DWL

DWL | Dynamic Weatherproof Louvres for SHX-UN

The DWL Exterior Dynamic Weather Louvre is designed to work alongside the SHX-UN universal pressure relief vent. It offers strong protection against wind and rain without limiting the Free Vent Area (FVA) of the internal vent. Compared to standard fixed vane weather louvres used in the HVAC industry, the DWL provides around twice the free vent area. This means fewer units are needed to achieve the same airflow performance, which can reduce the number of installations significantly.

Unlike fixed vane external louvres, the DWL achieves a 98% wind seal and offers improved sound and thermal performance. Its thin but strong blade profiles can close up to 99%, offering protection from storm-blown rain while also reducing heat loss caused by drafts. This makes the DWL an effective solution for maintaining building efficiency and protection in harsh weather conditions.

The DWL has been thoroughly tested in our in-house blast simulator. When used together with SHX-UN vents during a gas suppression system discharge, the external louvres increased back pressure by only 10%. Because AFP’s range of pressure relief vents is designed to operate well below the peak pressure levels predicted by the Vent Design Coefficient (vDc), this small increase does not affect performance. The DWL and SHX-UN combination remains one of the most effective pressure and blast relief solutions on the market.

This product is trusted and accepted in many locations worldwide, and every unit is backed by guaranteed quality.