15% fixed cost for the compressor, installation, depreciation and insurance. 20% operating cost for inspection, maintenance and repair. 65% power cost for energy and demand to operate the system at $0.06 per kWhr, the estimated cost of compressed air is $0.02 per 100 CFM ($0.0002 per cubic foot). A 10 HP compressor delivering 35 cfm =$0.007/minute, $0.42/hour, $10.08/day, $302.40/month or $3,628.80/year.