Brooks ALARM 2000 - Limitations of Smoke Alarms

Site Manual
Alarm 2000 Iss 5
28
 Surfaces that are normally warmer or colder than the rest of the room (for example
attic hatches, uninsulated exterior walls etc.), Temperature differences might stop
smoke from reaching the unit.
 Next to or directly above heaters or air conditioning vents, windows, wall vents
etc. that can change the direction of airflow.
 In very high or awkward areas where it may be difficult to reach the alarm (for
testing, maintenance etc.).
 Locate unit at least 1.5m (5 feet) and route wiring at least 1m (3 feet) away from
fluorescent light fittings as electrical “noise” and/or flickering may affect the unit.
 Locate away from very dusty or dirty areas as dust build-up in the chamber can
make unit too sensitive and prone to alarm. It can also block the insect screen
mesh and prevent smoke from entering the chamber.
 Do not locate in insect infested areas. Small insects getting in to the chamber
can cause intermittent alarms.
 Do not place Heat Alarms in bathroom, shower room or other room where the unit
may be triggered by steam or condensation.
 Ionisation Smoke Alarms should be placed away from kitchens or airflows likely to
carry cooking fumes.
 Photoelectric smoke alarms should be located away from bathrooms or other
potential sources of steam
Note: Electrical noise induced onto the Alarm power circuit can cause
intermittent chirping. Avoid power circuits with inductive loads or fluorescent
fittings. If unavoidable, a line filter may be required.
4.4 LIMITATIONS OF SMOKE ALARMS
Smoke / Heat Alarms have significantly helped to reduce the number of fire fatalities in
countries where they are widely installed.
However, independent authorities have stated that they may be ineffective in up to 35% of
all fires. There are a number of reasons for this:
 The Smoke / Heat Alarms will not work if the mains power is off and the battery is
depleted.
 Smoke / Heat Alarms will not detect fire if sufficient smoke or heat does not reach
the Alarm. Smoke / heat may be prevented from reaching the alarm if the fire is too
far away, for example, if the fire is on another floor, behind a closed door, in a
chimney, in a wall cavity, or if the prevailing air draughts carry the smoke away.
Installing Smoke / Heat Alarms on both sides of closed doors and installing more
than one Smoke / Heat Alarm as recommended in the installer’s instructions very
significantly improves the probability of early detection.
 Smoke / Heat Alarms which are not maintained or are tampered with may not
function reliably.
 The Smoke / Heat Alarm may not be heard.
 A Smoke / Heat Alarm may not wake a person who has taken drugs or alcohol.