Compressed Air Leak Cost Calculator
Quantify the annual energy cost of compressed air leaks. Enter the leak orifice diameter (or select a leak severity class), system pressure, and energy cost to get an instant £/$ annual loss figure.
A single 3 mm leak at 7 bar costs approximately £1,200–£1,800 per year in electricity (at UK average industrial rates). A typical manufacturing plant leaks 20–30% of its compressed air production. Ultrasonic leak detection surveys typically pay back in 1–3 months.
Leak cost calculator
Compressed air leak costs are calculated using the orifice flow equation at critical flow conditions. Actual costs vary with compressor specific power, load factor, and leak location. This figure provides a conservative estimate suitable for business case calculations.
Understanding compressed air leak costs
How are leaks costed?
The calculator uses the critical orifice flow equation for compressible gas flow. For a circular orifice at critical (choked) flow conditions — which applies at typical industrial pressures of 6–10 bar — the volumetric flow rate is:
Q (L/min) ≈ 0.0785 × d² × Pabs
where d is orifice diameter in mm and Pabs is absolute pressure in bar. The compressor power to produce this flow is then Q ÷ (specific power × 1000).
Leak size classification
| Class | Approx. diameter | Flow @ 7 bar | Annual cost* |
|---|---|---|---|
| Pinhole | 0.5 mm | ~14 L/min | ~£150/yr |
| Small | 1 mm | ~55 L/min | ~£600/yr |
| Medium | 3 mm | ~500 L/min | ~£1,500/yr |
| Large | 6 mm | ~2,000 L/min | ~£6,000/yr |
| Very large | 12 mm | ~8,000 L/min | ~£24,000/yr |
* Based on 6,000 hours/year, 18 p/kWh, specific power 7 kW/100 L/min
Detection methods
The gold standard for leak detection is ultrasonic leak detection — handheld ultrasonic detectors (e.g., UE Systems, SDT) can locate leaks at distances of 3–10 m during normal plant operation, without shutting down. A survey of a medium-sized plant (100 compressed air consumers) typically takes 4–8 hours and identifies 40–120 leak points.
See our full guide on compressed air leak detection methods and survey procedures.