How high must a side-mount air terminal project above the object being protected?

The requirement for a side-mount air terminal to project above the protected object by a minimum of 15 inches is specified in lightning protection standards to ensure effective lightning attraction and diversion. This height allows the terminal to sufficiently intercept lightning strikes rather than allowing the strike to hit the object itself.

By projecting above the object, the air terminal creates a zone of protection around the object, which helps in directing the lightning current safely to the ground through the grounding system. This particular minimum height of 15 inches is based on calculations and studies of electric field dynamics and the behavior of lightning, which demonstrate that a greater height provides better assurance against strikes.

Ensuring a proper height for side-mount air terminals is crucial in the design of lightning protection systems because it impacts the overall safety and effectiveness of lightning protection measurements.