Network Communications News (NCN) August 2016 | Page 31
intelligent buildings
S P E C I A L F E AT U R E
any building to choose and implement
an appropriate tried and tested BEMS
strategy, helping reduce its carbon
footprint, provide improved working
environments as well as one that will work
into the future easily reflecting changes
and variations in the buildings usage.
This means that services such as
HVAC and lighting are only used when
required. Parameters for ensuring a
steady temperature can be programmed
into the BEMS to ensure the building
stays within certain performance
parameters. But ultimately, the building
operates for and in response to the
requirements of occupants.
Data needs
Carlo Gavazzi’s
Dupline 2-wire bus
system simplifies
field level wiring.
However, controls technology is
changing and extending the possibilities
of what can be achieved. The technology
also means that the building occupant
can be the focus of the BEMS, which can
save energy while also providing better
comfort levels established on a demand
control based system.
Control solutions
Fortunately the market continues to
develop innovative and energy saving
control solutions which provide greater
visibility and performance tracking.
This makes it easier for occupants of
As buildings and building services
equipment become more advanced,
the functionality is also becoming more
complex. The demand for detailed
information on building performance
means that collecting and delivering
that data is crucial – and relies on the
communications networks of the BEMS,
which in turn rely on good quality wiring.
It may not be something that building
managers consider too closely, but
smart wiring systems can make all the
difference in terms of capital cost and
long term efficiency.
Communications networks are used
extensively in building management
systems at the automation and
management levels. These are often
known as the primary levels of a BEMS
network. Devices further down the
network, at the device level, such as
sensors, and I/O modules including
indicators and actuators, would
traditionally require separate wiring runs
to link them to primary level.
This means that if a project plan
includes a high number of these devices
spread over a wide area, then the wiring
costs using the traditional approach can
be high. This may result in a compromise
to the design of the system, with field
devices omitted because it is considered
too costly to include them. And so the
BEMS cannot offer the functionality that
the designer has in mind.
Smart wiring
Crucially, building managers should
think about smart wiring systems, more
importance on this could make all the
difference in terms of capital cost and
long term efficiency.
However, the very latest wiring
technologies and techniques overcome
this problem. For example, a 2-wire bus
system can link field devices together,
without the requirement to connect
each separate sensor or actuator back
to the primary level of the building
management system.
Essentially, this creates decentralised
sensors and I/O modules, giving much
greater flexibility on the distribution
of devices without the costs of extra
wiring. There are also sensors for CO2,
temperature and humidity that can now
be powered from the bus. This further
reduces the need for wiring to power the
devices. Also, a 2-wire bus cable can be
run from sensor to sensor, collecting all
the measured values. Each sensor does
not have to be individually wired back to
the main controller.
Forward thinking manufacturers
are leading the way on creating more
potential for a single-system approach.
For example, Carlo Gavazzi now offers
a DALI gateway from its Dupline wiring
system, making it possible to integrate
HVAC with lighting applications.
The current industry approach
to contracting means that lighting
is specified as ‘electrical’ and HVAC
as ‘mechanical’. This creates a false
message that the two have to be
controlled separately – an expensive and
unnecessary approach. By putting the
‘system’ firmly at the heart of building
management, designers and installers
will deliver all-round better buildings.
The market
continues to
develop innovative
and energy saving
control solutions.
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