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

The minimum diameter for a solid aluminum air terminal classified as Class I is indeed 1/2 inch. This standard is established to ensure that the air terminal is robust enough to withstand the forces and stresses encountered during a lightning event while providing adequate conductivity to effectively disperse the lightning current. Using an air terminal of this size helps to minimize the risk of melting or structural failure when subjected to high-energy discharges.

Choosing a larger diameter could provide added structural integrity, but the minimum requirement is specifically set at 1/2 inch to balance performance and material use. Ensuring compliance with this diameter specification is critical for the effectiveness and safety of the lightning protection system as a whole.