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Air-compressor demand

Job / reference: ______________________________Printed date: ____

Formula registry version 1.0.0 · researched 2026-07-24

PS-07 · Power & supply

Air-compressor demand

Enter free-air demand (FAD), expected simultaneity and required pressure for every pneumatic consumer. Displacement, HP and receiver size are not substitutes.

PLANNING ESTIMATE

Entered pneumatic consumers

Tool 1
Tool 2

Method and worked example

Qᵢ = FADᵢ × simultaneityᵢ

Q_demand = ΣQᵢ; Q_plan = Q_demand × (1 + margin ÷ 100)

Worked example: 6 CFM at 100% plus 4 CFM at 50% = 8.0 CFM average FAD demand; entered 20% margin gives 9.6 CFM FAD.

Blank worksheet

Tool / FAD / required pressure:
Tool / FAD / required pressure:
Simultaneity contributions:
Demand / entered margin / planned FAD:

Compressed-air demand result

Result recordPLANNING ESTIMATE

Worked example — default entered values

8.0 CFM average FAD demand
9.6 CFM FAD with entered margin
at 90 psi required pressure

Compare only with manufacturer delivered FAD at the required pressure; receiver and duty data remain separate.

Assumptions register

Tool 1: 6 CFM FAD × 100% = 6.00 CFM at 90 psi · Tool 2: 4 CFM FAD × 50% = 2.00 CFM at 90 psi · Entered margin: 20%

Every entered flow is FAD/free-air demand at the same required pressure, not displacement, air intake, HP or tank size.

Duty factors describe expected overlapping use.

The entered margin is a transparent planning assumption.

Receiver volume and short bursts are not modelled; leakage, wear, pressure loss and filters/dryers need separate allowance.

△ FAD and pressure data govern

Confirm delivered FAD at the required pressure and compressor duty rating. Account separately for leakage, wear, pressure drop, filters/dryers and overlap. Receiver volume can support bursts but does not replace sustained FAD.

PLANNING ESTIMATE. Check manufacturer FAD at the required pressure, compressor duty rating, pressure drop, receiver behaviour and overlapping use. Never turn this result into an unconditional compressor recommendation.

Source register · registry version 1.0.0

Atlas Copco, Compressed Air Manual, 9th edition — effective 2019-01-01 — accessed 2026-07-24

Atlas Copco, The importance of correct PET air compressor sizing — effective 2022-08-01 — accessed 2026-07-24

Formula researched 2026-07-24