9
Improved Audibility
The effectiveness of a Category LD2 system can
be significantly enhanced if an additional Alarm
(interconnected) is installed in the master bedroom. This
will help ensure that a responsible person will quickly
be alerted to a fire and can arrange for an orderly
evacuation of children and other vulnerable occupants.
Grade D System
The mains powered Smoke and Heat Alarms with
battery back-up, covered by these instructions are
suitable for the requirements for a Grade D System.
A Grade D system is needed for:
- New or materially altered dwellings up to three-storeys,
with no floor over 200m
2
in area.
- Existing dwellings with poor structural fire precautions,
up to three storeys, with no floor over 200m
2
in area.
- Houses in Multiple Occupation (HMOs) of one or
two-storeys, with no floor over 200m2 in area.
- Individual dwellings units of two or more rooms in
HMOs.
Check that a Grade D system is adequate for the
dwelling into which the system is being installed.
2.4 Where in the Room?
The locations must comply with applicable building
regulations.
Ceiling Mounting
Hot smoke rises and spreads out, so a central ceiling
position is the preferred location. The air is “dead” and
does not move in corners, therefore Alarms must be
mounted away from corners. Fit the Alarm:
- At least 300mm away from walls. (see Figure 1).
- At least 300mm from any light fitting or decorative
object which might obstruct smoke / heat entering the
Alarm.
300mm
300mm (min)
150mm
to 300mm
Fig.1