When it comes to ensuring that a new compressor
installation is as energy efficient as possible it is, according
to Mattei, essential to seek the advice of a compressed air
specialist. Here, general manager Andy Jones explains why

With energy prices remaining
volatile and carbon reduction
targets being critical, energy
efficiency has become a top priority for
many manufacturers. However, not all
businesses realise that compressors can have
a big impact on their utility bills and carbon
emissions, or understand how important it is
to ensure the compressors they use are
suitably sized and are appropriate for their
production processes.

Some businesses have a misconception
that compressed air is ‘free’ once they have
invested in the equipment, but the main cost
will always be the energy required to
produce the compressed air. The initial
purchase price actually makes up a very
small part of the total lifetime costs. The
electricity consumed during operation over a
five-year period, meanwhile, typically
accounts for around 75% of the total cost of
ownership, including the initial capital outlay
for the compressor.

In many cases, however, this is completely
overlooked during the specification process,
because very often the person responsible for
specifying the machine is not a compressor
specialist. Time and time again we see
purchasing decisions being made on a likefor-
like replacement basis, or on the
recommendation of a general consultant who
is not actually experienced in compressor
technology, rather than on actual
requirements. And because the purchaser –
or one of their general consultants – believes
they already know what they need, we often
find specifications being written before we
are even contacted. Sometimes this is based
around a specific manufacturer’s compressor,
or what is already in place.

However, this approach can result in an
unsuitable compressor being selected, that
won’t be efficient for the application.

Replacing like-for-like doesn’t mean the new
compressor will be automatically right; it
could be that a business has had an
inefficient system for some time, either
because of process/production changes or
simply because it was wrongly specified in
the first place. We recently found that one
company running a 75kW compressor could
actually fulfil its compressed air
requirements with a 45kW machine, with
estimated savings in the region of £10,000 a
year.We also see ‘oil-free’ and ‘class zero’ air
being specified without legitimate reason.

And, since the more stringent the purity, the
higher the cost to achieve it, businesses can
be unnecessarily wasting thousands of
pounds. Similarly, some companies are using
variable speed compressors when fixed speed
machines would be more appropriate, and
vice versa – again wasting energy. A variable
speed compressor will only be able to save
energy if it’s been established that there are
true peaks and troughs in the demand for air.

Compressor specialists don’t even need
huge amounts of information to determine
what equipment is required. For example, to
make a recommendation, all Mattei needs is
an air usage figure (which can be obtained
through a seven-day data logging exercise)
and the class of air required in accordance
with ISO 8573-1:2010. It is also possible that
a compressor specialist might arrive at the
conclusion that a new compressor isn’t
required at all. It could be that fixing leaks
in the system or upgrading/altering the
layout of the pipework could be sufficient to
improve performance and efficiency.

And, where ‘oil-free’ compressors are
concerned, a specialist would have the
knowledge and experience to identify
whether the entire system requires a certain
purity, or just a particular area that could
perhaps be served by point of use air
treatment or a dedicated smaller compressor.

Having said this, unfortunately we do have
to accept that there are compressed air
companies that are just interested in selling
new machines, whether it’s in the best
interests of the customer or not. So if the
purchaser wants an unbiased, independent
opinion, or reassurance they have been given
the correct advice, they can contact BCAS
(British Compressed Air Society).

Replacing a compressor presents an ideal
opportunity to improve energy efficiency –
so we would strongly urge businesses to seek
the advice of a specialist and where possible
invest in a data logging exercise before a
detailed specification is written.