What is the minimum height for the bottom of a horizontal termination terminal above finished ground level?

The minimum height for the bottom of a horizontal termination terminal above finished ground level is indeed 12 inches. This requirement is critical for ensuring proper venting and preventing any obstruction or interference with the outlet of combustion products. By positioning the terminal at this height, it helps to mitigate the risk of potential hazards such as ground-level obstructions, snow buildup, or flooding.

Additionally, this height guideline is designed to promote adequate airflow around the terminal, which is essential for the efficient functioning of the appliance it serves. Proper clearance also helps prevent the accumulation of debris that could impair venting efficiency. This specification is established in various codes and standards related to appliance installation and venting, which prioritize safety and operational efficiency in residential settings.