Has the EU focussed on the right area with machine
efficiency, or should the efficiency of the complete air
system be the subject of the forthcoming regulation? Greg
Bordiak, technical officer at BCAS (British Compressed Air
Society), comments

Compressor manufacturers, like many
other manufacturers, are working
hard to squeeze the last ounce of
energy efficiency from their packaged
products. The user, however, is looking for
more processing power from their packaged
unit, which can include air treatment,
controls and an electric motor, whereas the
EU wants to legislate the energy efficiency
rating of the product.

The standard, ISO 1217, used for positive
displacement compressors, identifies
acceptance tests from which the elements of
an energy statement can be calculated. The
statement is known as ‘specific energy
requirement’ and provides for the
relationship between packaged compressor
input power and output volume flow rate.

The EU has put in place legal provisions
to control the efficiency requirements of all
equipment that uses energy. The focus of
attention is now on compressors which,
under the umbrella of the Energy Related
Products Directive, are to follow electric
motors down the path of reducing energy use.

A consultant – VHK from the
Netherlands has been appointed by the EU
to produce a report and recommendations
on what and how the energy efficiency
requirement is to be identified for
compressors.

VHK has been liaising with the
compressor industry representative
PNEUROP, in which BCAS is actively
involved. Part of the report that VHK is
required to produce is a study to establish
the size and energy use of the market. An
estimate for the energy use of the total
compressor market in the EU produced a
result in the region of 240TWh for all
compressor technologies.

The PNEUROP working group is
developing an argument to restrict the scope
of the eventual legal provision so that the
appropriate resources can be focussed on
identifying the most beneficial sector of the
compressor market that can show real energy
efficiency savings.

The identity of a basic compressor
configuration will have to be representative
of the market sector. This then takes the
discussion back to what the customer wants
in the form of the packaged compressor
configuration. The question that needs to be
asked is whether a basic compressor
configuration can be reconciled with the
wants of the customer?
PNEUROP is struggling to find a solution
to this configuration, which in itself is
reducing the scope of what will eventually
become the legal provision. A basic
configuration for oil flooded rotary
compressors is evolving and one for
reciprocating compressors is being identified.

The PNEUROP working group met almost
once a month during 2012 to provide
assistance to VHK so that an industry
acceptable proposal for the coming legislation
can be put forward for EU agreement.

Its important to remember that although a
compressor is deemed efficient, it could still
be installed into a system that may not be
configured to take advantage of this
improved performance. This overall system
does not currently have an energy efficient
statement of its own.

However, an energy efficient statement for
the overall system can soon be obtained
using standardised methods and procedures
within the ISO 11011 ‘Compressed air —
Energy efficiency: Assessment’. The ISO
working group led by BCAS met in
November 2012 to discuss the comments
during the last voting phase where it received
100% support enabling publication of ISO
11011 during the first half of 2013.

The question that remains is what level of
energy saving can be achieved by compressor
technologies to satisfy the upcoming legal
provision from the EU, and how much
energy can the customer expect to save from
their system?
A 10% improvement in energy efficiency
for a compressor package may not be
possible, but savings of over 10% are
certainly possible when it comes to the
complete compressed air system.