen a study somewhere that showed a debilitating effect on mental agility as sound levels increase. Can?t find it but it wasn?t directly related to FA devices. However, I have experienced a kind of brain numbing effect when the banshee-type sounder operated during FA testing and I wasn?t wearing ear defenders.
Better to have more sounders and a more even distribution of sound levels.