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ATS cuts energy use by retrofitting ageing air compressors

It has exceeded its target of a 20 per cent reduction in the electricity consumption of its air compressors.

Eric Leung, corporate facilities director at ATS: "We have so far modified three air compressors at the Singapore plant, and six units in China. They are all running fine without any motors being burnt out."

ASM Technology Singapore introduced a device at its Singapore plant that made its ageing air compressors more energy efficient.

For a project that helped reduce the energy consumption of the air compressors at its facility here, ASM Technology Singapore (ATS) was honoured with the Best Practices award at this year's EENP Awards.

Air compressors accounted for around 18 per cent of ATS's total electricity consumption. To improve energy efficiency, the company aimed to reduce the electricity usage of its air compressors by 20 per cent from a benchmark established in May 2018.

To reach this target, it decided to install variable speed drives (VSDs) to its air compressors. VSDs are devices that can vary the speed of a fixed-speed motor, and are used in applications ranging from small appliances to large compressors.

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Having successfully installed external VSDs to existing air compressors in their China facilities in 2013, ATS decided to do the same for the Singapore facility.

"The purpose of VSD is to provide a means to vary the speed of the motor according to the loading demand. It is achieved by changing the frequency modulating by the VSD to control the speed," said Eric Leung, corporate facilities director at ATS.

However, air compressor manufacturers and VSD suppliers were resistant to the idea due to the potential problems involved.

"With today's technology, most air compressor manufacturers have a VSD built into their compressed air systems. As such, they prefer to sell a brand new air compressor rather than retrofit an old unit, which has no benefit to them at all. Furthermore, both the manufacturers and VSD suppliers are concerned that reducing the motor speed may cause insufficient cooling for the motor, which may result in a short circuit or the motor being burnt off," explained Mr Leung.

After weighing the risks, however, ATS management decided to push ahead with the project, installing a VSD in their oldest air compressor, which was about 14 years old. The project proved to be a success, and the company exceeded its target by achieving a 22 per cent reduction in electricity consumption.

This translated to an annual energy saving of 923 MWh and a payback period of less than a year.

Said Mr Leung: "We have so far modified three air compressors at the Singapore plant, and six units in China. They are all running fine without any motors being burnt out. This is because the heating effect is reduced as a result of the lower speed running. Therefore, the motor won't heat up as the manufacturers were afraid they would."

The success of the project was not without its challenges, however. The first one involved finding a space to install the VSD device, which needed to be as near to the air compressor as possible. This can be difficult to do in a plant room with a small layout. The second challenge is the cost of running the cables required in the retrofit, and the third is the machine down time that occurs during the testing and commissioning period.

"The downtime can be almost a week. As such, a backup air compressor for production has to be prepared before the retrofit project," said Mr Leung.


ATS, part of global technology group ASM Pacific Technology Limited (ASMPT), develops and provides leading-edge hardware and software solutions, through backend equipment, materials, surface mount technologies and smart factory technologies for the semiconductor assembly and packaging industries.

ATS' project to retrofit its air compressors with VSDs is aligned to the group's broader sustainability goals. According to the ASMPT website, this involves continually improving its "operating efficiency and resource stewardship" to build a sustainable future that will create long-lasting value for its business, stakeholders, community and the environment.

"We strive to embed sustainability in our innovations through the efficient use of resources, recycling measures and re-engineering of manufacturing processes. In 2018, various changes and upgrades were continually made in the group's factories and facilities to ensure operational and energy efficiency," ASMPT said in its 2018 Environmental, Social And Governance Report.