Compressed air products distribution company Goscor KLG recently performed a series of energy audits at various Barloworld facilities, including at Barloworld Power’s main Boksburg campus, which indicated that significant energy savings could be achieved by replacing existing oversized compressors with smaller, correctly sized units that use power more efficiently.

The audits typically take seven consecutive days to attain a realistic workload profile of the plant. In addition to Barloworld Power audit, energy audits were completed at Barloworld Equipment’s Isando, Bellville, Bloemfontein, Durban, Middelburg and Germiston branches.

Goscor KLG project engineer Colin Tyrrell says new Sullair compressors, manufactured by compressed-air solutions company Sullair, have been installed at Barloworld Equipment’s Isando and Bellville facilities and save about 70% and 25% respectively in energy consumption, when compared to the original compressor installation.

A Sullair ST1508RD 15 kW compressor was installed at Boksburg, while in Isando, a S-Energy 4507V 45 kW variable-speed drive compressor was installed. However, at Bellville, although the existing 75 kW compressor was replaced with another 75 kW compressor S-Energy 7507 variable capacity control (VCC) compressor, it was this compressor’s VCC feature – which enables a compressor to mechanically adjust to large variances in the load profile – that made the difference.

Installation of the compressors at the other branches is subject to capital expenditure processes. “Some of the plants require further investigation regarding medium-term plant expansion and other rationalisation matters that may affect the compressed-air requirements,” notes Tyrrell.

Energy audits require an in-depth investigation. Future expansion and/or reduction must be considered to ensure that the proposed installation is correct, not only for present plant conditions, but will remain efficient for the foreseeable future too.

He explains that the audit process was straightforward. “Our initial audit was based on establishing the exact load profile of the plant and our solution was then tailored to suit this profile.”

Tyrrell adds that older-generation plants are usually fitted with compressors that are oversized for the workload for which they were required. “It is the auditor’s job to accurately define the correct size machine and then determine the correct control system to maximise the savings the new machine can achieve.”

Once a new compressor has been fitted and operational, Goscor KLG performs a post-installation audit to verify that the predicted savings are attained. “If the savings are not being achieved, we are prepared to remove the equipment at no cost to the customer,” he says.

Barloworld Equipment energy efficiency manager TM Lesetla says constant change in the compressor work environment and the ever-increasing demand for improved productivity makes decreasing energy costs an imperative.

“For this reason, we decided to do a thorough investigation with Goscor KLG to test whether new compressors would be financially viable in the long run. “I am pleased to say that the exercise was, indeed, a great success,” he says.

Tyrrell says the entire process with Barloworld has been extremely productive. “Their decision to do the audit was a smart move and working with them has been a positive experience,” he concludes.