Electrical Contracting News (ECN) October 2016 | Page 51

LIGHTING

I

n commercial and industrial
buildings, lighting typically
accounts for around 20 per cent
of total electricity usage and in
some cases the figure can be as
high as 50 per cent. It is therefore
hardly surprising that lighting is a
prime target for efficiency savings.
It is not only a key factor in the design of
new buildings but a popular retrofit option
for facilities striving to reduce their energy
consumption. Where lighting systems are
15 to 20 years old, the adoption of newer
technology can bring the running cost of
lights down by 50 per cent or more.
It’s an appealing proposition. However,
the appetite for energy savings should not
be allowed to overshadow the need for a
holistic appraisal of lighting requirements
in a large industrial or commercial building
and a thorough understanding of the
expenditure involved.
Therefore, it is vital to answer a number
of key questions that will help ensure that
any upgrade or replacement of a lighting
system delivers not only an efficient but an
effective outcome.

1. What is the space
used for?
It is surprising how regularly this simple
but vital consideration is overlooked.
Establishing an answer to this question
is an important starting point for any

SPECIAL FEATURE

Consideration should also be given to the occupants of the building.

prospective installation. Lighting must be
designed to assist occupants in whatever
task they are undertaking.
In some manufacturing environments,
for example, it is vital that workers are
able to identify subtle differences in the
colour of materials. If the light offers poor
colour rendering, as may be the case with
the yellow tinge of an older high pressure
sodium installation, it could inhibit that
task. Instead, a more modern light source
with good colour rendering is crucial.
Another factor that typically influences
the quality of light in a building is the
extent to which replacement lamps
have been mixed and matched over the
preceding years.

2. What is the effect of
lighting on building
occupants?

Consideration should also be given to the
occupants of the building. Poor lighting will
have a detrimental effect on an individual’s
ability to perform tasks. Evidence also
strongly suggests that it can contribute
to depression (especially in the winter
months) and can even lower productivity.
On the plus side, appropriate and
suitable lighting has many positive benefits,
particularly where employees are fully
engaged in the process. According to
the HSE, studies have shown that giving
workers in open plan offices control of

lighting can increase job satisfaction and,
at the same time, decrease stress.
Indeed, a growing body of research
underlines this important link between
lighting and wellbeing. Lighting for
People, a research paper that was
produced as part of the European
Union’s programme for research
and technological development, has
drawn together a wealth of research to
demonstrate just how important