Compressed Air Leaks in Quarries and Mines: The Hidden Energy Cost and How to Stop It
On most quarry and mine sites, the compressor is the biggest energy user on the drilling line, and a large share of what it produces never reaches a drill. It escapes through worn couplings, cut hoses, open drains and loose fittings. The US Department of Energy notes that leaks often waste 20–30 % of a compressor’s output. That is fuel or electricity paid for, emissions released and drilling pressure lost, every shift. This guide shows how much air a single leak wastes, where leaks hide on a drilling site, how to measure your own leak rate and how to bring it down.
- A single 6 mm (1/4″) leak at about 7 bar can waste roughly 1.7 m³/min of air and 11 kW of compressor power, continuously.
- Leaks also lower the pressure at the drill. Below 6 bar, pneumatic rock drills strike more weakly and drill more slowly.
- On a drilling site, most leaks are at hose couplings, damaged hoses, line oilers, open drains and the drill connection.
- You can measure your leak rate in minutes with the compressor’s load/unload times or a pressure-decay test.
- Fixing leaks is the cheapest sustainability measure on site: less fuel, fewer emissions, and a smaller compressor for the same drilling output.
01Why leaks matter more on a drilling site
In a factory, a leak mostly wastes energy. On a quarry or mine site it does two kinds of damage at once.
It burns fuel or electricity for nothing
The compressor runs longer and more often to replace the air that escapes. On remote sites that air is usually made by a diesel compressor, so every leak shows up in the fuel bill and in the site’s emissions. Leaks also push operators to add compressor capacity they would not otherwise need [2].
It takes pressure away from the drills
Pneumatic rock drills such as the Y24 and YT28 are rated at 6 bar. Leaks cause a drop in system pressure, which makes air tools work less efficiently [2]. For a rock drill that means weaker blows, slower penetration and a higher cost per metre drilled. The common reaction, turning up the compressor pressure, makes it worse: a leak loses more air at higher pressure.
02How much air one leak wastes
The table converts the US Department of Energy leak rates into metric units and compares them with the air consumption of Set Makina rock drills. Small holes add up quickly: ten leaks of 3 mm waste more air than a YT24 air-leg drill consumes.
| Hole diameter | Air lost at ~7 bar | Compressor power wasted | Energy lost per 2,000 h | Roughly equal to |
|---|---|---|---|---|
| 1.6 mm (1/16″) | 0.11 m³/min (3.8 cfm) | ~0.7 kW | ~1,400 kWh | 8 % of a Y20 drill |
| 3.2 mm (1/8″) | 0.44 m³/min (15 cfm) | ~2.8 kW | ~5,500 kWh | One third of a Y20 drill |
| 6.4 mm (1/4″) | 1.74 m³/min (62 cfm) | ~11 kW | ~22,000 kWh | More than a Y20, over half a Y24 |
Based on the DOE leakage rates at 100 psig (about 6.9 bar) for a sharp-edged hole (factor 0.61) and about 18 kW of compressor power per 100 cfm [1]. 2,000 operating hours a year assumed, roughly one shift. At 6 bar the losses are slightly lower.
Orange: air lost through a leak. Blue: air used by a working rock drill at 6 bar.
The DOE’s own worked example: in a plant study, fixing just ten 1/4″ leaks accounted for almost 70 % of the total savings from the leak programme [1]. On a drilling site, the big leaks are usually easy to find. A cut hose or a coupling that hisses on every connection is worth fixing today.
03Where leaks hide on a drilling site
The DOE and the Compressed Air Challenge list couplings, hoses, fittings, quick disconnects, lubricators, condensate traps, valves and pipe joints as the most common leak points [1][2]. On a quarry or mine, the air line also lives in dust, gets dragged over rock and is connected and disconnected many times a day.
The six places to check first on a pneumatic drilling line.
| Leak point | Why it leaks on site | What to check |
|---|---|---|
| 1–2 Compressor and receiver drains | Left open after draining condensate, or a drain valve that no longer seals | Close after draining; listen at the valve with the system pressurised |
| 3 Hose couplings | Dragged through dust and over rock, seals worn by frequent connection | Replace worn seals; use safety clips; keep couplings capped when disconnected |
| 4 The hose itself | Cuts and abrasion from sharp rock, crushing by vehicles | Inspect the full length each week; replace, don’t tape, a cut pneumatic hose |
| 5 Line oiler and fittings | Bowl seals, filler caps and threaded fittings loosen with vibration | Check the cap and fittings on the FY200B line oiler when refilling |
| 6 Drill connection and seals | Worn O-rings and loose fasteners inside and on the drill | Listen at the drill while idle; renew O-rings during routine service |
| Valves and manifolds | Packings wear; valves left half open at the end of a shift | Close each drill line at the manifold when the drill is not working |
Air line
Pneumatic hose
Air supply from compressor to drill
View product →
Pressure stability
TIGER Air Receiver
Keeps pressure steady beyond ~100 m from the compressor
View product →
Lubrication
FY200B line oiler
Supplied with every Set Makina rock drill
View product →
04Measure your leak rate in minutes
You do not need special equipment to know how much air your site is losing. Run one of these tests at a break, when every drill is stopped but the air line is still connected and pressurised [2].
