Air Compressor Case Studies

The cost of compressed air leaks is the energy cost to compress the volume of the lost air from atmospheric pressure to the compressor operating pressure. The amount of lost air depends on the line pressure; the compressed air temperature and the point of the leak; the air temperature at the compressor inlet; and the estimated area of the leak.

A study of a 75-hp compressor that operates 8,520 hours per year was shown to have a leakage rate of 24%. The majority of these leaks were due to open, unused lines. The compressor, a single-stage screw type, provides compressed air at 115 psi, is 91.5% efficient, and operates with electricity costing $14.05 per million Btu.

The study identified eight major leaks ranging in size from 1/16 to 1/8 inch in diameter. The calculated total annual cost of these leaks was $5,730. Correcting the leaks in this system involved the following:

Replacement of couplings and/or hoses.
Replacement of seals around filters.
Repairing breaks in compressed-air lines.

The total cost of the repairs was $460. Thus, the cost savings of $5,730 would pay for the implementation cost of $460 in about a month.