Chimney Safety Institute of America (CSIA) Certification Practice Test

To improve flue flow and reduce smoking, what should be increased?

1. Flue size and fireplace opening

2. Flue size and decreased fireplace opening

3. Fireplace opening and decreased flue size

4. Fireplace size and increased flue opening

The correct answer is: Flue size and decreased fireplace opening

Increasing flue size while decreasing the fireplace opening is beneficial for improving flue flow and reducing smoking. A larger flue allows for better airflow, which facilitates the efficient expulsion of smoke and gases from the combustion process. This larger volume can help maintain a strong draft, thus pulling smoke up and out of the chimney more effectively. On the other hand, decreasing the fireplace opening complements this by preventing excessive intake of air that can disrupt the optimal draft and cause smoke to enter the living space rather than exit through the chimney. This balance helps maintain better combustion efficiency, reducing the incidence of smoke. The other options suggest combinations where the mechanics of airflow and pressure may not achieve the desired results. For instance, increasing both the fireplace and flue size could lead to an imbalance in airflow, while a decreased flue size would restrict smoke flow and possibly exacerbate smoking issues.