Calculation
| Summary | - About 12 percent of the electricity bill goes to the compressors, about $72,000 per year.
- If leaks and extra pressure are both there, 13 percent of that is lost, about $9,400 per year.
- After about $800 per year to find and fix leaks each quarter, about $8,600 is left.
- Nothing we saw rules it in or out, so no figure here is a reading at the plant.
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| What the compressors' electricity costs per year | $600,000 x 12 percent = $72,000 |
| Of that, lost to leaks that can be found and fixed, if they are there | $72,000 x 10 percent = $7,200 |
| Of that, spent holding pressure the presses do not need, if any | $72,000 x 3 percent, for 6 psi at 0.5 percent per psi = $2,160 |
| Less the repeat walks to find and fix leaks, per year | 4 walks x 4 hours x $40 + $160 of parts = $800 |
| What fixing it could save per year | $7,200 + $2,160 - $800 = $8,560 |
Not counted
- An idling compressor still uses 15 to 35 percent of its full-load power.
- We could not read how many hours the compressors idle, so that cost is left out.
- Air left on at presses that are not running, and compressors left on while the plant is closed, are left out too.
- The presses, the dryers and the chillers use most of the electricity, and none of that is counted here.
Illustrative sample. The plant, the walk and the footage are synthetic.