How much combustion air is required to burn and vent one cubic foot of natural gas?

To properly understand how much combustion air is required to burn and vent one cubic foot of natural gas, it's important to consider the basics of combustion. Natural gas primarily consists of methane (CH4), and efficient combustion of this gas requires a specific proportion of air, which provides the necessary oxygen.

For the complete combustion of natural gas, it is typically understood that about 10 cubic feet of combustion air are required to ensure that the fuel burns completely and safely. This is based on the stoichiometric calculations related to the combustion of methane, which indicates that approximately 10 parts of air (consisting of oxygen) are needed for the complete oxidation of every part of fuel.

Using this knowledge, one can see why the requirement of 10 cubic feet of combustion air aligns with the combustion principles of natural gas. It ensures that there is enough oxygen available for the process, preventing incomplete combustion, which can lead to the production of carbon monoxide and other harmful byproducts. Thus, determining the correct air-to-fuel ratio is crucial for safe and effective gas furnace operation.