What is the minimum diameter of a Class I aluminum air terminal?

The minimum diameter of a Class I aluminum air terminal is specified to be 1/2 inch. The standard for lightning protection systems establishes this requirement to ensure that the air terminals provide adequate conductivity and strength to safely dissipate lightning strikes without failing. A diameter of 1/2 inch also helps to optimize the terminal’s ability to absorb and redirect lightning energy, minimizing the risk of damage to structures and ensuring the safety of the surrounding area. This size ensures a balance between material use, structural integrity, and electrical performance, which is critical in effective lightning protection design.