Artificial Demand in Compressed Air Systems: What It Is and Why It Costs Money
Artificial demand is the extra compressed air consumed because a system operates above the pressure its applications actually need. It doesn’t produce more parts or improve the process. It sends additional air through leaks, unregulated blowoffs, and other pressure-dependent uses—and the compressors have to replace that air.
The challenge is separating unnecessary pressure from pressure that keeps production running. Lowering a compressor setpoint without understanding downstream conditions can create machine faults. Leaving pressure unnecessarily high costs money every operating hour. The practical approach is to identify the real pressure requirement, correct avoidable losses, and coordinate compressor controls around that requirement.
What Counts as Artificial Demand?
A compressed air system has productive demand, waste, and often an extra layer of consumption caused by excessive pressure. Artificial demand is that pressure-driven increment, not all the air the plant uses or wastes.
Consider an unregulated air nozzle. At higher supply pressure, it generally passes more air through the same opening. If the additional flow doesn’t improve the cleaning or drying task, that extra consumption is artificial demand.
The same distinction applies to leaks. A leaking fitting wastes air at the lowest acceptable operating pressure. Raising pressure makes that existing leak consume more. The increase attributable to unnecessary pressure is artificial demand; repairing the fitting removes the underlying leak as well.
Unregulated blowoffs: Higher header pressure can increase consumption without improving the result.
Leaking connections and open drains: More air escapes as upstream pressure rises.
Pneumatic equipment: Some devices consume more air per cycle when supplied at unnecessarily high pressure.
Properly regulated applications: These may see little change in consumption if their downstream pressure remains stable.
That last point matters. A reduction in header pressure does not reduce every application’s air consumption equally. The opportunity depends on how much demand is pressure-dependent and how effectively individual uses are regulated.
Why Higher Pressure Costs Money Twice
The compressor works against higher pressure
Producing air at a higher discharge pressure generally requires more energy per unit of delivered air. The actual change depends on the compressor design, operating range, and control method. Manufacturer performance data and measured input power are better guides than a blanket savings percentage.
The plant may consume more air
Higher pressure also pushes more air through pressure-dependent openings. This adds volume demand on top of the energy required to compress air to the higher pressure.
For a fixed opening discharging to atmosphere under choked-flow conditions, mass flow is approximately proportional to upstream absolute pressure, assuming temperature and opening geometry remain similar. Absolute pressure includes atmospheric pressure; gauge pressure does not.
You don’t need that relationship to run a plant, but it explains why a percentage change in gauge pressure should not be treated as the same percentage change in air consumption. It also explains why a pressure reduction cannot be assigned one universal savings figure.
Reduced air consumption is not automatically an equal reduction in electricity use. A load/unload compressor may spend more time unloaded while still drawing substantial power. A coordinated system may instead unload and stop an unnecessary compressor. Controls determine how much of the reduced demand becomes lower electrical consumption.
How Plants End Up Running Too High
Artificial demand often begins with a reasonable response to a production complaint: a machine needs more pressure, so someone raises the compressor setting.
The problem is that the machine may not be telling the whole system’s story. Adequate pressure at the compressor room and low pressure at a distant machine can point to restrictive filters, undersized piping, small hoses, restrictive couplings, or a sharp demand event—not insufficient compressor pressure.
Once the setting goes up, it often stays there. Another machine is added, another pressure complaint appears, and the setting rises again.
Consider a hypothetical West Tennessee manufacturer where a packaging machine faults during a simultaneous actuator cycle. Compressor-room pressure looks steady, but pressure falls at the machine inlet. Raising plant pressure keeps the machine running while increasing consumption through unregulated blowoffs elsewhere.
The better investigation is to log pressure during the event and check the branch line, filter, regulator, hose, and fittings. Depending on the findings, correcting a restriction or adding appropriately sized local storage may address the dip without keeping the entire plant at elevated pressure.
Find the Lowest Reliable Pressure Before Changing Settings
The target is not the lowest number the compressor can hold. It is the lowest practical supply pressure that supports every required application during actual production, with an appropriate operating margin.
