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NFPA 72 - Sound Calcs

Question asked by wbf on Oct 16, 2018
Latest reply on Apr 29, 2019 by rstadtman

I am short on time and need help going in the right direction.


The AHJ wants the sound levels in each room without a horn/strobe. I indicate horn/strobes in the corridors and common spaces.


I know the output for each horn/strobe: 98dBA


The distance from each room to the horn/strobe varies, but I plan on basing the calculation to the center of the room. For this example, we can use 12feet.


The walls for each room is double 5/8" GWB with STC of 40.


The sound levels needs to be 15dB above the average ambient sound of 54dBA.


I have found a lot of calculations for sound. But what am I missing?