Why a compressed air audit is worth the energy

It’s a commonly known industrial fact – between 10-15 per cent of industrial electricity is used to generate compressed air. And yet, compressed air is an inefficient form of energy – 90 per cent of the input energy used is discharged as waste heat. This is not only costly from a sustainability standpoint; wasting energy means wasting money. This is why both government and industry bodies recommend that businesses take measures to improve the efficiency of their compressed air systems. The first step is to organise an audit.

An audit can identify factors that are causing inefficiencies in an air compressor system such as leaks, poor controls, and pressure settings. However, not all audit systems are designed equally. CAPS Australia expert and branch manager for South Australia, Kevin Jones, said that unlike other audit systems that typically offer a simple compressor efficiency analysis, CAPS audits are designed from the ground up to be a comprehensive system analysis tool that considers a broad range of variables beyond the compressor.

These variables may include the demand profile, usage and potential misuse, pipework design, plant room and ancillary equipment selection and design, sources of leakage, and storage.

“CAPS invested in the development of this air audit system because we saw a need to help our customers solve efficiency and performance as well as help them save money. We consider these savings to be low-hanging fruit – as in they are easily achieved and the benefits are relatively swift,” he explained.

The audits CAPS provide are characteristically simple and low in cost. Moreover, energy-saving audits are scalable. Regardless of an organisation’s size, the percentage of savings after an audit will generally justify both the audit and the costs of a system upgrade.

“It would be a rare event if an audit didn’t find opportunities to improve efficiency,” said Jones. “For example, an automotive supplier in South Australia undertook an audit and a compressor upgrade through CAPS—they started seeing energy savings of 40 per cent after installing the upgraded compressor and will see a return on their investment in less than 2 years. These type of savings depend on the scope of the site. For instance, a large mining site – well, that would require a more complex and longer audit but the cost savings would likely be in the hundreds of thousands.”

CAPS usually run an audit over seven days at a site. Their process starts with getting an understanding of a customer’s requirements and operations. “We first discuss with the customer what they want to achieve – is it to simply cut costs or get the best option moving forward? This will drive how we conduct the audit. Then we will set up out at the site but in a way that is not intrusive, so we won’t disrupt production or interfere with their usual activity,” Jones explained.

“After one week of auditing (data logging) the information is uploaded to the CAPS software and reviewed. This is where we uncover the facts on the sites compressed air operation, and can determine efficiency gains resulting in energy savings.”

CAPS provide both supply side audits and demand side or leak audits – the latter uses ultrasonic technology to determine air leakage.

Jones further detailed another case study where CAPS had provided an audit and recommendations to an abattoir in Queensland, Kilcoy Pastoral.

The [management] at Kilcoy were looking to upgrade their compressed air system, so we logged and analysed the information, made some project recommendations and supplied a new air compressor system,” Jones explained. “We also did a verification air audit of the new equipment to prove that we had provided the results we had [originally] anticipated.”

The client was very happy with the result. Not only did they pay back their capital costs within two years; they are now experiencing electricity savings of $15,000 every month.

A CAPS compressed air audit will uncover the facts that allow good business decisions to be made.

“This is why an audit is recommended for any business who wants to improve their energy use and costs – if your system hasn’t been measured, how will you know how much you will save?” Jones asked.