Luftsperre

Luftsperre is a German term that denotes a barrier to the movement of air. It can refer to a structural or mechanical measure intended to prevent or reduce unintended air exchange between spaces that are at different pressures, temperatures, or contaminant levels. The exact meaning varies by field, but the central idea is to stop or redirect air flow.

In building technology, a Luftsperre usually means a continuous air barrier within the building envelope. This barrier blocks infiltration and exfiltration of air through joints, cracks, and openings in walls, roofs, and floors. Typical implementations include membranes, tapes, sealants, and carefully detailed connections around windows, doors, and service penetrations. A well-designed Luftsperre lowers energy consumption, reduces drafts, and improves indoor comfort and air quality. Verifying its effectiveness often involves airtightness testing, such as a blower door test, to ensure continuity of the barrier.

In practice, a Luftsperre can also be realized at doorways or entry points as an air curtain or similar device that projects a jet of air to separate spaces while allowing passage. Such air barriers help minimize heat loss, dust, and insects without requiring a physical door to be closed.

In controlled environments like cleanrooms or laboratories, Luftsperren contribute to maintaining differential pressures between zones. In these contexts, the term is sometimes used loosely to denote the barrier concept, while the term Luftschleuse is typically reserved for an actual airlock chamber used to isolate spaces physically.

Etymologically, the term combines Luft (air) and Sperre (barrier or stop). Its usage varies by discipline, but it generally describes a mechanism or layer that restricts air movement.