Compressor Types and Loads

Load / no-load compressors run continuously and are best suited to consistently high load situations (over 90%). Variable frequency drive (VFD) compressors speed up or slow down in response to load, and are most efficient for changing loads below 90%. Modulating compressors also adjust to demand, but are far less efficient than VFDs. Often, a VFD can be combined with either a modulating or a load / no-load compressor for optimal efficiency. Contact us to learn more.

  • Choose the right mix of compressor types for the load and its variability
  • Use multiple compressors for backup protection in case of primary unit failure
  • Size compressors based on required airflow and pressure

Supply-Side Efficiencies

Compressed air contains water that must be removed before it’s used. When run through a cycling refrigerated thermal mass dryer (called “cycling” because it operates only when needed), air cools down and water drains out. A no-loss drain is the most efficient way to remove that water, letting only condensate (not air) escape. An air receiver tank stores the air until it’s used, balancing the supply and demand sides of a compressed air system.

  • Use cycling refrigerated thermal mass dryers to save significantly on drying-related energy use
  • Drastically reduce drain air losses by using a no-loss drain that senses when water is present
  • Use receiver tanks to help VFDs give more stable pressure, and to help load / no-load systems save energy

Demand-Side Efficiencies

Air leaks can waste as much as 30% of a compressor’s output. Every hose, fitting, and quick-connect coupling is an opportunity for air leaks to develop. A professional auditor can meter your compressor for pressure fluctuations and look for system leaks with an ultrasonic detector. A written audit report helps you prioritize the most cost-effective measures. If your compressor uses nozzles, retrofitting with air-entraining nozzles is an easy, affordable way to reduce energy use. You can also boost efficiency by minimizing sharp bends in piping, replacing filters, turning off compressors when not in use, and reducing air pressure to the lowest acceptable level.

  • Reduce compressed air costs by 10–20% by identifying and fixing air leaks
  • Install permanent metering for ongoing leak detection and remediation
  • Reduce compressed air energy use by 40% or more with air-entraining nozzles