6.3.7 Air-termination systems for the protection of roof-mounted building technology structures

Roof-mounted structures such as air conditioning systems, cooling equipment for data centres, antennas, electrically operated domelights or illuminated advertising signs are typical features of modern office and industrial buildings. They protrude above the roof surface and usually have conductive connections to the interior of the building – for example, via power lines or installation ducts. This connection poses a significant risk, particularly with regard to the possibility of lightning or partial lightning currents entering these building technology systems and the associated disruptive or destructive effect on the systems (Figure 6.3.7.1).

To protect roof-mounted structures, isolated air-termination systems have therefore been used in recent years as part of a lightning protection system (LPS), whose air-termination rods and conductors were installed in such a way that the lightning current path did not come into contact with the structure to be protected.

Due to advances in lightning protection technology in recent years, lightning protection systems previously referred to as 'external lightning protection systems isolated from the structure to be protected' have been further differentiated and their nomenclature clarified as part of the revision of the lightning protection standard.