What should be avoided to prevent restrictions to flow in a chimney?

Using 30-degree elbows in a chimney system is preferable because they create less resistance to airflow compared to sharper angles. Elbows that are more acute, such as 90-degree angles, can significantly impede the flow of combustion gases. In contrast, a 30-degree elbow allows the gases to transition more smoothly, reducing turbulence and back pressure.

Additionally, the total number of offsets and the transitions in a chimney system can affect the overall efficiency. Each change in direction increases the chance of resistance, which can lead to a decrease in the performance of the chimney. Therefore, while using 30-degree elbows is more favorable for maintaining optimal airflow, it is also necessary to consider the overall design and minimize unnecessary connectors to promote efficient exhaust flow.