Fire Alarm -- Description
For a fire, the different compartments of a building are almost separate buildings, with common firewalls between the buildings. The zones shown on a fire alarm panel are linked to these fire zones.
What is a Fire Alarm Zone?
By Douglas Krantz
Building zones aren't determined by where the wires are run for the fire alarm system; building zones are determined by the building's fire-control/fire-fighting separations and by the building's smoke-control separations.
Bite Size Zones
A fire zone is a specific area of a building. Each fire zone is separated from all the other zones by "fire walls" and "fire doors". The zones are kept small enough to be "bite sized;" small enough that in a fire the zone can be dealt with as a whole.
Single Zone Buildings
Sometimes an entire building is a single zone. For escape from a fire
(evacuation), for smoke control, for firefighting, the building is small enough to be considered as a whole.
Multiple Zone Buildings
On the other hand, to be dealt with as a whole, many buildings just are too large. In order to be bite-sized, the building has to be divided up.
Original Fire Zones
Over time, as cities (villages) started to be assembled, the buildings (or huts) were sometimes close to each other. If one building caught on fire, the others next to them could also catch on fire. While each building had separate outside walls, to a fire, the walls may as well have been shared.
Nowadays, larger buildings are like that. To a fire, they're a cluster of smaller buildings that are built so close together that they share walls. To a person walking down the hall, there're sections of the building separated by fire doors that go through fire walls.
Firefighting -- No Time for Guessing
As one of the issues in firefighting and life-saving, firefighters are trying to go to the area of the building with the fire. Rather than making the firefighters guess where to go, sending the crews to the right zone, while the fire is burning the building down, would be quite helpful.
Conventional or Zoned Fire Alarm System
If the fire alarm system is wired correctly, with the devices wired together by fire zone, the fire alarm panel
or the annunciator (remote readout of the fire alarm panel) will show which zone needs attention. With proper zoning in the fire alarm system, the firefighters don't have to guess which zone to go to, they can quickly go to the correct zone and fight the fire.
For an overview of Life Safety and Fire Alarm Systems, get the book "Make It Work - Conventional Fire Alarms
" by Douglas Krantz.