EXP

EXP | Expander Box Weather Louvre for DUX

The EXP Expander Box Weather Louvre is designed to work with AFP’s DUX pressure relief vents in halocarbon gas systems. Its design ensures weather protection for two-way airflow through external walls, which cannot be achieved with sealed units. To allow this two-way flow while keeping weather out, the EXP external weather louvres use an open louvre design.

The louvre blades are built into a custom expander box that increases airflow capacity, matching the DUX vent’s 85% Free Vent Area. This design avoids any restriction and adds nothing to the Vent Dynamic Coefficient (vDc), unlike standard weather louvres, which typically offer only around 50% FVA. This allows the same airflow to be achieved with fewer units, significantly cutting down on the number of installations required.

The EXP 300 and 500 models include a specially designed storm shield. This mesh prevents rain from entering behind the louvre without affecting blast protection. The result is a reliable, high-capacity weather louvre that performs under pressure and maintains full compatibility with our DUX two-way pressure relief vent range.