Secondary Air Calculator
The Air That Finishes the Job
Secondary air is introduced after primary air has established ignition, completing combustion of any fuel not yet fully burned. It's simply what's left of total combustion air once primary air is subtracted.
The Formula
Secondary Air = Total Combustion Air − Primary Air
Worked Example
500 m3/hr total air with 150 m3/hr designated as primary air:
Secondary Air = 500 − 150 = 350 m3/hr (70%)
How to Use This Calculator
- Enter the Total Combustion Air supplied.
- Enter the Primary Air quantity.
- Select Calculate to get secondary air quantity and percentage.
Related Calculations
Find primary air directly in the Primary Air Calculator, or check overall excess air in the Excess Air Calculator.