Significant energy savings can be achieved by replacing existing oversized air compressors with correctly sized units that use power more efficiently, says compressed air products distributor Goscor.

The company performed a series of energy audits at various branches of industry-related global brands distributor Barloworld South Africa, which indicated that substantial energy savings could be achieved by using smaller air compressor units.

“The initial audit was based on establishing the exact load profile of the plant and our solution was then tailored to suit this profile,” explains Goscor project engineer Colin Tyrrell.

The audits typically took seven consecutive days in order to attain a realistic workload profile of the plant under scrutiny.

Tyrrell notes that older generation plants are usually fitted with compressors that are oversized for the workload for which they are 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 that the new machine can achieve.”

New compressors supplied by compressed air solutions manufacturers Sullair have been installed at Barloworld Equipment’s Isando branch in Johanneburg, and Bellville branch, in Cape Town, and these have facilitated a saving of 70% and 25% respectively in energy consumption when compared to the original compressor installation.

Energy audits require an in-depth investiga-tion, and future expansion or reduction must be considered to ensure that the proposed installation is correct not only for present plant conditions, but that it remains efficient for the foreseeable future too.

Once a new compressor has been fitted and is operational, Goscor 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 extra cost to the customer,” Tyrrell says.

A Sullair ST1508RD 15 kW compressor was installed at the Bellville branch, while an S Energy 4507 V 45 kW variable-speed drive compressor was installed at the Isando branch. The variable-capacity control feature of these compressors, which enable the compressor to mechanically adjust to large variances in the load profile, have been significant in producing energy savings.

Installation of the compressors at the other Barloworld branches that were monitored by Goscor are undergoing capital expenditure considerations. “Some of the plants require further investigation regarding medium-term plant expansion and other rationalisation matters that may affect the compressed air requirements,” explains Tyrrell.

Barloworld Equipment energy efficiency man-ager TM Lesetla says that 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 undergo a thorough investigation with Goscor to test whether new compressors would be financially viable in the long run. I am pleased to say that the exercise was, indeed, a 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. Energy audits are an important value-adding service that we offer at Goscor and I advise companies that use compressors to undertake what could be a major cost-cutting exercise,” he concludes.