What is the ultimate CO2 level for natural gas if excess air temperature is below 65 F?

The ultimate CO2 level for natural gas combustion, especially when excess air temperatures are below 65°F, is directly related to the efficiency of the combustion process and the degree of excess air present. When combustion is complete and efficient, a CO2 level around 8.9% is typical for natural gas under these conditions.

This level indicates that the gas is efficiently burning with optimal air supply, without excessive incomplete combustion, ensuring minimal production of carbon monoxide and other harmful byproducts. Higher percentages of CO2 could indicate incomplete combustion, which typically occurs with inadequate air supply or improper burner adjustments. Therefore, maintaining the CO2 level at around 8.9% signifies that the combustion system is operating safely and efficiently, which is crucial in residential and commercial settings for both safety and environmental concerns.