What size chimney should be installed in a home with one Category I gas appliance with a total BTU input of 92,000?

To determine the appropriate chimney size for a home with one Category I gas appliance and a total input of 92,000 BTU, it's essential to understand the flue sizing guidelines for gas appliances. Category I appliances typically operate with natural draft, which means they rely on the natural buoyancy of hot gases to vent through the chimney.

The International Fuel Gas Code (IFGC) indicates specific requirements for vent sizing based on the BTU input of the appliance. For a Category I gas appliance, the chimney diameter should be large enough to allow for efficient venting of combustion gases while preventing condensation and ensuring optimal draft.

In this case, a chimney size of 4 inches is appropriate for appliances with a total input ranging up to about 100,000 BTU. Therefore, with a 92,000 BTU input, a 4-inch diameter chimney will effectively handle the exhaust gases and provide a safe operating environment.

Selecting a larger chimney, such as 5 or 6 inches, could lead to insufficient draft and potential condensation issues within the flue system, while a smaller chimney, like 3 inches, would not accommodate the gas flow adequately and could result in backdrafting and unsafe conditions. Thus, the 4-inch option is the