I was reminded the other day of the importance of checking compressor hour meter readings regularly to see what they are saying. This is a very good exercise; it can not only tell you something about how efficiently your air compressors are running, but also it can help you detect big changes to your system, which can spur action.
I was disturbed to see that one compressor in a small two-compressor system I was assessing was running unloaded 91% of the time, and its unloaded power consumption was much higher than it should have been. The result was that the total system was consuming about double the energy it should have been and contributing about 20% of the facility's total energy costs.
I checked the maintenance records and found that the facility's service provider had dutifully come in to maintain the machines every three months over a number of years – maintenance that was triggered by compressor operating hours. I was left to wonder why the service technician hadn’t told the customer that the second compressor was running for no reason. This had been going on for many years; the compressors were approaching 80,000 hours operating time.
Perhaps it was because the service provider would have cut himself out of some nice, regularly spaced service calls and the sale of consumables; it's hard to tell. Or maybe the technician was never trained to check compressor status when servicing compressors, but this lack of action cost the customer more than $15,000 per year in wasted electricity and maintenance costs.
This may be just a bad example. I have seen many compressor service companies that take the customer’s best interest to heart. But it is something to think about. Realize that you, the user, must constantly monitor your system energy consumption and service records to ensure things are done correctly. And it doesn’t hurt to call in a third party to have a fresh look every once in a while.
Ron Marshall is a compressed air energy efficiency expert and a compressed air trainer with website at www.compressedairaudit.com
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