1
Some Fire authorities (concerned with the slow response of Heat Alarms) advise that Smoke Alarms (or
Multi-Sensor Alarms) should be fitted. This is acceptable according to BS 5839-6 provided there are clearly
not going to be problems with nuisance alarms. Fit Heat Alarms only if nuisance alarms are very likely and
it is acceptable that a warning will only be given by the Heat Alarm when there is a very significant flaming
fire in the room. If the door(s) and windows are not closed to contain the fire and heat, it is extremely
unlikely that the Heat Alarm would respond before a Multi-Sensor Alarm sited outside in the corridor.
2
In enclosed kitchens with doors closed.
3
Fast flaming fires generate considerable amounts of heat. The Multi-Sensor Fire Alarm has a heat
enhanced optical smoke sensor to improve the response of the sensor to these types of fires.
4
Do not install in kitchens.
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.
2.3 Grade D System
The mains powered, with battery back-up, Multi-Sensor Fire Alarm covered by these instructions
will meet 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 200m
2
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.
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