FA dB sound level

[cadpoint]

Could someone state where a go read about that and hopefully state how it sized!

Is it dB per square? Can the type of construction or space also be in play like shelved warehouses verses
office, etc, etc...

Thanks in advance!

 

[pete m.]

Perhaps 7.4.2 from 2007 NFPA 72 will provide a little help.

Pete

 

[nhfire77]

15dB above ambient noise levels, but to read about it, the annexes in 72 cover the basics. There are charts in 72 that have nominal dB values in typical occupancies, just an average.

If its loud, it's probably ok, but a simple dB meter can verify it for you. This is a good one. sub $400 range.

I use it when in doubt. It's very difficult to estimate when designing, commissioning must be done to confirm SPL. In Voice Evac, in can be even trickier with reverberation and echo. And then there is intelligibility. You gotta see the devices that meter that. Very cool.

Oh and Im not at my desk, but I believe there is a max dB now like 120, the approximate pain threshold.

 

[gadfly56]

15dB above ambient noise levels, but to read about it, the annexes in 72 cover the basics. There are charts in 72 that have nominal dB values in typical occupancies, just an average.

If its loud, it's probably ok, but a simple dB meter can verify it for you. This is a good one. sub $400 range.

I use it when in doubt. It's very difficult to estimate when designing, commissioning must be done to confirm SPL. In Voice Evac, in can be even trickier with reverberation and echo. And then there is intelligibility. You gotta see the devices that meter that. Very cool.

Oh and Im not at my desk, but I believe there is a max dB now like 120, the approximate pain threshold.

Yep, right on both counts. Also, audible appliances are rated at a 10' hearing distance. Double the distance and you drop 6db, all else being equal. In a dormitory setting, with the loudest horn/strobe right outside the door, you likely won't meet the minimum dbA at the pillow through a closed door.

 

[nhfire77]

Could someone state where a go read about that and hopefully state how it sized!

Is it dB per square? Can the type of construction or space also be in play like shelved warehouses verses
office, etc, etc...

Thanks in advance!

Were you referring to horns or speakers (voice evac)?

 

[cadpoint]

Were you referring to horns or speakers (voice evac)?

I was thinking of horns...

Thanks again for all the information!