The requirements for combustion and dilution air for gas-fired appliances follow what codes?

The correct answer emphasizes that the requirements for combustion and dilution air for gas-fired appliances are outlined in the International Flue Gas Code. This code is specifically designed to address the safety and performance standards for flue gas venting systems and outlines necessary provisions related to the intake of combustion air. Proper combustion air is crucial in ensuring that gas appliances operate efficiently and safely by allowing for complete combustion, minimizing hazardous emissions, and controlling the environment within which these appliances function.

Other codes mentioned, such as the National Building Code and the Uniform Plumbing Code, have their own scopes and regulations but do not specifically detail the requirements for combustion and dilution air in the context of gas-fired appliances like the International Flue Gas Code does. Similarly, while the Environmental Protection Agency offers guidelines that pertain to broader environmental regulations and emissions, they do not focus specifically on the technical aspects of combustion air for these appliances. Thus, the International Flue Gas Code provides the most appropriate guidance for ensuring the safe and efficient operation of gas-fired equipment.