High energy use in rotary screw compressors is rarely about the compressor itself—it's usually about how the system is controlled, maintained, or designed. Compressed air is expensive (often the largest utility cost in a plant), and small inefficiencies compound quickly.
The most common culprits are air leaks, poor load/unload control, running at higher pressure than necessary, and dirty filters that increase pressure drop. Most energy waste is preventable with proper system audits and basic maintenance.
Rotary Screw Troubleshooting
High Energy Use – Rotary Screw Air Compressor Troubleshooting
Excessive power consumption or unexpectedly high electricity bills, often caused by control problems, air leaks, oversized pressure settings, or inefficient system design.
Industrial systems
Field-tested diagnostics
Independent & unbiased
What this problem usually means
Check these first
5–10 minute checks before diving deeper
- Load/unload cycle frequency—excessive cycling wastes energy (check controller hours)
- Pressure setpoint vs. actual demand—are you running 20+ psi higher than needed?
- Air leaks audible in the system when compressor is off (walk the lines)
- VFD operation status if equipped—is it actually modulating or stuck at full speed?
- Inlet filter condition—restriction increases energy use 1% per 2 psi drop
- Compressor running loaded during low-demand periods (nights, weekends)
- Multiple compressors fighting each other due to poor sequencing or overlapping setpoints
- Pressure drop across dryers and filters—should be under 5 psi total
Common root causes
Why this happens in rotary screw compressors
Air leaks throughout the system
Leaks force the compressor to run longer and harder to maintain pressure. A single 1/4" leak at 100 psi wastes over $8,000/year in electricity.
Poor control strategy
Constant load/unload cycling, multiple compressors with overlapping setpoints, or no sequencing controller. Each unload cycle wastes the energy used to pressurize the sump.
Running at higher pressure than needed
Every 2 psi increase in discharge pressure adds roughly 1% to energy costs. Many plants run 20-30 psi higher than actually required.
Inefficient system design
Multiple fixed-speed compressors instead of a VFD unit for trim duty, undersized storage, or no load-sharing strategy between machines.
Dirty filters and coolers
Clogged inlet filters increase vacuum at the inlet, reducing efficiency. Dirty coolers raise operating temperatures, affecting oil viscosity and power draw.
What NOT to do
Don't assume high energy use is "normal" for your compressor size. Don't ignore small leaks—they add up fast. Don't disable VFD controls to "simplify" the system. Don't increase pressure to compensate for leaks or undersized piping—fix the root cause instead.
Full Rotary Screw Troubleshooting Manual
Step-by-step diagnostics, root cause logic, and practical fixes for oil-injected rotary screw compressors. Save time and reduce downtime with proven methods.
- Step-by-step diagnostics for common failures
- Root cause analysis techniques
- Practical fixes with parts notes
- Works across all major brands