Hi, I would like to ask how to calculate required # of Fire Alarm Horn notification appliance in a building? I believe NFPA 72 provides ambient Sound level based on location, and the Horn dBA should be 15 dB above the ambient sound level of a location.
- Is there a standard Horn dBA value that people use for design for example, can we assuming a horn would be rated for 85dBA (or a different number) at every 10ft?
- I was looking at a Horn product from Microm and based on the data sheet, there are different dBA values given in the table. I believe US installation should be based on UL464 table, but I am not sure which sound pattern and volume I should be looking at to determine the rating. (https://mircom.com/wp-content/uploads/product_documents/CAT-5360_FH-400_Wall-Ceiling_Mount_Horns.pdf)