Compressed Air Leak Cost Calculator
Find out what your compressed air leaks are costing you in rupees every year. Built for Indian plants — ₹/kWh tariffs, Nm³/hr, bar(g) and real shift patterns.
Enter how many leaks of each size you have. Not sure? A hiss you can hear from 1 m away in a noisy plant is usually 1–3 mm.
| Leak size | Sounds like | Qty |
|---|---|---|
| 0.5 mm | Faint hiss, close up | |
| 1 mm | Audible at ~1 m | |
| 2 mm | Clear hiss at 3 m | |
| 3 mm | Loud, felt by hand | |
| 5 mm | Blowing fitting / burst hose |
Stop guessing. Start measuring.
WiseAir ultrasonic leak detectors and acoustic imaging cameras find every one of these leaks in a single walk-through — and our flow meters prove the savings afterwards.
Book a Compressed Air Audit See Leak DetectorsThe formula we use — and why
Above roughly 0.9 bar(g), air escaping a hole reaches the speed of sound and the flow becomes choked — it depends only on the upstream pressure and hole area, not on what is downstream. We use the standard choked-flow equation for air:
Volume is normalised to 0 °C and 1013.25 mbar (Nm³), the convention used across Indian and European compressed air practice. SP is the compressor’s specific power in kWh per Nm³ of air generated.
Sanity check: a 1/16 inch (1.59 mm) hole at 100 psig gives 6.1 CFM at Cd = 1.0 with this equation — matching the widely cited Compressed Air Challenge figure of 6.5 CFM. We default to Cd = 0.85 because real leaks are rarely ideal orifices, which makes our numbers slightly conservative compared with most manufacturer charts.
Worked example: a typical 2-shift textile plant
A unit running 6,000 hours a year at 7 bar(g), paying ₹8.50/kWh, with a leak survey that found ten 1 mm leaks, four 2 mm leaks and one 3 mm leak:
- Total air lost: about 123 Nm³/hr (roughly 72 CFM of free air)
- Power wasted: about 14.2 kW running continuously
- Energy wasted: about 84,900 kWh per year
- Cost: roughly ₹7.2 lakh per year — and about 60 tonnes of CO₂
The single 3 mm leak alone accounts for about a quarter of that — one loose fitting costing more than ₹1.7 lakh a year. This is why leak surveys pay for themselves in weeks, not years: the repairs are usually a fitting, an O-ring, or a length of hose.
Frequently asked questions
How much of my compressed air is typically lost to leaks?
In plants that have never run a formal leak survey, 20–30% of generated air is a common finding. Well-managed systems with an ongoing leak programme hold it under 10%. If your calculated leak flow is more than about a fifth of your compressor capacity, you have a leak problem worth a formal audit.
Why does leak cost change so much with pressure?
Twice over. Higher pressure pushes more mass through the same hole, and it also costs more energy to make each cubic metre. Dropping system pressure by 1 bar typically cuts total compressor energy by 6–7%, and cuts leak losses on top of that.
Do compressed air leaks really run 24 hours a day?
They run whenever the system is pressurised — which in most plants includes nights, weekends and shift breaks when nothing is producing. If you leave the system charged over the weekend, add those hours. Fitting an isolation valve and depressurising non-production areas is often the single cheapest saving available.
How do I find leaks I cannot hear?
Ultrasonic leak detectors pick up the 40 kHz signature of a leak over plant noise, from several metres away, while the plant is running. Acoustic imaging cameras go further and show leaks as a visual overlay so you can survey a whole hall quickly. WiseAir manufactures both.
How accurate is this compressed air leak calculator?
It is an engineering estimate, and it is only as good as your leak count and your specific power figure. It is designed to tell you whether the problem is worth ₹50,000 or ₹5,00,000 a year — which is the decision most plants actually need to make. For a bankable number, measure actual flow with a flow meter and run a proper audit.
Assumptions: air at 20 °C, volumes normalised to 0 °C / 1013.25 mbar (1 Nm³/hr = 0.5886 CFM on the same basis), choked flow above 0.9 bar(g), CO₂ at 0.71 kg per kWh (CEA grid average for India). Results are indicative engineering estimates for planning purposes — verify with measured flow data before committing capital. Related tools: Flow Unit Converter · Pressure Dew Point Calculator.
