What is the typical amount of pre-mix air to an atmospheric burner?

The typical amount of pre-mix air to an atmospheric burner is indeed in the range of 30% to 40%. This is because atmospheric burners rely on natural draft or convection to facilitate combustion, which requires an adequate amount of air mixed with the gas for efficient burning. The pre-mix air contributes to stable flame operation and efficient combustion.

In a controlled environment, having this mixture ensures that the burner operates safely and effectively, producing the necessary heat while minimizing emissions. This range strikes a balance between providing enough oxygen for combustion and preventing excessive air that can lead to inefficiencies.

Other ranges provided in the options either do not meet the combustion requirements effectively or propose ratios that are typically used in different types of burners or specialized applications rather than standard atmospheric burners.