Air Leakage Cost Calculator – Free Online Tool

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About this calculator

This is the standard method used in compressed air energy audits to put a rupee value on air leaks: leak flow is converted to power using the compressor's specific power, then multiplied by operating hours and electricity rate. It is a common way to justify leak-repair programs to management.

Formula

Leak Power (kW) = SP × (Leak Flow ÷ 100); Cost/yr = Leak Power × Hours/yr × Rate

SPCompressor specific power — kW per 100 CFM
Leak FlowEstimated leakage — CFM
Hours/yrAnnual operating hours — hours
RateElectricity tariff — currency per kWh

Worked Example

Given: A leak survey estimates 10 CFM of leakage, on a compressor with specific power 20 kW/100 CFM, running 4000 hours/year at ₹8/kWh.

Result: Leak power = 20 × (10÷100) = 2 kW. Annual cost = 2 × 4000 × 8 = ₹64,000 per year — from leaks alone.

How to Use

Estimate leak flow — measured with an ultrasonic leak detector, or estimated using compressor load/unload timing with all points of use shut off.
Enter the compressor's specific power (see the Specific Power Calculator if unknown).
Enter annual operating hours and your electricity rate.
Click Calculate to see the estimated annual cost of the leakage.

Important Assumptions

Leak flow figures are approximate unless measured directly with an ultrasonic leak detector or a controlled load/unload timing test.
Assumes leaks are constant throughout all operating hours, which is realistic for most industrial compressed air systems.

Common Mistakes

Guessing leak flow without any measurement — even a rough ultrasonic survey gives far more reliable results than a visual guess.
Using the compressor's rated (nameplate) specific power instead of its actual measured specific power.

Frequently Asked Questions

How much of a typical plant's compressed air is lost to leaks?

Industry studies commonly cite 20–30% of compressed air generated in an average industrial plant being lost to leaks in untreated systems, making leak audits one of the highest-return energy-saving activities available.

How do I estimate leak flow without special equipment?

One common method: run the compressor with all air-consuming equipment switched off, and measure how long it takes to load and unload; the load fraction times compressor FAD gives an approximate leak flow.

These calculators are provided for informational and estimation purposes. Results depend on the assumptions and input values used. Always verify critical engineering calculations against applicable standards, manufacturer specifications, site measurements, and qualified professional advice.