Measure pressure where the work happens
Record pressure at the compressor discharge, after treatment equipment, in the main header, and at sensitive or distant applications. Measurements should be time-aligned so a pressure dip can be traced through the system.
Measure while equipment operates. A machine can show acceptable static pressure and still suffer a sharp drop when a valve opens. A gauge checked between cycles won’t reveal that problem.
Confirm application requirements
Use equipment documentation and production testing to establish the minimum acceptable inlet pressure under load. Don’t assume that every machine needs the pressure currently written on the compressor-room setpoint sheet.
Separate a genuine high-pressure application from a local distribution problem. If one process truly requires substantially higher pressure, evaluate whether a separate supply or booster makes sense rather than imposing that requirement on the whole plant.
Include treatment and distribution losses
Check pressure drop across compressed air filtration, dryers, piping, and point-of-use components at operating flow. Service dirty elements and investigate unusually restrictive components. Do not bypass air treatment to recover pressure; that can trade an energy issue for contamination and equipment problems.
Reduce Artificial Demand Without Disrupting Production
A controlled sequence is safer and more informative than a large setpoint reduction.
Establish a baseline. Record pressure, compressor power, operating hours, production rate, and flow where metering is available. Include peak-demand events and different shifts.
Repair obvious waste. Address compressed air leaks, failed drains, and blowoffs left running between production cycles.
Correct avoidable pressure losses. Review restrictive components before deciding the entire system needs more pressure.
Regulate appropriate end uses. Set applications to their documented operating needs and verify performance under load.
Lower pressure in small, documented steps. Coordinate trials with production and maintenance. Watch machine-inlet pressure, cycle times, reject rates, and faults.
Retune compressor operation. Review sequencing, load/unload settings, variable-speed operation, and stop delays with an experienced compressed air professional.
Don’t change pressure settings on safety-related pneumatic equipment without the required engineering review. Avoid repeated adjustments based on a single gauge reading or an unusually light production day.
Where Storage and Controls Fit
Air receiver tanks can buffer short demand events, but storage does not supply missing average compressor capacity. Useful storage depends on the event’s flow and duration, available pressure range, receiver location, and how quickly it can recharge.
A pressure/flow controller, used with suitable storage and compressor controls, can maintain a steadier downstream pressure while allowing an upstream pressure band for storage. That may reduce unnecessary downstream consumption.
It is not automatically an energy-saving purchase. Maintaining higher upstream pressure has an energy cost, and inadequate storage or poor control coordination can undermine the result. Evaluate the complete pressure profile and compressor response before requesting equipment.
Verify Savings at the Electrical Meter
Compare representative operating periods before and after changes, accounting for production volume, product mix, shifts, and compressor availability. Lower flow during a slow week is not proof of an improvement.
Use measured compressor kilowatts and operating hours to estimate energy savings. For illustration, a sustained 8 kW reduction over 6,000 annual operating hours equals 48,000 kWh. At an assumed energy rate of $0.10 per kWh, that is $4,800 annually before demand charges or other tariff effects. These are example inputs, not predicted savings.
Confirm that the lower-pressure operation also maintains machine performance. An energy reduction that creates rejects, delays, or nuisance faults is not a successful result.
Bottom Line
Artificial demand is reduced by removing unnecessary pressure—not by asking production equipment to operate below its requirements. Find the pressure losses, measure demand events, correct waste, and adjust controls so reduced air consumption produces measurable electrical savings.
Before buying a larger compressor or new control equipment, establish whether the problem is capacity, distribution, storage, or operating pressure. Gordon Air Compressor can help Tennessee facilities evaluate those conditions and consider the next practical step.
If your plant keeps raising pressure to solve recurring complaints, contact Gordon Air Compressor to discuss a system evaluation.
Gordon Air Compressor
706 Scott Street
Memphis, TN 38112
Sales and Service: 901-327-1327
Emergency Service: 901-482-5925
