Flue Gas Volume Calculator

For boiler engineers and thermal system operators balancing emissions against efficiency, knowing the exact wet versus dry exhaust volume at your current excess air setting prevents over-aeration waste and ensures compliant burner performance. This tool estimates wet and dry flue gas volume produced per unit fuel from stoichiometric combustion products.

Wet Flue Gas (Nm³/Nm³) -
Dry Flue Gas (Nm³/Nm³) -
O₂ in Dry Flue Gas (%) -

Disclaimer: for preliminary estimation only, not a substitute for review by a qualified engineer.

Formula Breakdown:


    

  


  


  

    
How to Use This Tool

    
    
      
  1. Type your hydrocarbon fuel’s carbon atom count into the first field.
    2. 
      
  2. Enter the hydrogen atom count into the second field.
    3. 
      
  3. Adjust the excess air slider to match your boiler’s current operating point.
    4. 
      
  4. Read the live wet/dry volume metrics and dry O₂ percentage.
    5. 
      
  5. Fine-tune the slider to find the lowest excess air that still maintains safe combustion stability.
    6. 
    

  


  

    
FAQ

    

      
How is the atmospheric nitrogen volume determined in the calculation?

      
It relies on the standard dry-air molar ratio of 3.76 moles of N₂ for every mole of O₂, scaled by your total oxygen requirement.

    

    

      
What strictly separates the wet volume reading from the dry volume reading?

      
Wet volume includes all gaseous products including water vapor generated from burned hydrogen; dry volume mathematically removes that H₂O component to match traditional Orsat or modern dry-exhaust analyzers.

    

    

      
Why track oxygen specifically on a dry basis rather than wet?

      
Steam condensation drastically changes wet percentages, making dry-basis O₂ the universal industry standard for tuning air-to-fuel ratios and calculating stack heat loss.

    

    

      
After getting these volume figures, which tool should I consult next?

      
Cross-reference your results with our gas-combustion-air-fuel-ratio-calculator to nail down your exact equivalence ratio before adjusting physical damper positions.