Introduction to Fire Safety Management

Figure 9.50 Sprinklers that moderate fi re growth and smoke can be vented from ceiling reservoirs
major role in ensuring that the extended travel distances
are kept free from smoke to allow safe evacuation.
Smoke controls are in general passive and comprise
reservoirs provided at high level which allow the smoke
from a fi re to accumulate without affecting people within
the mall. Once in the reservoirs the smoke can then be
vented clear of the building.
Smoke ventilation can be achieved either naturally
or mechanically.
Natural ventilation – is achieved by providing
openings from the building to fresh air; the building or
space is ventilated by the natural movement of the air. In
order for this natural ventilation to be effective suffi cient
vents must be provided to allow air to fl ow in and out.
The openings for natural ventilation can be permanent,
as in the case of multi-storey car parks, manual, as is
the case with openable windows in an escape stairway,
or automatic, for example at the head of an escape
staircase.
Mechanical ventilation – is achieved by either
forcing air in, forcing air out or by a combination of both
methods. When using mechanical means to ventilate
smoke, it is obviously important to ensure the equipment
is capable at operating at the temperatures that may be
expected. A common use of mechanical ventilation is
pressurisation. With this system the area that needs to
be protected against smoke seepage is pressurised,
often at the time of the actuation of a fi re alarm. This
pressurised area then establishes leakage of air through
door seals and other gaps which prevent the backfl ow
of smoke into the pressurised area. Some fi re fi ghting
stairways and other escape stairways have this additional
protection.
9.5.9 Emergency lighting
There are broadly two types of emergency lighting;
that which is provided for use when the normal supply
Fire protection in buildings
fails and emergency escape lighting, which provides
illumination for the safety of people leaving a building to
escape a potentially dangerous situation. BS 5266 Part
1: 2005 defi nes the acceptable standard for emergency
lighting both if the normal supply fails and for people
evacuating a premises.
Emergency lighting – in addition to emergency
escape lighting it may be appropriate to provide other
forms of lighting which will provide illumination if supplies
fail. This lighting will enable manufacturing process to
be shut down safely, assist people to fi nd fi re fi ghting
equipment and fi re alarm call points, or provide illumination
of disabled toilets, etc.
Emergency escape lighting – emergency escape
lighting is required along the escape routes from all places
of work, including plant rooms and storage facilities
where it is foreseeable that persons may be required
to work and where there is insuffi cient ambient light to
safely use the means of escape.
Figure 9.51 Emergency lighting unit
Requirements for luminance and response
The important aspect of an emergency system is that
it provides suffi cient lighting to enable the means of
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