What compressed-air leaks cost a European plant

Compressed air is one of the most expensive ways a factory can move energy around. The compressor turns electricity into pressure, and only a small part of that work comes back out at the tool. Every litre of air that escapes on the way has already been paid for in full.

Most of it escapes through leaks. Worn quick couplings, split hoses, push-in fittings that were never quite tight, condensate drains left cracked open. None of them looks serious on its own. In a system nobody has surveyed for a few years, the US Department of Energy puts leaks at 20 to 30% of what the compressors produce. In a well-kept system it is under 10%.

We took a plant with 150 kW of compressors running about 6,000 hours a year at 70% average load, and priced its electricity at the EU average for a mid-size industrial user.

The fix is a survey and a habit. An ultrasonic detector finds leaks you can't hear over a running line. Each one gets a tag and a line in a log, and most are fixed with parts that cost a few dollars. The survey repeats every few months, because fittings keep wearing and leaks come back.

Lowering the system pressure where the tools allow it helps as well, because every remaining leak then passes less air. Under the revised EU Energy Efficiency Directive, companies above the consumption thresholds need an energy audit every four years, and compressed air is usually one of the quickest paybacks in those reports.