Throughout the industrial world, compressed air systems are one of the largest electricity consumers around, second only to pump motors. But what can be done about it? One of the best ways to reduce waste and save is to properly stage the compressors to maximize overall system efficiency.
Air compressors are typically very inefficient when partially loaded, drawing upwards of 50% to even 100% of power when totally unloaded! Staging allows extra compressors to shut off while lead compressors run full out at maximum efficiency. Simple staging can be done by setting the required pressure for the lag compressor 5-10 psi below the lead compressor, resulting in significantly reduced run time for the lag compressor and significant energy savings.
An even better option is to install a VFD compressor to be used in the lead position. Because these compressors can vary their operation to match output, they are the most efficient option available. Using a VFD compressor as lead allows you to ramp up with demand until the compressor is fully loaded. At that point, a same-sized lag compressor can kick on to full capacity (its most efficient operating point) and allow the VFD compressor to ramp back to its minimum and start rising again as more output is needed.
To visualize these changes in system efficiency, the chart below shows total energy use vs loading for non-staged, simply staged, and VFD staged system.
In addition to the huge savings available from staging, the Entriq Solutions team can help you explore all of your compressor plant efficiency options. Call us today start the discussion.