APS Materials’ Waterford facility needed certified oil-free compressed air without the running costs usually associated with it. By replacing a 45 kW oil-lubricated fixed-speed compressor with an Ingersoll Rand oil-free variable-speed unit, the site achieved cleaner air, lower energy use and reduced maintenance in one move.
The challenge
Plant Manager Michael O’Sullivan set out to answer a simple question: does better air quality necessarily increase costs? The team’s primary goal was to bolster oil-free reliability. Moving from “contact-cooled with filtration to achieve oil-free” to true oil-free technology carried a higher upfront price; however, pairing the upgrade with variable speed drive (VSD) control transformed the business case.
Given the site’s variable load profile and historic pressure drops across downstream oil-removal filters, VSD control and the removal of oil-related ancillary stages offered a clear path to lower energy use and cleaner air.
The solution
APS replaced its legacy 45 kW fixed-speed unit with an oil-free, variable-speed screw compressor (IRN45OF), sized to real site demand and supported by optimised controls.
- Oil-free screw compressor (IRN45OF) sized to site demand.
- Variable Speed Drive to match output to real-time air demand and enable soft starts.
- System pressure optimisation to reduce leakage and avoid unnecessary over-pressurisation.
- Simplified downstream treatment by eliminating oil separators and coalescers.
- Controls tuning and monitoring to maintain stable pressures at lower setpoints.
- Maintenance plan focused on intake air quality and filtration to protect the oil-free elements.
- Full manufacturer support with a bumper-to-bumper 5-year warranty.
Results
- Energy savings up to ~35%, driven by VSD part-load efficiency and reduced unloading and idle losses; in more favourable profiles up to ~40% is achievable.
- Lower system pressure and reduced pressure drop, cutting leakage and further decreasing kWh consumption.
- Cleaner, certified oil-free air without the risk and cost of downstream oil contamination.
- Reduced maintenance: no compressor oil to purchase, manage or dispose of, and fewer oil-related components to service.
- Higher reliability with soft starts and fewer thermal and mechanical stresses.
- Reduced carbon footprint through sustained energy reduction.
- Improved total cost of ownership: energy and maintenance savings offset the higher capital cost, delivering a strong payback.
At APS Waterford, improved air quality did not mean higher operating costs. The VSD oil-free upgrade proved to be a game-changer for performance, reliability and cost.
Need certified oil-free air?
Harold Engineering is Ireland’s foremost Ingersoll Rand distributor, with more than 40 years of partnership and thousands of installations nationwide. Explore our air compressor range or request a quote for an oil-free or VSD upgrade. The same Ingersoll Rand range took Best Energy Efficient Product at the SEAI Energy Show.
