The light source you choose and
how it is installed can affect pro-
ductivity and concentration. Did
you know? A light source that is
incorrectly installed or adjusted
can cause glare, fatigue and
visual difficulties. There are two
ways in which glare can occur:
directly and indirectly. In case
of direct glare, the light source
shines directly into the eyes or
face. Indirect glare refers to the
reflection of the light source on a
reflective surface.
The Unified Glare Rating
The Unified Glare Rating (UGR)
is an indication of the extent
to which a light source causes
glare. The rating helps to de-
termine how likely a luminaire
is to cause discomfort to those
around it. The UGR is very impor-
tant when allocating light fittings
within a lighting plan. Paying
attention to this number can
help you ensure that the lighting
in your office is optimized.
When measuring the UGR,
one must consider a number of
important factors:
– The size and shape of the
space in which the light source
is present;
– The distribution of light fittings
across the space;
– The surface brightness or lumi-
nance of the walls, ceiling, floor
and other large surfaces (white
walls, for example, reflect lots of
light);
– The type of light fitting
and barrier;
– The position of the observer.
Quality levels and
the official standard
The higher the value, the more
light pollution there is. The av-
erage Unified Glare Rating lies
between 15 and 30. There are
5 different quality levels in the
UGR: 16, 19, 22, 25 and 28.
The particular quality lev-
el that should be applied to
a specific space is official-
ly determined in a Europe-
an EN standard (the NEN-
EN-12464-1 standard).
However, some places might re-
quire good lighting without pol-
lution in order to best serve their
particular purpose. For instance,
corridors require a UGR below 2.
Drawing studios or design of-
fices below 16. Office spaces in
general below 19 and staircases
and elevators below 25.
When the rating is below 10,
there is considered to be no
glare, the so-called ‘zero-glare’.
Variable rating
It is also important to mention
that the UGR rating is not a
characteristic of a light fitting.
It is the combination of the
brightness of the light fitting, the
brightness of the environment
and the interaction between
our position and the corner.
Only one of these three factors
can be adjusted: the brightness
of a light fitting. This means
that the UGR is variable, de-
spite what is often thought. This
also means the UGR can be
influenced by the presence or
absence of lighting.
Given the importance of good
lighting for the well-being of em-
ployees and their concentration,
it is definitely worth the effort to
think through the office lighting
with a lighting plan and to take
the UGR into account.
Why is good office lighting so important for your company and your
employees? And what are the factors you better pay attention to?
Discover how you can enhance employees’ performance and general
working conditions.
TECHNOLOGY
The importance
of good office
lighting
character serie
36
kreonicle
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