Air Receiver Size Calculator – Free Online Tool

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About this calculator

An air receiver stores compressed air to smooth out short-term demand spikes that exceed compressor output, without the system pressure falling too far. This calculator applies Boyle's Law to estimate the receiver volume needed to supply a given flow deficit for a given time within an allowed pressure drop.

Formula

V (litres) = (Q × T) ÷ (p₁ − p₂)

QDemand deficit (free air) — litres/second
TDuration of the spike — seconds
p₁Receiver starting absolute pressure — bar(a)
p₂Minimum allowed absolute pressure — bar(a)
VRequired receiver volume — litres

Worked Example

Given: A demand spike needs 20 l/s more than the compressor supplies, for 30 seconds, with receiver pressure allowed to fall from 8 to 6.5 bar(a).

Result: V = (20 × 30) ÷ (8 − 6.5) = 400 litres.

How to Use

Enter the flow deficit — how much more air the peak demand needs than the compressor can supply, in litres/second (free air).
Enter how long the demand spike typically lasts, in seconds.
Enter the receiver's starting pressure and the minimum pressure your equipment can tolerate.
Click Calculate to get the required receiver volume in litres.

Important Assumptions

Uses an isothermal (Boyle's Law) expansion model, the standard simplified basis for receiver sizing; it does not model compressor cycling or heat transfer during the spike.
Assumes the compressor's output stays constant during the spike (i.e. all of the extra demand is drawn from the receiver).

Common Mistakes

Using gauge pressure instead of absolute pressure for p₁ and p₂.
Undersizing by ignoring realistic peak demand, or oversizing by using an unrealistically long spike duration.

Frequently Asked Questions

Should I round up to the nearest standard tank size?

Yes — receivers are manufactured in standard sizes (e.g. 300L, 500L, 1000L); always round up to the next available standard size.

Does receiver size affect compressor cycling frequency too?

Yes — beyond spike buffering, a larger receiver also reduces how often a fixed-speed compressor loads and unloads, which is a separate sizing consideration from this spike-based calculation.

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.