Chris Dee, executive director of the British Compressed Air Society (BCAS) discusses his organisation’s concern at the widespread and costly inefficiencies being overlooked in one of manufacturing’s most ubiquitous plant technologies.
Almost three quarters of industries use compressed air for some aspect of their operations. Many of these industries operate around-the-clock, constantly adding to a plant’s energy costs. So it’s no surprise that energy efficiency and the reduction of energy consumption continue to be key drivers behind the majority of compressed air system improvements.
Whether it’s investing in the latest, high-efficiency compressor and downstream technology, or simply carrying out an air audit on an existing network, energy concerns have become the norm.
There are also certain legislative requirements that mean many manufacturers have an obligation to improve their carbon footprint, by investing in new, energy-efficient technologies.
At BCAS, we work closely with the Carbon Trust, helping our members and their customers understand the legislation and the grants or tax incentives available to help fund the installation of new compressors.
In a recent case study, a steel foundry in the UK was able to benefit from an interest-free loan from the Carbon Trust to fund the installation of two regulated-speed compressors. Thanks to the high energy efficiency of its new compressed air system, the foundry was able to increase productivity and cut its compressed air energy costs by more than a half.
Hot air venting from the foundry’s small compressor house ensures that 80% of the energy lost in the compression process is reclaimed. The hot air is ducted into the foundry during winter and out into the atmosphere in the summer, allowing heaters to be turned off, saving £10,000 per year in diesel costs.
The loan is expected to pay for itself within four years through energy savings alone.
The Carbon Trust recently published research which quantifies the substantial savings companies can make through addressing the efficiency of their compressed air systems.
Following on the research the organisation has also produced a simple ‘how to’ guide to gaining increased efficiency titled, the Compressed Air Overview.
According to the Carbon Trust the levels of energy consumed by compressed air systems are commonly underestimated. In fact, they claim that 10% of industry’s energy consumption is accounted for in compressed air systems, equivalent to the annual output of nearly 1.5 power stations and over 5 million tonnes of CO2.
Surveying national programmes to increase compressed air efficiency, The Carbon Trust has found that typical savings are in the region of 30%. This equates to average energy savings of £1,500 a year per company.
Richard Rugg, director of Carbon Trust Programmes, commented on a general misconception in industry that compressed air is a free or low cost resource. “In fact the opposite is true,” he says. “Just a single 3mm hole in a compressed air system creates a leak, which can cost a business an additional £1,000 a year in electricity costs.”
“This is not a niche problem,” he continues. “Compressed air is being used across industries as diverse as aircraft manufacturing, water treatment, electronics and engineering.”
Setting the standard
Many customers are keen to retain their existing compressors and BCAS members can work with them to improve the efficiency of their network, looking at areas such as a site’s compressed air requirements, including air pressure, power consumption and flow rates.
Detailed audits help to establish the best compressed air system for the application.
There have, however, been concerns for some time that the lack of a formal standard allows suppliers with differing levels of expertise to conduct a compressed air audit – and for that examination to then be considered as a comprehensive system assessment.
After more than four years of work between BCAS and the ISO Technical Committee 118, 2012 should see the publication of a new standard for compressed air system assessment, called ISO11011 (Compressed air – Energy efficiency – Assessment).
ISO11011 is designed to create a framework for the assessment process to improve on existing compressed air audit activities, which can also be embedded in to other requirements that exist around the globe.
The new standard considers the entire air system, from the energy inputs to the task performed and classifies compressed air in to three subsystems:
- Supply, which includes the conversion of the primary energy resource in to, compressed air energy.
- Transmission, which includes the movement of, compressed air energy from where it is generated to where it is used.
- Demand, which includes the total of all compressed air consumers, including productive end-use applications and various forms of compressed air waste.
One of the key features of ISO11011 will be the establishment of a baseline performance for a compressed air system. The purpose of baselining is to establish the current performance levels and costs of a compressed air system, and to correlate the results with the plant’s present production levels.
As improvements are made to the compressed air system, it will be possible to estimate improvements by comparing the new measurements with the original baseline.
“At BCAS, we work closely with the Carbon Trust, helping our members and their customers understand the legislation and the grants or tax incentives available to help fund the installation of new compressors” – Chris Dee, Executive Director of the British Compressed Air Society (BCAS)
Ongoing maintenance of the compressed air system is integral to its reliability and energy efficiency. We would always advise taking out a full support contract, to include regular performance and safety checks, to cover any emergency repairs alongside preventative maintenance.
As with much of today’s plant equipment and machinery, compressor performance and efficiency is affected by the components and lubricants within. Performance and benefits can be compromised if the user takes the decision to use non-genuine replacement consumables and parts.
Modern, high quality compressors will offer maximum performance, energy efficiency and low total cost of ownership over many years. Therefore a lot of time and care, not to mention cost, is taken to choose the right compressor for the job. Once this decision has been taken, it makes little sense to use non-genuine replacement components and undermine the initial investment.
Using genuine parts supplied by the manufacturer of the original equipment means the compressor will provide the expected performance and maintain its energy efficiency benefits. Genuine parts are the only sure way of keeping the cost of running a compressor within the service and maintenance budget rather than having to find the cash to pay for unexpected major repairs.