Inputs
Enter your electricity price and pick a currency; default values are examples only. Specific energy is about 0.11 kWh/m³ for a typical 7 bar system.
Results are estimates: real leaks are mostly cracks, fitting seepage and seal leaks rather than round holes. Ultrasonic and flow measurement are needed for exact figures.
Print / PDF
When you print, usage data (calculated values and the information you entered) is sent to Sistemay; your e-mail is not used for contact unless you give consent. Choose “Save as PDF” in the print dialog.Formulas and method
Two methods are offered. The first finds the compressor’s yearly electricity use and multiplies it by the leak rate, a practical estimate close to the upper bound of leak energy.
The second calculates the air flow of each hole assuming choked (sonic) flow; hole flow grows with the square of the diameter.
Total energy (kWh/yr) = Rated power × Annual hours × Load factor
Leak energy = Total energy × Leak rate | Cost = Leak energy × Unit price
CO₂ (t/yr) = Leak energy × Emission factor ÷ 1000
Hole flow: Q = Cd · A · P₀ · √(γ/(R·T)) · (2/(γ+1))^((γ+1)/(2(γ−1))) Cd = 0.65
Worked example
Example: 75 kW, 6,000 h/yr, 70% load → 315,000 kWh. A 25% leak is 78,750 kWh; at 4 currency units/kWh it costs 315,000 a year. Bringing the rate down to 10% saves about 47,250 kWh.
Practical tips
- To measure the leak rate, run a load/unload time test while production is stopped.
- If the load factor is unknown, use 0.6–0.8 (60–80%).
- In old, poorly maintained plants the leak rate can reach 20–35%; the target for well-kept systems is below 10%.
- Re-measure consumption after repair to confirm the saving.
Frequently asked questions
How do I find the leak rate?
Run the compressor while production is stopped and measure load and unload times; the leak rate is roughly load time ÷ total time. See our leak tracking article in the Technical Blog for details.
Which method is more accurate?
If the leak rate is known, the first method is more reliable. The hole method suits seeing the cost and repair priority of specific leaks you have found.
How is CO₂ calculated?
Leak energy (kWh) is multiplied by the emission factor you enter. Using the current grid factor is recommended.
Why can the result differ from real consumption?
Load profile, compressor type, pressure and leak form all affect it. The result guides decisions; exact figures come from measurement.
Related products and tools
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