Electrical Contracting News (ECN) November 2016 | Page 46

SPECIAL
FEATURE

HOME AUTOMATION & INTELLIGENT BUILDINGS

requirements than traditional incandescent
and discharge lighting. This enables
the electrical power, as well as data for
monitoring and control, to be carried over
the network cables (Power over Ethernet)
rather than requiring a separate power
supply. For instance, a single LED may only
require a voltage of 3V, so an array that
uses 10 LEDs will only require 30V.
Power-over-Ethernet (PoE) can be
deployed even in situations where the
majority of networking is carried out over
a Wi-Fi network, as is now the case in
many commercial environments, rather
than hard-wired ethernet connections to
devices. Despite the heavy reliance on WiFi there will still be ethernet cables present
to connect Wi-Fi repeaters throughout the
various spaces.
From an installation perspective, the
use of low voltage ethernet cable means
that the cabling work can be done more
efficiently. There is no need to terminate
individual wires and the strain relief is
integrated into the termination method.
However, if this opportunity is to be fully
exploited it is essential to ensure that all
of the lighting – including the emergency
lighting – is using a low voltage supply.
If the emergency lighting still requires
line voltage in the ceiling/luminaires then
costly isolation, as well as additional
terminations, are required.
It is immediately apparent that using
PoE in this way offers significant savings
in material costs and installation time
as less cable is used and connections
can be made for more quickly. There will
also be additional benefits in terms of the
reduced maintenance requirements for
the cabling infrastructure.

In addition, in using ethernet cabling
rather than the more traditional twistedpair control cable, larger volumes of data
can be transported more quickly between
the points on the network.
There are also aesthetic benefits, as
there are fewer constraints on luminaire
design when there is no need for a
separate power supply and LED drivers can
be located remotely with just a low voltage
connection to the luminaires.

Power-over-Ethernet
can be deployed in
situations where
the majority of
networking is carried
out over a Wi-Fi
network.

Opportunity
Beyond these basic lighting requirements,
though, there is considerable opportunity
to do much more with lighting, utilising
the lighting infrastructure that already
exists in the majority of buildings and
many outdoor spaces.
For example, most modern lighting
systems incorporate occupancy sensors
to switch or dim lighting in response to
people leaving and entering a space. Much
has already been written about using this
occupancy data to better understand how
such spaces are used through the days
and years.
Nor is this approach confined to
improving space utilisation. Measuring
occupancy and the movement of people is
also invaluable for retailers who want to
fine tune the layout of their stores. They
might, for instance, use that information to
optimise the positioning of special offers so
that they have higher visibility.
There is also potential to combine this
with mobile connectivity. A shopper with
an appropriate App might make a product
selection online before visiting a store, and
then be guided to those products within the

store by the App. In a highly competitive
retail environment this ability to add value
for the customer can deliver significant
competitive advantages.
In parallel, increased connectivity
enables lighting to become part of the
‘Internet of Things’ (IoT) that we now hear
so much about. Essentially, this just means
different devices communicating with each
other, as well as with us.
Most references to the IoT concern
domestic appliances – turn the heating on
from your smartphone or have your fridge
tell you what shopping you need. However,
there is also scope for the services within
a building to communicate with each other
more effectively. Again, this idea isn’t new
but its application has been hindered by
the use of different protocols. Improved
collaboration between the manufacturers
of such systems is now driving a move
towards interoperable systems where a
combination of comfort parameters can
be combined to create healthier and more
productive workplaces.
There are, of course, many other
examples of how better data about a
space – and exchange of data between
different systems – can be used to
positive effect. The challenge has always
been not just how to gather that data
but also how to bring it all together in a
central location for analysis. Making use
of an existing, connected infrastructure
that would be in the building anyway
clearly makes perfect sense.
For electrical specifiers, the challenge
now is to look beyond traditional
approaches and see how lighting systems
can be used more widely to add even more
value for the end client.

‘PoE offers
significant
savings in
material
costs and
installation
time as
less cable
is used and
connections
can be made
for more
quickly.’

Summary
The hierarchy of light is about meeting
basic needs and working our way up to
the ultimate interaction of light as part