A house has a 19-foot tall chimney with a 185,000 BTU input from one Category I natural draft vented appliance. What size Type B chimney is needed?

To determine the appropriate size of a Type B chimney for a natural draft vented appliance, you need to refer to the BTU input rating of that appliance and the height of the chimney. In this scenario, the appliance has an input of 185,000 BTU and a chimney height of 19 feet.

In general, Type B vent systems are used for gas appliances with a natural draft. The vent size must be able to accommodate the flue gases produced by the appliance while ensuring sufficient draft to safely vent those gases outdoors.

For appliances with higher BTU inputs, the required chimney size can increase due to the need for an adequate opening to allow for proper airflow and to prevent condensation and backdraft. With 185,000 BTUs, a 6-inch diameter Type B chimney is typically the standard choice to handle that level of output efficiently.

A smaller diameter chimney might lead to issues such as insufficient draft, resulting in poor venting performance and potential safety hazards. In contrast, a larger diameter might not be necessary for a single appliance of this size, but it could create other concerns, such as reduced efficiency or increased heat loss.

Utilizing a 6-inch Type B chimney for a 185,000 BTU input from a