What can cause pressurization in a venting system?

Pressurization in a venting system can occur due to various factors, and choosing a lateral run that is too long is indeed a significant contributor to this problem. When a venting system has a long lateral run, the resistance to the flow of exhaust gases increases. This increased resistance can lead to an accumulation of gases at certain points in the system, which subsequently creates pressure.

Long lateral runs can disrupt the proper flow dynamics of the exhaust gases, making it difficult for them to exit efficiently. As a result, the venting system may become pressurized, leading to potential issues such as poor combustion efficiency, backdrafting, and an increased risk of hazardous gases entering the living space.

In comparison, other factors like an insufficiently short vent or too many elbows generally create different issues, such as dead ends or increased turbulence, rather than specifically causing pressurization. Insufficient airflow is more about not allowing adequate fresh air for combustion rather than directly affecting the venting pressure. Thus, the selection of vent length and design is crucial in maintaining proper venting system function and pressure management.