Ward Lighting
The lighting of bedded or ward areas presents the lighting designer with a number
of technical problems. The design needs to provide sufficient task light for general
nursing procedures whilst also providing an amenable environment to aid the
patients' recovery i.e. an environment that is visually satisfying, wholly
appropriate and "emotionally compatible".
Good lighting helps promote an air of quality and competence within the hospital
providing a welcome reassurance for patients and visitors and will help them feel
more positive about their experiences there. LG2 2007 states that the general
lighting must be adequate for the clinical care of patients. The lighting should be
well-diffused and free from distracting glare or harsh contrasts. It goes on to
further define those requirements which have been extracted and presented in
diagrammatic form - click
here to view diagram.
For nursing care to be performed efficiently the average task illuminance over the
general area of the bed should be at least 300 Lux with a uniformity level
(min/average) of 50% or better. The general level of illuminance between the beds
and in the central space should be a minimum average of 150 Lux at floor level.
This level will cater for the general activities of ambulant and recumbent patients
without causing disturbance to any other patients in the room who may be at rest.
LG2 2007 does not prescribe any particular solution for ward lighting but states
that all wall or bed head luminaires irrespective of its relation to the bead-head
trunking services should only be installed if the minimum wall mounting height
of 1.8m can be achieved. The 1.8m minimum mounting refers to and is measured
from the finished floor level to the physical centre of the luminaire.
One of the major concerns with luminaires in multi-bedded areas is the issue of
glare experienced by patients in their beds. The sharp contrast between areas
immediately around a luminaire together with any bright areas or edges of the
luminaire in view can be a source of discomfort. LG2 2007 is very specific in its
recommendations regarding the control of luminance.
Luminance control requirements for all ceiling fixed lighting solutions
For ceiling or rail mounted surface luminaires the average luminance value at
elevation angles between and including angles (a) and (b) as defined above
should not exceed 1500Cd/m2 for all angles of azimuth. For all ceiling recessed
or semi-recessed luminaires the value shall be reduced to 1000Cd/m2.
Luminance control requirements for all wall fixed lighting solutions
Wall mounted luminaires shall be assessed for their luminance value which should
not exceed an average of 700Cd/m2 between and including angles (a) and (b).
The calculation should include the actual measured values relating to the specific
areas in question however, in the absence of any specific dimensional data for
h1, h2, h3, d1, d2 and d3 the following values should apply;
h1 = 850mm
h2 = 1450mm
h3 = (2.7m ceiling), (2.0m rail), (1.8m wall)
d1 = 900mm
d2 = 450mm
d3 = (4.0m ceiling), (5.0m rail), (8.0m wall)
LG2 2007 states that a patients reading light is required to provide an illumination
level of 300 Lux minimum together with a uniformity of 70% or greater. As most
people rest with their head or back against the pillows the actual task area
requiring illumination will probably be around the patients torso region. For this
reason and to allow for the various positions adopted by patients at rest the 300
Lux minimum value should be calculated over a 'virtual' horizontal area of 1m x 1m
(1.0 m2) centered at the bed-head and directed towards the bottom of the bed at
a working height of 1.0m above floor level. This virtual plane is illustrated in the
diagram below;
It is also important to note that while providing the 300 Lux for the patients reading
level any calculation must take into account the full shielding effect produced by the
patients head and shoulders.
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