An Auckland-based food manufacturer was experiencing intermittent issues with compressed air pressure across their facility. These fluctuations were causing equipment to trip on low pressure alarms and, in some cases, behave unreliably – particularly on a key production line.

From experience, we knew that such problems could stem from either insufficient compressor capacity or excessive pressure drop within the system. To accurately diagnose the issue, we recommended a data logging exercise: capturing real-time pressure data both at the compressor station and at the furthest point of the production line.

Step 1: Initial Logging & Analysis

The customer approved our proposal and coordinated the logging around the operation of their most problematic line.

Over the course of a week, we recorded:

  • Compressor output and compressor station pressure

  • System pressure at the farthest point in the factory

This dual-point approach allowed us to quantify the pressure drop across the system. The data was then analysed and presented in a series of easy-to-read charts.

Key Findings:

  • The air compressor was running at full output for extended periods and could not maintain required system pressure, leading to repeated low-pressure events.

  • A significant pressure drop of up to 2.2 bar was measured between the compressor room and the sauce line at the far side of the plant.

Step 2: Recommendations & Action

Based on the findings, we recommended:

  • Upgrading undersized piping between the compressor room and the production area (which could be done without hot work inside the production space).

  • Investigating compressed air consumption during downtime, which suggested a high likelihood of leaks.

The customer took action by:

  • Replacing a section of ½” pipe with 2½” piping between the compressor and main factory ring

  • Conducting a leak repair exercise, and reviewing opportunities to reduce air use, especially with their double-diaphragm pumps

Step 3: Post-Upgrade Data Logging

After the upgrades and repairs were completed, the customer requested a follow-up data logging exercise to measure improvements.

Results:

  • Leak reduction estimated at 0.4 m³/min, resulting in annual energy savings of approximately $4,500 (based on 8,500 operating hours and energy cost of $0.20/kWh)

  • Compressor’s 100% duty cycle reduced from 33% to 21% of operating time

  • Pressure drop reduced by two-thirds, from an average of 0.9 bar to 0.35 bar

Long-Term Outcome

With the improvements validated, the customer opted to reduce compressor pressure setpoints by 0.5 bar, achieving an additional $500/year in estimated energy savings. They also indicated plans to explore further pressure reductions, now confident in the system’s reliability.

This project is a clear example of how effective data logging and analysis can identify root causes in compressed air systems. By pairing the right tools with targeted action, Plummer Compressors helped the customer:

  • Resolve reliability issues

  • Improve system efficiency

  • Unlock measurable, long-term energy savings