Compressed air is used extensively as a
safe and versatile source of power.
Often referred to as the fourth utility,
manufacturers and processors rely on
its availability to power mission critical
processes 24/7. However, it is not free
and generating compressed air can be
very energy intensive, representing
between 5-30 percent of a site’s total
electricity bill, asserts Vanda Jones,
Executive Director, British Compressed
Air Society (BCAS)
According to a report entitled
‘Compressed Air Systems in the European
Union’, when looking at the most
important energy saving techniques
available to compressed air users, ‘the
energy savings amount to 32.9 percent,
achievable over a 15-year period’.
The drive to cut energy
Stringent environmental legislation sets
limits on carbon emissions, encouraging all
users to take steps to reduce their
electricity consumption to create a cleaner
and greener manufacturing environment.
For example, the Government’s Clean
Growth Strategy for meeting the UK’s legally-binding
carbon commitments, aims to help
businesses decarbonise. Part of the Strategy
includes the ‘Industrial Decarbonisation and
Energy Efficiency Roadmap Action Plan’. The
action plan will seek to reduce greenhouse
gas emissions and become more energy
efficient while remaining competitive
during the UK’s low carbon transition.
Yet, while compressed air energy
consumption represents a considerable
overhead for manufacturers, its
performance and efficiency can often be
overlooked, and improvement
programmes delayed. This can be
counterproductive, because there are
many simple ways that users can reduce
their energy usage, without investing in
new capital plant and equipment.
Simple ways to cut energy
The best place to start, when considering
upgrading an existing compressed air
system, is to speak to an expert.
BCAS members can advise on the best
equipment and system for your needs.
This could include incorporating fixed and
variable-speed drives or a combination of
both as well as efficient downstream
equipment. Where suitable, sophisticated
control systems can help proactively
manage the supply of air.
Equally, BCAS members can conduct a full
system audit and advise on some of the
simpler, low cost ways that energy usage
and wastage can be reduced.
BCAS’s ‘whole system approach’ article on
page 34 discusses some of the specific
ways that users can cut wastage and
thereby improve energy performance in
more detail, including:
Fix leaks - Just one 3mm hole could cost
over £600 a year in wasted energy. A leak
survey can help to size the issue – and to
tackle the largest leaks first
Heat recovery - As much as 95 percent
of the energy consumed by a compressor
is converted to heat and, unless captured,
will be wasted to the atmosphere. Many
manufacturers offer heat recovery
systems, which can often be retrofitted.
System design - When discussing
efficiency and the potential savings that
could be realised, it is important to take a
full, system approach – from generation
to air treatment to distribution and finally,
the point of use.
Improve control - Reducing pressure at
the point of use, switching off
compressors when there is no demand for
air and installing energy management
systems can all help you identify wastage
and take action
Manage air downstream - Excellent
savings are achievable by treating all the
generated air to the minimum acceptable
level and improving the purity (quality) to
the desired level at the usage point.
Behavioural change - You can make
substantial efficiency improvements by
implementing new processes and
encouraging staff to use compressed air
more efficiently and safely.
Tel: 020 7935 2464
Compressed air &
26 AirUser 2020/21