Method 1: load/unload time (start/stop or load/unload compressors)
With no air being used, the compressor still cycles to replace the leaks. Time how long it runs on load (T) and how long it stays off load (t) over several cycles.
Example: the compressor loads for 20 seconds and unloads for 80 seconds. Leakage = 20 × 100 / 100 = 20 % of its capacity. That is a typical figure for a system with no leak programme.
Method 2: pressure decay (any compressor)
Bring the system to working pressure, stop the compressor and time how long the pressure takes to fall to about half. You need the volume of the receiver and lines (V).
V in m³, P1 and P2 in bar gauge, T in minutes. The factor 1.25 corrects for the leak rate at full working pressure. Example: 1.5 m³ of receiver and hose volume, pressure falling from 7 to 3.5 bar in 5 minutes: 1.5 × 3.5 / (5 × 1.013) × 1.25 ≈ 1.3 m³/min, which is the whole air consumption of a Y20 rock drill.
Rule of thumb: if leakage is above 10 % of your compressor’s capacity, the system can be improved [2]. Well-maintained industrial systems typically run at 5–10 % [1].
05Find, fix and keep it fixed
The Compressed Air Challenge recommends a simple programme: identify and tag each leak, track it, repair it, verify the repair, and repeat the survey regularly [2].
| When | What to do |
|---|---|
| Every shift | Drain condensate and close the drains. Cap disconnected couplings. Close each drill line at the manifold when it stops. Switch the compressor off at breaks if no drill is working. |
| Every week | Walk the line with the system pressurised and the drills idle, and listen. Brush soapy water on suspect fittings. Tag every leak and note it. |
| Every month | Repair all tagged leaks and check each repair. Replace damaged hose sections and worn coupling seals. |
| Every quarter | Repeat the load/unload or pressure-decay test and compare with the last result. An ultrasonic leak detector finds leaks you cannot hear over site noise [1]. |
Design choices that prevent losses
- Keep hose runs short. Set Makina rock drills should work within about 100 m of the compressor. For longer distances, place an air receiver near the drilling point.
- Size the compressor for real demand, not for leaks. Add the consumption of the drills that run together, plus about 20 % for normal losses. Our rock drill guide gives the figures for each model.
- Do not raise the pressure to hide a leak. Fix the leak instead, and the drills get their 6 bar back at lower energy cost.
- Choose drills that use less air. The Y20 uses 1.32 m³/min at 6 bar, so a smaller compressor can run more drills.
06Why this is a sustainability measure, not just maintenance
Every cubic metre of compressed air that leaks has already cost fuel or electricity to produce. Cutting leaks from 25 % to under 10 % of output means the same drilling work is done with less energy, fewer emissions and often a smaller compressor class. It needs no new machine, and the savings start the day the leaks are fixed. For buyers and contractors who are asked to show what they do to reduce their environmental footprint, a documented leak programme is a simple, measurable answer.
07Frequently asked questions
How much compressed air do leaks waste?
In poorly maintained systems, leaks often waste 20–30 % of a compressor’s output. A well-run leak programme can bring this below 10 %.
How much air does a 6 mm leak lose?
At about 7 bar, a sharp-edged 6 mm (1/4″) hole loses roughly 1.7 m³/min (about 62 cfm). That is more air than a Y20 hand-held rock drill uses, and it wastes about 11 kW of compressor power.
How do I find air leaks on a noisy site?
Test during a break when the drills are stopped but the line is pressurised. Listen along the line, brush soapy water on fittings and couplings, or use an ultrasonic leak detector, which picks up leaks you cannot hear.
Do leaks affect rock drill performance?
Yes. Leaks lower the pressure at the drill. Pneumatic rock drills are rated at 6 bar, and below that pressure they strike more weakly and drill more slowly.
Get more drilling from the same compressor
Tell us your compressor, the drills you run and the length of your air lines. We will check your air supply and recommend the drills, hoses and receiver that fit it.
Request an Air Supply Check- US Department of Energy, Energy Tips: Minimize Compressed Air Leaks.
- Compressed Air Challenge, Fact Sheet: Compressed Air System Leaks.
- Set Makina product data for the Y20, Y24, YT24 and YT28 rock drills (2026).
Leak rates and power figures are converted from published US Department of Energy data and are estimates; actual losses depend on pressure, hole shape, compressor type and operating hours. Use the measurement methods above to establish the figures for your own site.
