Luftgaps

Luftgaps (air gaps) refer to deliberate spaces filled with air between components or layers in engineering systems. The term derives from the German Luft, air, and Spalt, gap, and is used in both German and English technical literature. Air gaps function as barriers to heat transfer, electrical conduction, or physical contact, and can also enable ventilation and moisture control in assemblies.

In building and architectural applications, luftgaps occur in cavity walls, double-skin facades, and between insulation layers. They reduce thermal bridging and can aid moisture management by promoting drainage and air circulation. The width and orientation of an air gap are selected to balance insulation performance with ventilation needs, and codes often specify tolerances and sealing requirements to minimize drafts and condensation.

In electrical and mechanical engineering, luftgaps describe the clearance between moving parts or insulation between conductors. In high-voltage equipment, air gaps provide electrical insulation; in turbomachinery, the axial or radial air gap between rotor and stator sets a clearance to prevent rubbing and control leakage. The performance of an air gap depends on geometry, temperature, and contamination.

In information security, an air-gapped system is purposely isolated from networks and external media; the term is sometimes discussed in German literature as luftgapped systems. While air gaps offer strong protection against remote compromise, covert channels and human-driven exfiltration have been demonstrated, and maintaining physical isolation imposes practical operational constraints.