Air compressor failures: Fix or replace?
Many decisions are made in keeping compressed air systems running smoothly, but one of the most important is equipment selection. From time to time, equipment failure forces us to choose to repair our old air compressor or select a new one.
Often, for a major component failure, the cost of the repair of the compressor may exceed 50% of the cost to buy a new unit. This is when we should carefully consider not only the replacement cost, but also the energy cost to keep the old compressor running. More often than not, the purchase of a new, more efficient compressor will quickly pay the additional cost of buying new.
The cost to purchase an air compressor is only about 12% of the 10 year cost of ownership. (Tweet this) About 76% of the total ownership cost goes towards supplying the electricity to keep it running. A typical continuously run fully loaded 100-hp compressor will cost about $74,000 per year in electricity costs at 10 cents per kWh.
An important step in preparing yourself for these decisions is to have your compressed air system analyzed beforehand so you can understand where you are now and how you could improve your system. This analysis can be done in-house or by one of many compressed air system services providers in your area. Once this analysis is done, should disaster strike your air compressors, you will be ready with the information necessary to make your repair or replace decision.
Times have changed in the compressed air industry and it is important that we realize that the selection of newer equipment capable of running in more efficient operating modes can significantly improve total air system efficiency and may even make your other compressor run better too. Some things to consider:
• Manufacturers have improved the efficiency of air compressors over the years by improving components such as motors and bearings, and optimizing machine design. These improvements can make new compressors much more efficient than old units.
• Years ago, when power prices were low, modulation mode was the typical control strategy for air compressors. These days, significant savings can be gained by running your compressors in load/unload, capacity control, or VSD mode by purchasing compressors capable of this type of operation and the necessary components, like storage receivers and controls, to enable efficient operation.
• Often the old compressors are too large and re-sized smaller, less expensive compressors can be purchased.
• Upgrading other components like air dryers, filters and piping at the same time can further increase your savings.
If you want to learn more about analyzing your system, check out our book “Best Practices for Compressed Air Systems” or attend one of our many seminars. Our upcoming Fundamentals webinar is open for registration, or check out the many in person seminars across the country. For more information, please visit www.compressedairchallenge.org.
By Ron Marshall, for the Compressed Air Challenge