When I read the NFPA fire alarm handbook (2013) requirements, I read that buildings should have a horn decibel rating around 15db higher than the ambient sound rating. With strobes buildings must meet certain strobe candela/flash rate requirements and is subject to the ADA 1994 laws. Private mode is an exception where I understand no strobes are required and the fire alarm can be as loud or low as desired if I understand correctly. What separates private/public mode in buildings? For example, can it be legal to install Simplex 4050/4051 like horns without strobes in new buildings today if the building is private. However what makes a building private or public when it comes to fire alarms?
“Private mode” applications are those where a signal is known to be in place and where someone is trained to take additional action upon notification from the alarm signal. Examples include control rooms, nurses’ stations and guard desks. These emergency signaling applications may not have to meet ADA requirements and may be satisfied through installation of UL 1638 appliances.
“Public mode” operation includes audible or visible signaling to occupants or inhabitants of the area protected by the fire alarm system.
The Americans with Disabilities Act, Section 301-7, defines a public accommodation as any facility that is privately operated, affects commerce with its operation, and falls into one of the 12 categories shown in the accompanying illustration.
These categories are fairly general and will encompass a wide variety of facilities. Social service facilities, for example, include not only homeless shelters, adoption agencies, senior citizen centers, food banks and day care centers, but also halfway houses, substance abuse treatment facilities and other crisis centers.
I’m wondering how the library where I work is able to get away with having chime/strobes (Cerberus Pyrotronics U-EC-MCS), as I don’t believe that is normally considered a “private” setting. It’s in a highly-populated, low-income urban environment, and the library is heavily staffed with a has a lot of security - not sure if that’s a factor. Or is it just because the library was built in the '70s and is therefore grandfathered in? The current system was installed in the early 2000s.
So that’s probably why Industrial factories still use Vibratone horns for signaling and the federal signal 350D is still manufactured. So basically any building that can be used by the public falls into public mode?
Most areas of libraries are intended to be very quiet or nearly silent spaces…perhaps an exception was made since the chime strobes satisfy the requirements of exceeding the ambient sound level by 15dB.
Although, I do believe these devices are explicitly labelled as private mode only.
Yeah, I noticed the labels on the bottom of the chime/strobes, which is why I question this. I’ve never seen this in any other libraries as far as I can remember, and this library definitely gets noisy on a fairly regular basis. The auditorium doesn’t even have any audible signals inside of it, and that would presumably be the most noise-prone part of the building!
But hey, good to know the alarm won’t make me jump out of my skin.
The libraries around here have speaker/strobes.
Basically.
Even in hospitals the private mode areas are designated and the rest of the hospital falls under public.
A lot of industrial complex’s i’ve run into barely have fire alarm systems.