KEVOS® MAKEOS · Pneumatics
Compressed-Air Leak Audit (Leak Flow, Power, Cost and Repair Payback)
How much air and money are these compressed-air leaks wasting, what share of the compressor do they use, and how quickly do repairs pay back?
Audit of compressed-air leaks grouped by equivalent hole size: choked flow through each hole as free air (as the air leak cost tool), the total leak flow, its share of compressor capacity, the compressor power and yearly energy cost from your specific power, and the payback of repairing the leaks at your repair cost per leak.
Open the calculatorRuns in your browser. No account needed.
How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Leaks by size | ||
| Leaks of size 1 | Number of leaks in the smallest group. | |
| Size 1 equivalent hole | mm | Equivalent orifice diameter for that group (from an ultrasonic survey estimate). |
| Leaks of size 2 | Leaks in the middle group. | |
| Size 2 equivalent hole | mm | Equivalent orifice for the middle group. |
| Leaks of size 3 | Leaks in the largest group. | |
| Size 3 equivalent hole | mm | Equivalent orifice for the largest group. |
| System | ||
| Line pressure | bar | Gauge pressure in the line at the leaks. |
| Discharge coefficient | Discharge coefficient of a leak (about 0.6–0.65 for sharp holes). | |
| Air temperature | °C | Air temperature in the line. |
| Compressor specific power | kW per m³/min | Compressor input power per m³/min of free air delivered (from the compressor data sheet). |
| Compressor capacity | m³/min | Air delivered by the running compressors, as free air. |
| Pressurised hours per year | h | Hours per year the system stays pressurised (leaks run even when production stops). |
| Electricity price | $/kWh | Price of electricity. |
| Repair cost per leak | $ | Average cost to repair one leak. |
| Largest leakage share accepted | % | Leakage share of capacity you set as acceptable (well-run systems aim below 10%). |
Method and formulas
- Choked flow per hole ṁ = C_d A p₀ √(k ÷ R T₀) [2 ÷ (k + 1)]^((k+1)/(2(k−1))), as free air at 1.204 kg/m³ (as the air leak cost tool).
- Power = free-air flow (m³/min) × specific power; cost = power × hours × price.
- Repair payback = leaks × repair cost ÷ yearly cost.
- Example: the leaks waste 65.211 L/s (7.8254% of capacity), 25.432 kW and 38,149 a year; repairs pay back in 7.1759 days.
Limitations
- Equivalent-hole estimates from surveys are rough; a drawdown or no-load test measures total leakage directly.
- Assumes the compressors unload efficiently; poor control makes leaks cost more.
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Turn a leak survey into a cost and a repair budget
- Show management what leaks cost
- Check leakage against a target share of capacity
Who it is for
- Maintenance engineers
- Energy managers
- Plant engineers
What you get
- Leak flow by group and in total
- Share of compressor capacity, power and yearly cost
- Repair cost and payback
Interpreting the result
- A few large leaks usually waste more than many small ones: fix the largest first.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 3032–3041. Topic reference; no source tables or recommended settings are reproduced.
WORKOS tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.
Open the Compressed-Air Leak Audit (Leak Flow, Power, Cost and Repair Payback) calculator
