Engineering calculator · Updated 17 September 2026
Boiler Combustion Air Calculator — Stoichiometric Air, Excess Air & Fan Flow
Estimate actual combustion-air mass and standard volumetric flow from fuel flow, stoichiometric air requirement and excess-air percentage.
Inputs
Live results
- Theoretical air 17,200 kg/h
- Actual combustion air 19,780 kg/h
- Standard air volume 16,428.571 m³/h
- Excess-air mass 2,580 kg/h
Formula
mair=mfuel×AFRstoich×(1+EA/100).
Worked example
1,000 kg/h fuel at AFR 17.2 and 15% excess air needs about 19.78 t/h air.
Assumptions and limits
- Enter a fuel-specific stoichiometric air/fuel mass ratio.
- Standard volumetric flow uses entered standard-air density and is not hot FD-fan inlet volume.
FAQs
What does this Boiler Combustion Air Calculator calculate?
Estimate actual combustion-air mass and standard volumetric flow from fuel flow, stoichiometric air requirement and excess-air percentage.
Is this suitable for final equipment selection?
Use the result for engineering screening and operating diagnostics. Confirm final selections against measured data, OEM curves and applicable codes.
Why are the assumptions explicit?
Plant results depend on reference conditions, pressure basis, efficiencies and measurement locations. Showing assumptions keeps the calculation auditable.