The load factor of an air compressor refers to the ratio of loaded (air-producing) time to the total operating time. It reflects the compressor’s actual operating load and is an important reference for equipment selection, energy consumption analysis, and maintenance planning.

Formula:
Load Factor (%) = (Loaded Time ÷ Total Operating Time) × 100%

Note:
Total operating time = loaded time (air-producing state) + unloaded time (idle, no-load, or stopped state)

What Different Load Factor Levels Indicate

100% – Full-load operation
The compressor runs continuously and produces air without interruption. Actual air demand is almost equal to the compressor’s rated output.

70–90% – Ideal operating range
This is generally considered a reasonable and healthy load factor. Loading and unloading cycles are well balanced, and both energy efficiency and equipment wear are close to optimal.

Below 50% – Light-load operation
This usually indicates that the selected compressor is oversized. Actual air demand is far lower than the compressor’s output. For fixed-speed compressors, this leads to excessive energy consumption and poor energy efficiency.

Near 100% with frequent overpressure and tripping
This is a typical sign that the compressor is undersized or that air consumption has increased suddenly. Such conditions can accelerate equipment wear and significantly shorten the compressor’s service life.